Data from: Eutrophication and predation risk interact to affect sexual trait expression and mating success
Cothran, Rickey Duane; Stiff, Andy R; Jeyasingh, Punidan D; Relyea, Rick A (2011), Data from: Eutrophication and predation risk interact to affect sexual trait expression and mating success, Dryad, Dataset, https://doi.org/10.5061/dryad.r471vs43
Sexual traits are especially sensitive to low food resources. Other environmental parameters (e.g., predation) should also affect sexual trait expression by favoring investment in viability traits rather than sexual traits. We know surprisingly little about how predators alter investment in sexual traits, or how predator and resource environments interact to affect sexual trait investment. We explored how increasing phosphorous (P) availability, at a level mimicking cultural eutrophication, affects the development of sexual, non-sexual, and viability traits of amphipods in the presence and absence of predators. Sexual traits and growth were hyper-sensitive to low P compared to non-sexual traits. However, a key sexual trait responded to low P only when predator cues were absent. Furthermore, investment tradeoffs between sexual traits and growth only occurred when P was low. The phenotypic changes caused by predator cues and increased P availability resulted in higher male mating success. Thus, eutrophication not only affects sexual trait expression but also masks the tradeoff between traits with similar P demand. Sensitivity of sexually selected traits to changes in P, combined with the important roles these traits play in determining fitness and driving speciation, suggests that human-induced environmental change can greatly alter the evolutionary trajectories of populations.