title: Constraints in the evolution of sex ratio adjustment.
abstract: When the relative fitness of male and female offspring varies with environmental conditions, evolutionary theory predicts that parents should adjust the sex of their offspring accordingly. Qualitative and even quantitative support for this prediction is striking in some taxa but much less convincing in others. Explaining such variation across taxa in the fit of sex ratio theory remains a major challenge. We use meta-analysis to test the role of two constraints in the evolution of sex ratios. Based on analysis of sex ratio skews in birds and wasps, we show that (i) mechanisms of sex determination do not necessarily constrain the evolution of sex ratio adjustment, and (ii) parental ability to predict their offsprings' environment influences the evolution of sex ratio patterns across taxa. More generally, our results show that multiple constraints may determine the precision of adaptation.
authors.affiliation: Institute of Cell, Animal, and Population Biology, University of Edinburgh, Edinburgh EH9 3JT, UK., Edward Grey Institute, Department of Zoology, University of Oxford, Oxford, UK.
authors.forename: Stuart A
authors.initials: SA
authors.lastname: West
authors.forename: Ben C
authors.initials: BC
authors.lastname: Sheldon
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D005075:Biological Evolution; D001717:Birds / Q000502:physiology*; D004777:Environment; D005260:Female; D008297:Male; D010058:Oviposition; D012098:Reproduction; D019849:Sex Determination Processes; D012744:Sex Ratio; D012726:Sexual Behavior, Animal; D014863:Wasps / Q000502:physiology*