title: The genetic sex-determination system predicts adult sex ratios in tetrapods.
abstract: The adult sex ratio (ASR) has critical effects on behaviour, ecology and population dynamics, but the causes of variation in ASRs are unclear. Here we assess whether the type of genetic sex determination influences the ASR using data from 344 species in 117 families of tetrapods. We show that taxa with female heterogamety have a significantly more male-biased ASR (proportion of males: 0.55 ± 0.01 (mean ± s.e.m.)) than taxa with male heterogamety (0.43 ± 0.01). The genetic sex-determination system explains 24% of interspecific variation in ASRs in amphibians and 36% in reptiles. We consider several genetic factors that could contribute to this pattern, including meiotic drive and sex-linked deleterious mutations, but further work is needed to quantify their effects. Regardless of the mechanism, the effects of the genetic sex-determination system on the adult sex ratio are likely to have profound effects on the demography and social behaviour of tetrapods.
authors.affiliation: Department of Limnology, University of Pannonia, Pf. 158, H-8201 Veszprém, Hungary.
authors.forename: Ivett
authors.initials: I
authors.lastname: Pipoly
authors.affiliation: Department of Limnology, University of Pannonia, Pf. 158, H-8201 Veszprém, Hungary.|Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó út 15, H-1022 Budapest, Hungary.
authors.forename: Veronika
authors.initials: V
authors.lastname: Bókony
authors.affiliation: Department of Integrative Biology, University of Texas, Austin, Texas 78712, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Kirkpatrick
authors.affiliation: RSPB Centre for Conservation Science, RSPB, The Lodge, Sandy, Bedfordshire SG19 2DL, UK.|University of Cambridge, Conservation Science Group, Department of Zoology, Downing Street, Cambridge CB2 3EJ, UK.
authors.forename: Paul F
authors.initials: PF
authors.lastname: Donald
authors.affiliation: Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, UK.
authors.forename: Tamás
authors.initials: T
authors.lastname: Székely
authors.affiliation: Department of Limnology, University of Pannonia, Pf. 158, H-8201 Veszprém, Hungary.
authors.forename: András
authors.initials: A
authors.lastname: Liker
mesh_terms: D000663:Amphibians / Q000235:genetics; D000818:Animals; D001717:Birds / Q000235:genetics; D005260:Female; D008297:Male; D008322:Mammals / Q000235:genetics; D008540:Meiosis / Q000235:genetics; D008957:Models, Genetic; D009154:Mutation / Q000235:genetics; D010802:Phylogeny; D012104:Reptiles / Q000235:genetics; D012730:Sex Chromosomes / Q000235:genetics*; D019849:Sex Determination Processes / Q000235:genetics*; D012744:Sex Ratio