Branches on the Family Tree
There is only one species of hominid on the planet today: modern humans, or Homo sapiens. But for most of our family's evolutionary history, a variety of early humans inhabited Earth. Between about 3.5 and 1.5 million years ago, at least 11 hominid species lived in Africa. Many of them were members of the genus Australopithecus. By the time the entire "australopith" group went extinct about 1.4 million years ago, the earliest members of our genus, Homo, had come on the scene. The precise origins of our genus are still unknown.
Australopithecus africanus: Often described as a light-bodied or "gracile" hominid, this species had relatively small jaws. It ate mostly fruits and leaves and possibly some meat.
Featured Fossil: Taung Child
In the early twentieth century, many scientists thought humans originated in Asia, the home of the oldest hominid fossils known at the time. The 1924 discovery of this ancient African fossil helped overturn that notion. Known as the Taung Child, it consists of a face and endocast--an impression of the brain formed when sand inside the skull hardened to rock.
Kenyanthropus platyops: This hominid lived much earlier than many of the others here, yet it had surprisingly advanced features, including a flat face. It may represent an entirely separate lineage.
Male vs. Female
The Paranthropus boisei skulls in the exhibit
both have wide, flat faces with flaring cheekbones and prominent browridges. But look closely: only the larger skull has a crest on top. In modern gorillas, males have a similar crest while the smaller females do not--so the larger skull with a crest probably belonged to a male P. boisei, and the smaller one to a female.
Evolutionary Dead End?
Human evolution is often thought of as a linear progression in which each successive species looks more like modern humans. But it took a much more complicated path. This species, Paranthropus robustus, seems to have died out leaving no descendants.