"In 600 BC there were probably several million American Indians living in the Americas. If a small group of Israelites, say less than thirty, entered into such a massive native population, it would be very hard to detect their genes today." - Simon Southerton, leading critic of the Book of Mormon based on DNA research.
Matt Roper, a scholar at the Neal A. Maxwell Institute, has written extensively on Book of Mormon issues. One of my favorites that I just read recently comes from the FARMS Review and covers two topics; 1) treatments on Book of Mormon geography from past LDS researchers and leaders and 2) whether or not the Book of Mormon talks about there being "others" than the Nehpites, Lamanites, Jaredites and Mulekites.
One of the key criticisms against the Book of Mormon based on DNA evidence is as follows:
1. The Book of Mormon claims that the Western Hemisphere was empty of native populations when Lehi and his family arrived.
2. This means that the peoples described in the Book of Mormon must therefore be the ancestors of modern Native Americans.
3. DNA has disproven that Native Americans come from a Middle Eastern background (as the Book of Mormon claims)
4. This means that the Book of Mormon is false, etc.
Furthermore, the critics contend, LDS scholars have been backed into the corner of a Limited Geography for the Book of Mormon because of DNA and any attempt to correlate the Book of Mormon in a small, localized area in Mesoamerica is not only ad hoc but also at odds with previous LDS leaders opinions on Book of Mormon geography.
As Matt Roper shows in this article, however, such reasoning is unfounded. First, Roper demonstrates that the idea of a Limited Geography for the Book of Mormon - which would entail the peoples described in the Book of Mormon intermarrying and intermingling with native populations - is nothing new. From the days or Orson Pratt in the late 1800's, LDS researchers have been postulating a Limited Geography. And while it is true that a popular interpretation of Book of Mormon geography amongst Latter-day Saints (including high ranking LDS leaders) has been to assume that the Book of Mormon events took place all over North and South America with Lehi as the ancestor of every single Native American, Roper shows how this interpretation has been seriously challenged by LDS researchers for decades.
Roper further goes on to write how the Book of Mormon gives clues and hints throughout its pages that Lehi and his family quickly began interacting with native populations and how the Nephite and Lamanite cultures quickly became assimilated into already existing Mesoamerican cultures and populations. As a matter of fact, Roper shows, the terms "Nephite" and "Lamanite" do not necessarily carry hereditary meanings but can also convey socio-political identifications and meanings.
In short, Roper concludes, there are just too many factors to deal with before we can safely test the Book of Mormon on DNA grounds. So, for a fascinating read and some very exciting insights, I recommend Matt Roper's essay as this article of the week.