Toolmaking folk went east early: hand ax innovators reached India 1.5 million years ago.
Finds unearthed in southeastern India offer a cutting-edge revision of hominid migrations out of Africa more than i million years ago that spread pivotal toolmaking methods.
Makers of a specific style of teardrop-shaped stone hand ax, flat-edged cleavers and other implements that originated in Africa around 1.6 million years ago (SN: 1/31/09, p. 11) reached South Asia not long afterward, between 1.5 million and 1 million years ago, say archaeologist Shanti Pappu of the Sharma Center for Heritage Education in Tamil Nadu, India, and colleagues.
Rather than waiting until around 500,000 years ago to head into South Asia, as many researchers have thought, the African hand ax crowd wasted relatively little time before hightailing it to India, Pappu's team concludes in the March 25 Science.
Archaeologists categorize stone hand axes and related implements as Acheulian tools. Most researchers regard Homo erectus, a species that originated around 2 million years ago, as the original brains behind Acheulian innovations.
"Acheulian toolmakers were clearly present in South Asia more than 1 million years ago," Pappu says. Several previous excavations in different parts of India have also yielded Acheulian tools, but these finds lack firm age estimates.
No fossil remains of hominids--members of the human evolutionary family- turned up among the new tool finds.
H. erectus must have rapidly moved from East Africa to South Asia, proposes archaeologist Robin Dennell of the University of Sheffield in England. Pappu's new finds raise the possibility that 800,000-year-old hand axes found in southeastern China (SN: 3/4/00, p. 148) indicate the presence of H. erectus groups that came from South Asia--or at least exposure of Chinese hominids to Acheulian techniques, Dennell writes in a commentary in the same issue of Science.
Until now, scientific consensus held that Acheulian toolmakers, presumably H. erectus, reached the Middle East at least twice, about 1.4 million and 800,000 A years ago, but went no farther. In this scenario, another species of Acheulian-savvy hominids, Homo heidelbergensis, then took Acheulian tools from Africa to both South Asia and Europe about 500,000 years ago.
Philip Rightmire isn't surprised by the sign of an earlier arrival of H. erectus in India. Other evidence suggests that H. erectus left Africa and reached several destinations in Asia beginning at least 1.8 million years ago, wielding simple chopping tools. "For now, it's enough to say that Homo erectus introduced Acheulian tools to India," Rightmire says.
The latest finds come from the Attirampakkam site, which has yielded more than 3,500 Acheulian artifacts, including 76 hand axes and cleavers. Measurements of radioactive
isotopes in six quartz tools unearthed there indicated that these finds had been buried about 1.5 million years ago.
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|Date:||Apr 23, 2011|
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