@article {308967,
	title = {Natural selection reduced diversity on human y chromosomes.},
	journal = {PLoS Genet},
	volume = {10},
	year = {2014},
	note = {http://www.plosgenetics.org/article/info\%3Adoi\%2F10.1371\%2Fjournal.pgen.1004064},
	month = {2014 Jan},
	pages = {e1004064},
	abstract = {<p>The human Y chromosome exhibits surprisingly low levels of genetic diversity. This could result from neutral processes if the effective population size of males is reduced relative to females due to a higher variance in the number of offspring from males than from females. Alternatively, selection acting on new mutations, and affecting linked neutral sites, could reduce variability on the Y chromosome. Here, using genome-wide analyses of X, Y, autosomal and mitochondrial DNA, in combination with extensive population genetic simulations, we show that low observed Y chromosome variability is not consistent with a purely neutral model. Instead, we show that models of purifying selection are consistent with observed Y diversity. Further, the number of sites estimated to be under purifying selection greatly exceeds the number of Y-linked coding sites, suggesting the importance of the highly repetitive ampliconic regions. While we show that purifying selection removing deleterious mutations can explain the low diversity on the Y chromosome, we cannot exclude the possibility that positive selection acting on beneficial mutations could have also reduced diversity in linked neutral regions, and may have contributed to lowering human Y chromosome diversity. Because the functional significance of the ampliconic regions is poorly understood, our findings should motivate future research in this area.</p>},
	keywords = {Chromosomes, Human, Y, Computer Simulation, DNA, Mitochondrial, Evolution, Molecular, Female, Genetic Drift, Genetic Variation, Genetics, Population, Genome, Human, Humans, Male, Mutation, Open Reading Frames, Selection, Genetic},
	issn = {1553-7404},
	doi = {10.1371/journal.pgen.1004064},
	url = {http://www.ncbi.nlm.nih.gov/pubmed/24415951},
	author = {Wilson Sayres, Melissa A and Lohmueller, Kirk E and Nielsen, Rasmus}
}
