I've already written about this recently, and also earlier, and see also Steve Smoot's excellent DNA and the Book of Mormon article. But here comes yet another bit of scientific discovery that blows this limited and antiquated Beringian population group idea out of the water.
Brazilian rock shelter proves humans inhabited Americas 23,000 years ago
"The “First Americans” are usually believed to be East Asian migrants that crossed the Bering Straits 15,000 years ago, members of the Clovis Culture (a reference to their stone tool technology). A small number of researchers have suggested that an earlier group of migrants, from Europe’s Solutrean culture, arrived in North America a couple of millennia before these Clovis settlers, a hypothesis which was hotly disputed by academics...
It now appears that researchers favoring both the Clovis and Solutrean models have got it all wrong and supporting the claim of “First Americans” should be given to a mysterious population living in Brazil over 23,000 years ago."
While there is still some reasonable doubt about the Solutrean (European) arrival and whether it was before or after the Beringian/Clovis culture, it's hard to find a way to refute the findings of the Brazilian site.
"Scientists utilized three separate dating methods to investigate samples of charcoal, sediment, and the sloth bones. The revealed dates securely place people at the Santa Elina site well over 23,120 years ago. Humans groups abandoned the site after a short period, but later groups utilized the rock shelter again between 10,120 and 2,000 years ago...
The new dates from Santa Elina further erode the consensus understanding that the first modern humans reached the Americas by walking across the land bridge between Northeast Asia and North America 15,000 years ago. The rock shelter is thousands of miles from the proposed entry site.
Not only is Santa Elina located far from even the earliest Clovis sites, it is also over 1,000 miles from the Brazilian coast in a heavily forested region. This seems like an unlikely first point of entry as it is logical to suspect that humans lived initially along the coastline before moving into the Brazilian interior by 23,000 years ago. This would seem to offer further support to claims that modern humans were in Brazil long before even this early period."
Again, what people thought they "knew" for certain is being upended by new findings. This is why when people say to me that there is no proof (such a sloppy word) or evidence (better) that there were Nephites or Lamanites or Jaredites or any connection whatsoever between ancient America and the Middle East, first I tell them all the new stuff we're finding followed by "and wait until you see what else the Lord will eventually reveal."
By faith and also by reason. That is how truth is discovered.