The discovery
of fire
Human species, origins of Evolution of humans
from ancestral primates . The African apes (gorilla
and chimpanzee) are shown by anatomical and molecular comparisons to be the
closest living relatives of humans. Humans are distinguished from apes by the
size of their brain and jaw, their bipedalism, and their elaborate culture.
Molecular studies put the date of the split between the human and African ape
lines at 5-10 million years ago. There are only fragmentary remains of ape and
hominid (of the human group) fossils from this period. Bones of the earliest
known human ancestor, a hominid named Australopithecus ramidus 1994, were found
in Ethiopia
and dated as 4.4 million years old.
Australopithecus afarensis
, hominids found in Ethiopia
and Tanzania,
date from 3.5 to 4 million years ago. These creatures walked upright and they
were either direct ancestors or an offshoot of the line that led to modern
humans. They may have been the ancestors of Homo habilis (considered by some to
be a species of Australopithecus ), who appeared about
a million years later, had slightly larger bodies and brains, and were probably
the first to use stone tools. A. robustus and A. africanus also lived in Africa at the same time, but these are not generally considered
to be our ancestors.
Over 1.5 million years ago, H. erectus , believed by some to be descended from H. habilis ,
appeared in Africa. The erectus people had
much larger brains, and were probably the first to use fire and the first to
move out of Africa. Their remains are found as
far afield as China, Java,
western Asia, Spain, Germany, and England. Modern humans, H. sapiens sapiens , and the Neanderthals, H. sapiens neanderthalensis
, are probably descended from H. erectus . Analysis of DNA in recent human
populations shows that H. sapiens originated about 200,000 years ago in Africa. The oldest known fossils of H. sapiens also come
from Africa, between 150,000 and 100,000 years
ago. Separation of human populations occurred later, with separation of Asian,
European, and Australian populations between 100,000 and 50,000 years ago.
Neanderthals were large-brained and heavily built, probably adapted to the cold
conditions of the ice ages. They lived in Europe and the Middle
East, and died out about 40,000 years ago, leaving H. sapiens
sapiens as the only remaining species of the hominid group. The most recent
fossil discovery is that of a lower jaw of a fossil ape found in the Otavi Mountains,
Namibia.
It comes from deposits dated between 10 and 15 million years ago, and it is
similar to earlier finds from E Africa and Turkey. This is the first record of
a fossil ape from S Africa and it extends the
known range of fossil apes by at least 3,200 km/2,000 mi. It is thought to be
close to the initial divergence of the great apes and humans, although genetic
studies indicate that the last common ancestor between chimpanzees and humans
lived 6 to 8 million years ago.
Human species, origins of A
reconstruction of Java Man. This fossil dates back to between 750,000 and
300,000 years ago. Since its discovery in the latter half of the nineteenth
century, Java Man has been shown by anthropologists to
be a human predecessor and it provides a valuable chronological marker for
human evolution.
