An Eyeful of Natural Selection
Posted by Richard Conniff on October 1, 2012
You are looking at the hind end [see correction below] of various rainforest caterpillars. But if you thought for just a moment that you were looking at snakes or lizards, well, so do a lot of predators. And that’s the point.
These false eye spots give defenseless caterpillars a moment of protection, startling birds, for instance, into sudden retreat. The caterpillars that don’t have that startle effect get eaten up. Thus natural selection has made the trait widespread in the caterpillar world.