Saturation refers to the depth, or richness, of a color: pastels are examples of highly desaturated colors. At the photoreceptor layer, saturation originates from imbalances in the relative response ...

Add Yahoo as a preferred source to see more of our stories on Google. Color patterns seen in fish and other animals evolved to serve various purposes. Lagunatic Photo/iStock via Getty Images Plus A ...

Similarities in how different organisms look can indicate a close evolutionary relationship. Conversely, great differences in appearance can suggest a very distant relationship, as in many adult ...

Scientists are moving closer to answering some age-old questions. How did the leopard get its spots? How did the zebra get its stripes? The answer may be a gene called Agouti, which the scientists ...

An international team of scientists working with Heliconius butterflies in Panama was faced with a mystery: how do pairs of unrelated butterflies from Peru to Costa Rica evolve nearly the same ...