Peking man—the group of early humans whose 1920s discovery gave a big boost to the theory of evolution—lived hundreds of thousands of years earlier than previously believed, a new study says.
Some researchers believe the discovery hints at two separate migrations of Homo erectus (of which Peking man is a subspecies) out of Africa: one into northeastern China and another into Southeast Asia.
The new dates would also place Peking man in a more hospitable, cooler time period in China's Zhoukoudian region, which today is the world's foremost source of Homo erectus fossils.
Obtained by measuring the decay of isotopes in buried quartz grains, the data suggest Peking man lived at Zhoukoudian about 750,000 years ago—200,000 years earlier than prior estimates, according to the study, led by Guanjun Shen of China's Nanjing Normal University.
(Related: "Ancestral Human Skull Found in China.")
Fork in the Road
The findings could redraw the map of Homo erectus's journey out of Africa, suggests anthropologist Russell Ciochon, of the University of Iowa, who published an accompanying analysis of the study (both papers appear in today's issue of the journal Nature).
Based on the new research, Peking man likely inhabited China at roughly the same time as other Homo erectus groups, Ciochon said.
Ciochon hypothesizes that a prolonged mass migration of Homo erectus from Africa, which began about two million years ago, eventually came to something like a fork in the road.
Reaching southern China, the early humans would have come upon a subtropical forest, which would have proved uninviting to Homo erectus, who were accustomed to savanna and open woodlands, Ciochon suggests.
One group probably turned southeast and settled in Southeast Asia, he said.
A second group likely turned northeast and moved into what is now China. Part of the group settled the Zhoukoudian region and eventually evolved into the Peking man subspecies, Homo erectus pekinensis.
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