Mitochondrial Diversity in Human Head Louse Populations Across the Americas

MARINA S. ASCUNCE; JACKIE FANE; GEBREYES KASSU; ARIEL C. TOLOZA; MARIA I. PICOLLO; ANGELICA GONZALEZ-OLIVER; DAVID L. REED

AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY

WILEY-LISS, DIV JOHN WILEY & SONS INC

Lugar: New York; Año: 2013 vol. 152 p. 118 - 129

0002-9483

Anthropological studies suggest that thegenetic makeup of human populations in the Americasis the result of diverse processes including the initial colonizationof the continent by the first people plus post-1492 European migrations. Because of the recent natureof some of these events, understanding the geographicalorigin of American human diversity is challenging. However,human parasites have faster evolutionary ratesand larger population sizes allowing them to maintaingreater levels of genetic diversity than their hosts. Thus,we can use human parasites to provide insights intosome aspects of human evolution that may be unclearfrom direct evidence. In this study, we analyzed mitochondrialDNA (mtDNA) sequences from 450 head licein the Americas. Haplotypes clustered into two wellsupportedhaplogroups, known as A and B. Haplogroupfrequencies differ significantly among North, Centraland South America. Within each haplogroup, we foundevidence of demographic expansions around 16,000 and20,000 years ago, which correspond broadly with thoseestimated for Native Americans. The parallel timing ofdemographic expansions of human lice and NativeAmericans plus the contrasting pattern between the distributionof haplogroups A and B through the Americassuggests that human lice can provide additional evidenceabout the human colonization of the New World.