The Mitochondrial Gene Tree Comes of Age

Mitochondrial DNA (mtDNA) has been illuminating human evolution for almost 20 years, but it is only now that complete mtDNA sequences are finally being published in substantial numbers. One of the great virtues of mtDNA—arising from its cytoplasmic inheritance, lack of recombination, and high mutation rate—is the opportunity it provides for detailed estimation of the human maternal genealogy. With the arrival of complete sequences, it is timely to make explicit the issue of genealogical resolution, since these data will give us as much information as we can expect ever to obtain on the shape of the mitochondrial gene tree. The issue of genealogical resolution has been a major, often unacknowledged factor from the very beginning, and has underlain many of the debates about demographic history that mtDNA has provoked