As an evolutionary biologist I focus on small mammals. My research has concentrated on rapid evolution, both genetic and morphological. I have found very rapid size changes in deer mice on the California Channel Islands and white-footed mice in NE Illinois over time spans as little as 30 years.
Much of my genetic work has been possible because I have been successful in utilizing DNA from museum skins. I have found complete genetic replacement occurring in conjunction with the morphological changes. It is so far unclear whether selection, plasticity, migration or some combination are responsible.
Publications