Florida Museum of Natural History, University of Florida
Thursday 11:30-11:45, Ballroom A
Human evolution is studied from many different perspectives, and recently much attention has been paid to the use of human parasites and pathogens as markers of human migration and human evolution. One particular parasite that has proven useful for studies of human evolution is the human head louse (genus Pediculus), which has been traveling on the lineage leading to modern human since it diverged from the lineage leading to chimpanzees. Pediculus was likely a parasite of every hominin that has existed. Because it cannot live on other hosts, it has journeyed with us, and its DNA contains a record of that journey. The mtDNA of head lice is for more diverse genetically than the mtDNA of modern humans, and the mtDNA of living lice dates back 2 million years unlike the much younger mtDNA coalescence of living humans. Our lab has just sequenced the full genomes of the chimpanzee louse (Pediculus schaeffi), as well as two deeply divergent clades of human head lice (P. humanus) whose mtDNA diverged 700,000 to 1.2 million years ago. These deeply divergent human lice offer a glimpse into our past evolutionary history. Our genomic studies suggest that the head lice of living humans originated on two different hominins living approximately 1 million years ago that remained isolated from one another until quite recently when admixture among the lice occurred. These results are consistent with the hypothesized isolation and recent admixture between Neanderthals and anatomically modern humans.