I AM BEGINNING TO SOUND LIKE A BROKEN GONG FOR THE PAST THREE DECADES TEACHING THE WORLD HWO WE DERAILED IN HUMAN RELIGIOUS FANATICISM, LEADING US TO A THIRD WORLD WAR.... YET HO ONE IS TAKING ME SERIOUSLY, ALL WORSHIP MONEY, WEALTH, WINE AND WOMEN.
WHAT CAN I SAY AGAIN, ..... THINK FOR YOURSELF, PLEASE JETTISON UNSCIENTIFIC DOCTRINES AND DOGMAS THAT YOU WERE BRAINWASHED AND PROGRAMMED BY NON-SCIENTISTS, ARM CHAIR PHILOSOPHERS, OR SIMPLY GROUP ALL OF THEM AS HUNGRY and/or DEMONIC SEMI-ILLITERATE DEMAGOGUES TO ACCEPT AS FAITH ;
ANOTHER INHUMANE WORD COINED TO COVER LIES, FALSEHOOD SINCE YOUR CHILDHOOD AT CATECHISM CLASSES, .., THAT IS OUR INTERNATIONAL ALBATROSS THAT GAVE RISE TO CRUSADES, JIHADS AND CURRENTLY I S I S
OUR DEAREST DR JIDEOFO KENECHUKWU DANMBAEZUE
The Current Revolutionary Professor of Modern Theosophy needs honest answers to our centuries of fables, legends, confabulations, doctrines and dogmas about all the superstitions we today label as ANCIENT & MODERN RELIGIONS
I HEREBY PROPOSE THAT EVE WAS OLDER THAN ADAM OR ELSE WHY DID BIBLE NARRATIVES MISS OUT THAT A FEMALE VERTEBRA IS THE OLDEST BONE FOUND IN OLDUVAI GORGE
RELIGION IS THE MOST HYPOCRITICAL POLILITCS IN EXISTENCE OR ELSE IT IS MORE REASONABLE THAT EVE WAS OLDER THAN ADAM .... DR KENEZ PROPOSES .... IF A FEMALE IS THE OLDEST BONE FOUND IN OLDUVAI GORGE
Paleoanthropologists have debated interpretations of the characteristics of A. afarensis and its place in the human family tree. One controversy centers on the Laetoli footprints, which some scientists believe show that the foot anatomy and gait of A. afarensis did not exactly match those of modern humans. This observation may indicate that early australopiths did not live primarily on the ground or at least spent a significant amount of time in the trees. The skeleton of Lucy also indicates that A. afarensis had longer, more powerful arms than most later human species, suggesting that this species was adept at climbing trees.
Footprints From the Past
In 1978 in Laetoli, Tanzania, a research team led by British paleoanthropologist Mary Leakey discovered these 3.6-million-year-old human footprints preserved in a layer of hardened volcanic ash. Two early humans of the species Australopithecus afarensis left the footprints as they walked across the African savanna.
John Reader/Photo Researchers, Inc.
Another controversy has to do with the scientific classification of the A. afarensis fossils. Compared with Lucy, who stood only 1.1 m (3.5 ft) tall, other fossils identified as A. afarensis from Hadar and Laetoli came from individuals who stood up to 1.5 m (5 ft) tall. This great difference in size leads some scientists to suggest that the entire set of fossils now classified as A. afarensis actually represents two species. Most scientists, however, believe the fossils represent one highly dimorphic species—that is, a species that has two distinct forms (in this case, two sizes). Supporters of this view note that both large (presumably male) and small (presumably female) adults occur together in one site at Hadar.
Lucy
In 1974 American paleoanthropologist Donald Johanson discovered the skeleton of “Lucy,” a 3.2-million-year-old female of the early human species Australopithecus afarensis, at Hadar, Ethiopia. Until the late 1990s, Lucy’s was the most complete skeleton of an australopithecine ever found. Australopithecines were primitive humans that first evolved over 4.4 million years ago. Lucy’s pelvis and leg bones, similar to those of modern humans, indicate that she regularly walked upright.
John Reader/Science Photo Library/Photo Researchers, Inc.
Can you imagine that theses millions of years were what simple folks TRIVIALISED in just two incoherent chapters of Bible narrative in Genesis besides the puerile confabulation of repeating the original naïve fable or call it the obsolete legendary cum prehistoric creation story dovetailed from Chapter 2 verse 3! The non-scientist reduced to simplicity a huge engineering feat that lasted millions of years and it makes archaeologists look stupid?
Gen 1:1-2:3
1:1 In the beginning God created the heaven and the earth.
2 And the earth was without form, and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters.
3 And God said, Let there be light: and there was light.
4 And God saw the light, that it was good: and God divided the light from the darkness.
5 And God called the light Day, and the darkness he called Night. And the evening and the morning were the first day.
6 And God said, Let there be a firmament in the midst of the waters, and let it divide the waters from the waters.
7 And God made the firmament, and divided the waters which were under the firmament from the waters which were above the firmament: and it was so.
8 And God called the firmament Heaven. And the evening and the morning were the second day.
9 And God said, Let the waters under the heaven be gathered together unto one place, and let the dry land appear: and it was so.
10 And God called the dry land Earth; and the gathering together of the waters called he Seas: and God saw that it was good.
11 And God said, Let the earth bring forth grass, the herb yielding seed, and the fruit tree yielding fruit after his kind, whose seed is in itself, upon the earth: and it was so.
12 And the earth brought forth grass, and herb yielding seed after his kind, and the tree yielding fruit, whose seed was in itself, after his kind: and God saw that it was good.
13 And the evening and the morning were the third day.
14 And God said, Let there be lights in the firmament of the heaven to divide the day from the night; and let them be for signs, and for seasons, and for days, and years:
15 And let them be for lights in the firmament of the heaven to give light upon the earth: and it was so.
16 And God made two great lights; the greater light to rule the day, and the lesser light to rule the night: he made the stars also.
17 And God set them in the firmament of the heaven to give light upon the earth,
18 And to rule over the day and over the night, and to divide the light from the darkness: and God saw that it was good.
19 And the evening and the morning were the fourth day.
20 And God said, Let the waters bring forth abundantly the moving creature that hath life, and fowl that may fly above the earth in the open firmament of heaven.
21 And God created great whales, and every living creature that moveth, which the waters brought forth abundantly, after their kind, and every winged fowl after his kind: and God saw that it was good.
22 And God blessed them, saying, Be fruitful, and multiply, and fill the waters in the seas, and let fowl multiply in the earth.
23 And the evening and the morning were the fifth day.
24 And God said, Let the earth bring forth the living creature after his kind, cattle, and creeping thing, and beast of the earth after his kind: and it was so.
25 And God made the beast of the earth after his kind, and cattle after their kind, and every thing that creepeth upon the earth after his kind: and God saw that it was good.
26 And God said, Let us make man in our image, after our likeness: and let them have dominion over the fish of the sea, and over the fowl of the air, and over the cattle, and over all the earth, and over every creeping thing that creepeth upon the earth.
27 So God created man in his own image, in the image of God created he him; male and female created he them.
28 And God blessed them, and God said unto them, Be fruitful, and multiply, and replenish the earth, and subdue it: and have dominion over the fish of the sea, and over the fowl of the air, and over every living thing that moveth upon the earth.
29 And God said, Behold, I have given you every herb bearing seed, which is upon the face of all the earth, and every tree, in the which is the fruit of a tree yielding seed; to you it shall be for meat.
30 And to every beast of the earth, and to every fowl of the air, and to every thing that creepeth upon the earth, wherein there is life, I have given every green herb for meat: and it was so.
31 And God saw every thing that he had made, and, behold, it was very good. And the evening and the morning were the sixth day.
Genesis 2
2:1 Thus the heavens and the earth were finished, and all the host of them.
2 And on the seventh day God ended his work which he had made; and he rested on the seventh day from all his work which he had made.
3 And God blessed the seventh day, and sanctified it: because that in it he had rested from all his work which God created and made.
King James Version
SO CAN OUR SO-CALLED CHURCH FATHERS AND ROMAN CATHOLIC JESUIT THEOLOGIANS ANSWER ME…WHY WERE THESE ERUDITE SCHOLARLY WORK NOT INCLUDED IN THE FORMULATION OF DOCTRINES AND DOGMAS THEY FED US WITH SINCE OUR INFANTHOOD? SO, WHO IS FOOLING WHO ? ?
DR JIDEOFO KENECHUKWU DANMBAEZUE
The Current Revolutionary Professor of Modern Theosophy needs honest answers o o
MY DEAR FRIENDS, PLEASE PUT ON YOUR THINKING CAPS AS WE TAKE OFF ON AN ALTITUDE YOU HAVE NEVER FLOWN BEFORE .......
YOU CANNOT SERVE GOD AND
MAMMON
HOWEVER YOU SERVE THE ALMIGHTY CREATOR OF THE ENTIRE
UNIVERSE OR CHOOSE TO SERVE A DEMON OR MAMMON IF AND ONLY IF, AND ONLY IF, YOU ARE
SMART ENOUGH DECIPHER THE DIFFERENCES
Dr Jideofo
Kenechukwu Danmbaezue, D.Sc.
Revolutionary
Professor of Modern Theosophy
Our
job here is so simple once you can see the title from the two opposing
perspectives it really denotes. But, let me first, introduce our readers and
true children of the Creator to the fundamental reason why “GOD” is the wrong
terminology for referring to the almighty Absolute Truth, Architect, Engineer
of this entire universe! The Founders of the International Cult today known as
“ILLUMINATI” coined it to simply derogate the Unitarian Godhead!
Witness; spell “GOD” or “gods” BACKWARDS and for the first time in
your life see exactly what you really mistakenly call the Almighty Creator,
Father of All the Exists! IS IT RIGHT, NO! But that is exactly what they had in
mind! So, my dear follower, denounce it totally!
None
of us has a right to even address this Divine Superlative Being “HE or “HIM”
for there is proof that feminists accept masculinising what sustains all that
exists. Since we exist, live by and move around in all what were designed by,
brought into materialisation, sustained and regulated by this Supreme Being, I
do hereby suggest we always classify as in neuter “IT”!
LET US HASTEN TO THE TOPIC UNDER
SCRUTINY
I
did not initiate the title, someone greater me in history really did propose
its relevance and we calculate our calendar years from his birth:
Matt 6:19-33
19 Lay not up for yourselves treasures upon
earth, where moth and rust doth corrupt, and where thieves break through and
steal:
20 But lay up for yourselves treasures in
heaven, where neither moth nor rust doth corrupt, and where thieves do not
break through nor steal:
21 For where your treasure is, there will
your heart be also.
22 The light of the body is the eye: if
therefore thine eye be single, thy whole body shall be full of light.
23 But if thine eye be evil, thy whole body
shall be full of darkness. If therefore the light that is in thee be darkness,
how great is that darkness!
24 No man can serve two masters: for either
he will hate the one, and love the other; or else he will hold to the one, and
despise the other. Ye cannot serve God and mammon.
25 Therefore I say unto you, Take no
thought for your life, what ye shall eat, or what ye shall drink; nor yet for
your body, what ye shall put on. Is not the life more than meat, and the body than
raiment?
26 Behold the fowls of the air: for they
sow not, neither do they reap, nor gather into barns; yet your heavenly Father
feedeth them. Are ye not much better than they?
27 Which of you by taking thought can add
one cubit unto his stature?
28 And why take ye thought for raiment?
Consider the lilies of the field, how they grow; they toil not, neither do they
spin:
29 And yet I say unto you, That even
Solomon in all his glory was not arrayed like one of these.
30 Wherefore, if God so clothe the grass of
the field, which to day is, and to morrow is cast into the oven, shall he not
much more clothe you, O ye of little faith?
31 Therefore take no thought, saying, What
shall we eat? or, What shall we drink? or, Wherewithal shall we be clothed?
32(For after all these things do the
Gentiles seek:) for your heavenly Father knoweth that ye have need of all these
things.
33 But seek ye first the kingdom of God,
and his righteousness; and all these things shall be added unto you.
From the Original King James Version
SEE
ANOTHER COMMENDABLE PASSAGE
Luke 16:8-17
8 And the lord commended the unjust
steward, because he had done wisely: for the children of this world are in
their generation wiser than the children of light.
9 And I say unto you, Make to yourselves
friends of the mammon of unrighteousness; that, when ye fail, they may receive
you into everlasting habitations.
10 He that is faithful in that which is
least is faithful also in much: and he that is unjust in the least is unjust
also in much.
11 If therefore ye have not been faithful
in the unrighteous mammon, who will commit to your trust the true riches?
12 And if ye have not been faithful in that
which is another man's, who shall give you that which is your own?
13 No servant can serve two masters: for
either he will hate the one, and love the other; or else he will hold to the
one, and despise the other. Ye cannot serve God and mammon.
14 And the Pharisees also, who were
covetous, heard all these things: and they derided him.
15 And he said unto them, Ye are they which
justify yourselves before men; but God knoweth your hearts: for that which is
highly esteemed among men is abomination in the sight of God.
16 The law and the prophets were until
John: since that time the kingdom of God is preached, and every man presseth
into it.
17 And it is easier for heaven and earth to
pass, than one tittle of the law to fail
……………………………..KJV
AND A RECAPITULATION OF MATTHEW’s ACCOUNT
Luke 16:18-17
11 If therefore ye have not been
faithful in the unrighteous mammon, who will commit to your trust the true
riches?
12 And if ye have not been faithful in
that which is another man's, who shall give you that which is your own?
13 No servant can serve two masters:
for either he will hate the one, and love the other; or else he will hold to
the one, and despise the other. Ye cannot serve God and mammon.
14 And the Pharisees also, who were
covetous, heard all these things: and they derided him.
15 And he said unto them, Ye are they
which justify yourselves before men; but God knoweth your hearts: for that
which is highly esteemed among men is abomination in the sight of God.
16 The law and the prophets were until
John: since that time the kingdom of God is preached, and every man presseth
into it.
17 And it is easier for heaven and
earth to pass, than one tittle of the law to fail.
KJV
EVE WAS OLDER THAN ADAM OR ELSE WHY DID BIBLE NARRATIVES MISS OUT
THAT A FEMALE IS THE OLDEST BONE FOUND IN OLDUVAI GORGE
Paleoanthropologists have debated interpretations of the
characteristics of A. afarensis and its place in the human family tree.
One controversy centers on the Laetoli footprints, which some scientists
believe show that the foot anatomy and gait of A. afarensis did not
exactly match those of modern humans. This observation may indicate that early
australopiths did not live primarily on the ground or at least spent a
significant amount of time in the trees. The skeleton of Lucy also indicates
that A. afarensis had longer, more powerful arms than most later human
species, suggesting that this species was adept at climbing trees.
Footprints From the Past
In 1978 in Laetoli, Tanzania, a
research team led by British paleoanthropologist Mary Leakey discovered these
3.6-million-year-old human footprints preserved in a layer of hardened volcanic
ash. Two early humans of the species Australopithecus afarensis left the
footprints as they walked across the African savanna.
John Reader/Photo Researchers, Inc.
Another controversy has to do with the scientific
classification of the A. afarensis fossils. Compared with Lucy,
who stood only 1.1 m (3.5 ft) tall, other fossils identified as A. afarensis
from Hadar and Laetoli came from individuals who stood up to 1.5 m (5 ft) tall.
This great difference in size leads some scientists to suggest that the entire
set of fossils now classified as A. afarensis actually represents two
species. Most scientists, however, believe the fossils represent one highly dimorphic
species—that is, a species that has two distinct forms (in this case, two
sizes). Supporters of this view note that both large (presumably male) and
small (presumably female) adults occur together in one site at Hadar.
Lucy
In 1974 American paleoanthropologist
Donald Johanson discovered the skeleton of “Lucy,” a 3.2-million-year-old
female of the early human species Australopithecus afarensis, at Hadar,
Ethiopia. Until the late 1990s, Lucy’s was the most complete skeleton of an
australopithecine ever found. Australopithecines were primitive humans that
first evolved over 4.4 million years ago. Lucy’s pelvis and leg bones, similar
to those of modern humans, indicate that she regularly walked upright.
John Reader/Science Photo
Library/Photo Researchers, Inc.
Can you imagine that theses millions of years were what
simple folks TRIVIALISED in just two incoherent chapters of Bible narrative in
Genesis besides the puerile confabulation of repeating the original naïve fable
or call it the obsolete legendary cum prehistoric creation story dovetailed
from Chapter 2 verse 3! The non-scientist reduced to simplicity a huge
engineering feat that lasted millions of years and it makes archaeologists look
stupid?
Gen 1:1-2:3
1:1 In the beginning God created
the heaven and the earth.
2 And the earth was without form,
and void; and darkness was upon the face of the deep. And the Spirit of God
moved upon the face of the waters.
3 And God said, Let there be
light: and there was light.
4 And God saw the light, that it
was good: and God divided the light from the darkness.
5 And God called the light Day,
and the darkness he called Night. And the evening and the morning were the
first day.
6 And God said, Let there be a
firmament in the midst of the waters, and let it divide the waters from the
waters.
7 And God made the firmament, and
divided the waters which were under the firmament from the waters which were
above the firmament: and it was so.
8 And God called the firmament
Heaven. And the evening and the morning were the second day.
9 And God said, Let the waters
under the heaven be gathered together unto one place, and let the dry land
appear: and it was so.
10 And God called the dry land
Earth; and the gathering together of the waters called he Seas: and God saw
that it was good.
11 And God said, Let the earth
bring forth grass, the herb yielding seed, and the fruit tree yielding fruit
after his kind, whose seed is in itself, upon the earth: and it was so.
12 And the earth brought forth
grass, and herb yielding seed after his kind, and the tree yielding fruit,
whose seed was in itself, after his kind: and God saw that it was good.
13 And the evening and the
morning were the third day.
14 And God said, Let there be
lights in the firmament of the heaven to divide the day from the night; and let
them be for signs, and for seasons, and for days, and years:
15 And let them be for lights in
the firmament of the heaven to give light upon the earth: and it was so.
16 And God made two great lights;
the greater light to rule the day, and the lesser light to rule the night: he
made the stars also.
17 And God set them in the
firmament of the heaven to give light upon the earth,
18 And to rule over the day and
over the night, and to divide the light from the darkness: and God saw that it
was good.
19 And the evening and the
morning were the fourth day.
20 And God said, Let the waters bring
forth abundantly the moving creature that hath life, and fowl that may fly
above the earth in the open firmament of heaven.
21 And God created great whales,
and every living creature that moveth, which the waters brought forth
abundantly, after their kind, and every winged fowl after his kind: and God saw
that it was good.
22 And God blessed them, saying,
Be fruitful, and multiply, and fill the waters in the seas, and let fowl
multiply in the earth.
23 And the evening and the
morning were the fifth day.
24 And God said, Let the earth
bring forth the living creature after his kind, cattle, and creeping thing, and
beast of the earth after his kind: and it was so.
25 And God made the beast of the
earth after his kind, and cattle after their kind, and every thing that
creepeth upon the earth after his kind: and God saw that it was good.
26 And God said, Let us make man
in our image, after our likeness: and let them have dominion over the fish of
the sea, and over the fowl of the air, and over the cattle, and over all the
earth, and over every creeping thing that creepeth upon the earth.
27 So God created man in his own
image, in the image of God created he him; male and female created he them.
28 And God blessed them, and God
said unto them, Be fruitful, and multiply, and replenish the earth, and subdue
it: and have dominion over the fish of the sea, and over the fowl of the air,
and over every living thing that moveth upon the earth.
29 And God said, Behold, I have
given you every herb bearing seed, which is upon the face of all the earth, and
every tree, in the which is the fruit of a tree yielding seed; to you it shall
be for meat.
30 And to every beast of the
earth, and to every fowl of the air, and to every thing that creepeth upon the
earth, wherein there is life, I have given every green herb for meat: and it
was so.
31 And God saw every thing that
he had made, and, behold, it was very good. And the evening and the morning
were the sixth day.
Genesis 2
2:1 Thus the heavens and the
earth were finished, and all the host of them.
2 And on the seventh day God
ended his work which he had made; and he rested on the seventh day from all his
work which he had made.
3 And God blessed the seventh
day, and sanctified it: because that in it he had rested from all his work
which God created and made.
King James Version
SO CAN OUR SO-CALLED CHURCH
FATHERS AND ROMAN CATHOLIC JESUIT THEOLOGIANS ANSWER ME…WHY WERE THESE ERUDITE
SCHOLARLY WORK NOT INCLUDED IN THE FORMULATION OF DOCTRINES AND DOGMAS THEY FED
US WITH SINCE OUR INFANTHOOD? SO, WHO IS FOOLING WHO ? ? ?
