The long-held theory that early human ancestors in East Asia crafted their tools from bamboo and wood is much more complicated than originally conceived, according to a new study. An experimental research confirms that it is possible to make a variety of bamboo tools with the simplest stone tools. However, rather than confirming the long-held 'bamboo hypothesis,' the new research shows there's more to the theory, says Metin I. Eren, a doctoral candidate in anthropology at Southern Methodist University in Dallas (USA).
     "Our research does not debunk the idea that prehistoric people could have made and used bamboo implements, but instead suggests that upon arriving in East and Southeast Asia they probably did not suddenly start churning out all of their tools on bamboo raw materials either." Eren said. "The importance of experimental archaeology, of replicating the production of bamboo tools with simple stone artifacts, was needed for a long time. Due to successful cooperation in every stage of the experiments with our Chinese colleagues, we managed to demonstrate the potential of a simple stone tool technology to produce many different daily tools made of bamboo," said archaeologist and lead author Ofer Bar-Yosef, professor of Stone Age archaeology at Harvard University.
     Unlike Africa and western Eurasia, where stone tools show increasing and decreasing complexity, East Asia's stone tools remain relatively simple. Stone tool discoveries there have been limited to a few hand axes, cleavers and choppers flaked on one side, indicating a lack of more advanced stone tool-making processes, innovation and diversity found elsewhere, say the authors.
     The lack of complex prehistoric stone tool technologies has remained a mystery. Some researchers have concluded that prehistoric people in East Asia must have instead crafted and used tools made of bamboo - a resource that was readily available to them. It's been suggested that human ancestors during the early Stone Age left Africa with rudimentary tools and were then cut-off culturally once they reached East Asia, creating a cultural backwater. Others theorize a lack of appropriate stone raw materials in East and Southeast Asia. In the new study, however, Bar-Yosef, Eren and colleagues showed otherwise by demonstrating that more complex stone tools could be manufactured on stone perceived to be 'poor' in quality.
     The authors worked with the Archaeological Field Research Station of the Hunan Provincial Institute of Archaeology and Cultural Relics in Shimen, China. The researchers gathered different kinds of cobble-sized rocks and from those rocks, Eren easily replicated flake tools and stone choppers. Using the crudely knapped stone choppers, the researchers developed a simple 'bamboo knife reduction sequence' that could produce 20 sharp, durable bamboo knives in about five hours. Using pork purchased from a local market, the researchers write, they found that the knives easily cut meat, but not hide. In other findings, the authors write that with a simple stone unifacial chopper, Bar-Yosef was able in 30 minutes to easily make a sharp spear that would have been capable of killing an animal. Also, using the replicated stone tools they were able to produce strips of bamboo thin enough for weaving baskets.
     "This unprecedented experimental study by Ofer Bar-Yosef, Metin Eren and colleagues represents a first step in the right direction, to confront a long-standing assumption about early human technological adaptations," said Chauhan, co-editor of the Quaternary International issue in which the article will be published.

Source: Southern Methodist University (7 April 2011)