Widespread origins of domestic horse lineages

Domestication entails control of wild species and is generally regarded as a complex process confined to a restricted area and culture. Previous DNA s equence analyses of several domestic species have suggested only a Limited number of origination events. We analyzed mitochondrial DNA (mtDNA) control region sequences of 191 domestic horses and found a high diversity of matr ilines. Sequence analysis of equids from archaeological sites and Late Plei stocene deposits showed that this diversity was not due to an accelerated m utation rate or an ancient domestication event. Consequently, high mtDNA se quence diversity of horses implies an unprecedented and widespread integrat ion of matrilines and an extensive utilization and taming of wild horses. H owever, genetic variation at nuclear markers is partitioned among horse bre eds and may reflect sex-biased dispersal and breeding.