Spatial and temporal stability of mtDNA haplogroup frequencies in native North America

Mitochondrial DNA lineage frequencies in prehistoric Aleut, eastern Utah Fr emont, Southwestern Anasazi, Pyramid Lake, and Stillwater Marsh skeletal sa mples from northwest Nevada and the Oneota of western Illinois are compared with those in 41 contemporary aboriginal populations of North America. The ancient samples range in age from 300 years to over 6,000 years. The resul ts indicate that the prehistoric inhabitants of North America exhibit the s ame level of mtDNA variability as contemporary populations of the continent . Variation in modern mtDNA haplogroup frequencies is highly geographically structured, and the prehistoric samples exhibit the same geographic patter n of variation. This indicates that differentiation of regional patterns of mtDNA lineage variation occurred early in North American prehistory (much more than 2,000 years B.P.), has remained relatively stable since its origi n, and was little influenced by the disruptions hypothesized for other gene tic systems as a result of population declines and relocations at contact.