Sex Reversal in Reptiles: Reproductive Oddity or Powerful Driver of Evolutionary Change?

Clare HOLLELEY, Stephen SARRE, Denis O'Meally, Arthur GEORGES

Research output: Contribution to journalArticlepeer-review

64 Citations (Scopus)


Is sex a product of genes, the environment, or both? In this review, we describe the diversity of sex-determining mechanisms in reptiles, with a focus on systems that display gene-environment interactions. We summarise the field and laboratory-based evidence for the occurrence of environmental sex reversal in reptiles and ask whether this is a widespread evolutionary mechanism affecting the evolution of sex chromosomes and speciation in vertebrates. Sex determination systems exist across a continuum of genetic and environmental influences, blurring the lines between what was once considered a strict dichotomy between genetic sex determination and temperature-dependent sex determination. Across this spectrum, we identify the potential for sex reversal in species with clearly differentiated heteromorphic sex chromosomes (Pogona vitticeps, Bassiana duperreyi, Eremias multiocellata, Gekko japonicus), weakly differentiated homomorphic sex chromosomes (Niveoscincus ocellatus), and species with only a weak heritable predisposition for sex (Emys orbicularis, Trachemys scripta). We argue that sex reversal is widespread in reptiles (Testudines, Lacertidae, Agamidae, Scincidae, Gekkonidae) and has the potential to have an impact on individual fitness, resulting in reproductively, morphologically, and behaviourally unique phenotypes. Sex reversal is likely to be a powerful evolutionary force responsible for generating and maintaining lability and diversity in reptile sex-determining modes
Original languageEnglish
Pages (from-to)279-287
Number of pages9
JournalSexual Development
Issue number5-6
Publication statusPublished - 2016


Dive into the research topics of 'Sex Reversal in Reptiles: Reproductive Oddity or Powerful Driver of Evolutionary Change?'. Together they form a unique fingerprint.

Cite this