Global warming brings confusing consequences to the wildlife that is highly exposed to all the changes in temperature. Australian lizards are affected to the point that their sex determination is now driven by climate change.
Hot temperatures impact the female sex chromosome that somewhere in the future may disappear completely.
A team of researchers from University of Canberra revealed the findings and established that sex reversal is a common genetic effect in the wild territories of life. The team of scientists has performed the study on 131 adult lizards, by controlled breeding experiments. The chromosomal changes related to temperatures getting higher are dramatic and may affect the entire population of bearded dragon lizards.
Gender determination in reptiles is not necessarily based on chromosomes but rather on the environmental conditions the combined chromosomes are exposed to. Their sex chromosomes are Z and W instead of X and Y, like the combo that makes up for the human reproductive process.
In lizards, females are ZW and males are ZZ. Both genders are designed with the Z chromosome, and the structure responsible with the female gene is the W chromosome. Hot temperatures act like an instant switch on the chromosome-based gender, killing the W in a potential female.
The team of scientists has observed that from the total of 131 specimens analyzed, 11 of them were female outwardly but had the ZZ chromosomes of a genetic male. Their sex determination was “switched into overdrive”, as researchers pointed out.
What is even more surprising is that the genetically modified females were capable not only of laying eggs, but acted as much better, highly protective mothers compared to the genetically determined females. Every down has an upside too and vice versa but this doesn’t change the fact that global warming brings heavy consequences on the entirety of animal species.
Sex reversal is only one of the many effects of the climate change and in Australia the phenomena is widespread with instances expanded over almost 15.000 square miles in remote and semi-arid areas.
Image Source: mid-day.com