The Church recently posted another new Gospel Topic. This one is entitled Book of Mormon and DNA Studies. It is quite lengthy, but a very fascinating read.
The section I found most fascinating was "The Ancestors of the American Indians." In this section, we basically read that there is a concession that other people lived in the Americas before Lehi and his family arrived and that they perhaps intermingled with the people already living there.
I remember in my Book of Mormon class at BYU, bringing up the idea that there were other people living with the Nephites. I could not imagine how Jacob (Lehi's son) could be preaching to the people about their concubines and many wives. How could there be so many people that there were men marrying multiple women. My professor (Ludlow) basically shot down this idea when I raised the point that the Nephites were living among other people who had already settled the land. It's good to see an official essay acknowledge this point.