Bruce Bower, Science News, June 6, 2011
Early members of the genus Homo, possibly direct ancestors of people today, may have evolved in Asia and then gone to Africa, not vice versa as many scientists have assumed.
Most paleoanthropologists have favored an African origin for the potential human ancestor Homo erectus. But new evidence shows the species occupied a West Asian site called Dmanisi from 1.85 million to 1.77 million years ago, at the same time or slightly before the earliest evidence of this humanlike species in Africa, say geologist Reid Ferring of the University of North Texas in Denton and his colleagues.
The new Dmanisi discoveries point to an Asian homeland for H. erectus, the scientists propose online June 6 in the Proceedings of the National Academy of Sciences.
Evidence remains meager for the geographic origins of the Homogenus, says anthropologist Bernard Wood of George Washington University in Washington, D.C. Several scenarios of Homo evolution are possible, and it’s possible that humankind’s genus got its start in Asia with H. erectus.
With the new Dmanisi dates, “it certainly looks as though the African origin of H. erectus must be reconsidered,” remarks Harvard University anthropologist Philip Rightmire.
The new Dmanisi discoveries come from just beneath soil that previously yielded 1.77-million-year-old H. erectus fossils, including skulls with surprisingly small brain cases suggestive of an early form of the species (SN: 9/22/07, p. 179). Excavations produced 73 stone tools for cutting and chopping, as well as 34 bone fragments from unidentified creatures. The artifacts came from a series of H. erectus camps at Dmanisi between 1.85 and 1.78 million years ago, the scientists say.