Have you ever wondered why some people have lighter eyes than others? Differences in iris coloration have traditionally been explained as a result of sexual selection, but a recent study led by ...

Composite images of Saturn’s rings, taken by NASA’s Hubble Space Telescope, have revealed mysterious color variations that hint that the rings could be made of materials from the outer solar system.

One of the curious things in the world of birds is why most species come in only one color form, while others come in many. We can start with the western tanager. Adult males all look the same. Adult ...

A variety of animals have male-specific ornament traits and these ornaments are favored by female choice. Which male traits are preferred by females often varies among females. Genetic mechanisms that ...

How are reptiles capable of generating such a diversity of bright colors? And how is it possible that within a single population of the same species, different individuals exhibit strikingly different ...