My research synthesizes the fields of cellular aging and sexual selection in order to shed light on the role of sperm age in sperm competition and use. Sperm age, long recognized in the fields of human medicine and animal breeding as an important factor in determining fertilization success and offspring viability, has been largely overlooked by evolutionary biologists. Given that much of the observed across-male variation in fertilization success remains unexplained by commonly-studied sperm and ejaculate traits like sperm number, motility, and morphology, sperm age is a likely candidate for predicting sperm function.
My research seeks (1) to describe the patterns of sperm use and allocation exhibited by males and females under natural conditions and (2) to reveal the mechanisms underlying these patterns. To these ends, I use various methods including fluorescence lifetime imaging microscopy (FLIM) to analyze metabolic parameters in stored sperm; time-resolved microfluorimetry, a novel approach to assessing the production rate of reactive oxygen species in sperm cells; and behavioral experiments.