INTRALOCUS TACTICAL CONFLICT IN DUNG BEETLES

My latest paper has recently been published online by the Journal of Evolutionary Biology (check it out here). In this paper my co-authors (Janne Kotiaho, Joe Tomkins and Leigh Simmons) and I analyse a huge data set from a half-sib breeding design in the dung beetle Onthophagus taurus, mainly looking for genetic correlations that could constrain the evolution of male dimorphism in this species. Since large horned males (fighters) and small hornless males (sneakers) of this species probably differ in their phenotypic optima for many traits (certainly for horns!), some alleles can be beneficial to one male morph but harmful to the other, generating intralocus tactical conflict (ITC). We found that the intrasexual genetic correlation between males of different morphs for horn length (sexually selected trait) did not differ significantly from intersexual correlations or from intrasexual correlations for naturally selected traits, failing to support the hypothesis that horns present a reduction of intrasexual genetic correlations due to ITC. We discuss these results under the light of the ideas of developmental reprogramming between male morphs and emphasise the importance of genetic correlations as constraints for the evolution of dimorphisms.