A long article explaining the emergence of geonomic archeology and the benefits thereof, from Harvard Magazine, titled "Who Killed The Men of Britain: The written record of history meets genomics, evolution, demography, and molecular archaeology," by Jonathan Shaw. Here's a pull:

In the Anglo-Saxon example, genomic archaeology--a new approach to genetics, demography, and mathematical simulation that uses genomic data from living people to illuminate major events in the past--eventually led to an explanation of how the males in Roman England might have been wiped out. Another study has traced the geographic spread of a gene variant that allows adults to digest the sugar in milk; possessing that allele appears to have conferred a tremendous evolutionary advantage during the last 10,000 years. Isotopic studies of human bone have revealed prehistoric dietary shifts, and shown that Neanderthals were more like us than previously imagined. Reconstructions of ancient mammalian DNA have led to new, climate-related theories about the extinction of megafauna (such as wooly mammoths) in which humans appear less to blame than previously supposed. And innovative technologies allow the identification of hearths and buildings in layers of soil, revealing the presence of entire villages at sites long thought to have been abandoned. The study of the human past, in other words, has entered a new phase in which science has begun to tell stories that were once the sole domain of humanists.