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Sexual selection

Publications filtered by: Sexual selection

Maternal sexual interactions affect offspring survival and ageing
Dowling, D. K., Williams, B. R., and Garcia-Gonzalez, F. 2014 Maternal sexual interactions affect offspring survival and ageing Journal of Evolutionary Biology, 27: 88-97

In many species, females exposed to increased sexual activity experience reductions in longevity. Here, in Drosophila melanogaster, we report an additional effect on females brought about by sexual interactions; an effect that spans generations. We subjected females to a sexual treatment consisting of different levels of sexual activity, and then investigated patterns of mortality in their offspring. We found reduced probabilities of survival, increases in the rate-of-senescence, and a pattern of reduced mean longevities, for offspring produced by mothers that experienced higher levels of sexual interaction. We contend that these effects constitute trans-generational costs of sexual conflict – the existence or implications of which have rarely been considered previously. Our results indicate that ongoing exposure by mothers to male pre-copulatory interactions is itself sufficient to drive trans-generational effects on offspring mortality. Thus, we show that increases in maternal sexual activity can produce trans-generational effects that permeate through to latter life-stages in the offspring. This helps to elucidate the complex interplay between sex and ageing, and provides new insights into the dynamics of adaptation under sexual selection.

Model Systems, Taxonomic Bias, And Sexual Selection: Beyond Drosophila
Zuk, M., Garcia-Gonzalez, F. Herbestein, M. E. and Simmons, L. W. 2014 Model Systems, Taxonomic Bias, And Sexual Selection: Beyond Drosophila Annual Review of Entomology, 59: 321-338

While model systems are useful in entomology, allowing generalizations to be made based on a few well-known species, they also have drawbacks. It can be difficult to know how far to generalize from information in a few species: are all flies like Drosophila? The use of model systems is particularly problematic in studying sexual selection, where variability among taxa is key to the evolution of different behaviors. A bias toward use of a few insect species, particularly Drosophila, is evident in the sexual selection and sexual conflict literature over the last several decades, although the diversity of study organisms has increased more recently. As the number of model systems used to study sexual conflict increased, support for the idea that sexual interactions resulted in harm to females decreased. Future work should choose model systems thoughtfully, combining well-known species with those that can add to the variation that allows us to make more meaningful generalizations.

Male, female – ah, what's the difference?
Garcia-Gonzalez, F., Dowling, D. K.& Nystrand, M. 2013 Male, female – ah, what's the difference? The Conversation
Assessing the potential for egg chemoattractants to mediate sexual selection in a broadcast spawning marine invertebrate
Evans, J. P., F. Garcia-Gonzalez, M. Almbro, O. Robinson, & J. L. Fitzpatrick. 2012 Assessing the potential for egg chemoattractants to mediate sexual selection in a broadcast spawning marine invertebrate Proceedings of the Royal Society of London B, 279:2855-2861

In numerous species, egg chemoattractants play a critical role in guiding sperm towards unfertilized eggs (sperm chemotaxis). Until now the known functions of sperm chemotaxis include increasing the effective target size of eggs, thereby promoting sperm-egg encounters, and facilitating species recognition. Here we report that in the broadcast spawning mussel Mytilus galloprovincialis egg chemoattractants may play an unforeseen role in sexual selection by enabling sperm to effectively ‘choose’ between the eggs of different conspecific females. In an initial experiment we confirmed that sperm chemotaxis occurs in M. galloprovincialis by showing that sperm are attracted towards unfertilized eggs when given the choice of eggs or no eggs in a dichotomous chamber. We then conducted two cross-classified mating experiments, each comprising the same individual males and females crossed in identical male x female combinations but under experimental conditions that offered sperm ‘no-choice’ (each fertilization trial took place in a petri dish and involved a single male and female) or a ‘choice’ of a female’s eggs (sperm were placed in the centre of a dichotomous choice chamber and allowed to choose eggs from different females). We show that male-by-female interactions characterized fertilization rates in both experiments, and that there was remarkable consistency between patterns of sperm migration in the egg choice experiment and fertilization rates in the no-choice experiment. These results reveal that sperm differentially select eggs on the basis of chemical cues, thus exposing the potential for egg chemoattractants to mediate mate choice for genetically compatible partners. Given the prevalence of sperm chemotaxis across diverse taxa, our findings may have broad implications for sexual selection in other mating systems.