Male-female coevolution in the wild: evidence from a time series in Artemia franciscana

Sexual conflicts are ubiquitous in nature and are expected to lead to an antagonistic coevolution between the sexes. This coevolutionary process is driven by selection on sexually antagonistic traits that can either be directional or fluctuating. In this study, we used dormant cysts of Artemia franciscana, collected in the same population in three different years over a 23-year period (corresponding to ~160 generations in this system), to investigate male-female coevolution in natural conditions over time. We performed a cross experiment study where reproduction of females mated to males from the past, present or future was monitored until death. In agreement with a model of ‘fluctuating selection’, we found that females survived better and had longer interbrood intervals when mated with their contemporary males compared to when mated with males from the future or the past. However, female weekly and lifetime reproductive successes displayed no differences between contemporary and non-c...