TY - JOUR T1 - Natural Selection Reduced Diversity on Human Y Chromosomes A1 - Wilson Sayres, Melissa A. A1 - Lohmueller, Kirk E. A1 - Nielsen, Rasmus Y1 - 2014/01/09 N2 - Author Summary The human Y chromosome is found only in males, and exhibits surprisingly low levels of genetic diversity. This low diversity could result from neutral processes, for example, if there are fewer males successfully mating (and thus fewer Y chromosomes being inherited) relative to the number of females who successfully mate. Alternatively, natural selection may act on mutations on the Y chromosome to reduce genetic diversity. Because there is no recombination across most of the Y chromosome all sites on the Y are effectively linked together. Thus, selection acting on any one site will affect all sites on the Y indirectly. Here, studying the X, Y, autosomal and mitochondrial DNA, in combination with population genetic simulations, we show that low observed Y chromosome variability is consistent with models of purifying selection removing deleterious mutations and linked variation, although positive selection may also be acting. We further infer that the number of sites affected by selection likely includes some proportion of the highly repetitive ampliconic regions on the Y. Because the functional significance of the ampliconic regions is poorly understood, our findings should motivate future research in this area. JF - PLOS Genetics JA - PLOS Genetics VL - 10 IS - 1 UR - https://doi.org/10.1371/journal.pgen.1004064 SP - e1004064 EP - PB - Public Library of Science M3 - doi:10.1371/journal.pgen.1004064 ER -