DR JIDEOFO KENECHUKWU DANMBAEZUE
The Current Revolutionary Professor of
Modern Theosophy needs honest answers o o
You must look at these pictures and
read a little of the carbon dated archaeological discoveries and findings
documented about the oldest humans excavated at the famous Olduvai Gorge in
Africa
Next, read from
WIKIPEDIA ENCYCLOPEADIA
Olduvai Gorge, or Oldupai Gorge,
in Tanzania is
one of the most important paleoanthropological sites
in the world; it has proven invaluable in furthering understanding of
early human evolution. A steep-sided ravine in
the Great
Rift Valley that stretches across East Africa, it is
about 48 km (30 mi) long, and is located in the eastern Serengeti Plains in
the Arusha
Region not far, about 45 kilometres (28 miles), from Laetoli,
another important archaeological site of early human occupation. The
British/Kenyan paleoanthropologist-archeologist team Mary and Louis Leakey established
and developed the excavation and research programs at Olduvai Gorge which
achieved great advances of human knowledge and world-renowned status.
Homo habilis, probably the first early
human species, occupied Olduvai Gorge approximately 1.9 million years ago
(mya); then came a contemporary australopithecine, Paranthropus boisei, 1.8 mya, then Homo erectus, 1.2
mya. Homo sapiens is dated to have occupied
the site 17,000 years ago.
The site is significant in showing the increasing developmental
and social complexities in the earliest humans, or hominins,
largely as revealed in the production and use of stone tools. And
prior to tools, the evidence of scavenging and hunting—highlighted
by the presence of gnaw marks that predate cut marks—and of the ratio of meat
versus plant material in the early hominin diet. The collecting of tools and
animal remains in a central area is evidence of developing social interactionand communal activity. All
these factors indicate increase in cognitive capacities
at the beginning of the period of hominidstransitioning
to hominin—that
is, to human—form and behavior.
Olduvai
also spelled Olduwai
paleoanthropological
site in the eastern Serengeti Plain, within the boundaries of the Ngorongoro Conservation Area in northern Tanzania. It is a steep-sided ravine
consisting of two branches that have a combined length of about 30 miles (48
km) and are 295 feet (90 metres) deep. Deposits exposed in the sides of the
gorge cover a time span from about 2,100,000 to 15,000 years ago. The deposits
have yielded the fossil remains of more than 60 hominins (members of the human
lineage), providing the most continuous known record of human evolution during the past 2,000,000
years, as well as the longest known archaeological record of the development of
stone-tool industries. Olduvai Gorge was designated part of a UNESCO World
Heritage site in 1979. Although Olduvai Gorge has often been called the
“Cradle of Mankind,” a different World Heritage site called the “Cradle of
Humankind” is located in South Africa. Compare Sterkfontein, Swartkrans, and Kromdraai.
- Rock formation at Olduvai Gorge, Tanzania.
The Olduvai fossil beds accumulated in a lake basin between 4
and 9 miles (7 and 15 km) in diameter. The lake is underlain by volcanic rocks
of the Pliocene Epoch (5.3 to 1.8 million years ago)
and, farther below, by metamorphic deposits of Precambrian time (more than roughly 540 million
years ago). Relatively continuous rift-valley fault movements and volcanic
action left Olduvai deeply incised. Water flow through the gorge further eroded
the rock, exposing a delineated sequence of strata from which evolutionary
events could be traced. Seven major stratigraphic units, or formations, have
been distinguished. From the oldest to the youngest they are: Bed I (about 1,700,000 to 2,100,000 years old), Bed II (1,150,000–1,700,000 years old), Bed III (800,000–1,150,000 years old), Bed IV (600,000–800,000 years old), the Masek Beds (400,000–600,000 years old), the Ndutu
Beds (32,000–400,000 years old), and the Naisiusiu
Beds (15,000–22,000 years old).
- Reconstructed replica of “Nutcracker Man,” a
1.75-million-year-old …
- Replica of “Twiggy,” a reconstructed Homo
habilis skull …
a more
humanlike species, were also found at Olduvai. These included OH 24, a skull
popularly known as “Twiggy” because it had to be reconstructed from a flattened
state.
The
remains of Bed I are found principally where streams from volcanic highlands
brought fresh water to the southern margin of an alkaline lake that existed at
Olduvai. Conditions for preservation were unusually favourable at these sites
because ashfalls from nearby volcanoes and fluctuations of the lake led to
rapid burial of the hominin and associated remains. Other finds include Oldowan
tools and the bones and teeth of various animals, notably medium-sized
antelopes. Long animal bones and others containing marrow generally have been
split and broken and often display bone-tool cut marks.
Living sites in Beds
II, III, and IV generally are found in former river or stream channels. Bed II
is 66–98 feet (20–30 metres) thick and consists of different rock formations
separated by a disconformity, or erosional break. Only the Oldowan industry occurs
below the disconformity; the so-called Developed Oldowan industry and the Acheulean industry occur above. H. habilis
remains were found in the lower one-third of Bed II, and a cranium of H.
ergaster (also called African H. erectus) was collected near the top of
Bed II. P. boisei occurs both in upper and lower parts of Bed II.
Beds III and IV were
deposited on an alluvial plain. These two units are
distinct only in the eastern part of the gorge and are elsewhere combined into
a single unit. The two beds have a maximum aggregate thickness of about 98 feet
(30 metres) and consist almost entirely of stream-laid detrital sediment.
Archaeological sites in Beds III and IV represent the Developed Oldowan and
Acheulean industries. Hominin remains there are assigned to H. erectus
and other species of Homo.
The Masek Beds
accumulated during a period of major faulting and explosive volcanism. They are
some 82 feet (25 metres) thick and consist of about equal amounts of
stream-laid detrital sediment and aeolian (wind-worked) tuff. Only one archaeological site, of the Acheulean
industry, is known in these beds. The Ndutu Beds were deposited during
intermittent faulting, erosion, and partial filling of the gorge. They consist
largely of aeolian tuffs, and their maximum thickness is 79 feet (24 metres).
The Naisiusiu Beds were deposited on the sides and in the bottom of the gorge
after it had been eroded to very near its present level. These deposits are as
much as 33 feet (10 metres) thick and consist largely of aeolian tuff. They
contain one archaeological site consisting of a microlithic tool assemblage and
a H. sapiens skeleton, both of which have an
age of about 17,000 years.
The earliest recognized members of the genus Homo belong
to the species H. habilis. First identified by Louis Leakey at Olduvai
Gorge, Tanzania,
H. habilis is also known from elsewhere in
Africa.
I CANNOT GO ON
REPRODUCING ALL THE DETAILS GET MORE
FROM THE INTERNET OR BRITANNICA ON LINE PLEASE
Leakey, Louis S.B.
in
full Louis Seymour Bazett Leakey
born
August 7, 1903, Kabete, Kenya
died
October 1, 1972, London, England
- Louis S.B. Leakey.
Kenyan
archaeologist and anthropologist
whose fossil discoveries in East Africa proved that human beings were far
older than had previously been believed and that human evolution was centred in
Africa, rather than in Asia, as earlier discoveries had suggested. Leakey was
also noted for his controversial interpretations of these archaeological finds.
Born
of British missionary parents, Leakey spent his youth with the Kikuyu people of Kenya, about whom he
later wrote. He was educated at the University of Cambridge and began his
archaeological research in East Africa in 1924; he was later aided by his
second wife, the archaeologist Mary Douglas Leakey (née Nicol),
and their sons. He held various appointments at major British and American
universities and was curator of the Coryndon Memorial Museum in Nairobi from
1945 to 1961.
In
1931 Leakey began his research at Olduvai Gorge in Tanzania, which became the site of
his most famous discoveries. The first finds were animal fossils and crude
stone tools, but in 1959 Mary Leakey uncovered a fossil hominin (member of the
human lineage) that was given the name Zinjanthropus (now generally
regarded as a form of Paranthropus, similar to Australopithecus) and was believed to be about
1.7 million years old. Leakey later theorized that Zinjanthropus was not
a direct ancestor of modern man; he claimed this distinction for other hominin
fossil remains that his team discovered at Olduvai Gorge in 1960–63 and that
Leakey named Homo habilis. Leakey held that H. habilis
lived contemporaneously with Australopithecus in East Africa and
represented a more advanced hominin on the direct evolutionary line to H. sapiens. Initially
many scientists disputed Leakey's interpretations and classifications of the
fossils he had found, although they accepted the significance of the finds
themselves. They contended that H. habilis was not sufficiently
different from Australopithecus to justify a separate classification.
Subsequent finds by the Leakey family and others, however, established that H.
habilis does indeed represent an evolutionary step between the
australopiths (who eventually became extinct) and H. erectus, who may have
been a direct ancestor of modern man.
Among
the other important finds made by Leakey's team was the discovery in 1948 at
Rusinga Island in Lake Victoria, Kenya, of the
remains of Proconsul africanus,
a common ancestor of both humans and apes that lived about 25 million years
ago. At Fort Ternan (east of Lake Victoria) in 1962, Leakey's team discovered
the remains of Kenyapithecus,
another link between apes and early man that lived about 14 million years ago.
Leakey's
discoveries formed the basis for the most important subsequent research into
the earliest origins of human life. He was also instrumental in persuading Jane Goodall, Dian Fossey, and Biruté
M.F. Galdikas to undertake their pioneering long-term studies of chimpanzees,
gorillas, and orangutans in those animals' natural habitats. The Louis Leakey
Memorial Institute for African Prehistory in Nairobi was founded by his son Richard Leakey as a fossil
repository and postgraduate study centre and laboratory.
Leakey
wrote Adam's Ancestors (1934; rev. ed., 1953), Stone Age Africa
(1936), White African (1937), Olduvai Gorge (1951), Mau Mau
and the Kikuyu (1952), Olduvai Gorge, 1951–61 (1965), Unveiling
Man's Origins (1969; with Vanne Morris Goodall), and Animals of East
Africa (1969).
To
cite this page:
- MLA Style: "Leakey,
Louis S.B." Encyclopædia Britannica. Encyclopædia Britannica
2009 Ultimate Reference Suite. Chicago: Encyclopædia
Britannica, 2009.
- APA Style: Leakey,
Louis S.B. (2009). Encyclopædia Britannica. Encyclopædia Britannica
2009 Ultimate Reference Suite. Chicago: Encyclopædia
Britannica.
MY
SEARCH FOR REASONS WHY THE BIBLE CHRONICLERS IMPOSED ADAM AS THE FIRST CREATED
HUMAN LED ME TO THIS ELDER SISTER IN THE GENUINE TRUTH …. So read this clip
honestly.
born Aug. 13, 1818, West Brookfield,
Mass., U.S.
died Oct. 18, 1893, Dorchester [part of
Boston], Mass.
- Lucy Stone.
American pioneer in the women's
rights movement.
Stone began to chafe at the
restrictions placed on the female sex while she was still a girl. Her
determination to attend college derived in part from her general desire to
better herself and in part from a specific resolve, made as a child, to learn
Hebrew and Greek in order to determine if those passages in the Bible that
seemed to give man dominion over woman had been properly translated. After
graduating from Oberlin College in Ohio in 1847, she became a lecturer for the
Massachusetts Anti-Slavery Society, which soon granted her permission to devote
part of each week to speaking on her own for women's rights. She helped
organize the first truly national women's rights convention in 1850 and was
instrumental in organizing several other women's rights conventions as well.
Human
Evolution
I
|
INTRODUCTION
|
Sites of Early Human Fossils and Artifacts
Scientists have discovered the bones
and artifacts of early humans in many parts of Africa and Eurasia. The earliest
humans, known as australopithecines, lived only in Africa. The modern human
genus, Homo, also evolved in Africa, but several middle and late Homo species
migrated to Europe and Asia. Early forms of Homo sapiens, or modern humans,
lived in Africa and Asia. Only fully modern humans populated the rest of the
globe.
© Microsoft Corporation. All Rights
Reserved.
Human Evolution, lengthy process of change by which
people originated from apelike ancestors. Scientific evidence shows that the
physical and behavioral traits shared by all people evolved over a period of at
least 6 million years.
One of the earliest defining human traits, bipedalism—walking
on two legs as the primary form of locomotion—evolved more than 4 million years
ago. Other important human characteristics—such as a large and complex brain,
the ability to make and use tools, and the capacity for language—developed more
recently. Many advanced traits—including complex symbolic expression, such as
art, and elaborate cultural diversity—emerged mainly during the past 100,000
years.
Humans are primates. Physical and genetic similarities
show that the modern human species, Homo sapiens, has a very close
relationship to another group of primate species, the apes. Humans and the
so-called great apes (large apes) of Africa—chimpanzees (including bonobos, or
so-called pygmy chimpanzees) and gorillas—share a common ancestor that lived
sometime between 8 million and 6 million years ago. The earliest humans evolved
in Africa, and much of human evolution occurred on that continent. The fossils of
early humans who lived between 6 million and 2 million years ago come entirely
from Africa.
Tree of Human Evolution
Fossil evidence indicates that the
first humans evolved from ape ancestors at least 6 million years ago. Many
species of humans followed, but only some left descendants on the branch
leading to Homo sapiens. In this slide show, white skulls represent species
that lived during the time period indicated; gray skulls represent extinct
human species.
© Microsoft Corporation. All Rights Reserved.
Most scientists distinguish among 12 to 19 different species
of early humans. Scientists do not all agree, however, about how the species
are related or which ones simply died out. Many early human species—probably
the majority of them—left no descendants. Scientists also debate over how to
identify and classify particular species of early humans, and about what
factors influenced the evolution and extinction of each species.
Early humans first migrated out of Africa into Asia
probably between 2 million and 1.7 million years ago. They entered Europe
somewhat later, generally within the past 1 million years. Species of modern
humans populated many parts of the world much later. For instance, people first
came to Australia probably within the past 60,000 years, and to the Americas
within the past 35,000 years. The beginnings of agriculture and the rise of the
first civilizations occurred within the past 10,000 years.
The scientific study of human evolution is called paleoanthropology.
Paleoanthropology is a subfield of anthropology, the study of human culture,
society, and biology. Paleoanthropologists search for the roots of human
physical traits and behavior. They seek to discover how evolution has shaped
the potentials, tendencies, and limitations of all people. For many people,
paleoanthropology is an exciting scientific field because it illuminates the
origins of the defining traits of the human species, as well as the fundamental
connections between humans and other living organisms on Earth. Scientists have
abundant evidence of human evolution from fossils, artifacts, and genetic
studies. However, some people find the concept of human evolution troubling
because it can seem to conflict with religious and other traditional beliefs
about how people, other living things, and the world came to be. Yet many
people have come to reconcile such beliefs with the scientific evidence.
II
|
THE PROCESS OF EVOLUTION
|
Modern and Early Humans
Humans have undergone major
anatomical changes over the course of evolution. This illustration depicts
Australopithecus afarensis (center), the earliest of the three species; Homo
erectus (left), an intermediate species; and Homo sapiens (right), a modern
human. H. erectus and modern humans are much taller than A. afarensis and have
flatter faces and much larger brains. Modern humans have a larger brain than H.
erectus and an almost flat face beneath the front of the braincase.
John Sibbick/National Geographic
Society
All species of organisms originate through the process of
biological evolution. In this process, new species arise from a series of
natural changes. In animals that reproduce sexually, including humans, the term
species refers to a group whose adult members regularly interbreed,
resulting in fertile offspring—that is, offspring themselves capable of
reproducing. Scientists classify each species with a unique, two-part
scientific name. In this system, modern humans are classified as Homo
sapiens.
The mechanism for evolutionary change resides in
genes—the basic units of heredity. Genes affect how the body and behavior of an
organism develop during its life. The information contained in genes can
change—a process known as mutation. The way particular genes are expressed—how
they affect the body or behavior of an organism—can also change. Over time,
genetic change can alter a species’s overall way of life, such as what it eats,
how it grows, and where it can live.
Genetic changes can improve the ability of organisms to
survive, reproduce, and, in animals, raise offspring. This process is called
adaptation. Parents pass adaptive genetic changes to their offspring, and
ultimately these changes become common throughout a population—a group
of organisms of the same species that share a particular local habitat. Many
factors can favor new adaptations, but changes in the environment often play a
role. Ancestral human species adapted to new environments as their genes
changed, altering their anatomy (physical body structure), physiology (bodily
functions, such as digestion), and behavior. Over long periods, evolution
dramatically transformed humans and their ways of life.
Geneticists estimate that the human line began to diverge from
that of the African apes between 8 million and 5 million years ago
(paleontologists have dated the earliest human fossils to at least 6 million
years ago). This figure comes from comparing differences in the genetic makeup
of humans and apes, and then calculating how long it probably took for those
differences to develop. Using similar techniques and comparing the genetic
variations among human populations around the world, scientists have calculated
that all people may share common genetic ancestors that lived sometime between
290,000 and 130,000 years ago.
III
|
CHARACTERISTICS, CLASSIFICATION, AND EVOLUTION OF THE PRIMATES
|
Humans belong to the scientific order named
Primates, a group of over 230 species of mammals that also includes lemurs,
lorises, tarsiers, monkeys, and apes. Modern humans, early humans, and other
species of primates all have many similarities as well as some important
differences. Knowledge of these similarities and differences helps scientists
to understand the roots of many human traits, as well as the significance of each
step in human evolution.
All primates, including humans, share at least part of a set
of common characteristics that distinguish them from other mammals. Many of
these characteristics evolved as adaptations for life in the trees, the
environment in which earlier primates evolved. These include more reliance on
sight than smell; overlapping fields of vision, allowing stereoscopic
(three-dimensional) sight; limbs and hands adapted for clinging on, leaping
from, and swinging on tree trunks and branches; the ability to grasp and
manipulate small objects (using fingers with nails instead of claws); large
brains in relation to body size; and complex social lives.
The scientific classification of primates reflects
evolutionary relationships among individual species and groups of species.
Strepsirhine (meaning 'turned-nosed') primates—of which the living
representatives include lemurs, lorises, and other groups of species all
commonly known as prosimians—evolved earliest and are the most primitive forms
of primates. The earliest monkeys and apes evolved from ancestral haplorhine
(meaning 'simple-nosed') primates, of which the most primitive living
representative is the tarsier. Humans evolved from ape ancestors.
Tarsiers have traditionally been grouped with prosimians, but
many scientists now recognize that tarsiers, monkeys, and apes share some
distinct traits, and group the three together. Monkeys, apes, and humans—who
share many traits not found in other primates—together make up the suborder
Anthropoidea. Apes and humans together make up the superfamily Hominoidea, a
grouping that emphasizes the close relationship among the species of these two
groups.
A
|
Strepsirhines
|
Strepsirhines are the most primitive types of living primates.
The last common ancestors of strepsirhines and other mammals—creatures similar
to tree shrews and classified as Plesiadapiformes—evolved at least 65 million
years ago. The earliest primates evolved by about 55 million years ago, and
fossil species similar to lemurs evolved during the Eocene Epoch (about 55
million to 38 million years ago). Strepsirhines share all of the basic
characteristics of primates, although their brains are not particularly large
or complex and they have a more elaborate and sensitive olfactory system (sense
of smell) than do other primates.
B
|
Haplorhines
|
B1
|
Tarsiers
|
Tarsiers are the only living representatives of a
primitive group of primates that ultimately led to monkeys, apes, and humans.
Fossil species called omomyids, with some traits similar to those of tarsiers,
evolved near the beginning of the Eocene, followed by early tarsier-like
primates. While the omomyids and tarsiers are separate evolutionary branches
(and there are no living omomyids), they both share features having to do with
a reduction in the olfactory system, a trait shared by all haplorhine primates,
including humans.
B2
|
Anthropoids
|
The anthropoid primates are divided into New World (South
America, Central America, and the Caribbean Islands) and Old World (Africa and
Asia) groups. New World monkeys—such as marmosets, capuchins, and spider
monkeys—belong to the infraorder of platyrrhine (broad-nosed)
anthropoids. Old World monkeys and apes belong to the infraorder of catarrhine
(downward-nosed) anthropoids. Since humans and apes together make up the
hominoids, humans are also catarrhine anthropoids.
B2a
|
The First Catarrhine Primates
|
The first catarrhine primates evolved between 50 million
and 33 million years ago. Most primate fossils from this period have been found
in a region of northern Egypt known as Al Fayyūm (or the Fayum). A primate
group known as Propliopithecus, one lineage of which is sometimes called
Aegyptopithecus, had primitive catarrhine features—that is, it had many
of the basic features that Old World monkeys, apes, and humans share today.
Scientists believe, therefore, that Propliopithecus resembles the common
ancestor of all later Old World monkeys and apes. Thus, Propliopithecus
may also be considered an ancestor or a close relative of an ancestor of
humans.
