Insights into the evolution of social systems and species from baboon studies

Abstract

Baboons, members of the genus Papio, comprise six closely related species distributed throughout sub-Saharan Africa and southwest Arabia. The species exhibit more ecological flexibility and a wider range of social systems than many other primates. This article summarizes our current knowledge of the natural history of baboons and highlights directions for future research. We suggest that baboons can serve as a valuable model for complex evolutionary processes, such as speciation and hybridization. The evolution of baboons has been heavily shaped by climatic changes and population expansion and fragmentation in the African savanna environment, similar to the processes that acted during human evolution. With accumulating long-term data, and new data from previously understudied species, baboons are ideally suited for investigating the links between sociality, health, longevity and reproductive success. To achieve these aims, we propose a closer integration of studies at the proximate level, including functional genomics, with behavioral and ecological studies.

Keywords: p. cynocephalus; Papio; baboon; evolutionary biology; fitness; phylogeography; social system; speciation.

Figure 1.. Distribution of the six Papio species.

Species distributions are modified from Zinner et al. (2013). Male baboon drawings by Stephen Nash. Reprinted with permission from Fischer et al. (2017).

Figure 2.. Illustration of key traits across baboon species.

(A) Phenotypic variation between species. Pictures show adult males and females. (B) Crania of male baboons. (C) Sexual swellings of female baboon during peak estrus. Species are grouped by social organization (uni- and multi-level) and dispersal behavior (male- or female-biased dispersal). Images from Alexis Amann, Andrea Cardini, Sarah Elton, Julia Fischer, Courtney Fitzpatrick, James Higham, Megan Petersdorf, Joan Silk and Larissa Swedell.