According to the Gospel Topics essay, the reason why Middle Eastern DNA isn’t found among Native Americans is because the Nephite/Lamanite DNA was dwarfed by a large population.  Dr. Thomas Murphy takes issue with that, but he does acknowledge that DNA can be lost.

GT:  Are you saying that it is possible to lose DNA, like the Incan boy and the Vikings and Egypt?

Thomas:  It’s possible for DNA lineages to go extinct. Yes.

GT:  Okay.

Thomas:  That’s definitely possible. It’s documented, no doubt about it. And so it’s possible for a small population to have come to the Americas, and if they did not do much interbreeding with others, and for some reason, like the Vikings ended up leaving, and it’s possible that there’s not a lot of genetic evidence of that. But the problem with that scenario is that’s not the story the Book of Mormon tells. The Book of Mormon tells a story of a population that arrives here and grows exponentially into hundreds of thousands, millions in the case of Jaredites, of people. When you have that population explosion, you’re not going to lose your genetic signature. Now, they tried to say, “Well, if they intermarried, if there was a large amount of intermarriage, it might swamp out the genetic signature. But again, as we discussed earlier, there’s not Book of Mormon evidence for that.  There’s not evidence in the Book of Mormon suggesting that that actually happened. It’s theoretically possible, but then we have to stop and say–let’s suppose we look at a mitochondrial lineage that disappears, like that Incan example. Well, what about the Y chromosome? What about nuclear DNA? What about the DNA of our gut microbes? What about the DNA of the ants of the animals and plants we brought with us? So, the essay makes a big emphasis on a couple of principles of population genetics, things like gene flow, genetic drift, mutation, or, excuse me, a founder effect, and suggests that these sorts of changes in the gene pool may explain the loss of DNA. But if we look at those practices, those are largely random practices, or largely random phenomenon, that you might randomly lose, one lineage doesn’t get passed on. What we see is across the genome, of not just humans, but our gut microbes, our dogs, our other domestic animals, and what we see [is] the same story being told across that group of gene pools. If we have a random event eliminating one mitochondrial lineage, we still have our paternal heritage. We still have all of our nuclear DNA. We still have our gut microbe DNA. We still have the DNA of our domesticated plants and animals. Random events don’t affect all of those at the same time in the same way, all resulting in extinction. Does that makes sense?

We’re concluding our conversation with Dr. Thomas Murphy.  Last time we talked about why modern Egyptians don’t match current Egyptians.  Dr. Murphy says a similar case arises with Native Americans.  We talk about how Native Americans migrated from Asia, and how long they’ve been in the Americas.

Thomas:  The dating of the entry into the Americas is hugely debated. There’s some archaeological evidence suggesting 130,000 years ago, but the DNA evidence suggests that indigenous people were separated from their closest Asian relatives around 30,000 years ago. Then, we’re finding more and more archaeological evidence pushing that date of the migration back. But our challenge is that not a lot of fossils older than 12,000 years old are in the Americas. There’s some archaeological sites and stuff that we found in the Americas that are older than that. But, the DNA suggests that the ancestors of the American Indians have been here longer than anthropologists typically thought, maybe used to think. So, now we’re much more open to the idea that people were here before the Ice Age. It’s really the ice age that is kind of the controlling factor there.  The assumption of most anthropologists before the rise of DNA evidence, was that people came after the melting of the ice, the end of the ice ages, so that would put it after 12,000 years ago, that the ancestors American Indians came.  Just down the road from me, there’s a mastodon that’s got a stone point embedded in the bone that’s older than the ice ages, 13,000 years old. So, how did it get there if there weren’t people? Most definitely, I think we can say now that people arrived here before the ice ages. That raised the point of how did they get here? Because that idea before was that there was this land bridge and then there was an ice-free corridor between two of the glaciers that opened up, and that people must have come down through that ice free corridor.

GT:  The Bering Strait, right?

Thomas:  Yes. They actually looked at the ice-free corridor and looked at the ecology of it using this environmental DNA work. The plants and animals weren’t there to sustain people early enough for that to be a viable entry point for people into the Americas.  So, from my perspective, that’s been refuted.

GT:  Whoa. There’s not a land bridge? They had to come a different way, not on the land bridge. Is that what you’re saying?

Thomas:  They had to come from Asia, because that’s where the relatives are. But coming through an ice-free corridor, from basically the Beringia through an ice-free corridor into the Americas, we know that’s wrong now.

What do you think of Murphy’s claims? Were you aware of the new theory of how ancient Asians populated the Americas?