Sex and the generation gap: seasonal changes in sex allocation

Sex allocation theory predicts the optimal investment into male and female reproduction (e.g. make sons or daughters/when to change sex). It is arguably the most successful theory in evolutionary ecology: empirical results often agree very closely with predictions. It underpins many key evolutionary questions (e.g. about the evolution of sex, sociality, parental care and sex chromosomes), with untapped potential to be applied to problems in agriculture, fisheries and human fertility. Surprisingly, however, we can not readily predict what happens when generations overlap (common in many taxa). We will extend theory, derive predictions and build on pilot data on seasonal sex ratio shifts to conduct critical tests on an invasive pest fish.