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Christopher S. Willett

Research Associate Professor

Contact Information

Office: 2252 Genome Sciences Building
Email: willett4[at]
Office Phone: (919) 843-8663
Lab Phone: (919) 843-2559

Willett Lab Website


B.S. in Zoology, Michigan State University, 1993
Ph.D. in Genetics and Development, Cornell University, 1999

Research Description

At a Glance

  • Speciation Genetics: Genetic basis of hybrid breakdown in copepods and the appearance of reproductive isolation via sterility
  • Genetic basis of physiological adaptation: Temperature and salinity tolerance in copepods
  • Comparative genomics and using next generation sequencing to study the genetic basis of speciation and adaptation
  • Population genetics and molecular sequence evolution
  • Conservation genetics: Outbreeding depression, population genetics of threatened species


My research addresses the nature of genetic variation that underlies speciation and adaptation. Specifically, I attempt to unravel how genetic changes at the molecular level can lead to phenotypic changes of evolutionary significance. A major thrust of my research program has been to understand how genetic variation within populations translates into variation between populations and species, and to determine the impact of natural selection on this process. In my current work I am targeting specific genetic systems and using genome-wide approaches to determine the regions of the genome that could be involved in generating reproductive isolation that occurs after mating (postzygotic reproductive isolation). I am also examining the physiological and fitness consequences of genetic variation using both targeted gene and genome-wide approaches. Specifically we are looking at the evolution of temperature and salinity adaptation across populations. My work to date has largely focused on two primary systems systems-copepods and moths.


The harpacticoid copepod Tigriopus californicus inhabits rocky, intertidal splash pools in a patchy distribution along the west coast of North America. Populations of this species display dramatic genetic differentiation even between relatively proximate localities. Crosses between these populations typically show hybrid breakdown (decreases in fitness of F2 individuals). Understanding the genetic basis of this hybrid breakdown could yield insights into the early stages of the process of speciation. Recent work in the lab has also focused on the nature of adaptation in thermal tolerance among populations of this species and its implications for reproductive isolation in this system. This work could help reveal how species will be able to handle future changes in temperature environments.






My work on moths dealt with the predominate mode of conspecific mate recognition in moths, the sex pheromone system, which is a key component of premating reproductive isolation among many moth species. Past work focused on the evolution of one protein, the pheromone-binding protein, and how it contributes to discrimination by male moths and differentiation among species.