Global warming calls forth male extinction
The much railed-against phenomenon of global warming affects an Australian lizard species past recall. According to the latest studies of Australian herpetologists, the female lizards from the island of Tasmania have difficulties in finding males. This is a consequence of the high temperatures brought by the last years, temperatures which strongly affect the eggs laid by these reptiles.
Erik Wastra, a herpetologist from the University of Tasmania, has observed an alarming phenomenon over the last few years, regarding the lizards which populate the Tasmanian island: a proportional increase of the number of females, while the number of males shrinks from one year to another.
As regards all reptiles, from crocodiles to lizards or turtles, the temperature of the environment before the hatching is the only agent determining the sex. In prevailingly warm periods, the hatching brood will be female. If, before the hatching, the weather is a little cooler, the brood will be male. The border temperature at which there is male brood is up to circa 17 degrees Celsius. Until Erik Wastra’s study, carried out between 2000-2008, this phenomenon was only observed experimentally, in the lab. The study underlines the negative impact of the global warming in the perimeter of Tasmanian lizards: if only female brood survives, whole reptile species are facing total extinction.
Source: National Geographic