Matthieu Delcourt

Learn More
The extent of variation in mating signals between environments can be an important determinant of reproductive isolation. We tested divergence in male courtship behavior between lake and stream three-spined stickleback (Gasterosteus aculeatus L.) in the Misty system, Vancouver Island. Presumably, genetically based divergence was assessed by comparing male(More)
Phenotypes tend to remain relatively constant in natural populations, suggesting a limit to trait evolution. Although stationary phenotypes suggest stabilizing selection, directional selection is more commonly reported. However, selection on phenotypes will have no evolutionary consequence if the traits do not genetically covary with fitness, a covariance(More)
A female's mate preference is a potentially complex function relating variation in multiple male phenotypes with her probability of accepting individual males as a mate. Estimating the quantitative genetic basis preference functions within a population is empirically challenging yet key to understanding preference evolution. We employed a recently described(More)
The intersex genetic correlation for fitness , a standardized measure of the degree to which male and female fitness covary genetically, has consequences for important evolutionary processes, but few estimates are available and none have explored how it changes with environment. Using a half-sibling breeding design, we estimated the genetic (co)variance(More)
Theory predicts that costly sexual displays should evolve condition dependence if the marginal fitness gain from trait exaggeration is greater for high- than for low-condition individuals and that the strength of condition dependence should increase with the strength of directional selection. While there is substantial support for the first prediction,(More)
In ecological speciation, reproductive isolation evolves as a consequence of adaptation to different selective environments. A frequent contributor to this process is the evolution of positive assortativemate choice between ecotypes.We tested this expectation for lake and inlet stream threespine stickleback (Gasterosteus aculeatus) from the Misty system(More)
Sexually dimorphic traits are likely to have evolved through sexually antagonistic selection. However, recent empirical data suggest that intralocus sexual conflict often persists, even when traits have diverged between males and females. This implies that evolved dimorphism is often incomplete in resolving intralocus conflict, providing a mechanism for the(More)
Sexually antagonistic genetic variation can pose limits to the independent evolution and adaptation of the sexes. The extent of sexually antagonistic variation is reflected in the intersex genetic correlation for fitness (rwFM). Previous estimates of this correlation have been mostly limited to populations in environments to which they are already well(More)
Mate preferences are costly and are thought to evolve due to the direct and/or indirect benefits they provide. Such costs and benefits may vary in response to intrinsic and extrinsic factors with important evolutionary consequences. Limited attention has been given to quantifying such variation and understanding its causes, most notably with respect to the(More)
Theory predicts that costly sexual displays should evolve condition dependence if the marginal fitness gain from trait exaggeration is greater for highthan for low-condition individuals and that the strength of condition dependence should increase with the strength of directional selection. While there is substantial support for the first prediction,(More)
  • 1