This is CBSI on the world. I'm John Batchewitt. Dan Florence, his new book is Wild New World,

the epic story of animals and people in America. The Clovis culture, so-called, because of where it was identified,

the tools were suggestive of a developing culture, is important first to establish where the sites are

and dance book wonderfully gives us a map

of what's been found so far, they're more defined.

And these are between, around 13,000 years ago.

There's speculation that human beings,

as we, the modern human beings,

we're here before them,

but it's important to establish why Clovis matters.

Dan, it's the tools, it's the hunting skills,

it's the remains of the sites.

Is that why we key on that 13,000 years ago?

It really is all those, all those things you mentioned. As you referred to, we do believe, we're pretty convinced, in fact,

by a set of footprints found in southern New Mexico just four or five years ago,

that people did get here, even before the glacial maximum, 23,000 years ago.

But it looks as if their populations were really small.

And one of the reasons we think that is because when the Clovis migration happens,

and it happens when the ice sheets in North America open sufficiently to allow an

overland migration out of Siberia into what is now Canada and the lower 48 states of the U.S.,

when that happens, this migration takes place with such rapidity that it implies that there's

not really anyone in the way of us.

...