Born in Marietta, Georgia, Wells grew up in Lubbock, Texas. He obtained a Bachelor of Science in Biology from the University of Texas at Austin in 1988, and a Ph.D. in Biology from Harvard University in 1994. He was a postdoctoral fellow at Stanford Universitybetween 1994 and 1998, and a research fellow at the University of Oxford between 1999 and 2000.
Wells did his Ph.D. work under Richard Lewontin, and later did postdoctoral research with Luigi Luca Cavalli-Sforza and Sir Walter Bodmer. His work, which has helped to establish the critical role played by Central Asia in the peopling of the world, has been published in journals such as Science, American Journal of Human Genetics, and the Proceedings of the National Academy of Sciences.