Dr. Elizabeth Hadly uses a combined field and laboratory approach to examine how ecological perturbations link or decouple levels of biological organization, because understanding the links among ecosystems, species, populations and genes is central to understanding how organisms exist, evolve and become extinct. She addresses problems in organismal biology from both evolutionary and ecological perspectives, primarily using extant mammals. One of the unique aspects of her overall approach is the focus on the decadal to millennial time scale, a scale that is little studied, although it is a scale that is integral to understanding links between ecology and evolution.