Human Evolution

Human Evolution
Ardipithecus ramidus
This species was announced in September 1994. It is thought to
be the oldest known hominid species. It was dated at 4.4 million
years old. The majority of the fossils found were skull fragments.
Other evidence suggests that this species was bipedal. The
individuals were about four feet tall. Some fossils found indicate
that ramidus may have been a forest dweller. The teeth resemble
something between earlier apes and A. afarensis. The fossils were
discovered by a team led by Tim White in Aramis Ethiopia. The
find consists of 17 individuals.


Australopithecus anamensis
This species was named in August 1995. The fossils were mostly
found in Kanapoi Kenya in 1988. Anamensis is thought to have
existed between 4.2 and 3.9 million years ago. The teeth and jaws
are very similar to those of older fossil apes. A partial tibia
supports bipedality. The first fossil of this species was found in
Kanapoi Kenya by Bryan Patterson. The fossil was a lower left
humerous dated to be about 4.0 million years old.

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Australopithecus afarensis
This species existed between 3.9 and 3.0 million years ago. It had
an apelike face with a low forehead, a bony ridge over the eyes, a
flat nose, and no chin. They had protruding jaws with large teeth.
The skull is similar to that of a chimpanzee except for more human
like teeth. The canines of this species were smaller than those of
earlier apes but larger than humans. Their pelvis and leg bones
left no doubt that they were bipedal. They had similar hands to
humans and were about 3.5 to 5.0 feet tall. Footprints of this
species were discovered in 1978 by Paul Abel at Laetoli in
Tanzania. The estimated age is 3.7 million years old.


Australopithecus africanus
A. africanus lived between 3 and 2 million years ago. Their body
sizes and brain sizes were slightly larger than afarensis. The shape
of their jaw was fully parabolic, like that of humans, and the
canine teeth have reduced in size. This species fossils were
discovered by Raymond Dart in 1924 at Taung in south Africa.
The find consisted of a full face, teeth and jaws, and an
endocranial cast of the brain. It is between 2 and 3 million years
old.


Australopithicus garhi
It is known from a partial skull that differs from previous
australopithecus species in the combination of its features. They
had extremely large teeth especially the rear ones. The skull was
discovered by Y. Haile-Selassie in 1997 at Bouri in Ethiopia. It is
about 2.5 million years old.


Australopithecus aethiopicus
A. aethiopicus existed between 2.6 and 2.3 million years ago. This
species is known from the Black Skull specimen discovered by
Alan Walker in 1985 near West Turkana in Kenya. The specimen
is almost completely intact. It has a small cranium capacity for a
hominid and has a strange combination of primitive and advanced
features. This species possessed the largest sagittal crest in any
known hominid.
Australopithecus robustus
A. robustus had a body similar to africanus but a larger and more
robust skull and teeth. It existed between 2 and 1.5 million years
ago. The massive grinding teeth indicate that this species had to
chew tough food. The first robustus fossils were discovered by a
schoolboy in 1938 at Kromdraai in South Africa.


Australopithecus boisei
This hominid existed between 2.1 and 1.1 million years ago and
was very similar to robustus, however the face and cheek teeth
were larger. Its brain size was also very similar to robustus. The
first boisei fossils were discovered by Mary Leaky in 1959 at
Olduvia Gorge in Tanzania.


Homo habilis
H. habilis existed between 2.4 and 1.5 million years ago. It was
thought to have used tools. The face is still primitive but it
projects less than A. africanus. The back teeth are smaller but still
larger than modern day humans. The brain shape is also more
humanlike. Habilis is thought to have been 5 feet tall and 100
pounds in weight. The bulge of Brocas area on the skull indicate
the possibility of it being capable of rudimentary speech. The first
habilis fossils were discovered by the Leakeys in the early 1960s
at Olduvia Gorge in Tanzania.


Homo erectus
H. erectus existed between 1.8 million years and 3000,000 years
ago. The face resembles that of habilis. The skeleton structure is
more robust than those of modern humans. Erectus may have
been more efficient at walking than modern humans. Erectus
probably used fire. The first erectus fossils were discovered by
Eugene Dubois in 1891 near Trinil on the Indonesian island of
Java. Its age is thought to be 700,000 years old.


Homo sapiens neanderthalensis
Neanderthal man lived between 230,000 and 30,000 years ago.
The brains are larger than those of modern humans. They usually
lived in cold climates and their bodies were much like those of a
modern day cold-adapted human. Their skeletons showed that
they endured brutally hard lives. Neanderthals are known to have
buried their dead. The first neanderthal fossils were discovered by
Johann Fuhlrott in 1856 in the Neander Valley in Germany.


Homo sapiens sapiens
We first appeared about 120,000 years ago. Modern humans have
an average brain size of about 1350 cc. This species looks exactly
like us.