How did ancestry related to MA-1 get from the Mal’ta region of south-central Siberia into the Americas?

The answer involves Beringia — the vast, now-submerged landmass that connected Siberia to Alaska during the Last Glacial Maximum when sea levels were low enough to expose the continental shelf.

Beringia was not a narrow land bridge in the popular imagination sense.

At its greatest extent, it was a broad, flat, grassy expanse extending roughly 1,500 kilometers from north to south — not a corridor but a continent-sized landscape.

It was inhabited by the same kinds of animals found in the Siberian steppe-tundra: mammoths, horses, bison, and the predators that followed them.