Chewing performance and the structure of primate communities.

Area of Science:

• Ecomorphology
• Primate Ecology
• Paleoanthropology

Background:

• Ecomorphological theory links trait morphology to ecological performance and community structure.
• The relationship between premolar size, chewing performance, and diet in wild primates remains under-investigated.
• Understanding these links is crucial for reconstructing primate evolutionary history.

Purpose of the Study:

• To test the functional relationship between premolar tooth size and chewing performance in a diverse primate community.
• To investigate how premolar-mediated seed-eating influences primate community composition.
• To explore the implications for paleoanthropology and fossil hominin tooth size.

Main Methods:

• Comparative analysis of premolar tooth size and chewing performance across chimpanzees and seven monkey species.
• Controlled experiments assessing food fracture capabilities.
• Statistical analysis to account for chewing effort and seasonal grit ingestion.

Main Results:

• Larger premolars significantly improved food fracture performance.
• Granivorous primates exhibited 51-56% higher chewing performance than folivores and 64-68% higher than frugivores.
• Convergent evolution of enlarged premolars was observed in granivorous species.
• Premolar size and seed-eating were shown to shape primate community composition across nine African forest sites.

Conclusions:

• Premolar morphology is a key ecomorphological trait structuring primate communities.
• The selective pressure for enlarged premolars favors diets of brittle foods, with implications for understanding hominin evolution.
• This study integrates ecomorphology, functional performance, and community ecology to explain primate diversity.