Biogeography and Primates: A Review

Abstract

In this paper, we present an introduction to primate biogeography at a continental level and then review the literature as it pertains to primate studies. Primate species diversity is highest in the Neotropics and Asia. Most primates range into rain/humid forests in Africa, Asia, and the Neotropics. Asia contains the highest total number of primate species (N = 38) that are considered to require conservation attention, followed closely by the Neotropics (N = 33 species). These biogeographic patterns reflect complex phylogenetic, geologic, and ecological processes. The various biogeographic theories and models used to explain these patterns can be organized into several broad categories (1) descriptive studies, (2) comparative-quantitative approaches, (3) refugia theory, (4) phylogenetic approaches, (5) community ecology, and (6) conservation biology. Descriptive models have been derived from distribution data obtained during collecting expeditions. These models focused on geographic variations in species characteristics and barriers to dispersal (e.g., Gloger’s Rule, Bergmann’s Rule, Allen’s Rule, river barrier hypothesis). With the advent of digitized statistical procedures, these barriers became testable biogeographic hypotheses using comparativequantitative models. Thus, many researchers have noted the importance of rivers as geographical subdivisions of populations of a species. Comparative-quantitative models have also involved studies of species-area and distribution-abundance relationships. Generally, larger areas are more species rich and widely distributed primates tend to exist at higher densities. Many researchers have also investigated various ecological correlates (e.g., rainfall, latitude) to patterns of primate species richness. There has been considerable debate regarding the importance of Pleistocene Refugia for understanding the historical biogeography of primates. Phylogenetic or cladistic biogeography focuses on shared derived characters, which can be used to reconstruct biogeographical history. The presence or absence of species within a geographic area has been investigated extensively through studies of community ecology. Similarities between primate communities are most likely if they share a common biogeographic history. Composition of primate communities can also reflect evolutionary niche dynamics. Finally, researchers studying primate conservation biology have synthesized methods from various biogeographic models to understand and predict primate rarity and extinction events. Much of the renewed interest in primate biogeography tends to focus on the spatial and temporal patterns that influence species origins and diversity.