I thought this was interesting: scientists from the University of Oregon have found artifacts indicating a seafaring and fishing economy operating in the early Amerindian civilizations in the area, indicating an age of approximately ten thousand years ago.
What interests me here is that if one combines this data with the data presented in my friend Igor Witkowski's Axis of the World, a fascinating study of the great antiquity of Indian civilizations in the Americas, one is getting even more indicators of problems with the old land bridge theory. Witkowski mentions in his book the remains of apparent civilization in southern Chile that are possible as old as 15,000 years, including pottery and tool-making. One need only contemplate such sites, and the apparent technological prowess of whatever civilization as built the massive - and self-evidently machined - remains of Tiahuanaco and Puma Punkhu in Bolivia, to see the nature of the problem.
Bluntly stated, it is this: the civilizations of the Americas were of a much higher order than the standard land bridge theory will allow, and they are also of greater antiquity than would seem to follow logically from that theory. There is an additional problem, one that Witkowski also mentions, namely, that one would expect, on standard models of human progress, to find civilization more advanced in North America rather than South America, but the reverse is true. It would appear that civilization spread from South to North, rather than vice versa as the standard model would have it.
Witkowski theorizes that this represents the spread from the Indian sub-continent, through Polynesia, and across the southern Pacific ocean, rather than the standard land-bridge theory. And that, of course, requires navigation and seafaring capability. Of course, the artifacts in California are a long way from proving such a seafaring capability, but neither do they counter it. Their antiquity, moreover, falls into the broad time frame of Witkowski's argued speculations.
There's one more thing that should be mentioned here, and that is the various Native traditions - from South to North America - that mention they came from some civilization that suffered a cataclysmic flood. If this is beginning to sound a bit like Atlantis, it is, except there is one major problem, and Witkowski also point this out. In Easter Island, the traditions speak of a cataclysm in the Western ocean, i.e., the Pacific. Whereas in Meso-America, Aztec tradition describes this as something occurring in the eastern ocean, i.e., the Atlantic. One need not be reminded here of the ruins of Nan Madol in Polynesia, with their mysterious roads that disappear into the ocean only to reemerge on islands sometimes hundreds of miles away, nor need on be reminded of the Bimini Road in the Caribbean. Slowly, but surely, we are finding things that are challenging the standard models... the vast work of a new synthesis into a new model, remains.