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?
What do you think of Murphy’s claims?  Check out our conversation….

Don’t miss our previous conversation with Dr. Murphy!
472: Who Killed the Indians?
471: Strengths & Weakness of DNA Essay/ Comparing Indian & BoM Stories
470: Behind the Scenes of DNA Essay
469: Untold Story of Indian Slavery in America
468: Religious Fights over DNA
467: Native American DNA Scholarship