Question

A biologist observes that a species of stick insects on a remote island has three different color traits, almost equally distributed among the population. One phenotype is dark green, a second is light green, and a third is light green with dark green stripes. Over a decade, the biologist observes that the dark green phenotype becomes the most abundant, making up nearly 70% of the population. Which statement is the best explanation for this phenomenon?

Answer 1

Mostly because of adaption to other areas in the world 

Answer 2

Natural selection, the dark green probably blends into trees better than the light green ones. The light green probably kept getting eaten so they had to adapt and change to dark green or get eaten.