Presentation
Genetically patterned dental phenotypes show evidence for diet-related evolutionary change in platyrrhine primates
The 87th Annual Meeting of the American Association of Physical Anthropologists
(2018)
Abstract
Genetically patterned (GP) dental phenotypes have been shown in catarrhine primates to change over evolutionary time in ways suggestive of dietary niche partitioning and replacement. Platyrrhine primates, as a radiation, have been hypothesized to have differentiated primarily due to dietary differences. To test this hypothesis, we used two GP dental phenotypes – the molar-molar inhibitory cascade (MMC) and the premolar-molar genetic module (PMM) – to investigate patterns of variation in platyrrhine mandibular dentition across 335 museum specimens representing 32 taxa in 14 genera. Preliminary results suggest that the majority of atelid and pitheciid platyrrhines occupy a relatively undifferentiated dental morphospace, consistent with hominoid morphology associated with frugivory. PGLS regressions of these traits using a molecular phylogeny modified from 10ktrees suggest that, although platyrrhines largely show variation consistent with Brownian motion models of evolutionary change (PMM: Pagel’s λ = 0.74; MMC: Pagel’s λ = 0.74), the genera Alouatta and Plecturocebus appear to be outliers. While the change seen in Alouatta is consistent with folivorous hominoids (like Gorilla), Plecturocebus occupies a unique morphospace that is difficult to interpret, comparable only to hominins. Among the Cebidae, the loss of the third molar in most callitrichin taxa may have resulted in changes to relative terminal molar size, suggesting potential selection for change in the MMC to accommodate M3 loss. With further analysis, the dietary and taxonomic signals in GP dental phenotypes should give greater resolution in determining both fossil platyrrhine taxonomy and behavior and patterns of evolutionary change in platyrrhines.
Keywords
- Dental phenotypes,
- Platyrrhine primates
Disciplines
Publication Date
April 14, 2018
Location
Austin, TX
Citation Information
Schmitt CA, Cooke SB, Brasil MF, Monson TA, Hlusko LJ. 2018. Genetically patterned dental phenotypes show evidence for diet-related evolutionary change in platyrrhine primates. American Association of Physical Anthropologists, Austin, TX.