tag:blogger.com,1999:blog-7785493.post3924399430569914046..comments2024-01-04T04:11:55.717+02:00Comments on Dienekes’ Anthropology Blog: Age estimation of Y chromosome lineages (Adamov & Karzhavin 2010)Dienekeshttp://www.blogger.com/profile/02082684850093948970noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-7785493.post-57784747422652971852010-08-19T10:27:37.310+03:002010-08-19T10:27:37.310+03:00Dear Dienekes:
I just wanted to say how much I en...Dear Dienekes:<br /><br />I just wanted to say how much I enjoy your site.<br /><br />SteveSteve Sailerhttps://www.blogger.com/profile/11920109042402850214noreply@blogger.comtag:blogger.com,1999:blog-7785493.post-81191087736905357762010-08-18T21:52:33.685+03:002010-08-18T21:52:33.685+03:00The authors write: "As the current
research ...The authors write: "As the current <br />research has shown, the size of tribal population is a critical parameter affecting the quality of the estimates of the initial ancestor life time and of <br />the ancestral haplotype values. Tribal populations with number of members less than 200-300 men, <br />can not be reliably investigated using above-mentioned parameters at all. It is concerned first of all the isolates in the Amazonian and the Indonesian jungles, as well as some nations on the Far North."<br /><br />Let's compare it with a statement made by Zhivotovsky (with a nod at Cavalli-Sforza) in his 2001 paper "Estimating Divergence Time with the Use of Microsatellite Genetic Distances":<br /><br />"Indeed, among the current human populations, South American aboriginals [and these are specifically the Surui and Karitiana that have low population sizes - GD] can be considered a reference for microsatellite variation in an ancient African ancestor because their population size is low and might be compared with that estimated for an African ancestor, from one to a few thousand gametes (Rogers and Harpending 1992 ; Rogers 1995 ; Rogers and Jorde 1995; Zhivotovsky et al. 2000), and they have maintained their style of life probably since they arrived in this area (L. L. Cavalli-Sforza, personal communication). On the other hand, the Southern American Indian populations have descended from Asians, whose variation is very high, and thus the time since human colonization of South America might not have been sufficient to reduce microsatellite variation to the level of that in the ancestral population in Africa. Also, gene flow between even small villages can greatly increase within-population variance at microsatellite loci (Feldman, Kumm, and Pritchard 1999). Nevertheless, there is no objective proof of whether or not variation at the studied loci in South Amerindians is close to an African ancestral value. Therefore, the corresponding estimates of TD should be taken cautiously."<br /><br />Any thoughts of how these two statements [I included full quotes for context] correlate or conflict with each other and what the implications might be?German Dziebelhttps://www.blogger.com/profile/10703679732205862495noreply@blogger.com