B2b
|
Hominoids
|
Hominoids evolved during the Miocene Epoch (24 million to 5
million years ago). Among the oldest known hominoids is a group of primates
known by its genus name, Proconsul. Species of Proconsul had
features that suggest a close link to the common ancestor of apes and
humans—for example, the lack of a tail. The species Proconsul heseloni
lived in the trees of dense forests in eastern Africa about 20 million years
ago. An agile climber, it had the flexible backbone and narrow chest
characteristic of monkeys, but also a wide range of movement in the hip and
thumb, traits characteristic of apes and humans.
Large ape species had originated in Africa by 23 million
or 22 million years ago. By 15 million years ago, some of these species had
migrated to Asia and Europe over a land bridge formed between the
Africa-Arabian and Eurasian continents, which had previously been separated. See
also Plate Tectonics: Continental Drift.
Early in their evolution, the large apes underwent
several radiations—periods when new and diverse species branched off
from common ancestors. Following Proconsul, the ape genus Afropithecus
evolved about 18 million years ago in Arabia and Africa and diversified into
several species. Soon afterward, three other ape genera evolved—Griphopithecus
of western Asia about 16.5 million years ago, the earliest ape to have
spread from Africa; Kenyapithecus of Africa about 15 million years ago;
and Dryopithecus of Europe about 12 million years ago. Scientists have
not yet determined which of these groups of apes may have given rise to the
common ancestor of modern African apes and humans.
Scientists do not all agree about the appropriate
classification of hominoids. They group the living hominoids into either two or
three families: Hylobatidae, Hominidae, and sometimes Pongidae. Hylobatidae
consists of the small or so-called lesser apes of Southeast Asia, commonly
known as gibbons and siamangs. The Hominidae (hominids) include humans and,
according to some scientists, the great apes. For those who include only humans
among the Hominidae, all of the great apes, including the orangutans of
Southeast Asia, belong to the family Pongidae.
In the past only humans were considered to belong to
the family Hominidae, and the term hominid referred only to
species of humans. Today, however, genetic studies support placing all of the
great apes and humans together in this family and the placing of African
apes—chimpanzees and gorillas—together with humans at an even lower level, or
subfamily.
According to this reasoning, the evolutionary branch of
Asian apes leading to orangutans, which separated from the other hominid
branches by about 13 million years ago, belongs to the subfamily Ponginae. The
ancestral and living representatives of the African ape and human branches together
belong to the subfamily Homininae (sometimes called hominines). Lastly, the
line of early and modern humans belongs to the tribe (classificatory level
above genus) Hominini, or hominins.
This order of classification corresponds with the genetic
relationships among ape and human species. It groups humans and the African
apes together at the same level in which scientists group together, for
example, all types of foxes, all buffalo, or all flying squirrels. Within each
of these groups, the species are very closely related. However, in the
classification of apes and humans the similarities among the names hominoid,
hominid, hominine, and hominin can be confusing. In this article the term early
human refers to all species of the human family tree since the divergence
from a common ancestor with the African apes. Popular writing often still uses
the term hominid to mean the same thing.
C
|
Humans as Primates
|
Gorilla Skull Compared with Human Skull
Modern human beings, like gorillas,
tarsiers, and chimpanzees, are primates. Sometime along the course of primate
evolution, human development diverged from that of gorillas and other primates.
Although many similarities exist between other primates, particularly gorillas
and chimpanzees, and modern humans, fundamental differences attest to the
divergence in development. This illustration of the skulls of a modern gorilla
and a modern human depict some of these differences. The gorilla possesses
larger canine teeth and a protruding jaw as compared with members of the
hominid line.
© Microsoft Corporation. All Rights
Reserved.
About 98.5 percent of the genes in people and chimpanzees
are identical, making chimps the closest living biological relatives of humans.
This does not mean that humans evolved from chimpanzees, but it does indicate
that both species evolved from a common ape ancestor. Orangutans, the great
apes of Southeast Asia, differ much more from humans genetically, indicating a
more distant evolutionary relationship.
Modern humans have a number of physical
characteristics reflective of an ape ancestry. For instance, people have
shoulders with a wide range of movement and fingers capable of strong grasping.
In apes, these characteristics are highly developed as adaptations for brachiation—swinging
from branch to branch in trees. Although humans do not brachiate, the general
anatomy from that earlier adaptation remains. Both people and apes also have
larger brains and greater cognitive abilities than do most other mammals.
Human social life, too, shares similarities with that of
African apes and other primates—such as baboons and rhesus monkeys—that live in
large and complex social groups. Group behavior among chimpanzees, in
particular, strongly resembles that of humans. For instance, chimps form long-lasting
attachments with each other; participate in social bonding activities, such as
grooming, feeding, and hunting; and form strategic coalitions with each other
in order to increase their status and power. Early humans also probably had
this kind of elaborate social life.
However, modern humans fundamentally differ from apes in many
significant ways. For example, as intelligent as apes are, people’s brains are
much larger and more complex, and people have a unique intellectual capacity
and elaborate forms of culture and communication. In addition, only people
habitually walk upright, can precisely manipulate very small objects, and have
a throat structure that makes speech possible.
IV
|
THE FIRST HUMANS: AUSTRALOPITHECINES
|
Raymond Dart and the Taung Child
Australian-born anatomist Raymond
Dart is shown here with the first known specimen of Australopithecus africanus,
which was unearthed at a lime quarry near Taung, South Africa, in 1924. Dart
was the first to examine the skull and recognize that it represented an early
stage in human evolution, although his findings were not fully accepted until
the 1940s.
John Reader/Science Photo
Library/Photo Researchers, Inc.
By around 6 million years ago in Africa, an apelike
species had evolved with two important traits that distinguished it from apes:
(1) small canine, or eye, teeth (teeth next to the four incisors, or front
teeth) and (2) bipedalism—that is, walking on two legs as the primary form of
locomotion. Scientists refer to these earliest human species as
australopithecines, or australopiths for short. The earliest australopith
species known today belong to three genera: Sahelanthropus, Orrorin, and
Ardipithecus. Other species belong to the genus Australopithecus
and, by some classifications, Paranthropus. The name australopithecine
translates literally as “southern ape,” in reference to South Africa, where the
first known australopith fossils were found.
The Great Rift Valley, a region in eastern Africa in
which past movements in Earth’s crust have exposed ancient deposits of fossils,
has become famous for its australopith finds. Countries in which scientists
have found australopith fossils include Ethiopia, Tanzania, Kenya, South
Africa, and Chad. Thus, australopiths ranged widely over the African continent.
A
|
From Ape to Human
|
Fossils from several different early australopith species
that lived between 4 million and 2 million years ago clearly show a variety of
adaptations that mark the transition from ape to human. The very early period
of this transition, prior to 4 million years ago, remains poorly documented in
the fossil record, but those fossils that do exist show the most primitive
combinations of ape and human features.
Fossils reveal much about the physical build and
activities of early australopiths, but not everything about outward physical
features such as the color and texture of skin and hair, or about certain
behaviors, such as methods of obtaining food or patterns of social interaction.
For these reasons, scientists study the living great apes—particularly the
African apes—to better understand how early australopiths might have looked and
behaved, and how the transition from ape to human might have occurred.
For example, australopiths probably resembled the great apes
in characteristics such as the shape of the face and the amount of hair on the
body. Australopiths also had brains roughly equal in size to those of the great
apes, so they probably had apelike mental abilities. Their social life probably
resembled that of chimpanzees.
B
|
Australopith Characteristics
|
Most of the distinctly human physical qualities in
australopiths related to their bipedal stance. Before australopiths, no mammal
had ever evolved an anatomy for habitual upright walking. Australopiths also
had small canine teeth, as compared with long canines found in almost all other
catarrhine primates.
Other characteristics of australopiths reflected their ape
ancestry. They had a low cranium behind a projecting face, and a brain size of
390 to 550 cu cm (24 to 34 cu in)—in the range of an ape’s brain. The body
weight of australopiths, as estimated from their bones, ranged from 27 to 49 kg
(60 to 108 lb), and they stood 1.1 to 1.5 m (3.5 to 5 ft) tall. Their weight
and height compare closely to those of chimpanzees (chimp height measured
standing). Some australopith species had a large degree of sexual dimorphism—males
were much larger than females—a trait also found in gorillas, orangutans, and
some other primates.
Australopiths also had curved fingers and long thumbs with a
wide range of movement. In comparison, the fingers of apes are longer, more
powerful, and more curved, making them extremely well adapted for hanging and
swinging from branches. Apes also have very short thumbs, which limits their
ability to manipulate small objects. Paleoanthropologists speculate as to
whether the long and dexterous thumbs of australopiths allowed them to use
tools more efficiently than do apes.
B1
|
Bipedalism
|
Evolution of Upright Walking
Unlike their ape ancestors, early
humans had anatomical adaptations for upright walking. The early human species
Australopithecus afarensis had a wide and short pelvis and femurs (upper leg
bones) that angled inward toward the knees. These adaptations provided
side-to-side balance and a fulcrum for the hip muscles to hold the torso erect.
In contrast, apes, such as chimpanzees, have a tall and narrow pelvis from
which the femurs extend straight down.
© Microsoft Corporation. All Rights
Reserved.
The anatomy of australopiths shows a number of
adaptations for bipedalism, in both the upper and lower body. Adaptations in
the lower body included the following: The australopith ilium, or pelvic bone,
which rises above the hip joint, was much shorter and broader than it is in
apes. This shape enabled the hip muscles to steady the body during each step.
The australopith pelvis also had a bowl-like shape, which supported the
internal organs in an upright stance. The upper legs angled inward from the hip
joints, which positioned the knees to better support the body during upright
walking. The legs of apes, on the other hand, are positioned almost straight
down from the hip, so that when an ape walks upright for a short distance, its
body sways from side to side. Australopiths also had shorter and less flexible
toes than do apes. The toes worked as rigid levers for pushing off the ground
during each bipedal step.
Other adaptations occurred above the pelvis. The australopith
spine had an S-shaped curve, which shortened the overall length of the torso
and gave it rigidity and balance when standing. By contrast, apes have a
relatively straight spine. The australopith skull also had an important
adaptation related to bipedalism. The opening at the bottom of the skull
through which the spinal cord attaches to the brain, called the foramen magnum,
was positioned more forward than it is in apes. This position set the head in
balance over the upright spine.
Australopiths clearly walked upright on the ground, but paleoanthropologists
debate whether the earliest humans also spent a significant amount of time in
the trees. Certain physical features indicate that they spent at least some of
their time climbing in trees. Such features include their curved and elongated
fingers and elongated arms. However, their fingers, unlike those of apes, may
not have been long enough to allow them to brachiate through the treetops.
Study of fossil wrist bones suggests that early australopiths had the ability
to lock their wrists, preventing backward bending at the wrist when the body
weight was placed on the knuckles of the hand. This could mean that the
earliest bipeds had an ancestor that walked on its knuckles, as African apes
do.
B2
|
Small Canine Teeth
|
Compared with apes, humans have very small canine teeth.
Apes—particularly males—have thick, projecting, sharp canines that they use for
displays of aggression and as weapons to defend themselves. The oldest known
bipeds, who lived at least 6 million years ago, still had large canines by
human standards, though not as large as in apes. By 4 million years ago
australopiths had developed the human characteristic of having smaller, flatter
canines. Canine reduction might have related to an increase in social cooperation
among humans and an accompanying decrease in the need for males to make
aggressive displays.
The australopiths can be divided into an early group of
species, known as gracile australopiths, which arose prior to 3 million years
ago; and a later group, known as robust australopiths, which evolved after 3
million years ago. The gracile australopiths—of which several species evolved
between 4.5 million and 3 million years ago—generally had smaller teeth and
jaws. The later-evolving robusts had larger faces with large jaws and molars
(cheek teeth). These traits indicate powerful and prolonged chewing of food,
and analyses of wear on the chewing surface of robust australopith molar teeth
support this idea. Some fossils of early australopiths have features resembling
those of the later species, suggesting that the robusts evolved from one or
more gracile ancestors.
C
|
Early Australopiths
|
Paleoanthropologists recognize at least eight species of early
australopiths. These include the three earliest established species, which
belong to the genera Sahelanthropus, Orrorin, and Ardipithecus, a
species of the genus Kenyanthropus, and four species of the genus Australopithecus.
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Sahelanthropus tchadensis
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The oldest known australopith species is Sahelanthropus
tchadensis. Fossils of this species were first discovered in 2001 in
northern Chad, Central Africa, by a research team led by French paleontologist
Michel Brunet. The researchers estimated the fossils to be between 7 million
and 6 million years old. One of the fossils is a cracked yet nearly complete
cranium that shows a combination of apelike and humanlike features. Apelike
features include small brain size, an elongated brain case, and areas of bone
where strong neck muscles would have attached. Humanlike features include
small, flat canine teeth, a short middle part of the face, and a massive brow
ridge (a bony, protruding ridge above the eyes) similar to that of later human
fossils. The opening where the spinal cord attaches to the brain is tucked
under the brain case, which suggests that the head was balanced on an upright
body. It is not certain that Sahelanthropus walked bipedally, however,
because bones from the rest of its skeleton have yet to be discovered.
Nonetheless, its age and humanlike characteristics suggest that the human and
African ape lineages had divided from one another by at least 6 million years
ago.
In addition to reigniting debate about human origins, the
discovery of Sahelanthropus in Chad significantly expanded the known
geographic range of the earliest humans. The Great Rift Valley and South
Africa, from which almost all other discoveries of early human fossils came,
are apparently not the only regions of the continent that preserve the oldest
clues of human evolution.
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Orrorin tugenensis
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Orrorin tugenensis lived about 6 million years ago. This
species was discovered in 2000 by a research team led by French paleontologist
Brigitte Senut and French geologist Martin Pickford in the Tugen Hills region
of central Kenya. The researchers found more than a dozen early human fossils
dating between 6.2 million and 6 million years old. Among the finds were two
thighbones that possess a groove indicative of an upright stance and bipedal
walking. Although the finds are still being studied, the researchers consider
these thighbones to be the oldest evidence of habitual two-legged walking.
Fossilized bones from other parts of the skeleton show apelike features,
including long, curved finger bones useful for strong grasping and movement
through trees, and apelike canine and premolar teeth. Because of this
distinctive combination of ape and human traits, the researchers gave a new
genus and species name to these fossils, Orrorin tugenensis, which in
the local language means “original man in the Tugen region.” The age of these
fossils suggests that the divergence of humans from our common ancestor with
chimpanzees occurred before 6 million years ago.
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Ardipithecus ramidus
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In 1994 an Ethiopian member of a research team led
by American paleoanthropologist Tim White discovered human fossils estimated to
be about 4.4 million years old. White and his colleagues gave their discovery
the name Ardipithecus ramidus. Ramid means “root” in the Afar
language of Ethiopia and refers to the closeness of this new species to the
roots of humanity. At the time of this discovery, the genus Australopithecus
was scientifically well established. White devised the genus name Ardipithecus
to distinguish this new species from other australopiths because its fossils
had a very ancient combination of apelike and humanlike traits. More recent
finds indicate that this species may have lived as early as 5.8 million to 5.2
million years ago. It has been suggested, however, that these older fossils may
represent a related species called Ardipithecus kadabba.
The teeth of Ardipithecus ramidus had a thin outer
layer of enamel—a trait also seen in the African apes but not in other
australopith species or most older fossil apes. This trait suggests a fairly
close relationship with an ancestor of the African apes. In addition, the
skeleton shows strong similarities to that of a chimpanzee but has slightly
reduced canine teeth and adaptations for bipedalism.
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Australopithecus anamensis
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In 1965 a research team from Harvard University
discovered a single arm bone of an early human at the site of Kanapoi in
northern Kenya. The researchers estimated this bone to be 4 million years old,
but could not identify the species to which it belonged or return at the time
to look for related fossils. It was not until 1994 that a research team, led by
British-born Kenyan paleoanthropologist Meave Leakey, found numerous teeth and
fragments of bone at the site that could be linked to the previously discovered
fossil. Leakey and her colleagues determined that the fossils were those of a
very primitive species of australopith, which was given the name Australopithecus
anamensis. Researchers have since found other A. anamensis fossils
at nearby sites, dating between about 4.2 million and 3.9 million years old.
The skull of this species appears apelike, while its enlarged tibia (lower leg
bone) indicates that it supported its full body weight on one leg at a time, as
in regular bipedal walking.
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Australopithecus afarensis
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Australopithecus afarensis
Australopithecus afarensis, one of
the earliest human species, lived between 4 million and 3 million years ago.
This skull cast is a composite of bone fragments from different individuals of
this species. The lighter portions represent bone fragments, and the missing
pieces are filled in to reveal what an entire skull probably looked like.
F. Schneidermeyer/Oxford Scientific
Films
Australopithecus anamensis was quite similar to
another, much better-known species, A. afarensis, a gracile australopith
that thrived in eastern Africa between about 3.8 million and 3 million years
ago. The most celebrated fossil of this species, known as Lucy, is a partial
skeleton of a female discovered by American paleoanthropologist Donald Johanson
in 1974 at Hadar, Ethiopia. Lucy lived 3.2 million years ago. Scientists have
identified several hundred fossils of A. afarensis from Hadar, including
a collection representing at least 13 individuals of both sexes and various
ages, all from a single site.
One of the most complete specimens of A.
afarensis found so far was announced in 2006. A team led by Ethiopian
scientist Zeresenay Alemseged unearthed the partial skeleton of a
three-year-old female at Dikika in the Afar region of Ethiopia. Nicknamed
“Selam,” the Dikika child dates from around 3.3 million years ago. The
well-preserved bones provide previously undocumented details of the skull and
skeleton. Some features such as the shape of the shoulder blades, the long,
curved fingers, and the semicircular ear canals involved in balance are more
apelike, suggesting an adaptation for climbing trees. However, the leg bones
and feet indicate an ability to walk upright even at an early age. The shape of
the brain was preserved and its size indicates the species grew to adulthood
more slowly than chimpanzees, a characteristic of later hominids, including
modern humans. The hyoid bone that supports the tongue was found, as well. The
bone is crucial to speech in modern humans but the shape in the Dikika child is
like that found in modern great apes, and not humans.
Researchers working in northern Tanzania have also found
fossilized bones of A. afarensis at Laetoli. This site, dated at
3.6 million years old, is best known for its spectacular trails of bipedal
human footprints. Preserved in hardened volcanic ash, these footprints were
discovered in 1978 by a research team led by British paleoanthropologist Mary
Leakey. They provide irrefutable evidence that australopiths regularly walked
bipedally.
Paleoanthropologists have debated interpretations of the
characteristics of A. afarensis and its place in the human family tree.
One controversy centers on the Laetoli footprints, which some scientists
believe show that the foot anatomy and gait of A. afarensis did not
exactly match those of modern humans. This observation may indicate that early
australopiths did not live primarily on the ground or at least spent a
significant amount of time in the trees. The skeleton of Lucy also indicates
that A. afarensis had longer, more powerful arms than most later human
species, suggesting that this species was adept at climbing trees.
Footprints From the Past
In 1978 in Laetoli, Tanzania, a
research team led by British paleoanthropologist Mary Leakey discovered these
3.6-million-year-old human footprints preserved in a layer of hardened volcanic
ash. Two early humans of the species Australopithecus afarensis left the
footprints as they walked across the African savanna.
John Reader/Photo Researchers, Inc.
Another controversy has to do with the scientific
classification of the A. afarensis fossils. Compared with Lucy,
who stood only 1.1 m (3.5 ft) tall, other fossils identified as A. afarensis
from Hadar and Laetoli came from individuals who stood up to 1.5 m (5 ft) tall.
This great difference in size leads some scientists to suggest that the entire
set of fossils now classified as A. afarensis actually represents two
species. Most scientists, however, believe the fossils represent one highly dimorphic
species—that is, a species that has two distinct forms (in this case, two
sizes). Supporters of this view note that both large (presumably male) and
small (presumably female) adults occur together in one site at Hadar.
Lucy
In 1974 American paleoanthropologist
Donald Johanson discovered the skeleton of “Lucy,” a 3.2-million-year-old
female of the early human species Australopithecus afarensis, at Hadar,
Ethiopia. Until the late 1990s, Lucy’s was the most complete skeleton of an
australopithecine ever found. Australopithecines were primitive humans that
first evolved over 4.4 million years ago. Lucy’s pelvis and leg bones, similar
to those of modern humans, indicate that she regularly walked upright.
John Reader/Science Photo
Library/Photo Researchers, Inc.
A third controversy arises from the claim that A.
afarensis was the common ancestor of both later australopiths and the
modern human genus, Homo. While this idea remains a strong possibility,
the similarity between this and another australopith species—one from southern
Africa, named Australopithecus africanus—makes it difficult to decide
which of the two species gave rise to the genus Homo.
