Heather R.L. Lerner, M.S., Ph.D. candidate
University of Michigan Department of Ecology and Evolutionary Biology
Lab Phone: 734-763-0310
My research uses molecular phylogenetics and phylogeography to investigate patterns and processes of avian speciation, particularly those of birds of prey. Phylogenies are the foundation of modern methods in evolution as they provide a framework for studying the evolution of behavioral and morphological traits and biogeographic impacts on speciation. Furthermore, molecular phylogenetic methods are useful in identifying monophyletic groups which may be priorities for species conservation.
In the very general sense I am interested in the assessment of natural genetic variation harbored by avian populations, and how it is relevant to their evolution, natural history, and survival. My long-term goal is to understand how ecology and genetics affect the persistence of raptor species through time, and use this information to make informed decisions pertinent to the conservation of biodiversity, not just within the Accipitridae. Accipitridae and other raptors are valuable indicators of environmental health as they are among the first and most visible taxa to show the effects of environmental degradation (e.g. peregrine falcon and bald eagle declines of the late 20th century). Furthermore, since sites occupied by raptors are associated with high species diversity, studying raptors can also provide insights relevant to the health of whole ecosystems.
My central hypotheses are that (1) lower genetic variability exists in most birds of prey resulting at least partially from their characteristically long generation times and low population sizes, such that raptors are highly prone to extinction when population declines are sustained, but are able to survive repeated short bottlenecks without great losses in genetic diversity or evolutionary potential; and, (2) high levels of morphological plasticity allow birds of prey to both colonize new environments and survive disruptions in their environments.
The objectives of my current work are to determine the historical patterns and timing of extinction and speciation in the Accipitridae, estimate the levels of genetic diversity within and among Accipitrid species for comparison with other non-predatory birds, identify morphological traits associated with high levels of diversification or extinction and develop a working hypothesis for divergence time estimates among major accipitrid groups that can be used to estimate mutation rates for population-level studies of raptors. The rationale for this research is that once we ascertain basic traits that have contributed to the extinction of raptor species, we shall be able to predict how future changes may affect populations of birds of prey; and thus, gain a better understanding of how anthropogenic changes affect raptors before more species are lost. Furthermore, a deep understanding of the evolutionary history of the Accipitridae will provide insights into the basic mechanisms of evolution that could be broadly applicable to environments occupied by raptors and to top-predators in other organismal groups.