A decade ago, the first reviews of the collective mitochondrial DNA (mtDNA) data from Native Americans concluded that the Americas were peopled through multiple migrations from different Asian populations beginning more than 30,000 years ago.1 These reports confirmed multiple-wave hypotheses suggested earlier by other sources and rejected the dominant Clovis-first archeological paradigm. Consequently, it appeared that molecular biology had made a significant contribution to the study of American prehistory. As Cann2 comments, the Americas held the greatest promise for genetics to help solve some of the mysteries of prehistoric populations. In particular, mtDNA appeared to offer real potential as a means of better understanding ancient population movements. A decade later, none of the early conclusions remain unequivocal. Nevertheless, in its maturity, the study of Native American mtDNA has produced a volume of reports that still illuminate the nature and timing of the first peopling and postcolonization population movements within the New World.