Latter-day Saint leaders have expressed a variety of opinions regarding whether or not all Amerindians are literal descendants of Lehi. Population genetics indicate that Lehi can likely be counted among the ancestors of all native Americans—a position that the Church has reinforced by changing the 1981 Book of Mormon introduction from "principal ancestors" to "among the ancestors."

Gospel Topics: "The Book of Mormon...does not claim that the peoples it describes were either the predominant or the exclusive inhabitants of the lands they occupied"

"Book of Mormon and DNA Studies," Gospel Topics on LDS.org:

The Book of Mormon provides little direct information about cultural contact between the peoples it describes and others who may have lived nearby. Consequently, most early Latter-day Saints assumed that Near Easterners or West Asians like Jared, Lehi, Mulek, and their companions were the first or the largest or even the only groups to settle the Americas. Building upon this assumption, critics insist that the Book of Mormon does not allow for the presence of other large populations in the Americas and that, therefore, Near Eastern DNA should be easily identifiable among modern native groups.

The Book of Mormon itself, however, does not claim that the peoples it describes were either the predominant or the exclusive inhabitants of the lands they occupied. In fact, cultural and demographic clues in its text hint at the presence of other groups.6 At the April 1929 general conference, President Anthony W. Ivins of the First Presidency cautioned: “We must be careful in the conclusions that we reach. The Book of Mormon … does not tell us that there was no one here before them [the peoples it describes]. It does not tell us that people did not come after.^[1]

Question: Does the Church claim that Native Americans were the exclusive descendants of Lehi or Mulek?

LDS leaders have expressed a variety of opinions regarding whether or not all Amerindians are literal descendants of Lehi

LDS leaders have expressed a variety of opinions regarding whether or not all Amerindians are literal descendants of Lehi. Population genetics indicate that Lehi can likely be counted among the ancestors of all native Americans—a position that the Church reinforced in the 2006 edition by changing the Book of Mormon introduction originally introduced in 1981 from "principal ancestors" to "among the ancestors." (see Book of Mormon Introduction on lds.org)

Many Church leaders, most notably Spencer W. Kimball, have made clear statements regarding the belief that Lehi was the exclusive ancestor of all native Americans. However, contrary to the claims of critics who attempt to use DNA evidence to discredit the Book of Mormon, many readers and leaders have also noted that those in Lehi's group were not the exclusive progenitors of the inhabitants of the American continents. When asked about the Church’s official position on this matter by a writer, a Church spokesman said:

As to whether these were the first inhabitants…we don't have a position on that. Our scripture does not try to account for any other people who may have lived in the New World before, during or after the days of the Jaredites and the Nephites, and we don't have any official doctrine about who the descendants of the Nephites and the Jaredites are. Many Mormons believe that American Indians are descendants of the Lamanites [a division of the Nephites], but that's not in the scripture.^[2]

In addition, apostles and seventies have made many statements which differ from critics’ understanding of the matter, taught them in General Conference, and the Church has published such perspectives in their magazines, study guides, and manuals. The Church’s university has passed them on to their students for generations. The Church’s official spokespeople disclaim the interpretation which critics insist we must hold. Why must we? Well, because critics’ DNA theory “disproving” the Book of Mormon is in deep trouble otherwise.

See also: Statements by 20th century Church leaders regarding the relationship between native Americans and Lehi

Question: Why did the Church modify the introduction to the Book of Mormon from "principal ancestors" to "among the ancestors?"

The Church changed the wording to remove the assumption (inserted into the Book of Mormon in the 1920's) that all of the inhabitants of the Americas were exclusive descendants of Lehi

The Church made the change in wording to the introduction to the Book of Mormon to remove the assumption, which inserted into the Book of Mormon introduction in the 1920's and not part of the original text, that all of the inhabitants of the Americas were exclusive descendants of Lehi. This had been the generally held belief from the time that the Church was restored.

This change makes the Book of Mormon introduction compatible with current DNA evidence and acknowledges the fact that Lehi's group likely intermingled with the native inhabitants of the American continents based upon current knowledge of the DNA composition of the inhabitants of the New World. There is substantial scientific evidence of habitation in the Americas for thousands of years prior to Lehi's arrival.

If Lehi had any descendants among Amerindians, then after 2600 years all Amerindians would share Lehi as an ancestor. Even if (as is probable) the Lehite group was a small drop in a larger population 'ocean' of pre-Columbian inhabitants, Lehi would have been an ancestor of virtually all the modern-day Amerindians if any of his descendants married into the existing New World population.

