Not necessarily. I mean, if some of those who had emigrated to the New World from Europe 26,000 years ago had then returned to Europe after some more  millenia of adaptation, then presumably, Europeans  would have adapted to New World foods like potatoes. And, of course, since scientific data from the Palaeolithic era is extremely sparse, we might well find, in a few decades, that those dates given were wrong, and that human colonisation of the New World went even further back.

Geoff



"But the big killer here 
is none of those early paleo people that made it to the New World 
were our ancestors."