WHY IS SEXUAL REPRODUCTION SO COMMON?
Sexual females produce both sons and daughters, while asexual females make only daughters. Since only females produce offspring, this "cost of males" predicts that sex should be rare because asexual females will leave many more descendants than will sexual females. In reality, however, sex predominates. Why sex is so common despite its costs remains unclear, and is considered one of the most important unanswered questions in evolutionary biology.
Because sex is distinguished from asexual reproduction by the production of genetically variable offspring, a better understanding of the benefits of sex will help illuminate the value of preserving genetic diversity within and among populations, species, and ecological communities. More broadly, our research program is relevant to scientists who use our snail study system as a model for ecotoxicology as well as those studying the causes and consequences of biological invasions. Our lab group is also very committed to training, mentoring, and community engagement, and we are involved in a variety of such efforts, from regular collaborations with 10th grade Biology students at a local high school to the development and testing of a genomics module for a national high school computer science curriculum to our central role in organizing the annual Iowa City Darwin Day celebration.
HOW ARE SEXUALS AND ASEXUALS DIFFERENT?
The expectation that sex should be rare is based on the assumption that sexuals and asexuals are similar. In other words, the two-fold cost of sex will be diminished or even negated if asexual females experience disadvantages related to asexuality. Accordingly, our research uses a variety of approaches to identify and understand the causes and consequences of the many ways in which asexuals and sexuals might differ, with a main goal of better understanding why sex is so common in natural population.