Bats are one of the most species-rich groups of modern mammals, and are particularly known for their ecological diversity. Bats fill numerous ecological niches worldwide, performing a variety of ecosystem functions and services. Evolutionary biologists often study ecological diversity in conjunction with morphology, as physical traits can be closely tied to performance and function. The bat skull has a highly complex shape that encodes information about ecological interactions. Multiple selective pressures influence the complex form of a modern bat skull, and by studying its morphological evolution, this research will reveal the ecological context of those evolutionary processes. This research will synthesize museum collections with cutting-edge imaging technology and shape analyses to model the evolution of a highly complex biological structure. The findings will be integrated into outreach programs in partnership with educational nonprofits and natural history museums. Both morphological and ecological diversity are critical components of biodiversity, and by emphasizing both facets in public education, the researchers will stress the importance of both ecological and evolutionary context in understanding ecosystem functions and services.
To accomplish these goals, the researchers will produce high-resolution X-ray computed microtomography (microCT) scans of a wide range of modern bat skulls. MicroCT scanning capture much of the complexity of biological structures that is lost with traditional, simple measurements. The data can be used for multidimensional analyses of trait evolution and physical reproductions. After scanning, bat skulls will be digitized for analysis using landmark-based geometric morphometrics, a method for quantifying shape variation. The researchers will then quantify the amount of morphological diversity present among modern bat skulls, and will model rates of shape evolution across the bat phylogenetic tree. Modules of the skull, which may be optimized for different functions like feeding, echolocation, and hearing, will be analyzed independently, to test the hypothesis that different ecological pressures interact with each other to govern skull shape evolution. Ultimately, these data will be used to test the links among morphological diversity, ecological function, and evolutionary diversification across modern bats.
