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Jeff Feder Dave Severson Jeanne Romero-Severson Michael Ferdig Nora Besansky Hope Hollocher |
My laboratory studies the patterns and processes of adaptation, flow of genes among populations, and evolutionary responses to novel environments. Researchers in my lab examine how populations and communities are altered by human-caused changes in the environment. Because no two individuals or populations in nature are exactly the same, we must ask consider how genetic diversity and the potential for evolution will influence the trajectory of biodiversity in a human-dominated world. Examples of research questions include:
1) Adaptation to local environments and extinction
risk
2.) Human impacts on the evolution of species
Dr. Hellmann's departmental homepage
Dr. Hellmann's personal homepage
Biological Sciences
178 Galvin Life Science
Notre Dame, IN 46556
574 631 7521
hellmann.3@nd.edu
1.) Local adaptation and extinction risk. We are working to understand how populations in different portions of a range are adapted to local conditions and how changes in those conditions affect population extinction risk. An assumption ecologists (and policy makers!) often make is that species and ecosystems will shift northward under climate change as conditions in the northern part of a species range become more like the core of a range. But is this assumption true? It might be true if there are strong rates of gene flow among populations and little adaptation to local conditions at the edges of a species’ range. But it might not be true if populations are isolated and local adaptation predominates. To address these alternate possibilities, we study contrasting species of butterfly over a latitudinal gradient in British Columbia and the coastal US. We also perform translocation and laboratory experiments with butterfly larvae and examine patterns of butterfly gene flow with molecular techniques. More info.
2.)
Human impact. Humanity’s impact on the environment
will affect not only the distribution and abundance of organisms but also
the evolutionary trajectory of species. To understand the potential for
climate change to drive evolutionary change, my lab is studying the impact
of regional warming on the frequency of genes controlling flight capacity
and reproductive output in populations of a butterfly inhabiting alpine
landscapes. With collaborators outside Notre Dame, we are building a model
of individual flight performance under climate change and examining whether
shifts in the climate will alter gene frequency. We then determine if
changes in gene frequency have negative feedbacks on population size,
increasing the risk of local extinction. More
info.
These areas of research are just two examples of how evolutionary biology is combined with ecology in the Hellmann lab. Students are invited to bring their skills in evolutionary biology to bear on a wide variety of applied issues in my research group. Questions concerning species interactions, the structure and dynamics of populations, and the trajectory of native biodiversity under change are especially encouraged.
