Stemelbow has been quoting the following paragraphs from Dr (medical) David Stewart in an attempt to convince trusting Mormons reading this thread that the X lineage may well have come into the Americas with Lehi. In fact Stewart argues that the A,B,C,D and X lineages all came into the Americas with Lehi and the hemispheric model is correct. This is the quote.
“Many scientists date the genetic divergence of modern Native Americans as having arisen from migrations between 10,000 and 15,000 B.C, rather than shortly after 600 B.C. as stated in the Book of Mormon account. Mitochondrial studies of New World DNA have led to vastly discrepant estimates of time of divergence. Ann Gibbons reports: "All this disagreement prompts [Stanford University linguist Dr. Joseph] Greenberg to simply ignore the new mtDNA data. He says: 'Every time, it seems to come to a different conclusion. I've just tended to set aside the mtDNA evidence. I'll wait until they get their act together.'"47
Martin Tanner explains:
"The idea [that] haplogroup X has been in the Americas for 10 to 35 thousand years is based solely upon the assumptions of the Hardy-Weinberg equilibrium, which include: (1) completely neutral variants, (2) no mutation, (3) no migration, (4) constant near infinite population size, and (5) completely random mate choice. In the Book of Mormon account, most of the Hardy-Weinberg equilibrium assumptions are inapplicable. The wilderness journey, the ocean voyage, and the colonization of the New World, result in patterns of genetic selection and DNA migration different from that found in Lehi's home environment. Closely related individuals married and we are dealing with [initially] a very small group, not a nearly infinite population which would dramatically alter DNA marker distribution and inheritance over time. If we take these assumptions about haplogroup X instead of the Hardy-Weinberg assumptions, haplogroup X could have been introduced into the Americas as recently as one to two thousand years ago, far less than the ten to thirty-five thousand years under the Hardy-Weinberg assumptions."48
The first paragraph contains a quote from Joseph Greenberg (ref 47), a prominent linguist whose theories have been influential (and controversial) for decades. The DNA evidence has been used to seriously challenge some of his central linguistic claims. Greenberg died in 2001 aged 86. The quote was first published in 1996. So Stewart is backing up one of his key apologetic arguments with the
outdated words of an
80-year old professor
defending his life's work. Nice one Dr Stewart.
The second paragraph is intriguing. Who is this Martin Tanner character who uses impressive words like “neutral variant” and “Hardy-Weinberg equilibrium”? You could be excused for thinking you are reading the words of a competent population geneticist. Interestingly, there is another version of this David Stewart rant where he starts this paragraph with “LDS apologist Martin Tanner explains". I wonder why there is even a version with "LDS apologist" missing?
So instead of outdated quotes from disgruntled professors and unqualified apologists, here are some recent quotes from active research scientists within peer-reviewed research articles.
Perego et al. 2009 Current Biology 19, 1–8. (Perego is a Mormon)
..we completely sequenced and analyzed a large number of mtDNAs belonging to the rare and poorly known haplogroups D4h3 and X2a, revealing that each marked a distinct entry path from Beringia, which contributed to the formation of Paleo-Indians.
Even when standard errors are considered, the largely overlapping sequence divergences observed for haplogroups D4h3 and X2a indicate a concomitant or very close temporal expansion of the two haplogroups, from either the same Beringian source population or different yet related Beringian sources.
Haplogroup D4h3 spread into the Americas along the Pacific coast, whereas X2a entered through the ice-free corridor between the Laurentide and Cordilleran ice sheets.
Fagundes et al. 2008 American Journal of Human Genetics 82, 583–592.Here we show, by using 86 complete mitochondrial genomes, that all Native American haplogroups, including haplogroup X, were part of a single founding population, thereby refuting multiple migration models. A detailed demographic history of the mtDNA sequences estimated with a Bayesian coalescent method indicates a complex model for the peopling of the Americas, in which the initial differentiation from Asian populations ended with a moderate bottleneck in Beringia during the last glacial maximum (LGM), around ~23,000 to ~19,000 years ago.
Perego’s team calculated the time to the most recent common ancestor for American Indian X lineages to be 14,200 years ago. Fagundes’ estimate was 18-21,000 years ago.
I am sure Perego would love to talk to any apologists still hanging on to the X lineage.