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Australopithecus africanus
|
Australopithecus africanus thrived in the Transvaal region of
what is now South Africa between about 3.3 million and 2.5 million years ago.
Australian-born anatomist Raymond Dart discovered this species—the first known
australopith—in 1924 at Taung, South Africa. The specimen, that of a young
child, came to be known as the Taung Child. For decades after this discovery,
almost no one in the scientific community believed Dart’s claim that the skull
came from an ancestral human. In the late 1930s teams led by Scottish-born
South African paleontologist Robert Broom unearthed many more A. africanus
skulls and other bones from the Transvaal site of Sterkfontein.
A. africanus generally had a more globular
braincase and less primitive-looking face and teeth than did A. afarensis.
Thus, some scientists consider the southern species of early australopith to be
a likely ancestor of the genus Homo. According to other scientists,
however, certain heavily built facial and cranial features of A. africanus
from Sterkfontein identify it as an ancestor of the robust australopiths that
lived later in the same region. In 1998 a research team led by South African
paleoanthropologist Ronald Clarke discovered an almost complete early
australopith skeleton at Sterkfontein. This important find may resolve some of
the questions about where A. africanus fits in the story of human
evolution.
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Kenyanthropus platyops
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Working in the Lake Turkana region of northern
Kenya, a research team led by paleontologist Meave Leakey uncovered in 1999 a
cranium and other bone remains of an early human that showed a mixture of
features unseen in previous discoveries of early human fossils. The remains
were estimated to be 3.5 million years old, and the cranium’s small brain and
earhole were similar to those of the very earliest humans. Its cheekbone,
however, joined the rest of the face in a forward position, and the region
beneath the nose opening was flat. These are traits found in later human
fossils from around 2 million years ago, typically those classified in the
genus Homo. Noting this unusual combination of traits, researchers named
a new genus and species, Kenyanthropus platyops, or “flat-faced human
from Kenya.” Before this discovery, it seemed that only a single early human
species, Australopithecus afarensis, lived in East Africa between 4
million and 3 million years ago. Yet Kenyanthropus indicates that a
diversity of species, including a more humanlike lineage than A. afarensis,
lived in this time period, just as in most other eras in human prehistory.
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Australopithecus garhi
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The human fossil record is poorly known between 3 million
and 2 million years ago, which makes recent finds from the site of Bouri,
Ethiopia, particularly important. From 1996 to 1998, a research team led by
Ethiopian paleontologist Berhane Asfaw and American paleontologist Tim White
found the skull and other skeletal remains of an early human specimen about 2.5
million years old. The researchers named it Australopithecus garhi; the
word garhi means “surprise” in the Afar language. The specimen is unique
in having large incisors and molars in combination with an elongated forearm
and thighbone. Its powerful arm bones suggest a tree-living ancestry, but its
longer legs indicate the ability to walk upright on the ground. Fossils of A.
garhi are associated with some of the oldest known stone tools, along with
animal bones that were cut and cracked with tools. It is possible, then, that
this species was among the first to make the transition to stone toolmaking and
to eating meat and bone marrow from large animals.
D
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Late Australopiths
|
By 2.7 million years ago the later, robust
australopiths had evolved. These species had what scientists refer to as megadont
cheek teeth—wide molars and premolars coated with thick enamel. Their
incisors, by contrast, were small. The robusts also had an expanded, flattened,
and more vertical face than did gracile australopiths. This face shape helped
to absorb the stresses of strong chewing. On the top of the head, robust
australopiths had a sagittal crest (ridge of bone along the top of the
skull from front to back) to which thick jaw muscles attached. The zygomatic
arches (which extend back from the cheek bones to the ears), curved out wide
from the side of the face and cranium, forming very large openings for the
massive chewing muscles to pass through near their attachment to the lower jaw.
Altogether, these traits indicate that the robust australopiths chewed their
food powerfully and for long periods.
Other ancient animal species that specialized in eating
plants, such as some types of wild pigs, had similar adaptations in their
facial, dental, and cranial anatomy. Thus, scientists think that the robust
australopiths had a diet consisting partly of tough, fibrous plant foods, such
as seed pods and underground tubers. Analyses of microscopic wear on the teeth
of some robust australopith specimens appear to support the idea of a
vegetarian diet, although chemical studies of fossils suggest that the southern
robust species may also have eaten meat.
Scientists originally used the word robust to refer to the
late australopiths out of the belief that they had much larger bodies than did
the early, gracile australopiths. However, further research has revealed that
the robust australopiths stood about the same height and weighed roughly the
same amount as Australopithecus afarensis and A. africanus.
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Australopithecus aethiopicus
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The earliest known robust species, Australopithecus
aethiopicus, lived in eastern Africa by 2.7 million years ago. In
1985 at West Turkana, Kenya, American paleoanthropologist Alan Walker
discovered a 2.5-million-year-old fossil skull that helped to define this
species. It became known as the “black skull” because of the color it had
absorbed from minerals in the ground. The skull had a tall sagittal crest
toward the back of its cranium and a face that projected far outward from the
forehead. A. aethiopicus shared some primitive features with A.
afarensis—that is, features that originated in the earlier East African
australopith. This may indicate that A. aethiopicus evolved from A.
afarensis.
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Australopithecus boisei
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Louis Leakey with Zinjanthropus
British-Kenyan paleoanthropologist
Louis Leakey examines the skull of the early human species Australopithecus
boisei (originally known as Zinjanthropus boisei), right, next to the skull of
a chimpanzee. British paleoanthropologist Mary Leakey, wife of Louis,
discovered the 1.8-million-year-old skull in the Olduvai Gorge of northern
Tanzania in July 1959. It was the first Australopithecus boisei skull ever
found. The species earned the nickname “Nutcracker Man” because of its
especially massive face, jaws, and molars.
UPI/THE BETTMANN ARCHIVE
Australopithecus boisei, the other well-known East African
robust australopith, lived over a long period of time, between about 2.3
million and 1.4 million years ago. In 1959 Mary Leakey discovered the original
fossil of this species—a nearly complete skull—at the site of Olduvai Gorge in
Tanzania. Kenyan-born paleoanthropologist Louis Leakey, husband of Mary,
originally named the new species Zinjanthropus boisei (Zinjanthropus
translates as “East African man”). This skull—dating from 1.8 million years
ago—has the most specialized features of all the robust species. It has a
massive, wide and dished-in face capable of withstanding extreme chewing
forces, and molars four times the size of those in modern humans. Since the
discovery of Zinjanthropus, now recognized as an australopith,
scientists have found great numbers of A. boisei fossils in Tanzania,
Kenya, and Ethiopia.
D3
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Australopithecus robustus
|
The southern robust species, called Australopithecus
robustus, lived between about 1.8 million and 1.3 million years ago in the
Transvaal, the same region that was home to A. africanus. In 1938 Robert
Broom, who had found many A. africanus fossils, bought a fossil jaw and
molar that looked distinctly different from those in A. africanus. After
finding the site of Kromdraai, from which the fossil had come, Broom collected
many more bones and teeth that together convinced him to name a new species,
which he called Paranthropus robustus (Paranthropus meaning
“beside man”). Later scientists dated this skull at about 1.5 million years
old. In the late 1940s and 1950 Broom discovered many more fossils of this
species at the Transvaal site of Swartkrans.
D4
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The Origins and Fate of Late Australopiths
|
Many scientists believe that robust australopiths represent a
distinct evolutionary group of early humans because these species share
features associated with heavy chewing. According to this view, Australopithecus
aethiopicus diverged from other australopiths and later gave rise to A.
boisei and A. robustus. Paleoanthropologists who strongly support
this view think that the robusts should be classified in the genus Paranthropus,
the original name given to the southern species. Thus, these three
species are sometimes referred to as P. aethiopicus, P. boisei, and
P. robustus.
Other paleoanthropologists believe that the eastern robust species,
A. aethiopicus and A. boisei, may have evolved from an early
australopith of the same region, perhaps A. afarensis. According to this
view, A. africanus gave rise only to the southern species, A.
robustus. Scientists refer to such a case—in which two or more independent
species evolve similar characteristics in different places or at different
times—as parallel evolution. If parallel evolution occurred in
australopiths, the robust species would make up two separate branches of the
human family tree.
The last robust australopiths died out about 1.4 million
years ago. At about this time, climate patterns around the world entered a
period of fluctuation, and these changes may have reduced the food supply on
which robusts depended. Interaction with larger-brained members of the genus Homo,
such as Homo erectus, may also have contributed to the decline of late
australopiths, although no compelling evidence exists of such direct contact.
Competition with several other species of plant-eating monkeys and pigs, which
thrived in Africa at the time, may have been an even more important factor. But
the reasons why the robust australopiths became extinct after flourishing for
such a long time are not yet known for sure.
E
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Why Did Humans Evolve?
|
Haven In the Trees
Australopithecines, very early human
ancestors, spent some of their time in trees. Australopithecines had long,
curved fingers that helped them grasp branches for climbing. In this artist’s
rendering, members of a group of the species Australopithecus africanus forage
for fruits and leaves in the treetops, where they are safe from such potential
predators as lions. Although australopithecines were good tree-climbers, they
also walked fully upright and spent much time on the ground.
Richard Schlecht/National Geographic
Image Collection
Scientists have several ideas about why australopiths first
split off from the apes, initiating the course of human evolution. Virtually
all hypotheses suggest that environmental change was an important factor,
specifically in influencing the evolution of bipedalism. Some well-established
ideas about why humans first evolved include (1) the savanna hypothesis, (2)
the woodland-mosaic hypothesis, and (3) the variability hypothesis.
The global climate cooled and became drier between 8
million and 5 million years ago, near the end of the Miocene Epoch. According
to the savanna hypothesis, this climate change broke up and reduced the area of
African forests. As the forests shrunk, an ape population in eastern Africa
became separated from other populations of apes in the more heavily forested
areas of western Africa. The eastern population had to adapt to its drier
environment, which contained larger areas of grassy savanna.
The expansion of dry terrain favored the evolution
of terrestrial living, and made it more difficult to survive by living in
trees. Terrestrial apes might have formed large social groups in order to
improve their ability to find and collect food and to fend off
predators—activities that also may have required the ability to communicate
well. The challenges of savanna life might also have promoted the rise of tool
use, for purposes such as scavenging meat from the kills of predators. These
important evolutionary changes would have depended on increased mental abilities
and, therefore, may have correlated with the development of larger brains in
early humans.
Critics of the savanna hypothesis argue against it on
several grounds, but particularly for two reasons. First, discoveries by a
French scientific team of australopith fossils in Chad, in Central Africa,
suggests that the environments of East Africa may not have been fully separated
from those farther west. Second, recent research suggests that open savannas
were not prominent in Africa until sometime after 2 million years ago.
Criticism of the savanna hypothesis has spawned
alternative ideas about early human evolution. The woodland-mosaic hypothesis
proposes that the early australopiths evolved in patchily wooded areas—a mosaic
of woodland and grassland—that offered opportunities for feeding both on the
ground and in the trees, and that ground feeding favored bipedalism.
The variability hypothesis suggests that early australopiths
experienced many changes in environment and ended up living in a range of
habitats, including forests, open-canopy woodlands, and savannas. In response,
their populations became adapted to a variety of surroundings. Scientists have
found that this range of habitats existed at the time when the early
australopiths evolved. So the development of new anatomical
characteristics—particularly bipedalism—combined with an ability to climb
trees, may have given early humans the versatility to live in a variety of
habitats.
Scientists also have many ideas about which benefits of
bipedalism may have influenced its evolution. Ideas about the benefits of
regular bipedalism include that it freed the hands, making it easier to carry
food and tools; allowed early humans to see over tall grass to watch for
predators; reduced exposure of the body to hot sun and increased exposure to
cooling winds; improved the ability to hunt or use weapons, which became easier
with an upright posture; and made extensive feeding from bushes and low
branches easier than it would have been for a quadruped. Scientists do not overwhelmingly
support any one of these ideas. Recent studies of chimpanzees suggest, though,
that the ability to feed more easily might have particular relevance. Chimps
move on two legs most often when they feed from the ground on the leaves and
fruits of bushes and low branches. Chimps cannot, however, walk in this way
over long distances.
Bipedalism in early humans would have enabled them to
travel efficiently over long distances, giving them an advantage over
quadrupedal apes in moving across barren open terrain between groves of trees.
In addition, the earliest humans continued to have the advantage from their ape
ancestry of being able to escape into the trees to avoid predators. The
benefits of both bipedalism and agility in the trees may explain the unique
anatomy of australopiths. Their long, powerful arms and curved fingers probably
made them good climbers, while their pelvis and lower limb structure was
reshaped for upright walking.
V
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THE GENUS HOMO
|
People belong to the genus Homo, which first evolved
at least 2.3 million to 2.5 million years ago. The earliest members of this
genus differed from the australopiths in at least one important respect—they
had larger brains than did their predecessors.
The evolution of the modern human genus can be divided
roughly into three periods: early, middle, and late. Species of early Homo
resembled gracile australopiths in many ways. Some early Homo species
lived until possibly 1.6 million years ago. The period of middle Homo
began perhaps between 2 million and 1.8 million years ago, overlapping with the
end of early Homo. Species of middle Homo evolved an anatomy much
more similar to that of modern humans but had comparatively small brains. The
transition from middle to late Homo probably occurred sometime around
200,000 years ago. Species of late Homo evolved large and complex brains
and eventually language. Culture also became an increasingly important part of
human life during the most recent period of evolution.
A
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Origins
|
The origin of the genus Homo has long
intrigued paleoanthropologists and prompted much debate. One of several known
species of australopiths, or one not yet discovered, could have given rise to
the first species of Homo. Scientists also do not know exactly what
factors favored the evolution of a larger and more complex brain—the defining
physical trait of modern humans.
Louis Leakey originally argued that the origin of Homo
related directly to the development of toolmaking—specifically, the making of
stone tools. Toolmaking requires certain mental skills and fine hand
manipulation that may exist only in members of our own genus. Indeed, the name Homo
habilis (meaning “handy man”) refers directly to the making and use of
tools.
However, several species of australopiths lived at the same
time as early Homo, making it unclear which species produced the
earliest stone tools. Recent studies of australopith hand bones have suggested
that at least one of the robust species, Australopithecus robustus,
could have made tools. In addition, during the 1960s and 1970s researchers
first observed that some nonhuman primates, such as chimpanzees, make and use
tools, suggesting that australopiths and the apes that preceded them probably
also made some kinds of tools.
According to some scientists, however, early Homo
probably did make the first stone tools. The ability to cut and pound foods
would have been most useful to these smaller-toothed humans, whereas the robust
australopiths could chew even very tough foods. Furthermore, early humans
continued to make stone tools similar to the oldest known kinds for a time long
after the gracile australopiths died out.
Some scientists think that a period of environmental cooling
and drying in Africa set the stage for the evolution of Homo. According
to this idea, many types of animals suited to the challenges of a drier
environment originated during the period between about 2.8 million and 2.4
million years ago, including the first species of Homo. A toolmaking
human might have had an advantage in obtaining alternative food sources as
vegetation became sparse in increasingly dry environments. The new foods might
have included underground roots and tubers, as well as meat obtained through
scavenging or hunting. However, some scientists disagree with this idea,
arguing that the period during which Homo evolved fluctuated between
drier and wetter conditions, rather than just becoming dry. In this case, the making
and use of stone tools and an expansion of the diet in early Homo—as
well as an increase in brain size—may all have been adaptations to
unpredictable and fluctuating environments. In either case, more scientific
documentation is necessary to strongly support or refute the idea that early Homo
arose as part of a larger trend of rapid species extinction and the evolution
of many new species during a period of environmental change.
B
|
Early Homo
|
Meat Eating Among Early Humans
Early species of the genus Homo may
have been the first human ancestors to eat meat on a regular basis. In the
lower foreground of this artist’s rendering, a mother and child share meat from
an animal carcass. Rather than hunting prey themselves, these early humans
often may have scavenged the kills of predatory animals, using simple stone
tools to cut up carcasses.
Richard Schlecht/National Geographic
Image Collection
Paleoanthropologists generally recognize two species of early Homo—Homo
habilis and H. rudolfensis (although other species may also have
existed). The record is unclear because most of the early fossils that
scientists have identified as species of Homo—rather than robust
australopiths who lived at the same time—occur as isolated fragments. In many
places, only teeth, jawbones, and pieces of skull—without any other skeletal
remains—indicate that new species of smaller-toothed humans had evolved as
early as 2.5 million years ago. Scientists cannot always tell whether these
fossils belong to late-surviving gracile australopiths or early representatives
of Homo. The two groups resemble each other because Homo likely
descended directly from a species of gracile australopith.
B1
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Homo habilis
|
Between 1960 and 1963, at Olduvai Gorge, Tanzania, a team
led by Louis and Mary Leakey discovered the remains of an early human that
seemed distinctly different from the australopiths. In 1964 Louis Leakey, South
African paleoanthropologist Philip Tobias, and British primate researcher John
Napier concluded that these remains represented a new species, which they named
Homo habilis. The scientists placed the species in the genus Homo
because its brain was estimated to be significantly larger than that of any
known australopith. Other scientists questioned whether the amount of brain
enlargement was sufficient for inclusion of the species in Homo, and
even whether H. habilis was different from Australopithecus
africanus, as the teeth of the two species look similar. However,
scientists now widely accept both the genus and species names designated by the
Olduvai team. According to recent estimates, H. habilis had a brain
volume that ranged from 590 to 690 cu cm (36 to 42 cu in), well above the range
for australopithecines.
H. habilis lived in eastern and possibly
southern Africa between about 1.9 million and 1.6 million years ago, and maybe
as early as 2.4 million years ago. Although the fossils of this species
somewhat resemble those of australopiths, H. habilis had smaller and
narrower molar teeth, premolar teeth, and jaws than did its predecessors and
contemporary robust australopiths.
A fragmented skeleton of a female from Olduvai shows that she
stood only about 1 m (3.3 ft) tall, and the ratio of the length of her arms to
her legs was greater than that in the australopith Lucy. At least in the case
of this individual, therefore, H. habilis had very apelike body
proportions. However, H. habilis had more modern-looking feet and
hands capable of producing tools. Some of the earliest stone tools from Olduvai
have been found with H. habilis fossils, suggesting that this species
made and used the tools at this site.
Scientists began to notice a high degree of variability
in body size as they discovered more early Homo fossils. This could have
indicated that H. habilis had a large amount of sexual dimorphism. For
instance, the Olduvai female skeleton was dwarfed in comparison with some other
fossils—exemplified by a sizable early Homo cranium from East Turkana in
northern Kenya. However, the differences in size actually exceeded those
expected between males and females of the same species, and this finding later
helped convince scientists that another species of early Homo had lived
in eastern Africa.
B2
|
Homo rudolfensis
|
Homo rudolfensis
In 1972 in East Turkana, Kenya, a
research team led by Kenyan paleoanthropologist Richard Leakey discovered this
1.8-million-year-old skull. British-Kenyan zoologist Meave Leakey (Richard’s
wife) reconstructed the skull, shown here, from over 150 fragments of bone.
Because the size and several anatomical features of the skull differed from
those of other early humans known at the time, scientists eventually classified
it as belonging to a new species, Homo rudolfensis.
John Reader/Photo Researchers, Inc.
This second species of early Homo was given the
name Homo rudolfensis, after Lake Rudolf (now Lake Turkana). The
best-known fossils of H. rudolfensis come from the area surrounding this
lake and date from about 1.9 million years ago. Paleoanthropologists have not
determined the entire time range during which H. rudolfensis may have
lived.
This species had a larger face and body than did H.
habilis. The cranial capacity of H. rudolfensis averaged
about 750 cu cm (46 cu in). Scientists need more evidence to know whether the
brain of H. rudolfensis in relation to its body size was larger than
that proportion in H. habilis. A larger brain-to-body-size ratio can
indicate increased mental abilities. H. rudolfensis also had fairly
large teeth, approaching the size of those in robust australopiths. The
discovery of even a partial fossil skeleton would reveal whether this larger
form of early Homo had apelike or more modern body proportions.
Scientists have found several modern-looking thighbones that date from
between 2 million and 1.8 million years ago and may belong to H.
rudolfensis. These bones suggest a body size of 1.5 m (5 ft) and 52 kg (114
lb).
C
|
Middle Homo
|
By about 1.9 million years ago, the period of middle
Homo had begun in Africa. Until recently, paleoanthropologists
recognized one species in this period, Homo erectus. Many now recognize
three species of middle Homo: H. ergaster, H. erectus, and
H. heidelbergensis. However, some still think H. ergaster is an
early African form of H. erectus, or that H. heidelbergensis is a
late form of H. erectus.
