An ongoing sexual conflict over wing length in birds

Males and females can have different adaptive optima. However, since they share the majority of genes, they are constrained from evolving sexual dimorphism, which causes a genetic sexual conflict. This conflict has been poorly investigated in wild populations. In a recent study, we – i.e. a team of CAnMove researchers – present novel evidences for a sexual conflict over wing length, a key trait for flight performance and migration, in the great reed warbler Acrocephalus arundinaceus. We have monitored this study population since the mid-80s and have information on phenotypes, reproductive success and relatedness between individuals in multiple generations. We found that wing length was controlled by the same genes in males and females, but that selection on this trait was acting in opposite directions in the sexes: long wings were favoured in males, short wings in females. We further confirmed the sexual conflict in that females that inherited alleles for long wings from their fathers suffered a fitness cost. This comprehensive study of a wild songbird population adds unique insight into how un-intuitive patterns of evolution may be explained. It also highlights the importance of taking genetic sexual conflicts into account when trying to understand how traits evolve.

You can read more about the study here: http://www.amnat.org/an/newpapers/JanTarka.html

Reference: Tarka et al. (2014) The American Naturalist 183: 62-73. DOI: 10.1086/674072

http://www.jstor.org/stable/10.1086/674072

Photo: August Thomasson