|Do behavioral differences predict levels of fluctuating asymmetry in the dimorphic sand cricket?|
|Amy M Worthington, Krista J Chang, Matthew R Whalen, Gabriel Rivera. Creighton University, Omaha, Nebraska, United States
Natural and sexual selection can shape morphologies to increase individual performance, and the degree of symmetry has been shown to impact the functionality of paired traits. As a result, traits vital for locomotion (legs or wings) or reproduction (ornaments or weapons) may rely more heavily on overall symmetry to remain functional than other non-vital structures, and therefore may be more developmentally constrained. Fluctuating asymmetry (FA) refers to deviations from perfect symmetry in bilateral structures and may serve as a useful tool in evaluating the strength of selection acting on individuals. In the sand cricket (Gryllus firmus), two distinct morphs with unique life histories exist: Short-wing (SW) morphs are incapable of flight but have high reproductive potential as early adults; Long-wing (LW) morphs have enlarged wings for dispersal but produce fewer offspring and do so later. Because the two morphs rely on different structures to maximize fitness, and many structures used by males for courtship and fighting do not serve the same function for females, we expect to see predictable differences in FA between morphs and sexes.