Population genetics is an exciting, cutting edge area of research. In the past we had a fairly simplistic picture of our deep history, with humans migrating out of Africa and then sequentially expanding from continent to continent. However, occasional findings of very early human remains, combined with the genetics revolution, paints a completely different picture of turbulent demographic back-and-forths with extinctions, conquests, deportations, and uprooted wanderings. Since writing came on the scene relatively late, most (chronologically speaking) of our history as a species is written down not on paper, but literally in our blood, whether it’s the history of mass sexual enslavement of Irish women by Viking raiders or the remote San people of South Africa being cut off from the rest of humanity for 100,000 years, these stories of our fathers and mothers are still recorded in our genes.
So what does this have to do with the gospel?
The most obvious issue is the Book of Mormon genetics question. In terms of apologetics, I feel like this issue is a draw; if you want it to be an issue it’s an issue, if you don’t want it to be an issue it’s not an issue.
The first classical Book of Mormon genetics discussion revolved around mitochondrial DNA. This is a kind of DNA that everybody inherits from their mother. Consequently, by measuring how often DNA mutates we can come up with a clock for how related you are to somebody else and when your lineages diverged, essentially tracing the deep history of your mother’s line (there’ a similar process for the father’s line using the Y chromosome). When Native American mitochondrial DNA was found to be Asian this forced a rethinking of the geographic and demographic scope of the Book of Mormon that I’m sure all readers of this post are aware of.
However, since then we have rapidly advanced in our use of normal (“autosomal”) DNA that is inherited from both parents to track the deep history of humans. As the tools become sharper and more precise, the proportion of Native American DNA that could be Lehite without us detecting it is becoming commensurately smaller. The cutting edge orthodox perspective on all this is that the Lehites landed and started intermixing with the indigenous peoples; (the only thing I would add to this is that, if the Book of Mormon is to be taken seriously as a historical document it has the problems of historical documents, and more straightforward descriptions of this early intermixing could have easily been scrubbed out of the histories as they were passed down and modified through the centuries). If a small landing party started intermixing in 600 BC, there’s a good chance with all of the demographic turbulence of the indigenous Americas that those genes could have been completely lost or diluted to the point of not being detected 2.5 millennia later.
However, if all the genes from Lehi are either lost or so massively diluted so as to be undetectable with the most cutting edge autosomal DNA analysis, that raises questions about what it means to be a descendant or inheritor of the promises made to the fathers and mothers. Of course, we already have an example of the role of adoption and non-genetic inheritance of promises made to the fathers through the seed of Abraham, and more recently, the widespread practice of spiritual parent-child adoption to church leaders in the early church. (Matter of fact, as far I can tell the only lineage requirement in scripture where literalness is specifically enumerated is in regards to the “literal descendants of Aaron” having the right to the Aaronic priesthood, and even here this is made a non-issue by the fact that Melchizedek priesthood holders can officiate in any office of the Aaronic priesthood).
That dynamic, plus the Book of Mormon’s own explicit veering away from biology and into tribal identification, makes me okay with seeing the Native Americans as the inheritors of the promises made to Lehi even if genetically they have very little from him, but again that is clearly a different perspective than was held classically, and I’m fine with that, we update our beliefs as new information comes in. Again, it’s a problem if you want it to be, but it’s easy enough to resolve if you don’t, you aren’t forced into a faith crisis corner.
(All that being said, interestingly the non-canonical belief that there’s a connection between indigenous Americans and Pacific Islanders does appear to be gaining scientific steam; I’ll leave it to others to speculate whether this is Hagoth or a Pacific Islander who was blown off course).
The idea that one can be an inheritor of blessings promised to a people that you aren’t biologically related to is actualized with the practice of patriarchal blessings. It is entirely possible that some refugee from the ten tribe deportations made it to Egypt and then their descendants gradually expanded into Bantu Africa, and another one had descendants that gradually made it to Celtic Europe, and another to Central Asia and thence into East Asia, but the vast majority of the genetic material in those areas are from elsewhere, there was no outward explosion of genetic material from Israel in 700 BC that we can detect, and that’s fine. We have a very clear theology of adoption for the House of Israel so we don’t have to tie ourselves into knots on this.
With lineage declarations in patriarchal blessings, I’m less inclined to hold to any sort of “blood quantum” approach. If you do the math, given how many ancestors you had going back to the Assyrian deportations, everybody in your area of the world is easily related to everybody else. If somebody from the long ago past has any living descendents today, then there’s a good chance virtually everybody in their region is descended from them. While the image we have of ethnicities and kinship groups maintaining their own gene pools might (arguably) make sense in the short run, in the long run our lines get so jumbled that I’m generally skeptical that a coherent group of a particular lost tribe maintained their genetic cohesiveness and distinctiveness across 2,500 years of admixture with neighbors and natives.
There are some very isolated groups that are able to do this to some extent, but those are very particular cases and we can usually tell where they originally came from. Consequently, I suspect that if there is a relatively genetically cohesive ethnic group that linearly descends from a particular lost tribe, they live in some cut isolated corner of the Middle East or Central Asia and go by some other ethnic name (i.e. we get to the other side and find out that the Pashtuns are the Ephraimites). Had they made their way to the British Isles or Europe (as some believe, including some in the Church) there would have been a lot of mixing with the native Celts and Germanic tribes on the way, and as a genetically cohesive group their migration out of Israel would have probably been detected by now.
Consequently, I see the lineage declaration as a spiritual inheritance more than a declaration of discrete genetic lineage (and no, this isn’t a heterodox belief, there is a long line of General Authority support for this perspective), which is a beautiful thing. I love the specificity and the concreteness of the promises made even to the adopted children of a very particular individual, or to the child who is descended from multiple tribes but who has a divinely endowed inheritance from one particular tribe.