Research interests
Curriculum vitae
Students
Publications
|
Josh Van Buskirk
Senior Research Associate
Phone +41 (0)44 635 49 85
Fax +41 (0)44 635 68 21
|
 |
|
| My background |
|
I have been teaching and doing research in ecology and evolution at the University of Zürich since 1996. Before coming here, I did my doctoral work at Duke University, held postdoctoral positions at North Carolina State University, the Institute of Ecosystem Studies, and the University of Michigan, and was an assistant professor at Texas Tech University.
|
    |
Research
I am interested in how individuals and populations respond to variation in space and time. Some projects center around the evolution of ecological specialists and generalists, with a focus on phenotypic plasticity. Others address the behavioral responses of individuals to variation in habitat quality. Some questions focus on the issue of why speciation occurs relatively infrequently (or frequently). Many of our questions are relevant for conservation, because they center around processes affecting small or isolated populations, or how organisms are predicted to respond to changing environmental conditions.
Evolution of habitat specialization
A common evolutionary response to environmental heterogeneity is local adaptation, in which populations adapt to specific features of their local environments. Less well understood is the process of host-race or habitat-race formation, which involves specialization onto broadly-occurring features of the environment, wherever they occur. This type of local adaptation has been reported in a few insects, and seems especially likely to lead to speciation. We are |
 |
studying the occurrence of habitat race formation in amphibians by measuring habitat heterogeneity, dispersal, and individual fitness in nature. This is part of a long-tern survey of a large collection of natural wetlands in northern Switzerland. Questions include how the continuous/discrete nature of habitat variation influences selection for specialization, and why habitat races nearly always fail to achieve complete reproductive isolation.
|
Evolutionary processes in small and isolated populations
|
Depending on who you listen to, you’ll learn that isolated populations are either potential sources of evolutionary novelty, harboring unique genetic variation, or are evolutionary dead-ends suffering from inevitable genetic erosion. We are addressing this paradox with empirical studies of evolutionary processing occurring in small and isolated amphibian populations. Questions include whether small populations have reduced levels of quantitative variation, experience more marginal conditions and stronger selection than large populations, or are more (or less) likely to be locally adapted. Our results are relevant for the debate over the origin of individuals used in genetic restoration, and may help anticipate evolutionary responses to habitat fragmentation.
|
|
 |
|
|
Evolution of phenotypic plasticity
Amphibian larvae react to habitat variation by developing dramatic changes in their phenotype. These include shifts in behavior, color, and internal and external anatomy, and are induced by variation in abiotic conditions, conspecific density, and predation risk. We use experiments to investigate questions about the evolutionary basis of these responses. Here, the emphasis is on measuring the relationship between phenotype and individual fitness in a variety of habitats, to test models of the evolution of plasticity. We also use data from our long-term field survey to characterize the spatial and temporal distribution of habitat types in nature. These data provide a real-world foundation for the experimental work, and help us develop predictions for how amphibian populations change as the habitat changes.
|
| A few recent publications: |
| Van Buskirk, J., and U. K. Steiner. 2009. The fitness costs of developmental canalization and plasticity. Journal of Evolutionary Biology 22:852-860. |
|
 212kB |
| Steiner, U. K., and J. Van Buskirk. 2008. Environmental stress and the costs of phenotypic plasticity. Journal of Evolutionary Biology 21:97-103. |
|
152kB |
| Willi, Y., J. Van Buskirk, and A. A. Hoffmann. 2006. Limits to the adaptive potential of small populations. Annual Review of Ecology, Evolution, and Systematics 37:433-458. |
|
184kB |
| Van Buskirk, J. 2005. Local and landscape influence on amphibian occurrence and abundance. Ecology 86:1936-1947. |
|
100kB |
| Van Buskirk, J. 2002. A comparative test of the adaptive plasticity hypothesis: relationships between habitat and phenotype in anuran larvae. American Naturalist 160:87-102. |
|
276kB |
|
|
