The Visual-Predation Theory: A Binocular Look Backward

Although there is general agreement nowadays that the last common euprimate ancestor looked something like a diminutive mouse lemur or the Eocene primate Teilhardina, debate continues over the adaptive meanings of the synapomorphies that distinguished it from more primitive mammals. We review the background and history of the visual-predation theory of the origin of the order Primates, evaluate the objections and alternatives to it that have been put forward since it was first proposed in 1970, and conclude that with some corrections and additions, the visual-predation account continues to be the best available explanation for the origins of the euprimate synapomorphies. Nevertheless, the theory has implications that need to be tested through broad-based, multidisciplinary comparative research.