Peking Man Lived 200,000 Years Earlier Than Thought
for National Geographic News
|March 12, 2009|
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.
(See an interactive map of ancient human migrations.)
The Peking man subspecies is believed to have walked fully upright, used sophisticated stone tools, and sported a brain three-fourths the size of a modern human's.
They Came for the Game?
In northeastern China during the newly suggested time period, Homo erectus would have likely found a food-rich region similar to the landscapes the species had been accustomed to.
Before Homo erectus' arrival in the Zhoukoudian region, "we think the climate got cooler and drier and maybe moved more toward grasslands, which would attract more game and, in turn, human hunters," Ciochon said.
"And there is every reason to believe that Peking man was eating meat." Telltale animal bones have been found at Peking man sites, for example.
New York University paleoanthropologist Susan Antón said she doesn't believe the new data provide evidence for two migrations into Asia.
"It's certainly possible that there were two migrations—or six or nine," said Antón, who was not involved in the new study.
"But in order to talk about that, you would really need to have some evidence along the routes of those pathways and also some sort of anchor point in Africa" that ties both migrations to a single origination region, she said.
Antón did suggest that, by shifting Peking man to the same, earlier time frame as fellow Homo erectus subspecies, the study helps solve a longstanding scientific mystery.
"It was always a bit puzzling as to why you'd have them persisting until relatively late in continental Asia," she said, "when you didn't really see them persisting, for example, in Africa."
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