Glowing sperm illuminate post-copulatory sexual selection in Drosophila

摘要

The spectacular diversity of ornaments and armaments of males in a wide range of taxa can be explained by sexual selection, defined as intra-specific variation in mating success among individuals of the same sex (Andersson 1994). A huge body of literature now shows how phenotypic traits that influence the outcome of male-male competition and female choice can be elaborated even if they are costly to survival (Cronin 1993). In addition to the critical importance of sexual selection for understanding processes such as speciation, insights from these studies can have important implications for pest management, captive breeding programs, and conservation of species at risk (e.g., Legendre et al. 1999; Moller & Legendre 2001). It is now clear, however, that influences of sexual selection on pre-mating dynamics are only the tip of the iceberg. Females of many (if not most) species mate with multiple males and mating success is not equivalent to fertilization success in many taxa (Keller & Reeve 1995). This is important because fertilization, rather than mating, determines reproductive success and thus the potential for evolutionary change (Birkhead & Moller 1998). Thus, post-copulatory sexual selection, or the processes affecting relative fertilizationsuccess, is of critical importance to our understanding of the evolution of male and female traits, and their interplay during mating.