Nor is it feasible to pretend that patterns of modern variation were established at the time of Out of Africa. At every turn we've seen that ancient populations are different than modern ones. We have an increased appreciation of gene-language correleations and the influence of agro-pastoral dispersals (occurring in the last 10,000 years) in shaping modern human variation. And, while we're at it, let's not forget selection, which must have been more intense the further away from the ancestral human habitat.
In short, there may very well be a pattern tracking an Out-of-Africa event in modern genetic variation -- if one overlooks a great number of confounding factors.
From the paper:
For the first time, we provide specific effective sizes for a wide range of Old World populations in relative and absolute values (Table S4) and a number of interesting patterns are revealed. The populations with the largest sizes other than Sub-Saharan Africans are North Africans (Moroccans and Egyptians), due to their known Sub-Saharan admixture (Krings et al. 1999; Bosch et al. 2001; Brakez et al. 2001). Outside of Africa, the largest Ne is found in South Asia; only recently, the high internal diversity of Indian populations is being appreciated (Xing et al. 2010). Europeans and East Asians have similar Ne. Tibetans and Basques showed the lowest values, a direct measure of small population size and isolation.
Mol Biol Evol (2011) doi: 10.1093/molbev/msr213
Recombination gives a new insight in the effective population size and the history of the Old World human populations
Marta Melé et al.
The information left by recombination in our genomes can be used to make inferences on our recent evolutionary history. Specifically, the number of past recombination events in a population sample is a function of its effective population size (Ne). We have applied a method, IRiS, to detect specific past recombination events in 30 Old World populations to infer their Ne. We have found that Sub-Saharan African populations have an Ne that is ∼ 4 times greater than those of non-African populations and that outside of Africa, South Asian populations had the largest Ne. We also observe that the patterns of recombinational diversity of these populations correlate with distance out of Africa if that distance is measured along a path crossing South Arabia. No such correlation is found through a Sinai route, suggesting that anatomically modern humans first left Africa through the Bab-el-Mandeb strait rather than through present Egypt.