NSF Postdoctoral Fellowships in Biology combine research and training components to prepare young scientists for careers in biology and require a plan to broaden participation of groups under-represented in science and engineering. The fellowships enhance NSF efforts to diversify the STEM workforce now and in the future. This fellowship to Mercedes Burns supports research on reproduction in insects and how different reproduction strategies evolve in different environments. The host institution for this fellowship is San Diego State University, and the sponsoring scientist is Dr. Marshal Hedin. The Fellow is broadening her scientific horizons also through a research collaboration with scientists in Japan. The main training goal is to achieve mastery of genomic sequencing techniques to be used in identifying population-level genetic variation.

The research investigates the role of the ratio of males to females in evolution of mating systems in two species of harvestmen, the insects commonly known as daddy-longlegs. Effective male/female ratios may drive evolutionary change in the reproductive structures and mating systems of species by altering selection over the control of mating rate of each gender. In these species, reproduction proceeds with or without male fertilization and female-biased populations of these species are common in high-latitude and altitude marginal habitats. The research goals are to 1) elucidate mechanisms producing the geographic distribution of female-biased populations by reconstructing the colonization of marginal habitats using molecular markers and 2) examine the effects of a long-term female-biased ratio on female fecundity, male morphology, and paternal diversity of egg clutches using a comparative approach.

The host institution is a Minority-serving institution that offers two courses in arthropod biology, providing the Fellow who serves as an effective role model an opportunity to identify highly motivated students for mentoring and assisting in the research once they learn functional morphology and molecular sequencing procedures.

National Science Foundation (NSF)
Division of Biological Infrastructure (DBI)
Application #
Program Officer
Michael Vanni
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Burns Mercedes M
College Park
United States
Zip Code