I'd like to apologize in advance for the many people I will offend, but ask that you please read what I have to say.
I largely leave people to their beliefs, but recent deception of the LDS church has compelled me to encourage my friends and family to evaluate their relationship with this institution to whom they pay 10% of their income.
In 1971, Spencer W Kimball said "Now the Lamanites number about sixty million; they are in all of the states of America from Tierra del Fuego all the way up to Point Barrows, and they are in nearly all the islands of the sea from Hawaii south to southern New Zealand."
https://www.LDS.org/ensign/1971/07/of-royal-bloodYet, a recent article refuting science makes quite a different pronouncement
https://www.LDS.org/topics/book-of-morm ... na-studiesIt blames its members for making assumptions about the size and exclusivity of the Book of Mormon culture, but fails to reference the articles from church leaders who preached those exact claims, or the introduction to the Book of Mormon which claimed, until very recently, that the Lamanites were the principal ancestors of the Native Americans.
They claim science cannot disprove the Book of Mormon, while changing their scriptures to evade conflict.
What I consider most deceptive is this article's egregious misuse of science in a section titled "Understanding the Genetic Evidence." It criticized Y-chromosome and mitochondrial testing, only mentioning autosomal DNA as a side note, despite autosomal DNA being used almost exclusively to test ethnic origins. The difficulties they enumerated do not invalidate autosomal tests. Their specific example about the founder effect is exactly why autosomal DNA is the preferred test for origin.
Their examples were overly simple and didn't address autosomal DNA, so I will provide my own:
--Imagine that every book had 23 chapters
--A book represents a person
--A chapter represents a chromosome
--The text represents the 0.1% unique DNA each person has (over 100,000 letters per chapter after all the shared DNA was deleted)
In order to reproduce 2 people swap text ONLY per chapter. Generally swaps are several pages at a time, rather than every other word or letter. Swaps are also of equal length & location (if 1 chapter offers the middle 3 pages to swap, the other book's chapter reciprocates with its middle 3 pages).
So after many generations of book-swapping, when we see the text "Thou shalt have no other gods before me" we quickly identify Exodus as one of its ancestors.
But what's more, we can see large swatches of text, and compare them to our library of books. While we don't have every book in our library, we do have a massive library. It is also a library of swapped books, so the odds that we have at least a few pieces of most book are quite high (except for isolated or extinct gene pools).
So we can quickly run a book through our computer and tell you most of its parents. Because of swap rates and mutation rates (a word getting copied down wrong) we can even tell you roughly how many swaps occurred first, and can identify if you came from a sub-group of books that came from a sub-ancestor that had half a page of Exodus ending with "Thou shalt have no other gods" abutted with a page of Hamlet starting with "to be or not to be".
So now that you understand autosomal DNA testing, let's talk about Lehi.
While we don't know the genome of Lehi, Sariah, Zoram, Ishmael or his wife's, we know when & where they lived, as well as Lehi's explicit ancestry of Manasseh. Unless all 5 were non-intermarried migrants (in a very exclusionary time), we have a good sense of their genotype. We also know that they were among the tribes of Israel, who considered marrying outside of their group a sin (very unlikely they were outsiders). Using Biblical text as metaphor for DNA, we might not find "Thou shalt have no other gods before me" in their gene books, but are sure to find several other snippets from the Old Testament identifying them with the other fairly homogenous group of self-isolating Israelites.
(I must note that the Israelites were exiled to Babylon after Lehi's departure, but we still have a large test sample of descendants who themselves show Old Testament DNA snippets in their genome).
So the options become either the extinction of Lehi's gene pool or extreme isolation.
Let's quickly rule out extinction. The Book of Mormon itself prophesies that it was written for the Lamanites: "Written to the Lamanites, who are a remnant of the house of Israel… Which is to show unto the remnant of the house of Israel what great things the Lord hath done for their fathers; and that they may know the covenants of the Lord, that they are not cast off forever", so if the Lamanites were extinct (removing the DNA concern) the book would be false for failed prophecy, & its account of the origins of the Americas would be untrustworthy. More importantly, for my LDS friends, it would not be divine scripture.
So we are left with isolation.
We have to assume that Spencer W Kimball was wrong to number sixty million Lamanite descendants, since doubtless many of those explicit groups have been tested. While outsiders would brush this aside, it carries more weight among LDS members who view Spencer W Kimball as a Prophet, Seer, & Revelator even though he was only acting President of the church at that time.