Desiccation tolerance and Starvation resistance exhibit opposite altitudinal cline in Indian populations of Drosophila immigrans

Altitudinal variations in desiccation tolerance and starvation resistance in D.immigrans populations are organized into adaptive clines. D.immigrans populations are characterized by increase in desiccation while starvation decreases and such opposite clines match climatic conditions. Regression analysis helps in explaining such adaptations. Upto now, there is no detailed data on altitudinal clines in Drosophila species and populations. Present data on genetic differentiation in D.immigrans populations evidence that such geographical clines are adaptive and maintained due to environmental gradients along the altitude.