The "Bering Strait theory" has long suggested that humans walked across the space between modern-day Russia and Alaska during a glacial period when sea-level was decreased.
And they did; but the new evidence suggests that the narrative is incomplete....
There seems to be evidence of human population in the Americas from at least 30,000 years ago. It's odd, because that's quite ancient (for the Americas) and because these old settlements are near the southern extremity of what is now called South America.
Standard theory of the population of the Americas has been that folks crossed from Asia via the Bering Strait, a narrow and shallow bit of ocean between Asia and America.
Certainly, most Americans before Columbus came via the Bering Strait. But to think that they walked all the way to Chile before leaving any material culture seems a bit imaginative.
Monte Verde is the site of an archeological discovery in Chile for which many accept a 12,500-year-old dating. This, already, is quite a bit older than the discoveries in and around Clovis New Mexico, which supported an earlier theory based upon human passage across the Bering region during brief periods of decreased sea-level.
The Clovis site bore evidence of human occupation about 11,500 years ago later and far north of Monte Verde.
A deeper layer at the site of the Monte Verde excavation produced material that appears to be more than 30,000 years old. Some dispute the methods used in the investigation, and/or the conclusions drawn therefrom. But if the interpretation is valid, it is evidence of human activity that is truly ancient by standards of the accepted models of human immigration to the American continents.