History of peopling the world

The Guardian has a story, with links to the journal Nature, on a newly reported site in Mexico that claims new evidence of human presence in the Americas substantially older than has been expected.  It's only a assemblage of what are interpreted as stone tools.... and I've heard a lot of archaeologists say one always needs better evidence than just a bunch of broken stones that might have been worked by human hands.  But these tools could be 30,000 years old.

But it's potentially another data point in a growing assemblage of sites that undermine the idea that human presence in the Americas goes back about 14,000 years.The real population explosion in the Americas may well dates to about that time, involving people of Asian origin whose DNA endures in indigenous Americans today.  But evidence accumulates that there were a few people here sooner, mostly along the Pacific coasts of the Americas, 25,000 and more years ago -- during the last glacial maximum. The Nature story cites more than 40 refereed publications that support the hypothesis.

I made an Ideas documentary on this subject so long ago there isn't even a digital record available. The subject has come a long way since then.