Southerton (2008/2014): "It's true that if a small group (say 10 people) entered a massive population (say 1 million), that it would be hard to detect their mitochondrial or Y chromosome DNA"

Dr. Simon Southerton is one of the most outspoken critics of the Church with regard to DNA and the Book of Mormon:

(2008) In case anyone from FAIR is unclear I will repeat what I wrote four years ago…“IF A SMALL GROUP OF ISRAELITES ENTERED SUCH A MASSIVE NATIVE POPULATION (SEVERAL MILLIONS) IT WOULD BE VERY, VERY HARD TO DETECT THEIR GENES.” Now that FAIR has finally conceded that American Indian DNA is essentially all derived from Asia, I also agree with them that the debate should be about the theology. ^[3]

(2014) I made the original statement at a time when whole genome sequence analysis was a long way off. It's true that if a small group (say 10 people) entered a massive population (say 1 million), that it would be hard to detect their mitochondrial or Y chromosome DNA. Your odds would be roughly 1 in 100,000 (10 in 1 Million). But technology has moved very rapidly and whole genome studies are now almost routine. So, my original statement is no longer true. ^[4]

Dr. Southerton is confused if he thinks FairMormon experts on DNA have ever questioned that a considerable portion of Amerindian DNA comes from Asia. They do not have to "concede" anything--they have always held this view. However, Dr. Southerton is mistaken if he believes that "American Indian DNA is essentially all derived from Asia":

a 2013 study states that as much as one-third of Native American DNA originated anciently in Europe or West Asia and was likely introduced into the gene pool before the earliest migration to the Americas.^[5]

Olson (2004): "People may like to think that they're descended from some ancient group while other people are not. But human ancestry doesn't work that way, since we all share the same ancestors just a few millenniums ago"

Non LDS-writer Steve Olson (an expert in population genetics^[6]) wrote:

If anyone living today is descended from Jesus, so are most of us on the planet. That absurd-sounding statement is an inevitable consequence of the strange and marvelous workings of human ancestry...Say you go back 120 generations, to about the year 1000 B.C. According to the results presented in our Nature paper, your ancestors then included everyone in the world who has descendants living today... If Jesus had children (a big if, of course) and if those children had children so that Jesus' lineage survived, then Jesus is today the ancestor of almost everyone living on Earth. True, Jesus lived two rather than three millenniums ago, but a person's descendants spread quickly from well-connected parts of the world like the Middle East...In addition to Jesus...we're also all descended from Julius Caesar, from Nefertiti, from Confucius...and from any other historical figure who left behind lines of descendants and lived earlier than a few thousand years ago. Genetic tests can't prove this, partly because current tests look at just a small fraction of our DNA. But if we're descended from someone, we have at least a chance—even if it's a very small chance—of having their DNA in our cells...People may like to think that they're descended from some ancient group while other people are not. But human ancestry doesn't work that way, since we all share the same ancestors just a few millenniums ago.^[7]

Notes

1. ↑ "Book of Mormon and DNA Studies," Gospel Topics on LDS.org (31 January 2014)
2. ↑ Stewart Reid, LDS Public Relations Staff, quoted by William J. Bennetta in The Textbook Letter (March-April 1997), published by The Textbook League (P.O. Box 51, Sausalito, California 94966).
3. ↑ Simon Southerton, "Finally, I agree with LDS scientists-apologists," posting to an ex-Mormon discussion board, Sept. 6, 2008. (emphasis in original)
4. ↑ Simon Southerton, explaining his 2008 statement to FAIR, February 2014. Cited in updated Letter to a CES Director (2014).
5. ↑ "Book of Mormon and DNA Studies," Gospel Topics Essays at lds.org (prepared beginning in 2013). The paper cited is Maanasa Raghavan et al., “Upper Palaeolithic Siberian Genome Reveals Dual Ancestry of Native Americans,” Nature 505 (20 November 2013): 87–91.
6. ↑ Olson is co-author of a letter to Nature, in which he discusses these ideas in a more technical format. See Douglas L. T. Rohde, Steve Olson, and Joseph T. Chang, "Modelling the recent common ancestry of all living humans," 431 Nature (30 September 2004): 562–566. off-site Olson provides a "semi-technical" description of his findings here.
7. ↑ Steve Olson, "Why We're All Jesus' Children," slate.com (15 March 2006). Last accessed 12 October 2006 (emphasis added). off-site