Meeting Abstract
Among mammals, harsh environments, such as deserts or tundra, pose physiological challenges for their inhabitants. In particular, relatively arid or cold environments present unique challenges for the respiratory system. Therefore, mammals living in these regions often have adaptations for enhanced air conditioning such as relatively large respiratory turbinates, sinuses, or nasal fossae. However, these adaptations have been noted primarily in relatively large bodied mammals (e.g. carnivorans, hominins). Here, we test whether the same patterns in environmental adaptations may be applied to smaller bodied mammals by testing for their presence in Rodentia, an order of mammals that includes those at small body sizes. We used computed tomography scans from 66 rodent species, including representatives from Anomaluromorpha, Castorimorpha, Hystricomorpha, Myomorpha, and Sciuromorpha, to quantify the respiratory turbinate surface area, a proxy for respiratory epithelial surface area, scaled relative to skull length. We found a strong linear relationship between skull length and respiratory turbinate surface area but also noted substantial differences in respiratory turbinate morphology when comparing sciuromorphs with other rodent suborders included in this analysis. Despite these morphological differences, when controlling for phylogenetic relatedness, there are no statistically significant differences between biome groups. These results suggest that alternative behavioral strategies (e.g. burrowing or hibernating) may be used to cope with these environmental challenges, creating microclimates thus ameliorating the survival of the animals inhabiting those regions.
