On the accurate description of social and genetic mating systems

Mating systems are critical determinants of the intensity of sexual selection and sexual conflict, but understanding how variation in reproductive behavior influences these phenomena requires consistent, accurate descriptions of the array of mating arrangements observed in nature. As understanding of animal mating systems has evolved, behavioral ecologists have shifted from using behavioral information to an increasing reliance on genetic data to characterize patterns of reproductive behavior and success. Although genetic data are critical for an accurate accounting of parentage and reproductive success, they exclude critical information regarding the nature of behavioral relationships among reproductive partners, thereby potentially confounding fundamentally different types of mating systems. I contend that the ability to identify common evolutionary trends and their underlying selective pressures is significantly enhanced by using a terminological framework that differentiates explicitly between social and genetic mating systems. Furthermore, inclusion of both types of information can reveal new and intriguing relationships between behavior and fitness that further our understanding of how selection shapes mating systems. Here, I offer behavioral ecologists a new terminological framework for the study of mating systems that allows us to more appropriately merge genetic with behavioral data in an attempt to improve our understanding of this critical aspect of animal behavior. Lastly, I suggest a potential way in which we can begin to fully embrace the complexity of animal mating systems, in part via the adoption of a more quantitative framework for behavioral and genetic data.