The Bushmen have provided a wealth of information for the fields of anthropology and genetics, even as their lifestyles change. Genetic evidence suggests the Bushmen's ancestors predate the genetic changes of the rest of the human population — making them a "genetic Adam" according to Spencer Wells, from which all humans can ultimately trace their genetic heritage. Arguably, though, their Haplogroup A is not the oldest DNA itself, but the oldest divergence from the "genetic Adam"'s DNA. In this case, they represent an isolated genetic group, and not a common ancestral group to the rest of humanity