9318770 Jacobs Color vision is extremely valuable for discriminating objects and yielding information about the contents of objects. Primates are often considered to have the keenest sense of color among mammals, but we have data on only about 20 of the roughly 200 non-human primate species. Recent findings show that the distribution of two or three distinct photopigments, termed dichromacy or trichromacy respectively, is far more complex than earlier understood, with a genetic polymorphism in the types of pigment in the photoreceptor cone cells of the eye, showing a striking gender difference in the squirrel monkey. This project uses a portable, non-invasive set of electrophysiological and behavioral tests to evaluate the correctness of emerging views on primate color vision and its evolution. Species to be tested have been selected for particularly appropriate comparisons to rigorously examine the generalization about high individual variation among the group known as the New World monkeys, the generalization about little variation and human-like properties of trichromacy of the Old World monkeys, and to extend the very limited knowledge about the prosimians which are a very important group for understanding the evolutionary issues. The impact of these studies will continue to extend beyond visual neuroscience into anthropology, molecular evolution, and genetics, and the testing methodology may stimulate novel efficient tests for human adult and infant visual capabilities. ***
