By examining DNA sequences in different populations, scientists can determine the closeness of relationships between populations (or within populations). Certain similarities in genetic makeup let molecular anthropologists determine whether or not different groups of people belong to the same haplogroup, and thus if they share a common geographical origin. This is significant because it allows anthropologists to trace patterns of migration and settlement, which gives helpful insight as to how contemporary populations have formed and progressed over time.
Molecular anthropology has been extremely useful in establishing the evolutionary tree of humans and other primates, including closely related species like chimps and gorillas. While there are clearly many morphological similarities between humans and chimpanzees, for example, certain studies also have concluded that there is roughly a 98 percent commonality between the DNA of both species. However, more recent studies have modified the commonality of 98 percent to a commonality of 94 percent, showing that the genetic gap between humans and chimps is larger than originally thought. Such information is useful in searching for common ancestors and coming to a better understanding of how humans evolved.
Q-M3 is the predominant haplotype in the Americas at a rate of 83% in South American populations, 50% in the Na-Dené populations, and in North American Eskimo-Aleut populations at about 46%. With minimal back-migration of Q-M3 in Eurasia, the mutation likely evolved in east-Beringia, or more specifically the Seward Peninsula or western Alaskan interior. The Beringia land mass began submerging, cutting off land routes.
A.C. Wilson first came to world attention when he published a paper titled Immunological Time-Scale For Human Evolution in Science magazine in December 1967. Together with doctoral student Vincent Sarich, Wilson argued that the origins of the human species could be seen through, what he termed, a "molecular clock". This was a way of dating, not from fossils, but from the genetic mutations that had accumulated since they parted from a common ancestor. The molecular clock estimated the length of time from divergence, given a certain rate of change. Wilson and his colleagues discovered that humans and chimpanzees were 99 percent identical in DNA sequence and that they shared a recent common ancestor far more recent than most paleoanthropologist at the time believed. Wilson also coordinated the discovery of the "Mitochondrial Eve" hypothesis, a female in Africa about 200,000 years ago from which all living females are related through their maternal ancestry.