tag:blogger.com,1999:blog-7785493.post597210625097030721..comments2024-01-04T04:11:55.717+02:00Comments on Dienekes’ Anthropology Blog: An excess of X-chromosomal diversity in Africans Dienekeshttp://www.blogger.com/profile/02082684850093948970noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-7785493.post-13252732454290291302014-05-30T17:20:18.025+03:002014-05-30T17:20:18.025+03:00Dienekes wrote: "In my opinion, an explanatio...Dienekes wrote: "In my opinion, an explanation for this phenomenon might be found in the back-migration into Africa of Eurasian males (belonging to Y-haplogroup E)."<br /><br />But how does that explain the the lower ratio in Europe? We see as much or more movement of all kinds of Y-haplotypes into Europe. And, when it comes to ancient DNA, that ever-present H X-haplotype shows up along with an alphabet soup of Y types. Why should they have less impact than E into Africa?<br /><br />I think the problem is in the phrase "the stronger impact of diversity-reducing selection on X." But localized selection actually has the opposite effect, creating pockets of diversity.<br /><br />I think this unnecessarily sees the African genes are a single population. If they instead represent isolated pockets of people/females, then the diversity can be explained by multiple small selection on X events that had less effect on autosomal genetics. In contrast, European females may have been more wide-ranging and X diversity would have been "diversity-reducing selection."LivoniaGhttps://www.blogger.com/profile/05589404219598229067noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-17101642898640713882014-05-16T06:10:54.718+03:002014-05-16T06:10:54.718+03:00Everything in modern anthropology and genetics was...Everything in modern anthropology and genetics was first put forth by the groundbreaking studies by Cavalli-Sforza.<br /><br />I seem to remember in his book, granted, speaking about autosomal diversity, he stated something like, "there is more genetic diversity in the typical African village than there is in the entire continent of Europe."mooreisbetterhttps://www.blogger.com/profile/17522884275516185288noreply@blogger.com