Monday, August 22, 2016

The Death of the Cordillera Ice Free Corridor Hypothesis?

A final blow to myth of how people arrived in the Americas
. . . It all comes down to timing, according to new research published Wednesday in the journal Nature. The ice-free corridor through the Canadian cordillera couldn't have supported human migration until about 12,600 years ago. But the Clovis people were already living south of the ice sheets by 13,500 years ago.

So what did happen?

The broad strokes haven't changed. When the Ice Age lowered sea levels and turned the Bering Strait into a land bridge, ancients migrated from Siberia to present-day Alaska, where they encountered a massive icy roadblock preventing further migrations deeper into the Americas. So the people hunkered down in that small Alaska region, called Beringia, for thousands of years.

It's not as simple as figuring out when the ice-free corridor opened up. The corridor is thought to have actually been open around 15,000 to 14,000 years ago – early enough to predate the Clovis settlements south of the ice (although they would have had to hustle to make it from Beringia to those settlements via the corridor).

But just because there wasn't an ice sheet in their way anymore, doesn't mean that people could have migrated down the approximately 930-mile-long corridor. After being scoured down to bedrock by mile-high ice sheets, it took time for the land to become biologically rich enough to support migrating humans.
Evidence from the rest of the world suggests that it doesn't take much of an environment to support people. There are, or at least were, primitive humans living in the most forbidding environments, from the arctic Greenland to the Kalahari desert.
Plants and animals would have to be thriving along the whole corridor to provide inviting food sources, wood for fire, and other survival needs. Humans venturing out from Beringia likely didn't know what lay to their south, so they wouldn't have prepared for a long journey. They would have simply seen a new region of land to settle.

And, as Meltzer told Nature, "It's 1,500 kilometres. You can't pack a lunch and do it in a day."
No, but supremely practiced survivalists could do it in less time than you think. A few practice round trips by the more adventuresome Beringians, and I suspect that they would be be itching to put together a mission to take the wife(s) and kids to the promised land of milk and honey, or at least mammoths and elk south of the ice.

I think it's a mistake to underestimate the adventuresome nature of mankind.  I'm sure that once the corridor opened, humans were exploring it, looking for something, anything really, they could exploit. And of all the people we know, the Clovis culture may have been the most adventuresome. In the course of a few hundred years, they left their tools over two continents, and then disappeared. It's hard to imagine it was from population pressures, or even lack of resources, as the last of the North American Megafauna were found all over the continent, having never been hunted by man previously and relatively naive to the threat posed by the simian invasive species. Nope, they just had a bad case of wanderlust.

I'm not arguing for the central corridor route over the coastal route. Humans have oriented to water for food and transportation for a long time, and likely had the ability to make canoes capable of long sea trips. However, in the absence of proof that they could not come through the ice free corridor, I would expect the answer to be both rather than one alone.

Wombat-socho snuck in late with "Rule 5 Sunday: Viva Los Lobos!".

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