(1) Mutation Rate:
This is the second published study to calibrate the substitution mutation rate for the YDNA based on fossil evidence, to do this, they used a combination of derived mutation rates from 2 separate fossils; the 12.6 KY old Anzick fossil from Montana belonging to haplogroup Q1b and the 4 KY old Saqqaq fossil from Greenland belonging to haplogroup Q2b. The first study, Fu (2014) used the 45 KY old Ust-Ishim fossil from Siberia belonging to haplogroup K(xLT). Interestingly, despite the big difference in age of these fossils of ~ 36 KYA (on average), the derived mutation rates were quite close to each other, with the current study's central estimate only ~8% slower than the rates derived from the Ust-Ishim fossil. The 95% CI bounds for this study were however less tight than the 95% CI bounds of Fu (2014). I have already incorporated these new rates into the TMRCA calculator under Karmin (2015).
(2) Coalescence of Non-African YDNA chromosomes:
The authors report :
....... a cluster of major non-African founder haplogroups in a narrow time interval at 47–52 kya, consistent with a rapid initial colonization model of Eurasia and Oceania after the out-of-Africa bottleneckWhich aligns almost perfectly with the recent find in Manot, Israel of the 49.2 - 60.2 KY old non-African AMH fossil believed of being closely related to the ancestors of all extant non-Africans, i.e. the first OOA migrants.
(3) A "New" E1b1b (E-M215) topology:
The "new" topology of E-M215 they outline below is in-fact over 3 years old, actually, we knew more back then than what they show in this paper today (see here)
|E-M215 Karmin (2015)|
The unanswered questions with respect to the major topology of E-M215 remain:
- What is the relationship, if any, of E-V92 with respect to E-Z827, E-Z830 or E-V68
- What is the relationship, if any, of E-V6 with respect to E-Z827, E-Z830 or E-V68
A recent bottleneck of Y chromosome diversity coincides with a global change in culture
It is commonly thought that human genetic diversity in non-African populations was shaped primarily by an out-of-Africa dispersal 50–100 thousand yr ago (kya). Here, we present a study of 456 geographically diverse high-coverage Y chromosome sequences, including 299 newly reported samples. Applying ancient DNA calibration, we date the Y-chromosomal most recent common ancestor (MRCA) in Africa at 254 (95% CI 192–307) kya and detect a cluster of major non-African founder haplogroups in a narrow time interval at 47–52 kya, consistent with a rapid initial colonization model of Eurasia and Oceania after the out-of-Africa bottleneck. In contrast to demographic reconstructions based on mtDNA, we infer a second strong bottleneck in Y-chromosome lineages dating to the last 10 ky. We hypothesize that this bottleneck is caused by cultural changes affecting variance of reproductive success among males.
Link (Closed Access)