The First Humans
Who were the first humans? When and where did they live? What did they look like? Fossils like the ones displayed in the hall, along with results from DNA studies, give us tantalizing clues about the earliest members of the human family, called hominids. We now know that the first hominids lived in Africa, most likely around six or seven million years ago. They probably walked upright when on the ground but still spent much of their time in trees.
A Very Ancient Relative
A skull from Chad, in north-central Africa, is the oldest hominid fossil represented in this gallery. Researchers think this species, Sahelanthropus tchadensis
lived at least six million years ago. Computer analysis of the fossil suggests the skull was balanced on top of an erect body--a trait unique to species that move upright.
Most scientists think the first members of our genus, Homo, evolved from a member of an earlier genus called Australopithecus. Some of the oldest evidence we have for a hominid of this genus dates back some four million years and was found in Kenya, in eastern Africa. Fossils of this hominid, called Australopithecus anamensis, include the lower jaw, part of the upper jaw and part of the lower leg.
Focus On: The Changing Landscape
Around 10 million years ago, the climate in Africa began to change--with profound consequences for human evolution.
As regions that had been home to lush tropical forests dried out, our ancestors had to adapt to woodland environments. They became less dependent on trees for food and shelter and more accustomed to moving about upright on the ground.
DNA Family Tree
Among living species, humans are thought to be most closely related to chimpanzees and bonobos. On average, the DNA of humans and chimpanzees is more than 98 percent the same. So it's easy for scientists to identify and count the number of changes, or mutations, that have occurred since the two species split apart. By analyzing these mutations, researchers have estimated that the last common ancestor of chimps and humans lived roughly seven million years ago.