The human-genetics websites are abuzz over two papers in the July 6 issue of Science. The papers discuss rare variants in the human genome, which highlight differences between big old localized populations.
Steve Hsu at infoproc:
Deep sequencing of the human genome, which reveals rare variants (here, defined as those found in fewer than 0.5 percent of the population), shows that there is actually more variation between groups than within groups. (So what you may have been taught in school is not true ? sorry, that`s how science works sometimes.) The figure below, from this July 6 Science article, shows that over 50 percent of rare genetic variants are found in African populations (which have greater genetic diversity) but not in European populations. About 41 percent of all rare variants are found only in Europeans and not in Africans, and only 9 percent of the variants are common to both groups.
Razib Khan at Gene Expression:
I suspect this is going to be a big deal for some time. For humans we are coming to toward the end of the SNP-age and entering into the whole-genome-age. That means that the emphasis on common variation at the genomic level is going to give way somewhat to rarer, more particular, variation. One of the major takeaways is that a lot of this variation is going to be population specific . . . If I read this right we may be entering into a golden age of demographic history reconstruction, as rare variants and whole-genome catalogs of a huge number of humans are going to allow us to generate a very fine-grained map of human population diversity.
One thing`s for sure: the continued survival of Lewontin`s Fallacy ? I still hear it all the time ? is ever more inexplicable.