Bearded males be warned: climate change could be turning you into a pack of girls, at least if you're a lizard.
Scientists at the University of Canberra will on Thursday release a study showing rising global temperatures pose a serious risk of turning many of the world's temperature-sensitive male reptiles into females, potentially creating entire female-only populations of some animals.
The study, conducted on Australian bearded dragons and published on the cover of the prestigious journal Nature, has for the first time confirmed that climate-induced changes are triggering sex changes in the wild, raising serious concerns about the future for some species.
Lead author of the study Dr Clare Holleley said the changes, which had previously only been produced in the lab, raised questions about the evolution of some species.
"What we have found is that temperature does potentially affect the evolution of the species. If they are going to be exposed to higher temperatures more frequently that is potentially going to affect their biology," Dr Holleley said.
She said one of the big questions the research raised was whether the animals would adapt to rising temperatures or face potential wipe-out.
"One of the things we will be looking at into the future is whether they would be on an evolutionary dead end where they become more and more female and become extinct, or whether they can adapt and adjust their temperature threshold," Dr Holleley said.
The researchers had also found entire populations that were on the precipice of making the switch from using genetic signals to temperature to determine their sex.
Co-author of the paper Professor Arthur Georges said once animals moved from using genetic triggers to temperature to determine sex they became much more vulnerable to extinction because they now had fewer options to adapt than in the past.
"Once they become temperature dependent, the risk is that if it keeps warming they'll produce 100 per cent females and they'll be at risk of extinction, so this is a concerning finding.
"The ways in which animals have responded in the past, those options are no longer available to them because we've fragmented the habitat so it's a really complex mix of factors that push species to extinction. We're just showing one small element of how that's going to pan out," Professor Georges said.
He said while society had largely accepted that the planet was warming and had considered what that meant for human environments and the economy, there had been less consideration of the implications for other species and how they were likely to be affected.
"The more we learn about them, the better equipped we'll be to predict evolutionary responses to climate change and the impact this can have on biodiversity globally," he said.
