`The initial settlement took place 65,000 years ago in the Andamans and in ancient south India around the same time, which led to population growth in this part,'' said Thangarajan. He added, ``At a later stage, 40,000 years ago, the ancient north Indians emerged which in turn led to rise in numbers here. But at some point of time, the ancient north and the ancient south mixed, giving birth to a different set of population. And that is the population which exists now and there is a genetic relationship between the population within India.''