The skulls and teeth of early African populations of
middle Homo differed subtly from those of later H. erectus
populations from China and the island of Java in Indonesia. H. ergaster makes
a better candidate for an ancestor of the modern human line because Asian H.
erectus has some specialized features not seen in some later humans,
including our own species. H. heidelbergensis has similarities to both H.
erectus and the later species H. neanderthalensis, although it may
have been a transitional species between middle Homo and the line to
which modern humans belong.
C1
|
Homo ergaster
|
Homo ergaster probably first evolved in Africa
around 2 million years ago. This species had a rounded cranium with a brain
size of between 700 and 850 cu cm (49 to 52 cu in), a prominent brow ridge,
small teeth, and many other features that it shared with the later H. erectus.
Many paleoanthropologists consider H. ergaster a good candidate for
an ancestor of modern humans because it had several modern skull features,
including relatively thin cranial bones. Most H. ergaster fossils come
from the time range of 1.8 million to 1.5 million years ago.
The most important fossil of this species yet found is a
nearly complete skeleton of a young male from West Turkana, Kenya, which dates
from about 1.55 million years ago. Scientists determined the sex of the
skeleton from the shape of its pelvis. They also determined from patterns of
tooth eruption and bone growth that the boy had died when he was between 9 and
12 years old.
The Turkana boy, as the skeleton is known, had
elongated leg bones and arm, leg, and trunk proportions that essentially match
those of a modern human, in sharp contrast with the apelike proportions of H.
habilis and Australopithecus afarensis. He appears to have been
quite tall and slender. Scientists estimate that, had he grown into adulthood,
the boy would have reached a height of 1.8 m (6 ft) and a weight of 68 kg (150
lb). The anatomy of the Turkana boy indicates that H. ergaster was
particularly well adapted for walking and perhaps for running long distances in
a hot environment (a tall and slender body dissipates heat well) but not for
any significant amount of tree climbing.
The oldest humanlike fossils outside of Africa have also
been classified as H. ergaster, dated around 1.75 million years old.
These finds, from the Dmanisi site in the southern Caucasus Mountains of
Georgia, consist of several crania, jaws, and other fossilized bones. Some of
these are strikingly like East African H. ergaster, but others are
smaller or larger than H. ergaster, suggesting a high degree of
variation within a single population.
H. ergaster, H. rudolfensis, and H.
habilis, in addition to possibly two robust australopiths, all might have
coexisted in Africa around 1.9 million years ago. This finding goes against a
traditional paleoanthropological view that human evolution consisted of a
single line that evolved progressively over time—an australopith species
followed by early Homo, then middle Homo, and finally H.
sapiens. It appears that periods of species diversity and extinction have
been common during human evolution, and that modern H. sapiens has the
rare distinction of being the only living human species today.
Although H. ergaster appears to have coexisted
with several other human species, they probably did not interbreed. Mating
rarely succeeds between two species with significant skeletal differences, such
as H. ergaster and H. habilis. Many paleoanthropologists now
believe that H. ergaster descended from an earlier population of Homo—perhaps
one of the two known species of early Homo—and that the modern human
line descended from H. ergaster.
C2
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Homo erectus
|
Homo erectus Skull
Homo erectus, or “upright man,” had a
larger brain, flatter face, and taller body than earlier human species.
Anthropologists believe that Homo erectus probably evolved in Africa and then spread
to Asia. It lived from about 1.8 million years ago to as recently as 30,000
years ago.
Tom McHugh/Field Museum,
Chicago/Photo Researchers, Inc.
Paleoanthropologists now know that humans first evolved in Africa
and lived only on that continent for a few million years. The earliest human
species known to have spread in large numbers beyond the African continent was
first discovered in Southeast Asia. In 1891 Dutch physician Eugène Dubois found
the cranium of an early human on the Indonesian island of Java. He named this
early human Pithecanthropus erectus, or “erect ape-man.” Today
paleoanthropologists refer to this species as Homo erectus.
H. erectus appears to have evolved in
Africa from earlier populations of H. ergaster, and then spread to Asia
sometime between 1.8 million and 1.5 million years ago. The youngest known
fossils of this species, from the Solo River in Java, may date from as recently
as 53,000 to 27,000 years ago (although that dating is controversial). So H.
erectus was a very successful species—both widespread, having lived in
Africa and much of Asia, and long-lived, having survived for possibly more than
1.5 million years.
H. erectus had a low and
rounded braincase that was elongated from front to back, a prominent brow
ridge, and an adult cranial capacity of 800 to 1,250 cu cm (50 to 80 cu in), an
average twice that of the australopiths. Its bones, including the cranium, were
thicker than those of earlier species. Prominent muscle markings and thick,
reinforced areas on the bones of H. erectus indicate that its body could
withstand powerful movements and stresses. Although it had much smaller teeth
than did the australopiths, it had a heavy and strong jaw.
In the 1920s and 1930s German anatomist and physical
anthropologist Franz Weidenreich excavated the most famous collections of H.
erectus fossils from a cave at the site of Zhoukoudian (Chou-k’ou-tien),
China, near Beijing (Peking). Scientists dubbed these fossil humans Sinanthropus
pekinensis, or Peking Man, but others later reclassified them as H.
erectus. The Zhoukoudian cave yielded the fragmentary remains of over 30
individuals, ranging from about 500,000 to 250,000 years old. These fossils
were lost near the outbreak of World War II, but Weidenreich had made excellent
casts of his finds. Further studies at the cave site have yielded more H.
erectus remains.
Other important fossil sites for this species in China include
Lantian, Yuanmou, Yunxian, and Hexian. Researchers have also recovered many
tools made by H. erectus in China at sites such as Nihewan and Bose, and
other sites of similar age (at least 1 million to 250,000 years old).
Ever since the discovery of H. erectus, scientists
have debated whether this species was a direct ancestor of later humans,
including H. sapiens. The last populations of H. erectus—such as
those from the Solo River in Java—may have lived as recently as 53,000 to
27,000 years ago, at the same time as did populations of H. sapiens.
Modern humans could not have evolved from these late populations of H.
erectus, a much more primitive type of human. However, earlier East Asian
populations could have given rise to H. sapiens.
C3
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Homo heidelbergensis
|
Many paleoanthropologists believe that early humans migrated into
Europe by 800,000 years ago, and that these populations were not Homo
erectus. A growing number of scientists refer to these early migrants into
Europe—who predated both Neandertals and H. sapiens in the region—as H.
heidelbergensis. The species name comes from a 500,000-year-old jaw found
near Heidelberg, Germany.
Scientists have found few human fossils in Africa for the
period between 1.2 million and 600,000 years ago, during which H. heidelbergensis
or its ancestors first migrated into Europe. Populations of H. ergaster (or
possibly H. erectus) appear to have lived until at least 800,000 years
ago in Africa, and possibly until 500,000 years ago in northern Africa. When
these populations disappeared, other massive-boned and larger-brained
humans—possibly H. heidelbergensis—appear to have replaced them.
Scientists have found fossils of these stockier humans at sites in Bodo,
Ethiopia; Saldanha (also known as Elandsfontein), South Africa; Ndutu,
Tanzania; and Kabwe, Zimbabwe.
Scientists have come up with at least three different
interpretations of these African fossils. Some scientists place the fossils in
the species H. heidelbergensis and think that this species gave rise to
both the Neandertals (in Europe) and H. sapiens (in Africa). Others
think that the European and African fossils belong to two distinct species, and
that the African populations—which, in this view, were not H.
heidelbergensis but a separate species—gave rise to H. sapiens. Yet
other scientists advocate a long-held view that H. erectus and H.
sapiens belong to a single evolving lineage, and that the African fossils
belong in the category of archaic H. sapiens (archaic meaning not
fully anatomically modern).
The fossil evidence does not clearly favor any of these
three interpretations over another. A growing number of fossils from Asia,
Africa, and Europe have features that are intermediate between early H.
ergaster and H. sapiens. This kind of variation makes it hard to
decide how to identify distinct species and to determine which group of fossils
represents the most likely ancestor of later humans.
C4
|
Why Did Humans Spread Out of Africa?
|
Humans evolved in Africa and lived only there for as long
as 4 million years or more, so scientists wonder what finally triggered the
first human migration out of Africa (a movement that coincided with the spread
of early human populations throughout the African continent). The answer to
this question depends, in part, on knowing exactly when that first migration
occurred. Some studies claim that sites in Asia and Europe contain crude stone
tools and fossilized fragments of humanlike teeth that date from more than 1.8
million years ago. Although these claims remain unconfirmed, small populations
of humans may have entered Asia prior to 1.8 million years ago, followed by a
more substantial spread between 1.6 million and 1 million years ago. Early
humans reached northeastern Asia by around 1.4 million years ago, inhabiting a
region close to the perpetually dry deserts of northern China. The first major
habitation of central and western Europe, on the other hand, does not appear to
have occurred until between 1 million and 500,000 years ago.
Scientists once thought that advances in stone tools could
have enabled early humans such as Homo erectus to move into Asia and
Europe, perhaps by helping them to obtain new kinds of food, such as the meat
of large mammals. If African human populations had developed tools that allowed
them to hunt large game effectively, they would have had a reliable source of
food wherever they went. In this view, humans first migrated into Eurasia based
on a unique cultural adaptation.
By 1.5 million years ago, early humans had begun to
make new kinds of tools, which scientists call Acheulean. Common
Acheulean tools included large handaxes and cleavers. While these new tools
might have helped early humans to hunt, the first known Acheulean tools in
Africa date from later than the earliest known human presence in Asia. Also,
most East Asian sites over 200,000 years old contain only simply shaped cobble
and flake tools. In contrast, Acheulean tools were more finely crafted, larger,
and more symmetrical. Thus, the earliest settlers of Eurasia did not have a
true Acheulean technology, and advances in toolmaking alone cannot explain the
spread out of Africa.
Another possibility is that the early spread of humans to
Eurasia was not unique, but rather part of a wider migration of meat-eating
animals, such as lions and hyenas. The human migration out of Africa occurred
during the early part of the Pleistocene Epoch, between 1.8 million and 780,000
years ago. Many African carnivores spread to Eurasia during the early
Pleistocene, and humans could have moved along with them. In this view, H.
erectus was one of many meat-eating species to expand into Eurasia from
Africa, rather than a uniquely adapted species. Relying on meat as a primary
food source might have allowed many meat-eating species, including humans, to
move through many different environments without having to quickly learn about
unfamiliar and potentially poisonous plants.
However, the migration of humans to eastern Asia may have
occurred gradually and through lower latitudes and environments similar to
those of Africa. If East African populations of H. erectus moved at only
1.6 km (1 mi) every 20 years, they could have reached Southeast Asia in 150,000
years. Over this amount of time, humans could have learned about and begun
relying on edible plant foods. Thus, eating meat may not have played a crucial
role in the first human migrations to new continents. Careful comparison of
animal fossils, stone tools, and early human fossils from Africa, Asia, and
Europe will help scientists to better determine what factors motivated and
allowed humans to venture out of Africa for the first time.
D
|
Late Homo
|
The origin of our own species, Homo sapiens,
is one of the most hotly debated topics in paleoanthropology. This debate
centers on whether or not modern humans have a direct relationship to H.
erectus or to the Neandertals, a well-known, more modern group of humans
who evolved within the past 250,000 years. Paleoanthropologists commonly use
the term anatomically modern Homo sapiens to distinguish people of today
from these similar predecessors.
Traditionally, paleoanthropologists classified as Homo sapiens
any fossil human younger than 500,000 years old with a braincase larger than
that of H. erectus. Thus, many scientists who believe that modern humans
descend from a single line dating back to H. erectus use the name
archaic Homo sapiens to refer to a wide variety of fossil humans that
predate anatomically modern H. sapiens. The term archaic denotes
a set of physical features typical of Neandertals and other species of late Homo
prior to modern Homo sapiens. These features include a combination of a
robust skeleton, a large but low braincase (positioned somewhat behind, rather
than over, the face), and a lower jaw lacking a prominent chin. In this sense,
Neandertals are sometimes classified as a subspecies of archaic H. sapiens—H.
sapiens neanderthalensis. Other scientists think that the variation in
archaic fossils actually falls into clearly identifiable sets of traits, and
that any type of human fossil exhibiting a unique set of traits should have a
new species name. According to this view, the Neandertals belong to their own
species, H. neanderthalensis.
D1
|
Neandertals
|
Neandertal Bones
A Neandertal skull, top right, and
several bones were found at the La-Chapelle-aux-Saints rock shelter in
southwestern France in 1908. Another Neandertal skull, bottom right, was found
at the nearby La Ferrassie site in 1909. The remains found at La-Chapelle-aux-Saints,
marked by arthritis and disease, did much to reinforce a conception of the
Neandertal as a slouching, degenerate human form. Scientists now believe
Neandertals were a strongly built and intelligent species that thrived in
Europe for more than 150,000 years.
Science Source/Photo Researchers,
Inc.
The Neandertals lived in areas ranging from western Europe
through central Asia from about 200,000 to about 28,000 years ago. The name
Neandertal (sometimes spelled Neanderthal) comes from fossils found in 1856 in
the Feldhofer Cave of the Neander Valley in Germany (tal—a modern form
of thal—means “valley” in German). Scientists realized several years
later that prior discoveries—at Engis, Belgium, in 1829 and at Forbes Quarry,
Gibraltar, in 1848—also represented Neandertals. These two earlier discoveries
were the first early human fossils ever found.
In the past, scientists claimed that Neandertals differed
greatly from modern humans. However, the basis for this claim came from a
faulty reconstruction of a Neandertal skeleton that showed it with bent knees
and a slouching gait. This reconstruction gave the common but mistaken
impression that Neandertals were dim-witted brutes who lived a crude lifestyle.
On the contrary, Neandertals, like the species that
preceded them, walked fully upright without a slouch or bent knees. In
addition, their cranial capacity was quite large at about 1,500 cu cm (about 90
cu in), slightly larger on average than that of modern humans. (The difference
probably relates to the greater muscle mass of Neandertals as compared with
modern humans, which usually correlates with a larger brain size.)
Compared with earlier humans, Neandertals had a high degree of
cultural sophistication. They appear to have performed symbolic rituals, such
as the burial of their dead. Neandertal fossils—including a number of fairly
complete skeletons—are quite common compared to those of earlier forms of Homo,
in part because of the Neandertal practice of intentional burial.
Neandertals also produced sophisticated types of stone tools known as Mousterian,
which involved creating blanks (rough forms) from which several types of tools
could be made.
Along with many physical similarities, Neandertals
differed from modern humans in several ways. The typical Neandertal skull had a
low forehead, a large nasal area (suggesting a large nose), a
forward-projecting nasal and cheek region, a prominent brow ridge with a bony
arch over each eye, a nonprojecting chin, and an obvious space behind the third
molar (in front of the upward turn of the lower jaw).
Neandertal and Modern Human Skulls
The skull of Homo neanderthalensis,
left, differs considerably from that of anatomically modern humans, or Homo
sapiens, right. Neandertals had large, protruding faces, low, sloping
foreheads, and heavy brow ridges. In contrast, modern humans have flatter
faces, high foreheads, and less prominent brow ridges. Neandertals also had
more pronounced and powerful jaws than do modern humans.
John Reader/Science Photo
Library/Photo Researchers, Inc.
Neandertals also had a more heavily built and large-boned
skeleton than do modern humans. Other Neandertal skeletal features included a
bowing of the limb bones in some individuals, broad scapulae (shoulder blades),
hip joints turned outward, a long and thin pubic bone, short lower leg and arm
bones relative to the upper bones, and large surfaces on the joints of the toes
and limb bones. Together, these traits made a powerful, compact body of short
stature—males averaged 1.7 m (5 ft 5 in) tall and 84 kg (185 lb), and females
averaged 1.5 m (5 ft) tall and 80 kg (176 lb).
The short, stocky build of Neandertals conserved heat and
helped them withstand extremely cold conditions that prevailed in temperate
regions beginning about 70,000 years ago. The last known Neandertal fossils
come from western Europe and date from approximately 28,000 years ago.
D2
|
Other Late Homo Populations
|
Miniature Human Species
Australian researchers stand with a
life-size illustration of a miniature human species that lived on the
Indonesian island of Flores until at least 18,000 years ago. The species, Homo
floresiensis, stood only about 1 m (3.3 ft) tall and had a tiny brain, yet it
was intelligent enough to make stone tools. The illustration shows a male who
has successfully hunted a giant rodent.
Courtesy of Mark Newsham
At the same time as Neandertal populations grew
in number in Europe and parts of Asia, other populations of nearly modern
humans arose in Africa and Asia. Scientists also commonly refer to these
fossils, which are distinct from but similar to those of Neandertals, as archaic.
Fossils from the Chinese sites of Dali, Maba, and Xujiayao display the long,
low cranium and large face typical of archaic humans, yet they also have
features similar to those of modern people in the region. At the cave site of
Jebel Irhoud, Morocco, scientists have found fossils with the long skull
typical of archaic humans but also the modern traits of a somewhat higher
forehead and flatter midface. Fossils of humans from East African sites older
than 100,000 years—such as Ngaloba in Tanzania and Eliye Springs in Kenya—also
seem to show a mixture of archaic and modern traits.
One of the most unusual branches of the human family
tree was discovered on the Indonesian island of Flores in 2003 and first
described in 2004. A research team digging in a cave, Liang Bua, uncovered the
nearly complete skeleton of what appeared to be a miniature human that lived as
recently as 18,000 years ago. The specimen, believed to be an adult female, was
estimated to stand only about 1 m (3.3 ft) tall. Its brain, estimated at 380 cu
cm (23 cu in), was as small as those of chimpanzees and the smallest
australopiths. It had fairly large brow ridges, and its teeth were large
relative to the rest of the skull. Despite being extremely small-brained, it
apparently made simple stone tools. On the basis of these unique traits, the
researchers assigned the skeleton to a new species, Homo floresiensis.
The researchers concluded that H. floresiensis was probably descended
from H. erectus, although this continues to be debated. The diminutive
stature and small brain of H. floresiensis may have resulted from island
dwarfism—an evolutionary process that results from long-term isolation on a
small island with limited food resources and a lack of predators. Pygmy
elephants on Flores, now extinct, showed the same adaptation.
D3
|
Anatomically Modern Homo sapiens
|
Ancient Human Footprints
The oldest known footprints of an
anatomically modern human are embedded in rock north of Cape Town, South
Africa. Geologist David Roberts and paleoanthropologist Lee Berger announced
the discovery of the footprints in August 1997. A human being made the
footprints about 117,000 years ago by walking through wet sand, which
eventually hardened into rock.
Kenneth Garrett/National Geographic
Society
The oldest known fossils that possess skeletal features
typical of modern humans date from 195,000 years ago. Several key features
distinguish the skulls of modern humans from those of archaic species. These
features include a much smaller brow ridge, if any; a globe-shaped braincase;
and a flat or only slightly projecting face of reduced size, located under the
front of the braincase. Among all mammals, only humans have a face positioned
directly beneath the frontal lobe (forward-most area) of the brain. As a
result, modern humans tend to have a higher forehead than did Neandertals and
other archaic humans. The cranial capacity of modern humans ranges from about
1,000 to 2,000 cu cm (60 to 120 cu in), with the average being about 1,350 cu
cm (80 cu in).
Scientists have found both fragmentary and nearly complete
cranial fossils of early anatomically modern Homo sapiens from the sites
of Singha, Sudan; Omo, Ethiopia; Klasies River Mouth, South Africa; and Skhūl
Cave, Israel. Based on these fossils, many scientists conclude that modern H.
sapiens had evolved in Africa by 195,000 years ago and started spreading to
diverse parts of the world beginning on a route through the Near East sometime
before 90,000 years ago.
E
|
Theories of Modern Human Origins and Diversity
|
Paleoanthropologists are engaged in an ongoing debate about where
modern humans evolved and how they spread around the world. Differences in
opinion rest on the question of whether the evolution of modern humans took
place in a small region of Africa or over a broad area of Africa and Eurasia.
By extension, opinions differ as to whether modern human populations from
Africa displaced all existing populations of earlier humans, eventually
resulting in their extinction.
Those who think modern humans originated only in Africa
and then spread around the world support what is known as the out of Africa
hypothesis. Those who think modern humans evolved over a large region of
Eurasia and Africa support the so-called multiregional hypothesis.
Researchers have conducted many genetic studies and carefully
assessed fossils to determine which of these hypotheses agrees more with
scientific evidence. The results of this research do not entirely confirm or
reject either one. Therefore, some scientists think a compromise between the
two hypotheses is the best explanation. The debate between these views has
implications for how scientists understand the concept of race in humans. The
question raised is whether the physical differences among modern humans evolved
deep in the past or relatively recently.
