Sex ratios and bimaturism differ between temperature-dependent and genetic sex-determination systems in reptiles

Veronika Bókony, Gregory Milne, Ivett Pipoly, Tamás Székely, András Liker

Research output: Contribution to journalReview article

2 Citations (Scopus)


Background: Sex-determining systems may profoundly influence the ecology, behaviour and demography of animals, yet these relationships are poorly understood. Here we investigate whether species with temperature-dependent (TSD) and genetic sex determination (GSD) differ in key demographic traits, using data from 181 species representing all major phylogenetic lineages of extant reptiles. Results: We show that species with TSD exhibit significantly higher within-species variance in sex ratios than GSD species in three major life stages: birth or hatching, juvenility and adulthood. In contrast, sex differences in adult mortality rates do not differ between GSD and TSD species. However, TSD species exhibit significantly greater sex differences in maturation ages than GSD species. Conclusion: These results support the recent theoretical model that evolution of TSD is facilitated by sex-specific fitness benefits of developmental temperatures due to bimaturism. Our findings suggest that different sex-determination systems are associated with different demographic characteristics that may influence population viability and social evolution.

Original languageEnglish
Article number57
Pages (from-to)57
JournalBMC Evolutionary Biology
Issue number1
Publication statusPublished - 18 Feb 2019


  • Age of sexual maturity
  • Environmental sex determination
  • Non-avian sauropsids
  • Sex chromosomes
  • Sex ratio
  • Survival

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics

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