Origins of Primates—Debates and Controversies

Abstract

Most current scenarios of primate origins depict small nocturnal animals feeding on insects and/or fruit, flowers and nectar in the complex small branch environments of tropical forests. Some of these elements, however, have been challenged, and still need to be comprehensively tested through formal comparative analyses or supported by fossil data. Key contextual elements of primate origins that require clarification include the phylogenetic relationships between primates, colugos, tree-shrews and plesiadapiforms, and the divergence times of associated clades. In addition, a consensus regarding patterns of phyletic size change in the primate stem lineage and the size of the last common ancestor of extant primates would help clarify both the likely physical environment that ancestral primates inhabited, and their dietary behavior.