Variations in primate color vision: Mechanisms and utility

Among mammals, only the primates have acquired the biological machinery needed for highly acute color vision. That distinction led Gordon Walls, perhaps the foremost authority on comparative vision of this century, to suggest long ago that “the color vision of the higher primates is assuredly a law unto itself, genetically and historically speaking.”1 Primate color vision is indeed unique. One manifestation of this uniqueness is that color vision abilities vary significantly, not only between some groupings of primate species, but, remarkably, among individuals of a considerable number of species. Although the functional significance of these variations remains, in large measure, to be sorted out, the past decade has brought much progress in revealing the mechanisms that underlie variation.