Despite this descent of only two genetic strains, today's Indian society is breaking up into many small groups. They are apparently not only culturally and geographically isolated from each other, but also genetically. The researchers attribute this to the so-called founder effect. Thus, when a new population is created by a few individuals, a group with significantly reduced genetic diversity is created. Moreover, if the newly formed populations do not remix, they will genetically evolve in different directions due to the different source material. That's exactly what has happened in India since its settlement some 60, 000 years ago.
On the one hand, it would be possible to identify the genetic ancestors of a group by the genome of a few members, the researchers draw a first conclusion from their study. On the other hand, it is difficult to give an overview of the genetic diversity of the entire Indian population. In addition, the scientists suspect that many hereditary diseases are widespread in India, because the founder effect may have similar effects as inbreeding. The genetic material of individual families or groups is not mixed during reproduction, which leads to an accumulation of disease genes. The researchers were also able to confirm that the individual castes developed from ancient tribes and did not have their own caste system in each tribe.David Reich (Harvard University, Boston) et al .: Nature, Vol. 461, p. 489 ddp / science.de - Martina Bisculm advertisement