The Pith:<\/b> The human X chromosome is subject to more pressure from natural selection, resulting in less genetic diversity. But, the differences in diversity of X chromosomes across human populations seem to be more a function of population history than differences in the power of natural selection across those populations.<\/i><\/p>\n
In the past few years there has been a finding that the human X chromosome exhibits less genetic diversity than the non-sex regions of the genome, the autosome. Why? On the face of it this might seem inexplicable, but a few basic structural factors derived from the architecture of the human genome present themselves.<\/p>\n
First, in males the X chromosome is hemizygous<\/a>, rendering it more exposed to selection. This is rather straightforward once you move beyond the jargon. Human males have only one copy of genes which express on the X chromosome, because they have only one X chromosome.<\/strong> In contrast, females have two X chromosomes. This is the reason why sex linked traits<\/a> in humans are disproportionately male. For genes on the X chromosome women can be carriers of many diseases because they have two copies of a gene, and one copy may be functional. In contrast, a male …<\/p>\n","protected":false},"excerpt":{"rendered":" The Pith: The human X chromosome is subject to more pressure from natural selection, resulting in less genetic diversity. But, the differences in diversity of X chromosomes across human populations seem to be more a function of population history than …<\/p>\n","protected":false},"author":12,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9,204,255,1635,4,82,30,713,720,481,525,299,12,714],"tags":[],"class_list":["post-42772","post","type-post","status-publish","format-standard","hentry","category-anthroplogy","category-evolutionary-genetics","category-evolutionary-genomics","category-genetic-diversity","category-genetics","category-genomics","category-human-evolution","category-human-evolutionary-genetics","category-human-evolutionary-genomics","category-human-genetics","category-human-genomics","category-out-of-africa","category-population-genetics","category-x-chromosome"],"_links":{"self":[{"href":"https:\/\/www.razib.com\/wordpress\/wp-json\/wp\/v2\/posts\/42772","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.razib.com\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.razib.com\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.razib.com\/wordpress\/wp-json\/wp\/v2\/users\/12"}],"replies":[{"embeddable":true,"href":"https:\/\/www.razib.com\/wordpress\/wp-json\/wp\/v2\/comments?post=42772"}],"version-history":[{"count":1,"href":"https:\/\/www.razib.com\/wordpress\/wp-json\/wp\/v2\/posts\/42772\/revisions"}],"predecessor-version":[{"id":42790,"href":"https:\/\/www.razib.com\/wordpress\/wp-json\/wp\/v2\/posts\/42772\/revisions\/42790"}],"wp:attachment":[{"href":"https:\/\/www.razib.com\/wordpress\/wp-json\/wp\/v2\/media?parent=42772"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.razib.com\/wordpress\/wp-json\/wp\/v2\/categories?post=42772"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.razib.com\/wordpress\/wp-json\/wp\/v2\/tags?post=42772"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}