Primate Fruit Color: Useful Concept or Alluring Myth?

Abstract

While the importance of frugivorous primates as seed dispersers is well established, the question of the extent to which they exert selective pressure on fruit color phenotypes is contested. Numerous studies have identified suites of primate fruit colors, but the lack of agreement among them illustrates the difficulty of identifying the match between primate foraging behavior and the extent of primate–plant coevolution. This may indicate that primates do not shape fruit traits, at least in a consistent direction, or that the evolution of fruit color is affected by a complex array of selection pressures in which primates play only a part. Here, we review the role of primates in shaping fruit color in the context of primate color vision phenotypes, and fruit phenotypic constraints and selective pressures. To test the hypothesis that fruit color is subjected to selection pressures by primates, we offer six testable predictions aimed at disentangling the complex array of factors that can contribute to fruit color phenotypes, including animal mutualists, animal antagonists, and developmental and phylogenetic constraints of fruits. We conclude that identifying the importance of primate seed dispersers in shaping fruit visual traits is possible, but more complex than previously thought.