Sharp stones found in India signal surprisingly early toolmaking advances

Homo sapiens didn’t introduce the technology after all, excavated artifacts suggest

stone tools

ROCK ON  Excavations at a site in India yielded these sharpened stones, among others. The find indicates that hominid populations there made big changes in toolmaking starting around 385,000 years ago, before Homo sapiens left Africa.

Sharma Centre for Heritage Education, India

Stone-tool makers in what’s now India redesigned their products in a revolutionary way much earlier than previously thought.

Excavated stone artifacts document a gradual shift from larger, handheld cutting implements to smaller pieces of sharpened stone, known as Middle Paleolithic tools, by around 385,000 years ago, researchers say. That shift mirrors a similar change seen in tools from a variety of hominid populations in Africa, Asia and Europe between about 400,000 and 200,000 years ago, including African Homo sapiens and European Neandertals.

Unlike earlier populations, Middle Paleolithic toolmakers followed a set of steps to prepare chunks of rock, or cores, before pounding off sharp tools, or flakes. Until now, many researchers had assumed that the transition from tools such as hand axes, which emerged in Africa nearly 2 million years ago, to Middle Paleolithic implements happened in South Asia between 140,000 and 90,000 years ago. At that relatively late date, H. sapiens populations experienced at making Middle Paleolithic tools would have been leaving Africa, and perhaps introduced the skill to South Asia.

The new finding suggests, however, that some humanlike populations reached South Asia shortly before H. sapiens even appeared in Africa, which possibly occurred around 300,000 years ago. Newcomers mingled to varying extents with local groups, introducing new toolmaking approaches, researchers propose online January 31 in Nature. Locals then developed their own variations on Middle Paleolithic tools, says a team led by archaeologists Kumar Akhilesh and Shanti Pappu, both of the Sharma Centre for Heritage Education, India, in the city of Chennai. Major changes in Stone Age toolmaking in the area were less dependent on movements of H. sapiens out of Africa than investigators have often proposed, Pappu contends.

Still, “we cannot be sure who made the Attirampakkam tools, because we lack fossil [hominids] for this time period in India,” Pappu says.

She and her colleagues studied about 7,200 stone artifacts unearthed at a site in southeastern India called Attirampakkam, mostly from 1999 to 2004. The finds range in age from roughly 385,000 to 172,000 years ago. Previous excavations at Attirampakkam, directed by Pappu, uncovered stone hand axes and other implements ranging in age from 1.77 million and 1.07 million years ago (SN: 4/23/11, p. 12). It’s unclear whether Homo populations lived at or near Attirampakkam between around 1 million and 385,000 years ago, Pappu says. Hand ax sites from that time period have been found elsewhere in India.

Populations that preceded H. sapiens likely reached India and developed regional versions of Middle Paleolithic tools over several hundred thousand years, says archaeologist Michael Petraglia of the Max Planck Institute for the Science of Human History in Jena, Germany. Genetic evidence suggests H. sapiens spread across South Asia only after 60,000 years ago, possibly influencing toolmaking techniques of the region’s native Homo populations only at that late date, Petraglia suggests.

Stone-tool making in South Asia, as in Eurasia (SN: 11/1/14, p. 8), evolved in complex ways among relatively small groups belonging to the Homo genus that were spread across the landscape and occasionally came in contact with each other, says archaeologist Daniel Adler. Those scattered, humanlike populations shared a common toolmaking ancestry, “but perhaps little else,” contends Adler, of the University of Connecticut in Storrs. Middle Paleolithic tool innovations, as a result, developed in fits and starts.

Bruce Bower has written about the behavioral sciences for Science News since 1984. He writes about psychology, anthropology, archaeology and mental health issues.

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