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Book of Mormon DNA Apologetic Arguments Have a Shelf-life
There have been a couple of scientific advances on Native American origins this summer. First, DNA was finally isolated from the 9,000 year-old Kennewick man (KM) and it is clear that he is closely related to several current Native American tribes. Some had argued based on skull morphology that KM was more closely related to Australians and that his ancestry was outside of the East Asian/Siberian mainstream. However, the genetic evidence now puts him firmly within the Native American mainstream.
The second finding, reported by two separate groups a couple of weeks ago, is that some Amazonian tribes have a small DNA contribution from a common ancestor of indigenous Australians and Melanesians. This Boston Globe article is one of the better ones I have seen (and it has a nice accompanying graphic). It is very easy to get confused by the differing interpretations of the data. From what I have read, it boils down to this: Does the Australian DNA come from migrants who came into the New World around the same time as the East Asians/Siberians (>15,000 years ago), or later through the Aleutian Islands around 9,000 years ago? Some news articles use the terms ancient and recent without being clear about the associated dates, which can lead people to imagine evidence of trans-Pacific voyages. That is NOT what is proposed here.
At first glance this has nothing to do with the Book of Mormon. The Asian ancestry of Native Americans is nothing new, and the timing of the migrations inferred from the above studies occurred long before the Book of Mormon chronology. Defenders might even point out that the added complexity that has been discovered shows that we must remain open-minded about Native American genetics because surprises do happen. However, there may be subtle implications for the future of Book of Mormon apologetics, which rely heavily on the population genetics principles of founder effect, genetic bottlenecks, and genetic drift.
To make things easy, I'll break my point up into several bite-sized propositions:
1. Although the exact genetic signatures that the Jaredites/Lehites would have carried are unknown, each advance in characterizing the ancient origins of Native American genetics helps to establish the background from which Jaredite/Lehite markers would stand out. We may not know exactly what we are looking for, but we have an increasing ability to recognize markers that are unusual.
2. Mitochondrial DNA and Y chromosome types are particularly sensitive to genetic drift, etc.--a point made in the two papers describing the Australian connection. Originally most ancient genetic research focused on mtDNA and Y chromosomes because they were easier to deal with. However, the technological advances in recovering and sequencing autosomes (i.e. most of the genome) have greatly improved in the last decade.
3. Autosomal markers are more resistant to disappearing from populations. It's one thing for mtDNA or Y chromosomes (which are inherited by daughters and sons, respectively, as a block) to go missing; it's another for all traces of autosomes (which mix by recombination each generation) to disappear. As an example, scientists initially ruled out interbreeding between modern humans and Neanderthals based on mtDNA differences. However, once the Neanderthal genome was sequenced, it became clear that modern humans of ancient European decent got about 4% of their DNA from Neanderthals (which went extinct ~30-40,000 years ago).
4. The increased ability to recover and sequence DNA from ancient remains means it is probably only a matter of time before a variety of genomes dating from Book of Mormon times--and in the favored locations--are recovered. It is one thing to explain why modern Native Americans do not show any genetic relationship to the Middle East; it is another to explain why two thousand year-old Mesoamerican remains do not show any genetic relationship.
I am not suggesting that genetic studies are going to definitively disprove the Book of Mormon as an ancient American record. What I am suggesting is that, as the science around Native American origins progresses and the realm of plausibility contracts, the current arguments that Book of Mormon defenders advance with respect to Native American DNA will begin to wear thin. That is, unless a pre-Columbian Middle-Eastern genetic signal is discovered. But if that happens, we won't need the current arguments any more. So either way, we are marching toward their expiration date.
9 comments:
Jared don't most discussions by apologists already deal with the autosomal issue of DNA? i.e. http://www.mormoninterpreter.com/is-decrypting-the-genetic-legacy-of-americas-indigenous-populations-key-to-the-historicity-of-the-book-of-mormon/
Clark, thanks for reminding me of that article. I don't disagree with it per se, but I think the discussion is based on an idealized minimalist scenario. It's one thing to talk about how much DNA you got from your great-grandparents, but you aren't the only person in the population with their DNA. In the Book of Mormon, even if the Nephites/Lamanites interbred with other groups, they would still also marry within their own group too. So various autosomal markers would have multiple opportunities to be amplified in the population and be passed on.
I would love to see a population geneticist run some simulations based on a variety of scenarios so that we could get a handle on what to expect given assumptions X, Y, Z.
Note also that the article is mostly focused on whether we should expect to find Lehite DNA in current Native Americans.
Jared, you make a good point about the difficulty of explaining "why two thousand year-old Mesoamerican remains do not show any genetic relationship." However, you seem to have overlooked a key point when you wrote this: "It is one thing to explain why modern Native Americans do not show any genetic relationship to the Middle East..."
In fact, modern Native Americans do show genetic relationship to the Middle East, but only those whose ancestors inhabited the Great Lakes region.
The article Clark cited mentions this: "Lineage X became X2a, and to this day it has been found only in North America, although there is still some uncertainty regarding its origin." Also, "A far more puzzling story surrounds the origin of the fifth Native American lineage, called X2a. This group of mtDNAs is found exclusively in North America, with its highest [Page 254]modern-day concentration in the Great Lakes region.27 While Native American mtDNAs A2, B2, C1, and D1 are clearly nested within Asian clades, lineage X2a has a hypothesized ancient Old World origin, probably in the Middle East.28"
Regarding X2a, it's more a question of when the North American lineage broke off than the presence of Middle-Eastern DNA among Native Americans.
