Journal Article

Environmental variation and rivers govern the structure of chimpanzee genetic diversity in a biodiversity hotspot

Thomassen, Henri A, Sesink Clee, Paul R, Mitchell, Matthew W, Gonder, Mary Katherine, Locatelli, Sabrina

2015

Overview

Background The mechanisms that underlie the diversification of tropical animals remain poorly understood, but new approaches that combine geo-spatial modeling with spatially explicit genetic data are providing fresh insights on this topic. Data about the diversification of tropical mammals remain particularly sparse, and vanishingly few opportunities exist to study endangered large mammals that increasingly exist only in isolated pockets. The chimpanzees of Cameroon represent a unique opportunity to examine the mechanisms that promote genetic differentiation in tropical mammals because the region is home to two chimpanzee subspecies: Pan troglodytes ellioti and P. t. trogolodytes . Their ranges converge in central Cameroon, which is a geographically, climatically and environmentally complex region that presents an unparalleled opportunity to examine the roles of rivers and/or environmental variation in influencing the evolution of chimpanzee populations. Results We analyzed microsatellite genotypes and mtDNA HVRI sequencing data from wild chimpanzees sampled at a fine geographic scale across Cameroon and eastern Nigeria using a spatially explicit approach based upon Generalized Dissimilarity Modeling. Both the Sanaga River and environmental variation were found to contribute to driving separation of the subspecies. The importance of environmental variation differed among subspecies. Gene-environment associations were weak in P. t. troglodytes, whereas environmental variation was found to play a much larger role in shaping patterns of genetic differentiation in P. t. ellioti . Conclusions We found that both the Sanaga River and environmental variation likely play a role in shaping patterns of chimpanzee genetic diversity. Future studies using single nucleotide polymorphism (SNP) data are necessary to further understand how rivers and environmental variation contribute to shaping patterns of genetic variation in chimpanzees.

• Publisher: BioMed Central,BioMed Central Ltd
• Subject: Africa / Analysis / Animal Systematics/Taxonomy/Biogeography / Animals / Biodiversity / Biodiversity and Ecology / Biological Evolution / Biomedical and Life Sciences / DNA, Mitochondrial - genetics / Entomology / Environmental aspects / Environmental associations / Environmental Sciences / Evolutionary Biology / Gene-Environment Interaction / Genetic Variation / Genetics / Genetics and Population Dynamics / Genetics, Population / Hominidae - genetics / Life Sciences / Microsatellite Repeats / Pan troglodytes / Pan troglodytes - classification / Pan troglodytes - genetics / Populations and Evolution / Research Article / Rivers / Troglodytes