What About DNA? (taken from the-Book-of -Mormon.com)
Practically every day, I receive emails from anti-Mormons asking the same question: "How can you believe in the Book of Mormon when DNA has proven it to be false?" My response is always the same - There is DNA evidence that supports both sides of the controversy, and the genetic evidence is far from conclusive either way. Recent discoveries regarding mitochondrial DNA (mtDNA) Haplogroup X in about 3% of Native Americans has challenged many (if not all) of the prevailing scientific beliefs regarding the genetic make-up of the earliest colonizers of the American continents.

In short, geneticists have found a DNA strain in ancient Native Americans that is found in populations of Europe and Asia Minor, to include certain Israelis! Except for a very small pocket of people called Altaians, it is specifically not found in Asians, and even the Altaian strain has been shown to be unrelated to the strain found in Native Americans. So, what does this mean? It means that a small percentage of precolumbian Native Americans derived their genetic lineage from Europe, not Asia. This flies in the face of the popular theory that all Native Americans are descended from Siberians who crossed the Bering Strait some 30,000 years ago.

What follows is a handful of excerpts and URLs which support these recent findings. Again, while they are still far from conclusive, they cast significant doubt on the generally accepted theories, and suggest that the genetic history of ancient America is still being written.

mtDNA haplogroup X: An ancient link between Europe/Western Asia and North America?
Am J Hum Genet. 1998 Dec;63(6):1852-61. - Brown MD, Hosseini SH, Torroni A, Bandelt HJ, Allen JC, Schurr TG, Scozzari R, Cruciani F, Wallace DC.
Center for Molecular Medicine, Emory University School of Medicine, Atlanta, GA, USA.

"On the basis of comprehensive RFLP analysis, it has been inferred that approximately 97% of Native American mtDNAs belong to one of four major founding mtDNA lineages, designated haplogroups "A"-"D." It has been proposed that a fifth mtDNA haplogroup (haplogroup X) represents a minor founding lineage in Native Americans. Unlike haplogroups A-D, haplogroup X is also found at low frequencies in modern European populations.... To date, haplogroup X has not been unambiguously identified in Asia, raising the possibility that some Native American founders were of Caucasian ancestry."

Brief Communication: Haplogroup X Confirmed in Prehistoric North America
Ripan S. Malhi and David Glenn Smith

"The most convincing evidence that Haplogroup X is not the result of Viking or even more recent European admixture would be its presence in ancient Native Americans. Ancient samples from the Norris Farms site (Stone and Stoneking, 1998), the Windover site (Hauswirth et al, 1994), and the Amazon Basin (Ribiero-Dos-Santos et al, 1996) exhibit the characteristic HVSI region control markers found in individuals assigned to Haplogroup X..."

Y Chromosome Haplogroups 4 and 1C and mtDNA Haplogroup X
Jeff Lindsay

"The evidence from mitochondrial DNA, passed on by mothers only, is supplemented by evidence from Y-chromosomes, which are passed on by fathers only. Native American Y-chromosomes show a variety of haplogroups, including haplogroups 4 and 1C (Karafet et al., 1999), which are also characteristic of Jewish peoples (Hammer et al., 2000). Haplogroup 1C is common enough in the New World that it has been proposed as a major founder haplogroup for the New World. "

"Researchers had already identified four common genetic variants, called haplogroups A, B, C, and D, in the mitochondrial DNA (mtDNA) of living Native Americans (Science, 4 October 1996, p. 31). These haplogroups turned up in various Asian populations, lending genetic support for the leading theory that Native Americans descended primarily from these peoples. But researchers also found a handful of other less common variants, one of which was later identified as X. "

"Haplogroup X was different. It was spotted by Torroni in a small number of European populations. So the Emory group set out to explore the marker's source. They analyzed blood samples from Native American, European, and Asian populations and reviewed published studies. "We fully expected to find it in Asia," like the other four Native American markers, says Brown. "

"To their surprise, however, haplogroup X was only confirmed in the genes of a smattering of living people in Europe and Asia Minor, including Italians, Finns, and certain Israelis. "

"Regarding recent discovery of a small group in Siberia with haplogroup X: "The recent work of Reidla et al. (2003) confirms the statements above indicating that the haplogroup X DNA in the Americas is not directly related to the unusual little pocket haplogroup X DNA in Siberia (the Altai region). "


Altaian Haplogroup X Strain Not Related to Amerindian Strain

Origin and Diffusion of mtDNA Haplogroup X

"The results of this study point to the following conclusions. First, haplogroup X variation is completely captured by two ancient clades that display distinctive phylogeographic patternsX1 is largely restricted to North and East Africa, whereas X2 is spread widely throughout West Eurasia. Second, it is apparent that the Native American haplogroup X mtDNAs derive from X2 by a unique combination of five mutations. Third, the few Altaian (Derenko et al. 2001) and Siberian haplogroup X lineages are not related to the Native American cluster, and they are more likely explained by recent gene flow from Europe or from West Asia."
http://www.journals.uchicago.edu/AJHG/journal/issues/v73n5/40218/40218.text.html and