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Climate Change Affects the Sex of Bearded Dragons
International, 7/17/2015

Australian scientists from several institutions, led by the University of Canberra, have mixed field data from a total of 131 Australian adults’ bearded dragons (Pogonavitticeps) with controlled breeding experiments in the laboratory, to prove that climate change cause sex reversal in these species.

Molecular analyzes shows that 11 animals studied, who were in the warmest area of distribution of its habitat, had a set of male chromosomes but in reality were female.

According to Sinc Arthur Georges, co-author of the study and researcher at the University of Canberra (Australia), increased environmental temperature in the nests of reptiles, caused by global warming through habitat alteration, largely makes nests more exposed to solar radiation, which can cause reversal of sex.

Reptiles have an amazing number of ways to determine the sex of their offspring. Some have sex chromosomes, where the father determines the sex of the offspring as in humans. Others have chromosomes where the mother is the one that determines the sex, like birds. Some are parthenogenetic, where it totally ignores males and unfertilized egg segments.

According to scientists, when these females with reversed sex mated with males, none of the babies had sex chromosomes, and sex was determined entirely by the incubation temperature of the eggs.

The researchers also found that mothers with reversed sex laid eggs almost twice per year than mothers without the condition, which leads to more feminized populations.

This study also highlights the potential role of extreme climate in altering the biology and genome of climate-sensitive reptiles. For experts, this greater flexibility in the method of determining the sex could be a useful weapon in evolutionary response to unpredictable weather, but more research is needed to understand the cost and the real advantages of this mechanism.



Topic(s):    BiodiversityClimate