Shapur
June 18th, 2004, 12:34 PM
Is HG3 the proto Indo-European marker?
The distribution of HG 3 chromosomes resembles the third principal component of varioation of classical gene frequencies. There are several possible interpretations of this pattern. One explanation (Cavalli-Sforza et al. 1994) is that it marks the Kurgan expansion from north of the Caspian Sea, dated to ~7,000 YBP. However, alternative explanations - such as the spread of pastoralism, or east-to-west movements of people such as the Scythians, Mongols, and Huns - seem equally likely (Renfrew 2000). Globally, HG3 chromosomes are absent from Africa and Americas, but their distribution is wide within Asia as well as in Europea (Zerjal et. al 1999), consistent with their association with a recent and major expansion within Eurasia. Microsatellite diversity analysis (Zerjal et al. 1999) used the mutationrate estimates of Heyer et al. (1997) to date the most recent common ancestor of a set of European and Asian HG3 chromosomes to 3,800 YBP (95% confidence interval [CI] 1,600-13,000 YBP); the use of more-recent mutation-rate estimates (Kayser et al. 2000) would yield a date of 2,550 YBP (95% CI 1,650-4,260 YBP). Coalecent analysis has dated the SRY-1532 mutation defining HG 3 to ~7,500 YBP (Karafet et al. 1999). If these datas are to be relied on, they seem to suggest that the expansion of HG 3 chromosomes was due to population movements later then those of the Kurgan people.
Curenntly, dates cannot be attached to the clines, and the modern distributions of lineages are the outcome of many millennia of population movement, Assigning plausible daet to demofraphic movements is important, and here the Y chromosome can potentially contribute. Finer-scale definitions of monophyletic linages within Europe, by use of new markers, and the analysis of these, by use of microsatellites, offers the possibilty that thimescales for the major demoraphic events can be inferred.
The distribution of HG 3 chromosomes resembles the third principal component of varioation of classical gene frequencies. There are several possible interpretations of this pattern. One explanation (Cavalli-Sforza et al. 1994) is that it marks the Kurgan expansion from north of the Caspian Sea, dated to ~7,000 YBP. However, alternative explanations - such as the spread of pastoralism, or east-to-west movements of people such as the Scythians, Mongols, and Huns - seem equally likely (Renfrew 2000). Globally, HG3 chromosomes are absent from Africa and Americas, but their distribution is wide within Asia as well as in Europea (Zerjal et. al 1999), consistent with their association with a recent and major expansion within Eurasia. Microsatellite diversity analysis (Zerjal et al. 1999) used the mutationrate estimates of Heyer et al. (1997) to date the most recent common ancestor of a set of European and Asian HG3 chromosomes to 3,800 YBP (95% confidence interval [CI] 1,600-13,000 YBP); the use of more-recent mutation-rate estimates (Kayser et al. 2000) would yield a date of 2,550 YBP (95% CI 1,650-4,260 YBP). Coalecent analysis has dated the SRY-1532 mutation defining HG 3 to ~7,500 YBP (Karafet et al. 1999). If these datas are to be relied on, they seem to suggest that the expansion of HG 3 chromosomes was due to population movements later then those of the Kurgan people.
Curenntly, dates cannot be attached to the clines, and the modern distributions of lineages are the outcome of many millennia of population movement, Assigning plausible daet to demofraphic movements is important, and here the Y chromosome can potentially contribute. Finer-scale definitions of monophyletic linages within Europe, by use of new markers, and the analysis of these, by use of microsatellites, offers the possibilty that thimescales for the major demoraphic events can be inferred.