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Hilary Callahan

Title Associate Professor
Affiliation/Department Department of Biological Sciences, Barnard College
Telephone 212-854-5405 
Professional degree Ph.D. in Botany, University of Wisconsin-Madison, 1996
Research Keywords Changing environments, ecological genetics, microevolution, natural selection, phenotypic plasticity, plant reproductive ecology
Research Description To Hilary Callahan, each organism is a genotype, the genetic information that it carries in each cell, inherited from its ancestors. Each organism is also phenotype, an observable set of morphological, physiological, and behavioral characteristics that interact with the environment. As a plant evolutionary ecologist, Dr. Callahan integrates these two perspectives using the concept of phenotypic plasticity: the ability of a genotype to express different phenotypes in response to different environments. She typically focuses on the phenotypic plasticity of flowering time in the model organism Arabidopsis thaliana, investigating the fitness benefits and costs of this plasticity. Although much of her work is conducted in growth chambers, she works with naturally variable wild populations and considers field tests essential.
Representative Publications

Callahan, H. S., and M. Pigliucci. 2002. Shade-induced plasticity and its ecological significance in wild populations of Arabidopsis thaliana. Ecology 83:1965-1980.

Callahan, H. S., and D. M. Waller. 2000. Phenotypic integration and the plasticity of integration in an amphicarpic annual. International Journal of Plant Sciences 161:89-98.

Callahan, H. S., C. L. Wells, and M. Pigliucci. 1999. Light-sensitive plasticity genes in Arabidopsis thaliana: mutant analysis and ecological genetics. Evolutionary Ecology Research 1:731-751.

Callahan, H. S., M. Pigliucci, and C. D. Schlichting. 1997. Developmental phenotypic plasticity: where ecology and evolution meet molecular biology. Bioessays 19:519-525.