Indirect-fitness benefits hypotheses suggest that offspring of preferred mates should exhibit greater survival or reproductive success. For example, good-genes hypotheses propose that female mating preferences are mediated by secondary sexual traits because they honestly reflect the ability to pass on genes that will enhance offspring survival or reproduction. Conversely, complementary-genes hypotheses propose that mating preferences are mediated by complementary-genes because they enhance offspring viability. While these two research traditions are not strict alternatives and both may operate simultaneously, they have never been tested together. Here we explore the multiple potential underlying factors influencing mating preference evolution in Jamaican field crickets, Gryllus assimilis. After evaluating female preferences for randomly selected males, we tested if preferred males differed from nonpreferred males in their body size, relative mass, or mate attraction signals. We then mated females to their preferred or non-preferred partners and tested offspring viability. Results revealed: (1) females preferred larger males, (2) larger females oviposited more eggs, (3) neither morphology nor mate attraction signaling explained variation in offspring viability, and (4) mating with a preferred partner did not enhance offspring viability. Overall, in our current study population, cricket mate preferences were inconsistent with complementary-genes and goodgenes hypotheses for indirect-fitness-benefits. Our current research explores whether male secondary sexual traits honestly reflect the ability to pass on genes that enhance offspring reproduction. or the attractiveness of sons in the subsequent generation (Fisher 1930; Zahavi 1975; Heywood 1989; Andersson 1994). For example, Fisher (1930) and later Zahavi (1975) posited that secondary sexual traits reflect their bearers' health and viability (good-genes). When both secondary sexual traits and female preferences are heritable, females that mate with more elaborate males (males with brighter, louder, or more complex secondary sexual traits) will produce offspring that may inherit their father's good-genes for health and viability, and their mothers' good-genes for preference, resulting in greater survival and/or reproductive success. A correlation may result between preference and viability [demonstrated by Lande (1981)]. The difficulty with these hypotheses is that continuous directional selection for elaborate traits may remove heritable variation, resulting in the elimination of the indirect benefits associated with mate preference (e.g. Falconer and Mackay 1996; Borgia 1979; Andersson 1994; but see Heywood 1989; Pomiankowski 1988). The main rationale for Hamilton and Zuk's (1982) insightful paper on mate choice was to with laboratory rearing, cricket care, egg counting and morphological measurements. We thank

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The social environment is an important driver of developmental plasticity in juveniles and behavioural plasticity in adults. An individual's ability to accurately assess cues during development and predict its future social dynamics plays an important role in ensuring that its phenotype at adulthood will match their anticipated environment.However, because the overall plasticity of an individual is the result of a concomitant interaction between development, environment, and behaviour over the entire lifetime, constraints arising from development may hinder adult behaviour. My dissertation examines the influence of the developmental social environment on life-history traits and fitness-conferring adult behaviours to enhance our understanding of how these two life phases interact in the fall field cricket Gryllus pennsylvanicus. Through play-back experiments that altered the density of adult male acoustic signals, my findings reveal that male and female development time decreases and female residual mass at adulthood increases in higher perceived population densities. Contrary to my expectations, neither adult male aggressive nor mate attraction signalling were significantly influenced by developmental social environments. Adult female mate preference behaviour was influenced by developmental social environment, as females raised in social isolation were more responsive than females raised exposed to signals. Furthermore, the acoustic social environment experienced during development had significant indirect effects on all adult behaviours through constraints imposed on adult body size. Crickets reared in the high density environments developed faster, and a faster development time resulted in larger body sizes. Because body size significantly influenced male aggression and signalling behaviour, and female mate preference behaviour, the ability to express iii behavioural plasticity at adulthood may have been limited. However, my experiment that switched acoustic social environments between juvenile and adult stages showed that males who experienced a switched environment were able to adjust specific aspects of their signalling to match the unanticipated adult social dynamics. I also examined whether anthropogenic noise pollutes the bioacoustics network. Anthropogenic noise influenced male development time and signalling behaviour, and female residual mass and preference functions. Further, anthropogenic noise sometimes interacted with the acoustic social environment experienced during rearing, causing individuals to be mismatched with their social environment in adulthood.iv

Male mating preferences are often a neglected aspect of studies on sexual selection. Male mating preferences may evolve if they provide males with direct‐fitness benefits such as increased opportunity to fertilize more eggs or indirect‐fitness benefits such as enhanced offspring survival. We tested these ideas using Jamaican field crickets, Gryllus assimilis, previously shown to exhibit male mating preferences. We randomly mated males to either their preferred or non‐preferred potential mates and then asked whether mating treatment influenced egg oviposition or offspring viability. Preferred females were not significantly more fecund and did not produce more viable eggs or offspring than non‐preferred females. Male mate preferences were therefore inconsistent with both the direct‐ and indirect‐fitness benefits hypotheses under the conditions of our experiment. Our null results leave us with an open question about what is driving the evolution of mating preferences in male crickets. Future research should explore the whether the offspring of preferred females are more attractive, have stronger immune systems, and/or experience higher adult longevity.