Factors Governing the Genetics of Primitive Human Populations

During his million or more years on Earth man has lived only a small portion of this time, certainly no more than 10,000 years, in cities, towns, and villages. Most of his sojourn as a species on Earth has been spent, undoubtedly, as a member of a small hunting or food-gathering band or in small shifting hamlets or scattered dwellings as a primitive hoe or digging-stick agriculturalist. It would, furthermore, appear unlikely that his human horizons from birth to death ever brought him face to face with as many as one thousand members of his species—more likely, the upper limit of his close intimate contact with other human beings has been only a few hundred individuals. The small, nomadic or semi-nomadic bands or primitive agricultural communities rarely attained a population of over one hundred individuals, and contacts with outside groups were probably in-frequent, dangerous, and never free-and-easy.