Opportunity for natural selection among the Indian populations.

A critical review of data on opportunity for natural selection among the Indian populations has been made. These data on 96 populations were analysed according to regional, habitat, and socioeconomic backgrounds. The trends observed on the basis of these Indian data have been compared with worldwide data and data from industrialized nations. As in the industrialized nations, a gradual decrease in I(m) and I(t) is observed with improving socioeconomic and technological status in the Indian populations. The Indian situation is similar to that of the first phase in the modern demographic transition among the industrialized nations.