E1
|
The Out of Africa Hypothesis
|
According to the out of Africa hypothesis, also
known as the replacement hypothesis, early populations of modern
humans from Africa migrated to other regions and entirely replaced existing
populations of archaic humans. The replaced populations would have included the
Neandertals and any surviving groups of Homo erectus. Supporters of this
view note that many modern human skeletal traits evolved relatively
recently—within the past 200,000 years or so—suggesting a single, common
origin. In addition, the anatomical similarities shared by all modern human
populations far outweigh those shared by premodern and modern humans within
particular geographic regions. Furthermore, biological research indicates that
most new species of organisms, including mammals, arise from small,
geographically isolated populations.
E2
|
The Multiregional Hypothesis
|
According to the multiregional hypothesis, also known as
the continuity hypothesis, the evolution of modern humans began
when Homo erectus spread throughout much of Eurasia around 1 million
years ago. Regional populations retained some unique anatomical features for
hundreds of thousands of years, but they also mated with populations from
neighboring regions, exchanging heritable traits with each other. This exchange
of heritable traits is known as gene flow.
Through gene flow, populations of H. erectus
passed on a variety of increasingly modern characteristics, such as increases
in brain size, across their geographic range. Gradually this would have
resulted in the evolution of more modern looking humans throughout Africa and
Eurasia. The physical differences among people today, then, would result from
hundreds of thousands of years of regional evolution. This is the concept of
continuity. For instance, modern East Asian populations have some skull
features that scientists also see in H. erectus fossils from that
region.
Some critics of the multiregional hypothesis claim
that it wrongly advocates a scientific belief in race and could be used to
encourage racism. Supporters of the theory point out, however, that their
position does not imply that modern races evolved in isolation from each other,
or that racial differences justify racism. Instead, the theory holds that gene
flow linked different populations together. These links allowed progressively
more modern features, no matter where they arose, to spread from region to
region and eventually become universal among humans.
E3
|
Testing the Two Theories
|
Scientists have weighed the out of Africa and multiregional
hypotheses against both genetic and fossil evidence. The results do not
unanimously support either one, but weigh more heavily in favor of the out of
Africa hypothesis.
E3a
|
Genetic Evidence
|
Geneticists have studied the amount of difference in the DNA
(deoxyribonucleic acid) of different populations of humans. DNA is the molecule
that contains our heritable genetic code. Differences in human DNA result from
mutations in DNA structure. Mutations may result from exposure to external elements
such as solar radiation or certain chemical compounds, while others occur
naturally at random.
Geneticists have calculated rates at which mutations can be
expected to occur over time. Dividing the total number of genetic differences
between two populations by an expected rate of mutation provides an estimate of
the time when the two shared a common ancestor. Many estimates of evolutionary
ancestry rely on studies of the DNA in cell structures called mitochondria.
This DNA is referred to as mtDNA (mitochondrial DNA). Unlike DNA from the
nucleus of a cell, which codes for most of the traits an organism inherits from
both parents, mtDNA inheritance passes only from a mother to her offspring.
MtDNA also accumulates mutations about ten times faster than does DNA in the
cell nucleus (the location of most DNA). The structure of mtDNA changes so
quickly that scientists can easily measure the differences between one human
population and another. Two closely related populations should have only minor
differences in their mtDNA. Conversely, two very distantly related populations
should have large differences in their mtDNA.
MtDNA research into modern human origins has produced two
major findings. First, the entire amount of variation in mtDNA across human
populations is small in comparison with that of other animal species. This
means that all human mtDNA originated from a single ancestral
lineage—specifically, a single female—fairly recently and has been mutating
ever since. Most estimates of the mutation rate of mtDNA suggest that this
female ancestor lived about 200,000 years ago. In addition, the mtDNA of
African populations varies more than that of peoples in other continents. This
suggests that the mtDNA of African populations has changed for a longer time than
it has in populations of any other region, and that all living people inherited
their mtDNA from one woman in Africa, who is sometimes called the Mitochondrial
Eve. Some geneticists and anthropologists have concluded from this evidence
that modern humans originated in a small population in Africa and spread from
there.
MtDNA studies have weaknesses, however, including the
following four. First, the estimated rate of mtDNA mutation varies from study
to study, and some estimates put the date of origin closer to 850,000 years
ago, the time of Homo erectus. Second, mtDNA makes up a small part of
the total genetic material that humans inherit. The rest of our genetic
material—about 400,000 times more than the amount of mtDNA—came from many
individuals living at the time of the African Eve, conceivably from many
different regions. Third, the time at which modern mtDNA began to diversify
does not necessarily coincide with the origin of modern human biological traits
and cultural abilities. Fourth, the smaller amount of modern mtDNA diversity
outside of Africa could result from times when European and Asian populations
declined in numbers, perhaps due to climate changes.
Despite these criticisms, many geneticists continue to favor
the out of Africa hypothesis of modern human origins. Studies of nuclear DNA
also suggest an African origin for a variety of genes. Furthermore, in a
remarkable series of studies in the late 1990s, scientists recovered mtDNA from
the first Neandertal fossil found in Germany and two other Neandertal fossils.
In each case, the mtDNA does not closely match that of modern humans. This
finding suggests that at least some Neandertal populations had diverged from
the line to modern humans by 500,000 to 600,000 years ago. This also suggests
that Neandertals represent a separate species from modern H. sapiens. In
another study, however, mtDNA extracted from a 62,000-year-old Australian H.
sapiens fossil was found to differ significantly from modern human mtDNA,
suggesting a much wider range of mtDNA variation within H. sapiens than
was previously believed. According to the Australian researchers, this finding
lends support to the multiregional hypothesis because it shows that different
populations of H. sapiens, possibly including Neandertals, could have
evolved independently in different parts of the world.
E3b
|
Fossil Evidence
|
As with genetic research, fossil evidence also does not
entirely support or refute either of the competing hypotheses of modern human
origins. However, many scientists see the balance of evidence favoring an
African origin of modern H. sapiens within the past 200,000 years. The
oldest known modern-looking skulls come from Africa and date from perhaps
195,000 years ago. The next oldest come from the Near East, where they date
from about 90,000 years ago. Fossils of modern humans in Europe do not exist
from before about 40,000 years ago. In addition, the first modern humans in
Europe—often referred to as Cro-Magnon people—had elongated lower leg bones, as
did African populations that were adapted to warm, tropical climates. This
suggests that populations from warmer regions replaced those in colder European
regions, such as the Neandertals.
Fossils also show that populations of modern humans lived
at the same time and in the same regions as did populations of Neandertals and Homo
erectus, but that each retained its distinctive physical features. The
different groups overlapped in the Near East and Southeast Asia for between
about 30,000 and 50,000 years. The maintenance of physical differences for this
amount of time implies that archaic and modern humans either could not or
generally did not interbreed. To some scientists, this also means that the
Neandertals belong to a separate species, H. neanderthalensis, and that
migratory populations of modern humans entirely replaced archaic humans in both
Europe and eastern Asia.
On the other hand, fossils of archaic and modern
humans in some regions show continuity in certain physical characteristics.
These similarities may indicate multiregional evolution. For example, both
archaic and modern skulls of eastern Asia have flatter cheek and nasal areas
than do skulls from other regions. By contrast, the same parts of the face
project forward in the skulls of both archaic and modern humans of Europe.
Assuming that these traits were influenced primarily by genetic inheritance
rather than environmental factors, archaic humans may have given rise to modern
humans in some regions or at least interbred with migrant modern-looking
humans.
E4
|
A Compromise Theory
|
Each of the competing major hypotheses of modern human
origins has its strengths and weaknesses. Genetic evidence appears to support
the out of Africa hypothesis. In the western half of Eurasia and in Africa,
this hypothesis also seems the better explanation, particularly in regard to
the apparent replacement of Neandertals by modern populations. At the same
time, the multiregional hypothesis appears to explain some of the regional
continuity found in East Asian populations.
Therefore, many paleoanthropologists advocate a theory of
modern human origins that combines elements of the out of Africa and the
multiregional hypotheses. Humans with modern features may have first emerged in
Africa or come together there as a result of gene flow with populations from other
regions. These African populations may then have replaced archaic humans in
certain regions, such as western Europe and the Near East. But
elsewhere—especially in East Asia—gene flow may have occurred among local
populations of archaic and modern humans, resulting in distinct and enduring
regional characteristics.
All three of these views—the two competing positions
and the compromise—acknowledge the strong biological unity of all people. In
the multiregional hypothesis, this unity results from hundreds of thousands of
years of continued gene flow among all human populations. According to the out
of Africa hypothesis, on the other hand, similarities among all living human
populations result from a recent common origin. The compromise position accepts
both of these as reasonable and compatible explanations of modern human
origins.
VI
|
THE EVOLUTION OF CULTURAL BEHAVIOR
|
Routes of Human Migration
It is widely agreed upon that
original routes of human migration began with emigrations from Africa into the
Mideast, Asia, and Europe, and only much later from Asia to the Americas.
Exactly when and how migrations occurred is highly debated. Nonetheless, it is
clear that people encountered and overcame substantial geographic and climactic
barriers, including deserts, mountain ranges, bodies of water, and glaciers
(especially during periodic Ice Ages).
© Microsoft Corporation. All Rights
Reserved.
The story of human evolution is as much about the
development of cultural behavior as it is about changes in physical appearance.
The term culture, in anthropology, traditionally refers to all human
creations and activities governed by social customs and rules. It includes
elements such as technology, language, and art. Human cultural behavior depends
on the social transfer of information from one generation to the next, which
itself depends on a sophisticated system of communication, such as language.
The term culture has often been used to
distinguish the behavior of humans from that of other animals. However, some
nonhuman animals also appear to have forms of learned cultural behavior. For
instance, different groups of chimpanzees use different techniques to capture
termites for food using sticks. Also, in some regions chimps use stones or
pieces of wood for cracking open nuts. Chimps in other regions do not practice
this behavior, although their forests have similar nut trees and materials for
making tools. These regional differences resemble traditions that people pass
from generation to generation. Traditions are a fundamental aspect of culture,
and paleoanthropologists assume that the earliest humans also had some types of
traditions.
However, modern humans differ from other animals, and probably
many early human species, in that they actively teach each other and can pass
on and accumulate unusually large amounts of knowledge. People also have a
uniquely long period of learning before adulthood, and the physical and mental
capacity for language. Language of all forms—spoken, signed, and
written—provides a medium for communicating vast amounts of information, much
more than any other animal appears to be able to transmit through gestures and
vocalizations.
Ape Using Tool
A chimpanzee uses a palm-sized stone
to crack open palm nuts he has placed on a larger stone. Chimpanzees, the
closest evolutionary relatives of humans, exhibit several tool-using skills and
can also make simple tools. Many chimps use sticks they have stripped of leaves
to fish termites out of their mounds. Some chimps also chew leaves to make
sponges for soaking up drinkable rainwater from crevices.
Clive Bromhall/Oxford Scientific
Films
Scientists have traced the evolution of human cultural
behavior through the study of archaeological artifacts, such as tools, and
related evidence, such as the charred remains of cooked food. Artifacts show
that throughout much of human evolution, culture has developed slowly. During
the Paleolithic, or early Stone Age, basic techniques for making stone tools
changed very little for periods of well over a million years. See also Archaeology:
Prehistoric Archaeology.
Human fossils also provide information about how culture
has evolved and what effects it has had on human life. For example, over the
past 30,000 years, the basic anatomy of humans has undergone only one prominent
change: The bones of the average human skeleton have become much smaller and
thinner. Innovations in the making and use of tools and in obtaining
food—results of cultural evolution—may have led to more efficient and less
physically taxing lifestyles, and thus caused changes in the skeleton.
Culture has played a prominent role in the evolution
of Homo sapiens. Within the last 60,000 years, people have migrated to
settle almost all unoccupied regions of the world, such as small island chains
and the continents of Australia and the Americas. These migrations depended on
developments in transportation, hunting and fishing tools, shelter, and
clothing. Within the past 30,000 years, cultural evolution has sped up
dramatically. This change shows up in the archaeological record as a rapid
expansion of stone tool types and toolmaking techniques, and in works of art
and indications of evolving religion, such as burials. By 10,000 years ago,
people first began to harvest and cultivate grains and to domesticate animals—a
fundamental change in the ecological relationship between human beings and
other life on Earth. The development of agriculture provided people with larger
quantities and more stable supplies of food, which set the stage for the rise
of the first civilizations. Today, culture—and particularly
technology—dominates human life.
Paleoanthropologists and archaeologists have studied many topics in
the evolution of human cultural behavior. These have included the evolution of
(1) social life; (2) subsistence (the acquisition and production of food); (3)
the making and using of tools; (4) environmental adaptation; (5) symbolic
thought and its expression through language, art, and religion; and (6) the
development of agriculture and the rise of civilizations.
A
|
Social Life
|
Most primate species, including the African apes, live in
social groups of varying size and complexity. Within their groups, individuals
often have multifaceted roles, based on age, sex, status, social skills, and
personality. The discovery in 1975 at Hadar, Ethiopia, of a group of several Australopithecus
afarensis individuals who died together 3.2 million years ago appears to
confirm that early humans lived in social groups. Scientists have referred to
this collection of fossils as The First Family.
One of the first physical changes in the evolution
of humans from apes—a decrease in the size of male canine teeth—also indicates
a change in social relations. Male apes sometimes use their large canines to
threaten (or sometimes fight with) other males of their species, usually over
access to females, territory, or food. The evolution of small canines in
australopiths implies that males had either developed other methods of
threatening each other or become more cooperative. In addition, both male and
female australopiths had small canines, indicating a reduction of sexual
dimorphism from that in apes. Yet, although sexual dimorphism in canine size
decreased in australopiths, males were still much larger than females. Thus,
male australopiths might have competed aggressively with each other based on
sheer size and strength, and the social life of humans may not have differed
much from that of apes until later times.
Scientists believe that several of the most important changes
from apelike to characteristically human social life occurred in species of the
genus Homo, whose members show even less sexual dimorphism. These
changes, which may have occurred at different times, included (1) prolonged
maturation of infants, including an extended period during which they required
intensive care from their parents; (2) special bonds of sharing and exclusive
mating between particular males and females, called pair-bonding; and
(3) the focus of social activity at a home base, a safe refuge in a
special location known to family or group members.
A1
|
Parental Care
|
Humans, who have a large brain, have a prolonged
period of infant development and childhood because the brain takes a long time
to mature. Since the australopith brain was not much larger than that of a
chimp, some scientists think that the earliest humans had a more apelike rate
of growth, which is far more rapid than that of modern humans. This view is
supported by studies of australopith fossils looking at tooth development—a
good indicator of overall body development.
In addition, the human brain becomes very large as it
develops, so a woman must give birth to a baby at an early stage of development
in order for the infant’s head to fit through her birth canal. Thus, human
babies require a long period of care to reach a stage of development at which
they depend less on their parents. In contrast with a modern female, a female
australopith could give birth to a baby at an advanced stage of development
because its brain would not be too large to pass through the birth canal. The
need to give birth early—and therefore to provide more infant care—may have
evolved around the time of the middle Homo species Homo ergaster.
This species had a brain significantly larger than that of the australopiths,
but a narrow birth canal.
A2
|
Pair-Bonding
|
Pair-bonding, usually of a fairly short duration, occurs in a
variety of primate species. Some scientists speculate that prolonged bonds
developed in humans along with increased sharing of food. Among primates,
humans have a distinct type of food-sharing behavior. People will delay eating
food until they have returned with it to the location of other members of their
social group. This type of food sharing may have arisen at the same time as the
need for intensive infant care, probably by the time of H. ergaster. By
devoting himself to a particular female and sharing food with her, a male could
increase the chances of survival for his own offspring.
A3
|
The Home Base
|
Humans have lived as foragers for millions of years.
Foragers obtain food when and where it is available over a broad territory.
Modern-day foragers (also known as hunter-gatherers)—such as the San people in
the Kalahari Desert of southern Africa—also set up central campsites, or home
bases, and divide work duties among men and women. Women gather readily
available plant and animal foods, while men take on the often less successful
task of hunting. Female and male family members and relatives bring together
their food to share at their home base. The modern form of the home base—which
also serves as a haven for raising children and caring for the sick and
elderly—may have first developed with middle Homo after about 1.7
million years ago. However, the first evidence of hearths and
shelters—common to all modern home bases—comes from only after 500,000 years
ago. Thus, a modern form of social life may not have developed until late in
human evolution.
B
|
Subsistence
|
Human subsistence refers to the types of food humans eat, the
technology used in and methods of obtaining or producing food, and the ways in
which social groups or societies organize themselves for getting, making, and
distributing food. For millions of years, humans probably fed on-the-go, much
as other primates do. The lifestyle associated with this feeding strategy is
generally organized around small, family-based social groups that take
advantage of different food sources at different times of year.
The early human diet probably resembled that of
closely related primate species. The great apes eat mostly plant foods. Many
primates also eat easily obtained animal foods such as insects and bird eggs.
Among the few primates that hunt, chimpanzees will prey on monkeys and even
small gazelles. The first humans probably also had a diet based mostly on plant
foods. In addition, they undoubtedly ate some animal foods and might have done
some hunting. Human subsistence began to diverge from that of other primates
with the production and use of the first stone tools. With this development,
the meat and marrow (the inner, fat-rich tissue of bones) of large mammals
became a part of the human diet. Thus, with the advent of stone tools, the diet
of early humans became distinguished in an important way from that of apes.
Scientists have found broken and butchered fossil bones of
antelopes, zebras, and other comparably sized animals at the oldest
archaeological sites, which date from about 2.5 million years ago. With
the evolution of late Homo, humans began to hunt even the largest
animals on Earth, including mastodons and mammoths, members of the elephant
family. Agriculture and the domestication of animals arose only in the recent
past, with H. sapiens.
B1
|
Models of Subsistence in Early Homo
|
Paleoanthropologists have debated whether early members of the
modern human genus were aggressive hunters, peaceful plant gatherers, or
opportunistic scavengers. Many scientists once thought that predation and the
eating of meat had strong effects on early human evolution. This hunting
hypothesis suggested that early humans in Africa survived particularly arid
periods by aggressively hunting animals with primitive stone or bone tools.
Supporters of this hypothesis thought that hunting and competition with carnivores
powerfully influenced the evolution of human social organization and behavior;
toolmaking; anatomy, such as the unique structure of the human hand; and
intelligence.
Beginning in the 1960s, studies of apes cast doubt on the
hunting hypothesis. Researchers discovered that chimpanzees cooperate in hunts
of at least small animals, such as monkeys. Hunting did not, therefore,
entirely distinguish early humans from apes, and therefore hunting alone may
not have determined the path of early human evolution. Some scientists instead
argued in favor of the importance of food-sharing in early human life.
According to a food-sharing hypothesis, cooperation and sharing within
family groups—instead of aggressive hunting—strongly influenced the path of
human evolution.
Scientists once thought that archaeological sites as much as 2
million years old provided evidence to support the food-sharing hypothesis.
Some of the oldest archaeological sites were places where humans brought food
and stone tools together. Scientists thought that these sites represented home
bases, with many of the social features of modern hunter-gatherer campsites,
including the sharing of food between pair-bonded males and females.
Critique of the food-sharing hypothesis resulted from
more careful study of animal bones from the early archaeological sites.
Microscopic analysis of these bones revealed the marks of human tools and
carnivore teeth, indicating that both humans and potential predators—such as
hyenas, cats, and jackals—were active at these sites. This evidence suggested
that what scientists had thought were home bases where early humans shared food
were in fact food-processing sites that humans abandoned to predators. Thus,
evidence did not clearly support the idea of food-sharing among early humans.
The new research also suggested a different view of early
human subsistence—that early humans scavenged meat and bone marrow from dead
animals and did little hunting. According to this scavenging hypothesis, early
humans opportunistically took parts of animal carcasses left by predators, and
then used stone tools to remove marrow from the bones.
Observations that many animals, such as antelope, often die
off in the dry season make the scavenging hypothesis quite plausible. Early
toolmakers would have had plenty of opportunity to scavenge animal fat and meat
during dry times of the year. However, other archaeological studies—and a
better appreciation of the importance of hunting among chimpanzees—suggest that
the scavenging hypothesis is too narrow. Many scientists now believe that early
humans both scavenged and hunted. Evidence of carnivore tooth marks on bones
cut by early human toolmakers suggests that the humans scavenged at least the
larger of the animals they ate. They also ate a variety of plant foods. Some
disagreement remains, however, as to how much early humans relied on hunting,
especially the hunting of smaller animals.
