South Asia 44.6 k yaThough I feel sure Maju will complain that once again I'm concentrating too much on that which suits my purpose, it's impossible for me to ignore this additional evidence for a genetic gap exactly where I see a very significant cultural gap. For reasons that the authors themselves find difficult to explain, the M haplogroups confined mostly to South Asia are estimated by their own procedures to be significantly younger than those for East Asia, Oceania or Southeast Asia. To be consistent with a straightforward, continuous Out of Africa scenario, they should be older than the others, not younger. A very similar result was obtained by Soares et al (see Post 262 for discussion). To be fair, I'll quote their explanation for what to them is clearly an anomaly:
East Asiaa 69.3 k ya
Oceania 73.0 k ya
SE Asia 55.7 k ya
The abnormal younger age (~44 x 10 cubed years) of the Indian M lineages may be attributed to the unequal age contributions from different M haplogroups to the total M age estimate. The frequency composition of the particular M haplogroups in a population sample from India then matters a lot because the ages contributed by the different branches range from 21 x 10 cubed years (M30a) to 93 x 10 cubed years (M6b). Our sample drawn for complete sequencing does not reflect the natural frequencies and therefore could bias the age estimation.
To investigate this, we simulated a natural frequency distribution by assigning the mtDNAs sampled from the Chenchu and Koya populations (Kivisild et al. 2003) to
their respective haplogroups by (near) matching control region motifs (Yao et al. 2002). Fewer than 5% of the mtDNAs were virtually unassignable, so that the remaining 142 mtDNAs could be used to evaluate the natural frequency of each M branch in [the] Indian population (table 2).