Comparison of the physiology and morphology of white-footed mice (Peromyscus leucopus) under semi-natural, laboratory, and wild environments

Abstract

Environment can be an incredibly impactful factor on the physiology and morphology of an animal. Research is often conducted under highly controlled laboratory conditions or in the field on wild populations. Experiments conducted under laboratory conditions minimize variation in the environment which provides clearer results and interpretations from experimental manipulations. On the other hand, field experiments have a highly variable environment, but provide a snapshot of the physiology of wild animals in the environment they evolved under providing results that are ecologically relevant. Recently, semi-natural enclosures are being used to provide the experimental control of laboratory experiments in an ecologically relevant environment. Semi-natural enclosures are often outdoors to provide natural environmental conditions but are contained so some resources like food and shelter can be manipulated while maintaining a consistent population over time. However, there is little research on how laboratory, semi-natural, and wild experiments compare. In this dissertation, I first examine the mitochondrial physiology, sperm morphology, and bone morphology of white-footed mice (Peromyscus leucopus) reared under laboratory conditions, semi-natural enclosures, and a wild population. Overall, I found many differences in the wild and laboratory populations. Importantly, in many measurements the semi-natural population were like the wild population offering evidence that semi-natural enclosures can create phenotypes similar to wild counterparts and bring ecological relevance to laboratory-like experiments by providing natural environmental factors. Finally, to build on these findings, I use the semi-natural enclosures to explore the relationship between the unfolded protein response and mitochondrial physiology.