Hannah M. Buchanan-Smith

This multidisciplinary paper integrates long-standing ideas on the evolution and ecology of primate color vision, and analyzes them in the light of field data. This is a lively but quite small subject, and citations come perhaps because it addresses a number of topics of interest.

There are some new ideas, but the main purpose in our view is to use substantial field data on fruit eaten by monkeys to consolidate and perhaps clarify long-standing questions about the ecology and evolution of primate trichromacy.

Daniel Colaco Osorio

Members of a troop of New World monkeys, such as the tamarins that we studied, have different types of color vision, which correspond roughly to normal human color vision (trichromacy), and the range of red-green color deficiencies found amongst humans (dichromacy). All males are dichromatic (red-green color blind), as are about half the females. Other females have trichromatic color vision.

We ask how this natural diversity of color vision is maintained by natural selection.

Will animals within a troop do better if they do not have the same type of color vision as their companions, or are the many forms of color vision maintained because it allows a few females to attain the ideal of standard trichromatic color vision (that is by "heterozygote advantage")?

This is interdisciplinary research. Daniel Osorio and Misha Vorobyev are visual neuroscientists, with a particular interest in the ecology and evolution of color vision. They work on a wide variety of animals by modelling, psychophysical experiments.

Andrew C. Smith and Hannah M. Buchanan-Smith are primatologists with an interest in the social and feeding biology of tamarins.

The study is based on extensive fieldwork in Peru, and is one of a number of projects based throughout the tropics that have looked at color vision and the foraging ecology of primates. A notable challenge here is to make accurate spectroscopic measurements under field conditions.

Our work has no major social implications. It does however show how that primate senses are evolved to serve particular needs, such as finding food, and so emphasizes our place in the natural world.