Jonathan,
You may be technically right, although even in the passage you quote Perego says the Middle-Eastern origin of X2a is hypothesized.
In Perego's published scientific work, he has taken the position that X2a entered the New World along with original undisputed Asian types. (E.g. here and here.) His inference now has empirical support in that Kennewick Man was/is X2a. This puts a floor under the entrance of X2a into the New World of at least 8-9,000 years ago. It is thus hard to see how X2a could have any relevance to the Book of Mormon.
Ugo has assumed Darwinian evolutionary timeframes for the ascent of man with X2a arriving in North America some 2 to 3 thousand years before Adam. Darwinian timeframes might be suitable in a purely scientific discussion among scientists, but this is a religious discussion on Book of Mormon (Judeo-Christian) scripture and timeframes. Acceptance of the source document as correct is a necessary prerequisite to a science/religion conversation otherwise the entire exercise is moot.
Evidently, Perego feels that his argument is strengthened when he picks and chooses--like a Chinese menu--those parts of scripture he will accept while rejecting others (such as Adam being the first man).
No prophet (ancient or modern) has ever suggested that man (in any form) pre-dated Adam. Which begs the question: whence derives Ugo his authority to override the scriptures and the prophets in a religious discussion on DNA and the Book of Mormon?
Have we now reached that "enlightened" state where our self-appointed "scholar/apologists" are dictating "correct" interpretation of scripture? In Ugo's world, it would appear that we have.
finepix,
I think Ugo has every right to bring the best science to bear on the topic. The Church encourages integration of knowledge. If you don't like his conclusions, you don't have to agree with him. A book published by the Religion department at BYU and edited by Robert Millet included a chapter of Ugo's, and he has clearly influenced the Gospel Topics essay at LDS.org, so the Brethren probably think his views are within the acceptable range of LDS opinions.
To say that he is assuming Darwinian evolutionary time frames is a little odd because i) he's basing his analysis on empirical realities and ii) a few thousand years is NOTHING in the evolutionary scheme of things.
Jared, the Ugo articles you cited are from 2009 and 2012; the one Clark referenced (the Interpreter article from which I quoted) is from 2014. I don't know whether Ugo's views have changed, but the single instance of Kennewick Man's DNA doesn't change what Ugo wrote in the Interpreter.
Your point about the floor of at least 8-9,000 years ago highlights one of the conflicts between science and religion. Contrary to what you wrote to finepix, a divergence 8-9,000 years ago certainly does assume Darwinian evolutionary time frames; this is a relatively recent (in evolutionary terms) divergence of a much older DNA sequence. I'm not sure what you mean by "empirical realities" here. The time frames you refer to are theoretical, not empirical. No one has observed these mutation rates.
That said, you do raise an important question by invoking Millet and the lds.org essay. Each of those suggest that "the Brethren" have now embraced Darwinian evolution. Whether that is official policy is another question, but certainly that is the implication.
Back to the Interpreter. It's helpful to see what Ugo actually wrote, in context. I won't excerpt the entire section on X2a, but this part is relevant:
"A far more puzzling story surrounds the origin of the fifth Native American lineage, called X2a. This group of mtDNAs is found exclusively in North America, with its highest [Page 254]modern-day concentration in the Great Lakes region.27 While Native American mtDNAs A2, B2, C1, and D1 are clearly nested within Asian clades, lineage X2a has a hypothesized ancient Old World origin, probably in the Middle East.28
"Although a small number of X2 samples have also been observed in Central Asia,29 they most likely represent a recent migratory event to that region. In an mtDNA tree, the Asian X (called X2e) contains more recent mutations than the Native American X2a, and therefore it is not ancestral to the latter. Although it cannot be completely excluded that ancestors of X2a once lived in Northeast Asia and then became extinct, at the present time the closest relatives of the Native American X2a lineage have been identified in a single sample from Iran30 and in Bedouin groups from Egypt.31
"The potential connection between New World and Middle Eastern mtDNA X types could be seen by some as a candidate for Book of Mormon DNA in the Americas. However, some data confounds this hypothesis, as the mtDNA molecular clock32 — the estimated average number of years before a mutation is expected to appear — dates X2a at about the same time as the arrival of all the other Asian-like lineages to the Americas [Page 255](toward the end of the Last Ice Age). Data from ancient DNA studies on pre-Columbian specimens presumably belonging to lineage X are, for the most part, also inconclusive.33"
Jonathan,
I'm not really sure what the main point of disagreement is. What Ugo wrote in the Interpreter article is not in conflict with his scientific papers. Currently the closest relatives to X2a are found in the Middle East. That may or may not mean that X2a originated there. But the mutation rate and its distribution in North America (which coincides with another rare Asian type) suggest it entered North America during the original time of migration from Asia. As I mentioned previously, Kennewick Man now provides a floor on dating the entry of X2a, and is directly pertinent to the last paragraph you quoted. Kennewick Man adds to the data that confounds the hypothesis that X types are relevant to the Book of Mormon.
Kennewick Man and other ancient Native American remains (and archaeological sites) have been dated by radiometric and other methods. These methods are quite empirical.
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