Ecomorphology of sexual dimorphism

NSF DEB-2447166


Mammals display remarkable variation in the form and function of their skulls, related to what and how they eat. However, the skulls of individuals within a species can vary. If we ignore these differences, we risk missing important clues about how animals behave and adapt to their environments. This project will investigate which carnivoran mammals (i.e., bears, cats, dogs, and their relatives) show differences between males and females and why. The researchers will measure traits such as size and shape, biting ability, bone structure, and bone strength of skulls using computer models based on 3D scans of samples from local and national museum collections. The researchers will then test for differences in skull form between the sexes and whether they translate to differences in skull function. Finally, the researchers will test whether differences can be explained by diet or other aspects of their biology. The project will produce large datasets of 3D skull models. These will be saved in an online database that experts, educators, and the public alike can use to explore and learn. The project will also support training of undergraduate students and outreach and educational programs at a museum that reaches thousands of visitors a year.

As the primary feeding apparatus, the skull serves as a trophic morphology that is tightly linked to dietary variation and thus an ideal model to investigate the relationships between sexual dimorphism, ecomorphology, and phenotypic diversification. This project has four aims:

AIM I. Determine if and how sexually dimorphic morphologies translate to intersexual differences in the structural mechanics, performances, and biomechanics of the skull using lever mechanics and finite element analyses.
AIM II. Test how sexual selection, niche divergence, and other factors influence the evolution of sexual dimorphism of the morphological and functional traits.
AIM III. Examine how intraspecific variation produced by sexual dimorphism influences the diversity, tempo, and mode of skull evolution.
AIM IV. Test how static allometry contributes to the degree of sexual dimorphism within species and the evolutionary allometry of sexual dimorphism across the clade.


Mobirise





<= Phylogeny of carnivorans with examples of skull sexual dimorphism in which the degree of dimorphism ranges in size, shape, both size and shape, or neither size nor shape. Sexes are correctly scaled relative to each other, but size comparisons between species are not to scale.

Mobirise

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