|
The twentieth century brought a great many more fossils of humans and
hominids. Today twenty hominid
species have been identified, the oldest of which date back six million years. They point to an
African origin, as Darwin had proposed. Hominid evolution was sometimes pictured as a single
line of descent and a steady progression from primitive forms to more advanced forms. The fossils
suggested otherwise. Instead, hominid evolution produced a dense thicket of branches, with several
species co-existing at any given time except for the last 30,000 years or so. Added to this
wealth of data is the knowledge gathered from comparisons of
DNA from humans, apes, and even
Neanderthals. While many questions remain to be answered about human evolution, scientists have
a growing treasury of evidence at their disposal. |
 |
 |
|
Left: One possible model of the somewhat bushy path of human evolution. The letters correspond to the
following species:
A-Ardipithecus ramidus
B-Australopithecus anamensis
C-Australopithecus afarensis
D-Australopithecus africanus
E-Paranthropus aethiopicus
F-Paranthropus robustus
G-Paranthropus boisei
H-Australopithecus garhi
I-Homo rudolfensis
J-Homo habilus
K-Homo ergaster
L-Homo erectus
M-Homo heidelbergensis
N-Homo neanderthalensis
O-Homo sapiens |
