Suppose we take 25 years per generation. Then there would be roughly 100 generations between now and when Lehi was supposed to have come. So let us use that number.

Let us suppose we have a million people in the Americas 100 generations
ago (actually assume a million minus one). And let us assume that the
Lehi party was composed of one person. In other words, assume the Lehi
party of one brought the total population to one million people.

Now let us assume that through these 100 generation the population size
doesn’t change and that there is random intermarriage or mixing in the
population. So today the sample size is still one million people. The
births and deaths randomly keep the population constant.

Now, a person of that sample population today will receive their nuclear
DNA from two parents, four grandparent, eight grandparents, and so
forth. If we continue this to the 100th generation back, this one person
would have received their nuclear DNA from roughly 10-to-the-power-of-30
ancestors. But this is so large compared to the fact that the person
today could only have one million ancestors 100 generations ago, we must
conclude simply that one person of the sample today (because of mixing)
is a descendant of all one million of the original population. There
has been a thorough mixing and equal chances of lines dying out. So all
one million of the people-sample today are descendants of any one of the
original sample (of a million people) 100 generations ago. That is, all
of the one million today will probably be the descendant of the one
person of the Lehi party (an everyone else too, of course.)

That is the case for nuclear DNA, which determines descent. Now what
about mtDNA? If I understand the situation, one person of the sample
today can receive their mtDNA only from ONE of the original population,
since it comes only through the mother. A person can only have one
mother’s mother’s, … of a particular generation. Thus if today we
test the mtDNA of one person of the modern sample we will have only one
chance in a million of finding the mtDNA of the original Lehi party of
one. If we test “thousands” of the modern population, if that
“thousands” is still small compared to the modern total population of a
million, we will still have a small chance of finding the mtDNA of the
original Lehi party of one. (Even if we found the one, it would
probably be thought of as a fluke or a mutation.)

I assume that the Lehi party represented a very small part of the
original population and that there has been thorough mixing. (See the
article “When Lehi’s party arrived, Did They Find Others in the Land?”
by John L. Sorenson in Journal of Book of Mormon Studies, vol. 1, no. 1,
fall 1992, pp. 1-34.)

Therefore I suggest, using the simplified reasoning above, my thought
experiment, that all of modern Amerinds could very well be descendants
of the original Lehi party and yet that the chances of proving whether
or not there even was a Lehi party by DNA is essentially nil.

So, despite the exciting prospects of DNA measurements, we come out the
same door we came in. DNA will probably tell us nothing about the BofM.

(Frisbeeites believe that when you die, your soul goes up on the roof and you can’t get it down.)

(Now I know the truth: the roof has three levels.)

Hi, Crane. :-)

I think it is ridiculous to suggest that the Historian is somehow being dishonest when he suggests that informed Mormon opinion subscribes to a limited geography model and multiple ancestry model. Give me a break!

Yes it is true that lots and lots of Mormons think that the Book of Mormon provides the only account for Native American ancestry. Yes it is true that there are probably a whole lot of general authorities that subscribe to this view. So what?

It is not a textually or historically defensible position. Nor is it theologically necessary in some way. Why insist on it?

Finally, it is worth remembering that the Historian’s letter was written to a New Testament scholar at Harvard Divinity School who was unaware of the shape of Mormon scholarlly discussion. It is hardly disingenous or dishonest to tell him what Mormon scholars think on the subject, especially since the professor was being asked to comment as a scholar. The positions taken by the Historian have been common places of serious study of the Book of Mormon since Sidney Sperry’s work in the 1940s for crying out loud!