Research

Figure caption: Tibal spur condition indicates male mating success in Allonemobius ground crickets. During mating, females chew on the male’s tibal spur to obtain a hemolymph nuptial gift. Thus, the condition of the spur (chewed or unchewed) provides an assessment of male mating history; which provides a useful indicator of male fitness in wild populations.

RESEARCH INTERESTS: There are two fundamental truths in biology: (1) the goal of every organism is to reproduce, and (2) all organisms are under a constant threat from parasites. My research program investigates how these ‘truths’ interact antagonistically to shape immune and reproductive systems. Currently, my major research initiatives include, if/how/why male seminal fluid proteins weaken immune function in their mates, how the necessity of immune defense constrains reproductive potential within a sex (and vice versa), and the role the male Y-chromosome plays in limiting immune system evolution across all sexually reproducing species with genetic sex determination (e.g. XY or ZW systems).

My lab is also interested in eco-immunology. Eco-immunology is an emerging field that investigates the ecological causes of host immune system variation and pathogen susceptibility. Theoretically, variation in host immunity can result from the interaction between host physiology, pathogen prevalence and numerous environmental factors. My interests in this new field revolve around two areas, including (1) how spatially / temporally variable environments indirectly shape immune system expression and evolution, and (2) the potential for hosts to strategically alter their immune system investment according to host population parameters (density, sex ratio, breeding season), pathogen type (virulent vs. avirulent) and host status (age, sex, nutrition and reproductive opportunity).

RESEARCH APPROACH: My research program has become an amalgamation of methods, drawing theory and technique from several different disciplines within evolutionary biology. For instance, to understand general evolutionary constraints within metapopulations or within whole organisms, we draw on population and quantitative genetic techniques, respectively. To understand complex interactions between the environment and organism physiology, we employ a life histories approach. To understand the constraints on immune system evolution, we use sub-organismal genetic analysis and transcriptomics.

Although my research objectives are generalizable to all animals, I have come to rely heavily on two insect systems, including the ground cricket Allonemobius socius and the fruit fly Drosophila melanogaster. Both systems offer me the ease of laboratory manipulation while also providing the opportunity for field-based projects.

CURRENT PROJECTS: My lab is interested in a diversity of questions regarding adaptive evolution and its constraints. Below I list some of our current projects.

  • The role of the mating environment in modifying male ejaculate composition
  • Terminal investment and the production of dishonest male signals
  • The antagonistic coevolution of reproductive and immune systems
  • The role of the thermal environment in shaping innate immunity
  • The role of the Y-chromosome in immune system evolution
  • The role of gene flow asymmetry in constraining species range expansion.

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