Variation in white-tailed and mule deer dental metrics is associated with precipitation gradients in the Americas

Investigating the relationship between the physical environment and organismal adaptation is crucial to understanding the selective pressures that drive mammalian evolution. Of the varied approaches to exploring this relationship, macroscopic tooth wear analyses have become widely used due to their economic and simple methodologies. However, more work is needed to understand how assessments of wear patterns operate within finer levels of dietary and environmental contexts. It is specifically unclear if and how tooth wear differs inter- and intraspecifically between geographically widespread, large-bodied mammalian populations. This project characterizes molar hypsodonty indices and mesowear scores of white-tailed deer (Odocoileus virginianus) and mule deer (Odocoileus hemionus) populations across North and Central America, investigating if and how molar wear and morphology vary over the deer's large and ecologically variable geographic distribution. While mesowear scores generally do not strongly track environmental signals within and between Odocoileus species, hypsodonty indices reveal a strong correlation between crown height and aridity, which likely represents an adaptive response to abrasive diets in areas with low precipitation.