Human evolution (2 of 2)
How did humans evolve?
About six million years ago in Africa, the chimpanzee lineage and our own
split. What happened to us after that split?
The hominid lineage did not
march in a straight line to Homo sapiens. Instead, the early hominid lineage gave
rise to many other (now extinct) hominids. Examining the fossils, the artifacts, and even
the DNA of these relatives has
helped us understand how this complex hominid tree evolved, and how modern humans came
to exist.
Here are some of the important events in human history, with approximate dates, which
reflect the evidence currently available:
2) Before 4 mya: The hominid
Australopithecus anamensis walked around what is now Kenya on its hind legs. |
3) 3 mya: Australopithecus afarensis
("Lucy") lived in Africa. |
4) 2.5 mya: Some hominids made tools by
chipping stones to form a cutting edge. There were perhaps four or more species of hominid living
in Africa. |
5) 2 mya: The first members of the Homo
clade, with their relatively large brains, lived in Africa. |
6) 1.5 mya: Hand axes were used. Also,
hominids had spread out of Africa and into much of Asia and Europe. These hominids included the
ancestors of Neanderthals (Homo neanderthalensis) in Europe and Homo erectus in Asia. |
7) 100,000 years ago: Human brains reached
more or less the current range of sizes. Early Homo sapiens lived in Africa. At the same time,
Homo neanderthalensis and Homo erectus lived in other parts of the Old World. |
8) 50,000 years ago: Human cultures produced
cave paintings and body adornment, and constructed elaborate burials. Also, some groups of modern
humans extended their range beyond Africa. |
9) 25,000 years ago: Other Homo species
had gone extinct, leaving only modern humans, Homo sapiens, spread throughout the Old World. |
|