Visionary Research
Scientists delve into the evolution of color vision in primates
By John Travis
The next time you appreciate the beauty of a rainbow or the subtle hues of an impressionist masterpiece, you’ll be taking advantage of the human brain’s palette of an estimated 2.3 million colors. Why do people and many nonhuman primate species have the capability to distinguish so many hues? How did it benefit our ancestors to evolve this trait? After all, most mammals seem to do just fine with a less-discerning color vision. Dogs, cats, and many other familiar mammals, for example, can’t discriminate between reds and greens.
Perhaps the first person to address this issue was 19th-century biologist Grant Allen. His theory, developed while he was a professor in Jamaica, was that primates need their superior color vision to find fruits hidden among green leaves.