Squirrel monkeys, which are naturally red-green color-blind, can attain humanlike color vision when injected with the gene for a human photoreceptor. The research, performed in adult animals, suggests ...

Scientists reconstructed 500 million years of evolutionary history to reveal which came first: colorful signals or the color vision needed to see them. The natural world is awash with color, and many ...

Bold hues of red, orange, yellow, blue and purple help plants and animals communicate with their own species and others in their efforts to survive. Vivid orange dart frogs warn predators of their ...

Two male squirrel monkeys now see the world in a whole new way — in full color. Female squirrel monkeys can see in color, but male squirrel monkeys are normally red-green colorblind because they lack ...