B2
|
The Rise of Hunting
|
Mastodon Hunt
More than 10,000 years ago early
inhabitants of the Americas, known as Paleo-Indians, hunted large mammals such
as bison, mammoth, and mastodon. The hunting of such large prey was a late
development in human prehistory, as it required sophisticated stone weaponry
and a kind of planning and coordination possible only with an elaborate system
of communication, such as language. This diorama from the National Museum of
Anthropology in Mexico City depicts Mesoamerican Paleo-Indians killing a
mastodon.
Gianni Dagli Orti/Corbis
Scientists debate about when humans first began hunting on a
regular basis. For instance, elephant fossils found with tools made by middle Homo
once led researchers to the idea that members of this species were hunters of
big game. However, the simple association of animal bones and tools at the same
site does not necessarily mean that early humans had killed the animals or
eaten their meat. Animals may die in many ways, and natural forces can
accidentally place fossils next to tools. Recent excavations at Olorgesailie,
Kenya, show that H. erectus cut meat from elephant carcasses but do not
reveal whether these humans were regular or specialized hunters.
Humans who lived outside of Africa—especially in colder
temperate climates—almost certainly needed to eat more meat than their African
counterparts. Humans in temperate Eurasia would have had to learn about which
plants they could safely eat, and the number of available plant foods would
drop significantly during the winter. Still, although scientists have found
very few fossils of edible or eaten plants at early human sites, early
inhabitants of Europe and Asia probably did eat plant foods in addition to
meat.
Sites that provide the clearest evidence of early hunting
include Boxgrove, England, where about 500,000 years ago people trapped a great
number of large game animals between a watering hole and the side of a cliff
and then slaughtered them. At Schöningen, Germany, a site about 400,000 years
old, scientists have found wooden spears with sharp ends that were well
designed for throwing and probably used in hunting large animals.
Neandertals and other archaic humans seem to have eaten
whatever animals were available at a particular time and place. So, for
example, in European Neandertal sites, the number of bones of reindeer (a
cold-weather animal) and red deer (a warm-weather animal) changed depending on
what the climate had been like. Neandertals probably also combined hunting and
scavenging to obtain animal protein and fat.
For at least the past 100,000 years, various human
groups have eaten foods from the ocean or coast, such as shellfish and some sea
mammals and birds. Others began fishing in interior rivers and lakes. Between
probably 90,000 and 80,000 years ago people in Katanda, in what is now the
Democratic Republic of the Congo, caught large catfish using a set of barbed
bone points, the oldest known specialized fishing implements. The oldest stone
tips for arrows or spears date from about 50,000 to 40,000 years ago. These
technological advances, probably first developed by early modern humans,
indicate an expansion in the kinds of foods humans could obtain.
Beginning 40,000 years ago humans began making even more
significant advances in hunting dangerous animals and large herds, and in
exploiting ocean resources. People cooperated in large hunting expeditions in
which they killed great numbers of reindeer, bison, horses, and other animals
of the expansive grasslands that existed at that time. In some regions, people
became specialists in hunting certain kinds of animals. The familiarity these
people had with the animals they hunted appears in sketches and paintings on
cave walls, dating from as much as 32,000 years ago. Hunters also used the
bones, ivory, and antlers of their prey to create art and beautiful tools. In
some areas, such as the central plains of North America that once teemed with a
now-extinct type of large bison (Bison occidentalis), hunting may have
contributed to the extinction of entire species.
C
|
Tools
|
Stone Toolmaking
Humans first made tools of stone at
least 2.5 million years ago, initiating the so-called Stone Age. The Stone Age
advanced through three stages over time—the Paleolithic (which is subdivided
into Lower, Middle, and Upper periods), Mesolithic, and Neolithic. Blade
toolmaking, as demonstrated in this video, was a development of the Upper
Paleolithic, which began about 40,000 years ago. This technique produced a far
greater variety and higher quality of tools than did earlier methods of
toolmaking.
The Natural History Museum, London
The making and use of tools alone probably did not
distinguish early humans from their ape predecessors. Instead, humans made the
important breakthrough of using one tool to make another. Specifically, they
developed the technique of precisely hitting one stone against another, known
as knapping. Stone toolmaking characterized the period sometimes
referred to as the Stone Age, which began at least 2.5 million years ago in
Africa and lasted until the development of metal tools within the last 7,000
years (at different times in different parts of the world). Although early
humans may have made stone tools before 2.5 million years ago, toolmakers may
not have remained long enough in one spot to leave clusters of tools that an
archaeologist would notice today.
Oldowan Tools
About 2.5 million years ago early
humans in Africa made the first tools of stone. Scientists call these tools and
the technique used to make them Oldowan, after the site of Olduvai Gorge in
Tanzania, where many have been unearthed. Oldowan toolmaking involved hitting
one palm-sized cobblestone against another. This process created large,
sharp-edged core tools capable of breaking bones and slicing meat or
vegetation, and smaller flakes that could scrape hides and sharpen wooden
sticks.
University of California Berkeley
Collection and University of Indiana Collection/Lithic Casting Lab
The earliest simple form of stone toolmaking involved
breaking and shaping an angular rock by hitting it with a palm-sized round rock
known as a hammerstone. Scientists refer to tools made in this way as Oldowan,
after Olduvai Gorge in Tanzania, a site from which many such tools have come.
The Oldowan tradition lasted for about 1 million years. Oldowan tools include
large stones with a chopping edge, and small, sharp flakes that could be used
to scrape and slice. Sometimes Oldowan toolmakers used anvil stones (flat rocks
found or placed on the ground) on which hard fruits or nuts could be broken
open. Chimpanzees are known to do this today.
Acheulean Handaxes
The style of toolmaking known as
Acheulean developed in Africa over 1.5 million years ago. It spread to Europe
and Asia and continued for well over a million years, the longest period of any
toolmaking tradition. Some of the most common Acheulean tools were large,
symmetrical, teardrop-shaped handaxes, such as these two found in southeast
England.
Len and Janie Weidner
Collection/Lithic Casting Lab
Scientists once thought that Oldowan toolmakers intentionally
produced several different types of tools. It now appears that differences in
the shapes of larger tools were a byproduct of detaching flakes from a variety
of natural rock shapes. Learning the skill of Oldowan toolmaking certainly
required observation, but not necessarily instruction or language. Thus,
Oldowan tools were simple, and their makers used them for such purposes as
cutting up animal carcasses, breaking bones to obtain marrow, cleaning hides,
and sharpening sticks for digging up edible roots and tubers.
Prehistoric Tools and Their Uses
Prehistoric humans made a great
variety of stone tools, many of which were designed for particular tasks.
Larger forms, such as axes and adzes, were used to cut and shape wood.
Knifelike blade tools were used to butcher animals. Small arrowheads of a
variety of shapes and sizes made precise weapons for hunting.
© Microsoft Corporation. All Rights
Reserved.
Oldowan toolmakers sought out the best stones for making tools
and carried them to food-processing sites. At these sites, the toolmakers would
butcher carcasses and eat the meat and marrow, thus avoiding any predators that
might return to a kill. This behavior of bringing food and tools together
contrasts with an eat-as-you-go strategy of feeding commonly seen in other
primates.
Prehistoric Flint Tools
Humans have been toolmakers for at
least 2.5 million years. The earliest technology was a practically oriented
tool kit of haphazardly shaped chopping, cutting, and scraping implements
fashioned from pebbles. From the later stone ages, archaeologists have
identified some 60 or 70 standard kinds of intricate tools with very specific
purposes; some had ceremonial uses. While the ax-head, arrowhead, scrapers,
borers, and flakes in this picture were all made of stone, materials such as
bone and ivory were also used. Tools like these can be made by direct
percussion (using a hammerstone or other implement to knock flakes from the raw
material) or indirect percussion (using the hammerstone to strike a chisel-like
tool that is precisely positioned on the raw material).
G.A. Maclean/Oxford Scientific Films
The Acheulean toolmaking tradition, which began sometime
between 1.7 million and 1.5 million years ago, consisted of increasingly
symmetrical tools, most of which scientists refer to as handaxes and cleavers.
Acheulean toolmakers, such as Homo erectus, also worked with much larger
pieces of stone than did Oldowan toolmakers. The symmetry and size of later
Acheulean tools shows increased planning and design—and thus probably increased
intelligence—on the part of the toolmakers. The Acheulean tradition continued
for over 1.35 million years.
Early Hunting and Gathering Tools
An assortment of prehistoric tools
provides evidence of the hunting and gathering methods of early peoples. Slabs
of bark were often used to gather nuts and berries and functioned as crude
dishes or bowls (top left). Reproductions of fishing tackle and arrows believed
to have been used around 8000 bc are displayed on the lower left. Recovered
tools for digging and cutting (right) are shown with recreated wooden handles.
The heads of the adzes are made from flint, as is the fire-starter shown below
them.
Dorling Kindersley
The next significant advances in stone toolmaking were
made by at least 200,000 years ago. One of these methods of toolmaking, known
as the prepared core technique (and Levallois in Europe),
involved carefully and exactingly knocking off small flakes around one surface
of a stone and then striking it from the side to produce a preformed tool
blank, which could then be worked further. Within the past 40,000 years, modern
humans developed the most advanced stone toolmaking techniques. The so-called prismatic-blade
core toolmaking technique involved removing the top from a stone, leaving a
flat platform, and then breaking off multiple blades down the sides of the
stone. Each blade had a triangular cross-section, giving it excellent strength.
Using these blades as blanks, people made exquisitely shaped spearheads,
knives, and numerous other kinds of tools. The most advanced stone tools also
exhibit distinct and consistent regional differences in style, indicating a
high degree of cultural diversity.
D
|
Environmental Adaptation
|
Thule Artifacts
Arctic peoples of the early
aboriginal Thule culture made many kinds of tools from stone, bone, ivory, and
antler. The Thule culture developed between 1,100 and 400 years ago and was
based around the hunting of whales, seals, walrus, and caribou, as well as
fishing. One Thule technological innovation was the use of harpoon heads that
were attached by lines to floats of sealskin.
Lithic Casting Lab
Early humans experienced dramatic shifts in their environments
over time. Fossilized plant pollen and animal bones, along with the chemistry
of soils and sediments, reveal much about the environmental conditions to which
humans had to adapt.
By 8 million years ago, the continents of the world,
which move over very long periods, had come to the positions they now occupy.
But the crust of the Earth has continued to move since that time. These
movements have dramatically altered landscapes around the world. Important
geological changes that affected the course of human evolution include those in
southern Asia that formed the Himalayan mountain chain and the Tibetan Plateau,
and those in eastern Africa that formed the Great Rift Valley. The formation of
major mountain ranges and valleys led to changes in wind and rainfall patterns.
In many areas dry seasons became more pronounced, and in Africa conditions
became generally cooler and drier.
By 5 million years ago, the amount of fluctuation in
global climate had increased. Temperature fluctuations became quite pronounced
during the Pliocene Epoch (5 million to 1.6 million years ago). During this
time the world entered a period of intense cooling called an ice age, which
began around 2.8 million years ago. Ice ages cycle through colder phases known
as glacials (times when glaciers form) and warmer phases known as interglacials
(during which glaciers melt). During the Pliocene, glacials and interglacials
each lasted about 40,000 years each. The Pleistocene Epoch (1.6 million to
10,000 years ago), in contrast, had much larger and longer ice age
fluctuations. For instance, beginning about 700,000 years ago, these
fluctuations repeated roughly every 100,000 years.
Between 5 million and 2 million years ago, a mixture of
forests, woodlands, and grassy habitats covered most of Africa. Eastern Africa
entered a significant drying period around 1.7 million years ago, and after 1
million years ago large parts of the African landscape turned to grassland. So
the early australopiths and early Homo lived in relatively wooded
places, whereas Homo ergaster and H. erectus lived in areas of
Africa that were more open. Early human populations encountered many new and
different environments when they spread beyond Africa, including colder
temperatures in the Near East and bamboo forests in Southeast Asia. By about
1.4 million years ago, populations had moved into the temperate zone of
northeast Asia, and by 800,000 years ago they had dispersed into the temperate
latitudes of Europe. Although these first excursions to latitudes of 40° north
and higher may have occurred during warm climate phases, these populations also
must have encountered long seasons of cold weather.
All of these changes—dramatic shifts in the landscape,
changing rainfall and drying patterns, and temperature fluctuations—posed
challenges to the immediate and long-term survival of early human populations.
Populations in different environments evolved different adaptations, which in
part explains why more than one species existed at the same time during much of
human evolution.
Some early human adaptations to new climates involved
changes in physical (anatomical) form. For example, the physical adaptation of
having a tall, lean body such as that of H. ergaster—with lots of skin
exposed to cooling winds—would have dissipated heat very well. This adaptation
probably helped the species to survive in the hotter, more open environments of
Africa around 1.7 million years ago. Conversely, the short, wide bodies of the
Neandertals would have conserved heat, helping them to survive in the ice age
climates of Europe and western Asia.
Increases in the size and complexity of the brain,
however, made early humans progressively better at adapting through changes in
cultural behavior. The largest of these brain-size increases occurred over the
past 700,000 years, a period during which global climates and environments
fluctuated dramatically. Human cultural behavior also evolved more quickly
during this period, most likely in response to the challenges of coping with
unpredictable and changeable surroundings.
Humans have always adapted to their environments by
adjusting their behavior. For instance, early australopiths moved both in the
trees and on the ground, which probably helped them survive environmental
fluctuations between wooded and more open habitats. Early Homo adapted
by making stone tools and transporting their food over long distances, thereby
increasing the variety and quantities of different foods they could eat. An expanded
and flexible diet would have helped these toolmakers survive unexpected changes
in their environment and food supply.
When populations of H. erectus moved into the
temperate regions of Eurasia, they faced new challenges to survival. During the
colder seasons they had to either move away or seek shelter, such as in caves.
Some of the earliest definitive evidence of cave dwellers dates from around
800,000 years ago at the site of Atapuerca in northern Spain. This site may
have been home to early H. heidelbergensis populations. H. erectus
also used caves for shelter.
Eventually, early humans learned to control fire and to use it
to create warmth, cook food, and protect themselves from other animals. The
oldest known fire hearths date from between 450,000 and 300,000 years ago, at
sites such as Bilzingsleben, Germany; Verteszöllös, Hungary; and Zhoukoudian
(Chou-k’ou-tien), China. African sites as old as 1.6 million to 1.2 million
years contain burned bones and reddened sediments, but many scientists find such
evidence too ambiguous to prove that humans controlled fire. Early populations
in Europe and Asia may also have worn animal hides for warmth during glacial
periods. The oldest known bone needles, which indicate the development of
sewing and tailored clothing, date from about 30,000 to 26,000 years ago.
E
|
Symbolic Thought—Language, Art, and Religion
|
The evolution of cultural behavior relates directly to
the development of the human brain, and particularly the cerebral cortex, the
part of the brain that allows abstract thought, beliefs, and expression through
language. Humans communicate through the use of symbols—ways of referring to
things, ideas, and feelings that communicate meaning from one individual to
another but that need not have any direct connection to what they identify. For
instance, a word—one type of symbol—does not usually relate directly to the
thing or idea it represents; it is abstract. English-speaking people use
the word lion to describe a lion, not because a dangerous feline looks like
the letters l-i-o-n, but because these letters together have a meaning
created and understood by people. See also Culture: Culture Is
Symbolic.
People can also paint abstract pictures or play pieces of
music that evoke emotions or ideas, even though emotions and ideas have no form
or sound. In addition, people can conceive of and believe in supernatural
beings and powers—abstract concepts that symbolize real-world events such as
the creation of Earth and the universe, the weather, and the healing of the
sick. Thus, symbolic thought lies at the heart of three hallmarks of modern
human culture: language, art, and religion.
E1
|
Language
|
In language, people creatively join words together in an
endless variety of sentences—each with a distinct meaning—according to a set of
mental rules, or grammar. Language provides the ability to communicate complex
concepts. It also allows people to exchange information about both past and
future events, about objects that are not present, and about complex philosophical
or technical concepts.
Language gives people many adaptive advantages, including the
ability to plan for the future, to communicate the location of food or dangers
to other members of a social group, and to tell stories that unify a group,
such as mythologies and histories. However, words, sentences, and languages
cannot be preserved like bones or tools, so the evolution of language is one of
the most difficult topics to investigate through scientific study.
It appears that modern humans have an inborn instinct for
language. Under normal conditions it is almost impossible for a person not to
develop language, and people everywhere go through the same stages of
increasing language skill at about the same ages. While people appear to have
inborn genetic information for developing language, they learn specific
languages based on the cultures from which they come and the experiences they
have in life.
The ability of humans to have language depends on the
complex structure of the modern brain, which has many interconnected, specific
areas dedicated to the development and control of language. The complexity of
the brain structures necessary for language suggests that it probably took a
long time to evolve. While paleoanthropologists would like to know when these
important parts of the brain evolved, endocasts (inside impressions) of
early human skulls do not provide enough detail to show this.
Some scientists think that even the early australopiths had
some ability to understand and use symbols. Support for this view comes from
studies with chimpanzees. A few chimps and other apes have been taught to use
picture symbols or American Sign Language for simple communication.
Nevertheless, it appears that language—as well as art and religious
ritual—became vital aspects of human life only during the past 100,000 years,
primarily within our own species.
E2
|
Art
|
Chauvet Cave Art
The Chauvet cave paintings in southeastern
France are some of the oldest and most spectacular examples of Ice Age art ever
found. The red and black drawings and engravings depict a wide range of
animals, from the more common horses and bison to the rarer lions and
rhinoceroses. The paintings have been dated to 32,000 years ago.
Ministere De La Culture/Liaison
Agency
Humans also express symbolic thought through many forms
of art, including painting, sculpture, and music. An apparent stone human
figurine painted with red ocher was found at Tan-Tan, Morocco, in 1999. The
object, which is at least 300,000 years old and possibly as old as 400,000
years, may be a naturally formed stone that was reworked by humans to emphasize
its humanlike shape, making it the earliest sculpture known. Another object
found at a site in Berekhat Ram, Israel, and made of red volcanic rock, has
been interpreted as representing the outline of a female body. The piece dates
from about 250,000 years ago and is controversial—some experts see it as the
result of natural geological processes rather than human handiwork.
Cave Painting, Lascaux
This portion of the cave painting in
Lascaux, France, was done by Paleolithic artists in about 13,000 bc. The
leaping cow and group of small horses were painted with red and yellow ochre
that was either blown through reeds onto the wall or mixed with animal fat and
applied with reeds or thistles. It is believed that prehistoric hunters painted
these to gain magical powers that would ensure a successful hunt.
Bridgeman Art Library, London/New
York
Claims for the earliest art made by modern humans also
come from Africa and the Middle East. Small, perforated shells found in
Algeria, Israel, and South Africa, dating from between 100,000 and 75,000 years
ago, may represent beads worn as personal ornaments. Pieces of ocher, a soft
red iron mineral, were found at Blombos Cave in South Africa and have been
dated to between 75,000 and 70,000 years ago. The objects were scraped and
ground to create a flat surface and then etched with complex geometric lines as
apparent decoration or symbolic meaning. Some researchers have interpreted
grooves made on a large rock in a cave in Botswana as possible artistic or
ritual acts that also might date to around 70,000 years ago. Part of the
natural rock formation is said to resemble the head of a python. The proposed
date for the markings and the artifacts found in the cave, as well as their
possible significance, will require further study.
Venus of Willendorf
This so-called Venus figurine from
the area of Willendorf, Austria, is one of the earliest known examples of
sculpture, dating from about 23,000 bc. The figure, which is carved out of
limestone, is only 11.25 cm (4.5 in) high, and was probably designed to be held
in the hand. It is believed the Venus may be a fertility symbol, which would
explain the exaggerated female anatomy.
Ali Meyer/Bridgeman Art Library,
London/New York
Only a few other possible art objects are currently
known from between 200,000 and 50,000 years ago. These items come from western
Europe and are usually attributed to Neandertals. They include two objects that
may have been simple pendants—a tooth and a bone with bored holes—and several
grooved or polished fragments of tooth and bone.
Aboriginal Rock Art
This ancient Aboriginal rock painting
is located at Nourlangie Rock in Australia’s Kakadu National Park. The park
contains more than 1,000 Aboriginal rock paintings, some dating from 35,000
years ago. The rock paintings exhibit remarkable consistency in iconography,
materials, and technique. Many of them depict scenes from the Aboriginal
creation stories known as the Dreaming.
SuperStock/age fotostock
Sites dating from at least 400,000 years ago contain
fragments of red and black pigment. Humans might have used these pigments to
decorate bodies or perishable items, such as wooden tools or clothing of animal
hides, but this evidence would not have survived to today. Solid evidence of
the sophisticated use of pigments for symbolic purposes—such as in religious
rituals—comes only from after 40,000 years ago. From early in this period,
researchers have found carefully made types of crayons used in painting and
evidence that humans burned pigments to create a range of colors.
