By Michael Balter
Science NOW Daily News
18 December 2009

"A tidy house, a tidy mind." Some of the more slovenly among us might bristle at this scolding old proverb, but to human evolution researchers it makes perfect sense. One of the hallmarks of modern behavior is the sophisticated way Homo sapiens organizes the spaces it lives in, with everything in its place. But new work at a nearly 800,000-year-old hominin site in Israel suggests that the roots of tidiness may lie deep in our evolutionary past.

Prehistoric humans did not start building permanent dwellings until about 15,000 years ago, but earlier hominins--the term now commonly used by scientists for humans and their ancestors but not other apes--frequented caves and open-air sites as they hunted and gathered food. Whereas sites occupied by modern humans often show signs of separate "activity areas" such as hearths, stone-tool knapping areas, food preparation areas, sleeping areas, and so forth, not so long ago there was little evidence that other hominins engaged in such organized behavior.

More recently, however, work at Neandertal sites has demonstrated that our evolutionary cousins also divided up their living spaces into activity areas. New research at rock shelters like Abric Romaní in Spain and Tor Faraj in Jordan, where Neandertals lived between 50,000 and 70,000 years ago--before modern humans migrated into Europe and Asia--has demonstrated spatial organization at times indistinguishable from that typical of H. sapiens. Now, a team working at Gesher Benot Ya'aqov (GBY), a 790,000-year-old site in northern Israel's Hula Valley, claims that a much older species also showed tendencies toward tidiness. GBY is thought to have been occupied by H. heidelbergensis, a species that may have given rise toH. sapiens in Africa and the Neandertals in Europe. It is also the site of the earliest widely accepted mastery of fire by prehistoric humans.

The researchers, led by archaeologists Nira Alperson-Afil and Naama Goren-Inbar of the Hebrew University in Jerusalem, mapped the precise locations and densities of thousands of plant and animal remains as well as stone tools found in one of GBY's 14 archaeological levels. The excavated area, a long strip covering about 26 square meters, had been covered rapidly by lake sediments in ancient times, thus preserving the remains in place.

The team found that hominin activities were concentrated in two main areas at opposite ends of the strip. Knapping of stone tools made from flint was concentrated in the northwest area, while production of tools made from basalt and limestone was concentrated around a hearth in the southeast. There was also a clear pattern of animal and plant remains. For example, remains of crabs consumed by the hominins were clustered around the hearth, as were the remains of nuts and stone tools, such as anvils and choppers, suitable for cracking them open. On the other hand, fish bones were found in two clusters, one at each end of the excavated area.

The team concludes, in its report on the findings in the 18 December issue of Science, that the GBY hominins' division of their living space into designated activity areas is a sign of "sophisticated cognition" once thought to be the special preserve of modern humans. Clive Gamble, an archaeologist at Royal Holloway, University of London, says the new work confirms other research showing that H. heidelbergensis "was a very tidy species." At the 500,000-year-old site of Boxgrove in southern England, Gamble points out, "across a landscape with no hearths they followed rules about where to get, make, and throw away their stone tools. There was nothing random in these activities, and GBY now extends this pattern back in time."

But Lyn Wadley, an archaeologist at the University of the Witwatersrand in Johannesburg, South Africa, sounds a cautionary note. "The GBY site is remarkable and the use of space there is more complex than one might expect for the age of the occupation," Wadley says. But she thinks it would be a sure sign of sophisticated cognition only if the GBY hominins had attributed symbolic meanings to the way they divided their living quarters—something the research team has yet to demonstrate.

http://sciencenow.sciencemag.org/cgi/content/full/2009/12