Amazonians share an unexpected genetic link with Asian islanders,

[Yo_Mama]

2. It does seem to be in Aleutian groups

As part of a study tracing the timing of humans’ migration across the Bering land bridge, Eske Willerslev, an evolutionary geneticist at the Natural History Museum of Denmark in Copenhagen, and his colleagues also noticed the link. But they contend that Australasian DNA reached the Americas less than 9,000 years ago. They discovered traces of Australasian ancestry in contemporary Aleutian islanders living off the coast of Alaska and propose that ancient Aleutians introduced the DNA into other Native American groups after the islands were first settled. Their study is published in Science1.

That's a different study which separately found a similar kinship, but in a different group.

Studies are continuing.

My guess is that this is probably a boat faring culture, which would explain the wide dispersion. Also it's evident that Native American DNA is under sampled to represent true diversity in the population.

The earlier dating is probably better.