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?
Wheat & Tares 
Murphy did not mention the possibility that Asians arrived in the Americas on space ships, a serious oversight.
Zero diff between Biblical & BoM literalism: if you believe large Semitic populations in Americas there should be no doubt that the whale actually swallowed Jonah.
I had no idea that we could trace the DNA of gut microbes. I had not heard the theories he put forth, which were very interesting. It seems that new archaeological findings are challenging old theories (some of which aren’t even that old) on a regular basis. But that being the case, why should we expect Joseph Smith’s theory about the ancient Americas to remain intact through all of these new archaeological and scientific discoveries?
I hear believers often prose themselves in saying that the textbooks are always changing and that the scriptures and doctrine remain constant. But shouldn’t things be like the former? Shouldn’t we treat all knowledge as somewhat tentative and be willing to adjust how we explain things in light of new findings?
If you believe the BOM is literally a historical document, like most TBMs, then you have to try to resolve these DNA issues. You end up playing a lot of mental games trying to work out the possibilities. I’m not being critical of those types of people…I used to be one myself and I made a lot of effort to figure it out.
If, on the other hand, you believe the BOM is a product of JS’s time, you become liberated from all the homeland vs Mesoamerica debate. You are free to actually believe in the foundations of DNA science without trying to undermine it. You are free to travel to Mexico and Central America and enjoy the sites without trying to retrofit them into the BOM.
I guess what I’m saying is that people like me have the luxury now of sitting back with popcorn and enjoying others debate science and history in a way that seems kind of silly. Again, I don’t mean to be disrespectful. I used to be in the middle of those debates.
Separated out, the DNA component of the “where did BoM peoples come from” question will probably remain in dispute because DNA evidence is difficult to fully understand and there will probably always be a believing member who provides a morsel that feeds the belief of many members. The more compelling question to me is the one Thomas asks about how to possibly reconcile the BoM narrative with the argument that Jewish DNA was fully subsumed by Native American DNA. If Nephi, etc., were fully absorbed by the locals to the point that no archeological, linguistic or DNA evidence can be found now, then how could the BoM story be remotely accurate? In my mind, it cannot, but the book is still an impressive feat of creativity, memorization and continuity.
Great point jaredsbrother. To your post question, Rick, what theory is Murphy proposing beyond the Beringia migration? Murphy seems pretty confident in the quote you shared that the Beringia migration is completely refuted. Is that really his position?
My understanding is that most scholars who study this accept a majority Beringia migration but possibly with some additional boating migrations from Asia along the coast. The reason they’ve expanded beyond Beringia only is because there is evidence of some early colonies before the last glacial maximum when migration through the Bering strait would have been easiest. Some of these early colonies extend as far as south america, challenging the migration patterns you’d typically see spreading gradually from north to south. How to account for some early colonies so early and so deep into the continent? And thus, additional theories of coastal migration possibly using boats was born, but it’s important to realize that there isn’t any direct physical evidence for this (that I’m aware of) other than the existence of the early colonies themselves.
At least Murphy is still accepting Asia migration rather than some of the really “out there” theories like the Solutrean hypothesis, which posits that Europeans came across the Atlantic via polar ice cap migration as the first migrations around 15000 years ago.
How exactly those early migrations occurred is a but irrelevant to BoM historicity questions, since the overwhelming consensus (beyond fringe ideas like the Solutrean above) is that all natives from north america to the tip of south america came originally from Asia starting at least 15000 years ago and no genetic evidence has challenged that to date.
And as Murphy and jaredsbrother point out, the most recent apologetic stance that reduces the Lehites to a small group of Israelites who were completely absorbed by a much larger society not only has absolutely none of the expected physical evidence, but also is refuted by the narrative presented in the BoM itself.
That is for the article, very interesting. In my literal believing days I used to get caught up in this. Read everything I could that “proved” God was scientifically findable or that the BofM was historically accurate. I gave up. There’s simply no way to prove the BofM is an account of actual real live people.
And, on the days I believe in God, I don’t think He wants us to prove His existence or the BofM is a history book. Faith means much more if you do what’s right because simply because it’s good and virtuous, regardless of who’s keeping score.