Engraved Mammoth Tusk
This engraved mammoth tusk, dating
from 25,000 to 30,000 years ago, was found at Dolní Věstonice, an important
archaeological site in the Czech Republic. An artist of the Paleolithic era is
thought to have engraved it using a sharp tool made of flint.
The Natural History Museum, London
People began to create and use advanced types of symbolic
objects after about 50,000 years ago. The archaeological record shows a
tremendous blossoming of art between 32,000 and 15,000 years ago. During this
period much of the art appears to have been used in rituals—possibly ceremonies
to ask spirit beings for a successful hunt. People also adorned themselves with
intricate jewelry of ivory, bone, and stone. They carved beautiful figurines
representing animals and human forms. Many carvings, sculptures, and paintings
depict stylized images of the female body. Some scientists think such female
figurines represent fertility.
Early wall paintings made sophisticated use of texture
and color. The area of what is now southern France contains many famous sites
of such paintings. These include the caves of Chauvet, which contain art over
32,000 years old, and Lascaux, in which paintings date from as much as 18,000
years ago. In some cases, artists painted on walls that can be reached only
with special effort, such as by crawling. The act of getting to these paintings
gives them a sense of mystery and ritual, as it must have to the people who
originally viewed them, and archaeologists refer to some of the most
extraordinary painted chambers as sanctuaries. Yet no one knows for sure what
meanings these early paintings and engravings had for the people who made them.
See also Paleolithic Art.
E3
|
Religion
|
A cave site near Atapuerca in Spain dated to around
400,000 years ago may contain the earliest evidence of human religion or
ritual. The site includes a pit called Sima de los Huesos (“Pit of Bones”),
which holds thousands of human bones belonging to about 30 individuals. Humans
apparently did not live in the cave so the bodies must have been brought to the
pit and deliberately thrown in. A single, carefully worked symmetrical hand ax
was found with the bones. The remains have been attributed to Homo heidelbergensis,
the human species common in Europe at the time and the possible ancestor of
Neandertals.
Graves from Europe and western Asia indicate that the
Neandertals were the first humans to bury their dead, at least on occasion.
Some sites contain very shallow graves, which group or family members may have
dug simply to remove corpses from sight. In other cases it appears that groups
may have observed rituals of grieving for the dead or communicating with
spirits. Some researchers have claimed that grave goods, such as meaty animal
bones or flowers, had been placed with buried bodies, suggesting that some
Neandertal groups might have believed in an afterlife. In a large proportion of
Neandertal burials, the corpse had its legs and arms drawn in close to its
chest, which could indicate a ritual burial position.
Other researchers have challenged these interpretations,
however. They suggest that perhaps the Neandertals had practical rather than
religious reasons for positioning dead bodies. For instance, a body manipulated
into a fetal position would need only a small hole for burial, making the job
of digging a grave easier. In addition, the animal bones and flower pollen near
corpses could have been deposited by accident or without religious intention.
Many scientists once thought that fossilized bones of
cave bears (a now-extinct species of large bear) found in Neandertal caves
indicated that these people had what has been referred to as a cave bear cult,
in which they worshiped the bears as powerful spirits. However, after careful
study researchers concluded that the cave bears probably died while hibernating
and that Neandertals did not collect their bones or worship them. Considering
current evidence, the case for religion among Neandertals remains controversial.
The earliest evidence for religion or ritual in modern humans
may come from Ethiopia, where paleoanthropologists found three skulls dated to
about 160,000 years ago. The skull bones of two adults and a child show
evidence of repeated handling and polishing, along with apparent decoration
with scratch marks. The skulls were not found with other bones from the bodies,
suggesting early modern Homo sapiens possibly carried around the
detached skulls for ritual purposes. See also Religion: Rituals and
Symbols.
F
|
Domestication, Agriculture, and the Rise of Civilizations
|
One of the most important developments in human
cultural behavior occurred when people began to domesticate (control the
breeding of) plants and animals. Domestication and the advent of agriculture
led to the development of dozens of staple crops (foods that form the basis of
an entire diet) in temperate and tropical regions around the world. Almost the
entire population of the world today depends on just four of these major crops:
wheat, rice, corn, and potatoes. See also Crop Farming.
F1
|
Human Manipulation of the Environment
|
Early Agricultural Tools
Humans began farming about 12,000
years ago. The ability to control their food supply freed people from a nomadic
lifestyle, which allowed for the beginning of cities and towns. These early
farming tools date from about 6000 bc. The picture portrays an axe (bottom),
used for clearing; flint sickles (left), used for harvesting cereal crops; a
flat rock and rounded stone (center), used for grinding flour; and perforated
clay slabs (upper right), probably used to ventilate bread ovens.
Dorling Kindersley
The growth of farming and animal herding initiated one of
the most remarkable changes ever in the relationship between humans and the
natural environment. The change first began just 10,000 years ago in the Near
East and has accelerated very rapidly since then. It also occurred
independently in other places, including areas of Mexico, China, and South
America. Since the first domestication of plants and animals, many species over
large areas of the planet have come under human control. The overall number of
plant and animal species has decreased, while the populations of a few species
needed to support large human populations have grown immensely. In areas
dominated by people, interactions among plants and animals usually fall under
the control of a single species—Homo sapiens.
By the time of the initial transition to plant
and animal domestication, the cold, glacial landscapes of 18,000 years ago had
long since given way to warmer and wetter environments. At first, people
adapted to these changes by using a wider range of natural resources. Later
they began to focus on a few of the most abundant and hardy types of plants and
animals. The plants people began to use in large quantities included cereal
grains, such as wheat in western Asia; wild varieties of rice in eastern Asia; and
maize, of which corn is one variety, in what is now Mexico. Some of the animals
people first began to herd included wild goats in western Asia, wild ancestors
of chickens in eastern Asia, and llamas in South America.
By carefully collecting plants and controlling wild herd
animals, people encouraged the development of species with characteristics
favorable for growing, herding, and eating. This process of selecting certain
species and controlling their breeding eventually created new species of
plants, such as oats, barley, and potatoes; and animals, including cattle,
sheep, and pigs. From these domesticated plant and animal species, people
obtained important products, such as flour, milk, and wool.
F2
|
Effects of Food Production on Human Society
|
By harvesting and herding domesticated species, people
could store large quantities of plant foods, such as seeds and tubers, and have
a ready supply of meat and milk. These readily available supplies gave people
some long-term food security. In contrast, the foraging lifestyle of earlier
human populations never provided them with a significant store of food. With
increased food supplies, agricultural peoples could settle into villages and
have more children. The new reliance on agriculture and change to settled
village life also had some negative effects. As the average diet became more
dependent on large quantities of one or a few staple crops, people became more
susceptible to diseases brought on by a lack of certain nutrients. A settled
lifestyle also increased contact among people and between people and their
refuse and waste matter, both of which acted to increase the incidence and
transmission of disease.
People responded to the increasing population density—and
a resulting overuse of farming and grazing lands—in several ways. Some people
moved to settle entirely new regions. Others devised ways of producing food in
larger quantities and more quickly. The simplest way was to expand onto new
fields for planting and new pastures to support growing herds of livestock.
Many populations also developed systems of irrigation and fertilization that
allowed them to reuse cropland and to produce greater amounts of food on
existing fields.
F3
|
The Rise of Civilizations
|
Cradle of Civilization
Known as the “cradle of
civilization,” Mesopotamia served as the site for some of the world’s earliest
settlements. Named after the Greek word meaning “between the rivers,”
Mesopotamia occupied the area between the Tigris and Euphrates rivers that now
constitutes the greater part of Iraq. The Sumerian civilization, which began in
the region in about 3500 bc, built a canal system and the world’s first cities.
© Microsoft Corporation. All Rights
Reserved.
The rise of civilizations—the large and complex types of
societies in which most people still live today—developed along with surplus
food production. People of high status eventually used food surpluses as a way
to pay for labor and to create alliances among groups, often against other
groups. In this way, large villages could grow into city-states (urban centers
that governed themselves) and eventually empires covering vast territories.
With surplus food production, many people could work exclusively in political,
religious, or military positions; or in artistic and various skilled vocations.
Command of food surpluses also enabled rulers to control laborers, such as in
slavery. All civilizations developed based on such hierarchical divisions of
status and vocation.
The earliest civilization arose over 7,000 years ago in Sumer
in what is now Iraq. Sumer grew powerful and prosperous by 5,000 years ago,
when it centered on the city-state of Ur. The region containing Sumer, known as
Mesopotamia, was the same area in which people had first domesticated animals
and plants. Other centers of early civilizations include the Nile Valley of
Northeast Africa, the Indus Valley of South Asia, the Yellow River Valley of
East Asia, the Oaxaca and Mexico valleys and the Yucatán region of Central
America, and the Andean region of South America. See also Egypt: History;
China: History; Aztec; Maya Civilization; and Inca Empire.
All early civilizations had some common features. Some of
these included a bureaucratic political body, a military, a body of religious
leadership, large urban centers, monumental buildings and other works of
architecture, networks of trade, and food surpluses created through extensive
systems of farming. Many early civilizations also had systems of writing,
numbers and mathematics, and astronomy (with calendars); road systems; a
formalized body of law; and facilities for education and the punishment of crimes.
See also Writing: History of Writing; Number Systems;
Mathematics: History of Mathematics; History of Astronomy: Ancient
Origins; and Calendar: Ancient Calendars.
With the rise of civilizations, human evolution
entered a phase vastly different from all that came before. Prior to this time,
humans had lived in small, family-centered groups essentially exposed to and
controlled by forces of nature. Several thousand years after the rise of the
first civilizations, most people now live in societies of millions of unrelated
people, all separated from the natural environment by houses, buildings,
automobiles, and numerous other inventions and technologies. Culture will
continue to evolve quickly and in unforeseen directions, and these changes
will, in turn, influence the physical evolution of Homo sapiens and any
other human species to come.
Contributed By:
Richard B. Potts
Microsoft
® Encarta ® 2009. ©
1993-2008 Microsoft Corporation. All rights reserved.
NOW
SEE THE AGE OF DISTORTIONS IN ARCHIVES
1975: Archaeology
Archives consist of articles that originally appeared in Collier's Year
Book (for events of 1997 and earlier) or as monthly updates in Encarta Yearbook
(for events of 1998 and later). Because they were published shortly after
events occurred, they reflect the information available at that time. Cross
references refer to Archive articles of the same year.
1975: Archaeology
Human origins.
Year by
year the story of man is changing, as the origins of the species are pushed
further and further back in time. And as the timetable of human history
undergoes revision, it is also becoming increasingly, incredibly complex. What
is emerging, it appears, is a picture of an evolutionary process that worked
not at all smoothly but by fits and starts, with perhaps dozens of side
branches and unproductive dead ends. Eerily, modern man's ancestors apparently
had a number of collateral relatives, some perhaps with rudimentary tools and
language, whose extinction man may have used as a ladder to evolutionary success.
One important element in this emerging new picture
is the discovery in 1974, by a joint American-French team of
paleoanthropologists digging in Ethiopia, of a new hominid (manlike) creature
more ancient than any other human precursor then known—around 3 million years
old. This impressive discovery, attained under the direction of Donald Carl
Johanson of Case-Western Reserve University, includes not only skull fragments
and fragments of jaw and limb bones, but also some complete limb bones. It
makes up about 40 percent of a complete skeleton. Lucy, as the skeleton is
called, was a young adult female standing 3½ to 4 feet tall, and her brain size
and other characteristics were quite advanced for such an early period.
Only a
year earlier, Richard Leakey, son of the pioneer African paleoanthropologists
Louis and Mary Leakey, had discovered at Lake Rudolph in Kenya the oldest human
ancestor to date, a hominid dated to 2.6 million or perhaps 2.9 million years
ago. Its brain was an impressive 800 cubic centimeters (contrasted with 450 cc
for modern chimpanzees and 1,200 cc to 1,800 cc for modern humans).
And in
October 1975 it was announced that bones found in Tanzania by Mary Leakey had
been dated to approximately 3.75 million years ago.
The
significance of these finds and of some other less widely publicized East
African discoveries is that if there were hominids as early as 4 million years
ago, then the emergence of the human line may actually predate the existence of
a number of other creatures themselves long believed to have been ancestral to
humans. Among these is the entire group of near-men called australopithecines,
low-browed creatures with small brains (450 cc), who walked at least
semiupright and used crude tools. There is some indication that even as the
human line (Homo) was emerging, the competitive apelike line (Australopithecus)
was undergoing its own evolution and speciation.
It is
believed that the australopithecines died about 1 million years ago, by which
time the human line had long been well established with the emergence of the
fossil man known as Homo erectus, remains of whom have been discovered
in Africa, Asia, and Europe. Included in Homo erectus are the well-known
Peking man (formerly Sinanthropus) and the Asian species called Pithecanthropus
erectus. Homo erectus brains ranged from 800 cc to 1,000 cc.
This new
picture of human evolution will continue to be revised and filled in for years
to come. At the moment it proposes a parent stock living about 4-6 million
years ago, giving rise to a hominid line (which eventually led to Homo
erectus and thence to Homo sapiens) and to a parallel
australopithecine line. This evolutionary flowering does seem to correspond to
a similar explosion among other mammals. In almost the same period many
mammalian species began their emergence from their now-extinct primitive
ancestral stocks.
The Hadrian find.
For New
York City stockbroker Morton Leventhal it was the event of a lifetime. Perhaps
only the devoted bird-watcher who has had the first sighting of what proves to
be a new species could understand the thrill. Leventhal, an avid amateur
archaeologist, was visiting his sister on a kibbutz in northern Israel. Ever
hopeful that something would turn up one day, he had brought a metal detector
along on his trip and was trying it out in a wheat field overlooking the Jordan
River. Suddenly, a beep told him that metal was buried nearby. After years of
digging up rusty pipes, old machinery, and an occasional coin, Leventhal had no
great expectations. But he dutifully got out his Boy Scout penknife and began
to dig. After a foot and a half of hard work, he struck metal—the head and
eventually the body of a magnificent life-size bronze statue of Hadrian,
emperor of Rome from ad 117 to 138
and one of the harshest of the rulers of ancient Judea. Only one bronze of
Hadrian had ever been found before, and this new find, definitely a prize of
historic significance, was in superb condition, easily cleaned and repaired,
with no pieces missing. The statue depicts a middle-aged Hadrian standing in
full battle dress, right arm raised. The magnificently detailed features—full
cheeks, large nose, receding chin, curling hair—are distinctly those of
Hadrian. The statue's stunning breastplate shows six warriors fighting in three
pairs.
The new
Hadrian, valued at about $3 million, was promptly taken over by the Israeli
government's Department of Antiquities, under a national law governing
archaeological treasures, to be put on display in Jerusalem. Leventhal's reward
for his persistence will be some Roman coins for his collection, gifts of the
Department of Antiquities—and, of course, no small measure of satisfaction for
having made one of the finds of the decade.
Ancient sailors.
American
archaeology scored another major unexpected success this year with the
discovery of the oldest shipwreck ever found. A team led by Peter Throckmorton,
an American expert on underwater archaeology, came upon the wreckage by chance
near the island of Hydra off the coast of Greece. Its cargo of pottery is
believed to date from about 2500 bc,
the Early Bronze Age; about one-twentieth of the original wood also remained.
The National Geographic Society, which financed the Throckmorton expedition,
said the vessel was probably sailed by natives of the Cyclades Islands, located
in the Aegean Sea southeast of Athens, who were the earliest known sailors in
the region.
Archaeological looting.
While
Leventhal's find can be attributed to some extent to the application of modern
technology, that same technology has contributed significantly to the loss of a
part of the archaeological heritage, especially in the United States, where
such gadgetry is extremely popular. According to published reports, sales of
metal detectors have soared; the largest manufacturer reported more than 40,000
of the units sold in 1974, at approximately $250 each. The impact has been
devastating, as souvenir hunters, hobbyists, and treasure seekers have
descended on prime sites, such as Civil War battlefields, to 'liberate' any
metal objects—bullets, cannonballs, buttons, belt buckles, swords, pistols, and
even an occasional cannon or wagon wheel—that they can turn up.
Aside
from the fact that removal of such objects is illegal under the Antiquities Act
of 1906, the damage done by the diggers has been extremely serious. For
example, earthworks, which are the critical landmarks of old battlefields, have
been so perforated by pits that they are beginning to erode and even disappear.
Thus far
there has been very little protection against such depredations. Some national
park superintendents have tried sowing the battlefield sites with scrap metal
fragments, a kind of 'jamming' akin to using metal foil streamers to interfere
with radar signals. But determined diggers, especially when big money is
involved (a prime belt buckle can fetch $700 from collectors), are not easily
discouraged and have been perfecting their equipment and the ways they use it
to overcome the attempted deception.
Chinese treasure trove.
During
the summer of 1974 a group of Chinese peasants digging near their commune in
the province of Shensi came across a series of underground chambers. The area
had long been known as the site of the tomb of Shih Huang-ti, who was the
founder of the Ch'in dynasty (221-206 bc)
and the first emperor of a unified China. There was even a mound marking the
place. But apparently no one in more than 2,000 years had come upon the tomb
itself. The chambers discovered by the farmers were the tomb's anterooms, and
they turned out to contain one of the most extraordinary finds of all time—an
assemblage of 6,000 life-size ceramic figures of warriors and horses. The
pottery army was in perfect condition, the 6-foot helmeted warriors carrying
real bows and arrows, spears, and crossbows, and their officers armed with
swords that had remained untarnished for more than 21 centuries.
Art
experts declared the figures to be of extraordinary sophistication, more akin
to sculpture than to simple ceramics. Meticulously executed, they are highly
individual, with varying facial features and even a wide range of hairstyles.
Shih
Huang-ti's tomb has not yet been opened—or at least an opening has not been
reported by the Chinese government—but it is expected that with such a
spectacular army to guard it, the burial chambers will yield a truly fabulous
hoard of gold, jade, silks, and other treasures.
Microsoft
® Encarta ® 2009. ©
1993-2008 Microsoft Corporation. All rights reserved.
KEEP YOUR SCIENTIFIC REASONING ALIVE AND WAIT FOR THE NEXT INSTALLMENT..... A DISMANTLING OF RELIGIONS, THE DIRTIEST AND OLDEST POLITICS THAT AHD AND STILL ENXLVES ALL OF US TO DATE
https://plus.google.com/100752842609304318747/posts/ZEZKe1nBs24
Agunabu Biafra Publication in WIKIPEDIA the Free Encyclopaedia
A CROSS-CULTURAL HARMONISATION OF YOUTH DEVELOPMENT
THE PANACEA FOR RACISM
By
Dr. J. K. Danmbaezue, D. Psych., FACRS,
Consultant Clinical Psychologist / Existential Family Therapist.
M.D. Kenez Health Clinic, & ANIMATOR, Happy Family Network International
Block: C, House: 82, Federal Housing Estate, Trans-Ekulu, Enugu.
P. O. Box 1995. Phone 042-551199 or 550344
ENUGU STATE OF NIGERIA
Being the Paper presented at
THE UNITED NATIONS CONFERENCE ON RACISM
Holding at Durban, South Africa
23rd August – 2nd September 2001.
Abstract
This guest paper emphasizes the origins and development of prejudice, discrimination, ethnocentrism, stereotypy and religious bigotry as the seeds that germinate into racism or racialism, dominant and minority ethnic groups that culminate in stressful relations, violence and wars.
A cross-cultural harmonization of child-rearing practices is the author’s therapeutic prescription if youths must be re-oriented towards the universal brotherhood of mankind. We have the same basic anatomy and physiology; we share the same air, water, food and rest periods. Blood groupings, emotions, motivations, and libido allow for similar sex attractions, pregnancies and births. So, where do these ethnic superiority and inferiority complexes come from?
The “Kenezian Creed” and “The Letter to Educationists all over the world”, epitomize the ideals that this Existential Therapeutic Programme enunciates. The panacea for racism is a systematic re-education, religious liberalism and socio-political equality, which should form the foundations of cross-cultural harmonization of youth counselling and personality development initiatives.
Concise C. V.
Dr. J. K. Danmbaezue is a sixty-four year old privately employed Psychotherapist & Psychometrician with an outfit where the counsels young adults about to wed, administering psychological tests and utilizing them objectively to re-direct incompatible couples. He is a certified Consultant Clinical Psychologist and Existential Family Therapist registered in Nigeria. He also has an NGO-christened HAPPY FAMILY NETWORK INTERNATIONAL, which aims at the globalization of those principles neatly encapsulated in the Kenezian Creed and His letter to All Educationists. He is happily married and has three kids. He holds a Doctor of Science degree in psychometrics besides his Fellowship of the African College of Research Scientists.
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