Tuesday, February 27, 2007

Very Early Americans

In an enormous variety of distinct fields of inquiry the same general pattern is becoming clear: there is no such thing as "right," the very concept needs to be replaced with "progressively less wrong." ~ Paul Grobstein

A Clovis point (about half way down the page) is a lovely piece of craftsmanship. Named for Clovis, New Mexico, where the first examples were found, it has also been considered to be the signature of the first people to come to the North American continent some 11,500 years ago. According to this theory, people came across the Bering land bridge near the end of the last Ice Age, found an ice-free corridor, and followed it into more temperate climes on the North American land mass. This group spread rapidly from the north to South America, thanks in large part to the advantages provided by the Clovis points which they developed.

A neat and tidy theory to be sure, but one that has been reconsidered of late thanks to recent discoveries and re-evaluations of old ones.

For starters, the idea of “ice-free corridor” has been considered a questionable way for anyone to get here. Tom Koppel's book Lost World points out that such a route would be difficult from a survival standpoint. There may be little or no ice, but there would also be little or no game to be had either. A trek of the length proposed would be difficult to imagine without sources of food. Mr. Koppel's own theory involves an earlier incursion, perhaps 13,000 to 14,000 years ago.

In Mr. Koppel's view, supported by evidence from digs along the Alaskan and Canadian coast, is that the immigrants came by boat, along a shore line that was ice-free. They would have fished and hunted, stopping on islands or on exposed shorelines when necessary. Much evidence, according to Lost World, is underwater now, because the water levels were much lower due to glaciation.

Then there are the Peruvian sites of human habitation that date from around 12,000 years. Even assuming some degree of uncertainty in the 11,500 year time frame, it is virtually inconceivable that humans could have progressed the length of North America and settled in South America in, say, a 500 year period.

Even the Clovis point is now being questioned. In a new paper, Michael Waters has reviewed the carbon dating of Clovis finds. Methods get better, and carbon dating is more sophisticated now, with considerably smaller error bars than in years previous. The Clovis period, it seems, was only about 300 years long, which is far too short a time to account for the spread of humans throughout the two continents. So, according to Mr. Walters, scientists should be looking for earlier tools, earlier habitations.

Perhaps they've found some. In Walker,Minnesota, archaeologists have found what appear to be stone tools of a more primitive make than Clovis. They date to 13,000 to 15,000 years ago. The problem is that even to those who found them, “they don't look like much.” This is always a problem with looking at a previously unknown primitive tool. Louis Leakey felt he had found such tools in the Southwest but was later found to be in error in the opinion of most scientists. These tools may yet turn out to be a disappointment.

But, if they are real, did these people come down the ice-free corridor, despite Mr. Koppel's theory that it was a sterile no-food zone?

There's another wrinkle about the Clovis points. One would expect to find some sort of pre-Clovis architecture in Siberia, where the North American settlers were supposed to have originated. In fact, nothing of the sort has been found there. But, it turns out that in France, there was a culture referred to as the Solutreans, who made points that appear to be direct precursors of Clovis. Some think it's possible that this group made their way across the Atlantic, pausing on the ice when need be, coming to North America as the true first settlers.

In fact, settlements have been found in the eastern United States, that may be older than Clovis. One has even yielded a point that appears to be a transition between the Souletrean point and Clovis. But it is always risky to form theories on a single data point.

It is intriguing that we seem to know more about the movements of the Neanderthals than we do modern humans in the New World. But, given that some of the most critical evidence may be underwater, that may be understandable. Techniques for finding such evidence is improving, and obviously, given finds in the eastern U.S. and in Minnesota, there are still finds of consequence to be located on dry land. There's only one choice for the archaeologists.

Yea, verily, dig they must.

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