A new analysis of fossil wrist bones shows our ancestors opted for a new way of life on the ground beginning as early as 4.2 millions ago. This new information has implications for better understanding an important ecological adaptation our ancestors made on the plains of East and Southern Africa millions of years ago. Their new ecological relationship is one most paleoanthropologists believe had a significant effect on the emergence of stone tool making and use, a new form of new social organization, and perhaps increased animal protein consumption. It may also have represented a preadaptation for the later emergence of other unique human biological and cultural characteristics.... JEL
Ancestors of Humans Left Trees 4.2 Million Years Ago
Ancient Footprints Show Human-Like Walking Began Nearly Four Million Years Ago
A reconstructed head of Australopithecus afarensis for an exhibit at the Smithsonian's National Museum of Natural History. John Gurche/Smithsonian
