March 4, 2011
Ancient Tools Uncovered On California Island
Archaeologists have uncovered caches of tools and animal remains from about 12,000 years ago on islands off the coast of California.
The discovery shows fine tool technology and a rich maritime economy existed there.
The tools vary markedly from mainland cultures of the era such as the Clovis.
The finds suggest that early humans may have used coastal routes, rather than a land route, to South America.
A team studying California's Channel Islands has found that the islands show evidence both of differing technologies and a differing diet, even among the few islands.
"On San Miguel island we found a lot of pretty remarkable tools, but the animal materials there were largely shellfish," Torben Rick, an anthropologist from the Smithsonian Institution in Washington DC, told BBC.
"Over on Santa Rosa, that site was dominated by bird remains and a few sea mammal and fish remains... and no shellfish at all."
"What's interesting about that is it shows us not only were these people out there living a coastal life, but they were taking advantage of the full suite of resources available to them; they had a very diversified maritime economy."
The tools discovered are different than those of mainland cultures like the Clovis and Folsom.
Points found on the islands are thin, serrated, and have barbed points, which shows striking workmanship for the period.
Inland tools had fluted points and they were known to be used to hunt large animals. The island points were so delicate that scientists believed they were used to hunt fish.
"These are extremely delicate, finely made tools that don't occur later in time," Rick told BBC. "Finding these types of tools at all three of these sites really suggests a similar group of people, in terms of technology and subsistence - and were pretty different from what came later."
Rick said the evidence supported the idea that the islands were short-term or seasonal encampments, rather than permanent settlements.
"The Coso obsidian source [is] on the mainland a couple hundred miles away, so we know they were participating in long-distance exchange networks," he told BBC.
Scientists believed that after reaching North America through the Bering Straits off Alaska, a concerted push southward led early humans including the Clovis culture across inland parts of the continent to South America.
However, anthropologist Tom Dillehay of Vanderbilt University said that the Channel Island finds were part of a mounting body of evidence against that theory.
"What they tell us is that there was widespread cultural diversity at the outset of human entry and dispersion throughout the Americas, and that the old, now-dead Clovis first model often misleads us to believe that there was only one major way of first human expansion throughout the Western Hemisphere," he told BBC News.
"As today, there are cultural continuities but there also is constant change, which is well evidenced by these and other sites being discovered throughout the Americas. As more research produces more sites, we will see that the story of the first Americans is not linear and that there will continue to be more surprises."
"As I have published and said before, there were probably many different migrations and many different migration routes overland and along the coastal ways, and this evidence is pointing in that direction too."
However, Rick said that it was too early to upend the larger picture of human migration across the Americas, and that further discoveries could shed more light on the story.
"My colleague Jon Erlandson refers to them as 'postcards from the past'," Rick told BBC. "They give us just a brief snapshot of 'hey, we were here and here's what we were doing for a brief period of time'.
"We have to be a little cautious in our interpretations; we're trying to put together a puzzle, and the puzzle may have 150 pieces and we've got five of them. So it's really difficult to get the full picture of what they were doing."
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