Baboon biogeography, divergence, and evolution: Morphological and paleoecological perspectives.

Area of Science:

• Primate evolution
• Paleoecology
• Biogeography

Background:

• The genus Papio (baboons) originated in the early Pleistocene, diversifying into six extant species with notable phenotypic differences.
• Understanding baboon evolutionary history, including biogeography and divergence, is crucial for primate evolutionary studies.

Purpose of the Study:

• To examine baboon biogeography, divergence, and evolution, focusing on skull form and body mass.
• To investigate the evolutionary pressures shaping baboon morphology and distribution.

Main Methods:

• Historical biogeography techniques combining modern distribution data with fossil records to estimate ancestral ranges.
• Geometric morphometrics and partial least squares analysis to correlate skull form with diet and environment.
• Bayesian modeling to reconstruct ancestral body mass and analyze evolutionary patterns.

Main Results:

• The ancestral range of Papio was estimated to be in South Tropical Africa, with subsequent migrations south and west.
• Diet, particularly the exploitation of subterranean foods, was a more significant driver of skull morphology than environment.
• Accelerated body mass evolution was observed in several lineages, linked to Pliocene terrestrial niche exploitation.
• Male body mass heterogeneity suggests sexual selection as a primary driver of size differentiation.

Conclusions:

• Baboon evolutionary history is characterized by significant dietary influences on skull morphology and adaptive radiation into terrestrial niches.
• Sexual selection likely plays a key role in the observed body mass variation within the genus Papio.