Alumnus Jered Stratton (BS Genetics, 2016) presented his preliminary PhD research from the University of Wisconsin-Madison at the national Evolution Conference in Rhode Island on June 25th, 2019. The abstract of his talk is below:
Organisms on islands often evolve extreme phenotypes. Novel environmental conditions such as a lack of predators can shift long-standing adaptive peaks to new optima. Gough Island house mice are a prime example of rapid and extreme phenotypic evolution following island colonization. These mice have nearly doubled in body size and frequently predate on nesting seabirds including albatross and petrels. We hypothesized that the lack of natural predators for these mice has induced behavioral changes in boldness and exploratory tendencies. To investigate this question, we conducted a series of behavioral tests in a controlled setting using inbred strains derived from wild populations of mice on Gough Island and the Eastern United States. Open field and Light-Dark tests show Gough Island mice are more active and spend more time in open, brightly-lit areas than mainland mice. These differences are more pronounced after sexual maturity suggesting a life-history component is involved. A predator-cue test shows that Gough Island mice have reduced (but not absent) aversion to fox urine compared to mainland mice. F1s from crosses between Gough Island and mainland mice suggest an additive genetic framework for most behavioral traits. These results suggest Gough Island mice have evolved a reduction in anxiety-like behaviors following colonization likely due to the lack of natural predators. This study paves the way for a genetic dissection of behavioral evolution in a natural population of island mice.