> Discovering sites along these routes won’t be easy, because most are now likely to be underwater. But this summer, Davis and his colleagues began surveying areas of the Pacific Ocean...<p>It's surprising this was just given two or three sentences, because this is kind of a crux of the argument. If people had done a coastal migration that long ago, they'd be doing it when sea levels were significantly lower, meaning a lot of the evidence is gone at this point. (Something inside me hopes they find something, though.)