How all the Stone Age people learned the same tricks at the same time.

Nature examines – and possibly answers – a long-standing archaeological puzzle. How did a bunch of unrelated paleolithic people in different parts of the world develop the same technological tricks at the same time? They didn’t have little caveman radios, did they? No. It might just be that it steam engines when it’s steam-engine time, and we all figure out how to cut rocks when it’s rock-cutting time:

In the 1990s, archaeologists proposed that the Levallois method first evolved in Africa, and that it became widespread after a group of hominids migrated to Europe and Asia and carried it with them…. It assumed that the superior method would quickly replace the simpler bifacial technique that had been used for the previous million years.

But the idea was controversial because it invoked an unproven migration of unknown hominids out of Africa, and did not explain why some Levallois tools found in Eurasia are smaller, or otherwise different, from African ones.

The latest research, led by palaeolithic archaeologist Daniel Adler at the University of Connecticut in Storrs, is based on an excavation at Nor Geghi between 2008 and 2009.

Using chemical analysis they were also able to work out that the obsidian (a type of volcanic rock) that the Stone Agers used for tools came, in part, from various local sources, but also from sources up to 120 kilometres away. But the team was particularly surprised to find a mixture of tools made using both technologies.

“We wouldn’t have found this mixture if the Levallois technology had simply replaced the old method,” says Adler. “The communities probably worked out for themselves how to make bifacial tools and then it was a short step to the Levallois method.”