Washington (AFP)
Some turtle embryos play a role in determining their sex by moving inside their eggs, which could save them from climate change, scientists said in a study released Thursday.
In some species of turtles, the temperature of the eggs determines whether the offspring is male or female. Scientists feared that this feature endangered these species in the face of climate change, as a two-degree change in temperature can dramatically alter the ratio of sexes within a species.
Researchers in China and Australia have discovered that embryos are able to move within their eggs to find a zone that is neither too hot nor too cold, thus playing a role in determining their own sex. The study was published Thursday in Current Biology.
"Our research shows that a reptile embryo is not only a passive victim of global warming, but that it can control to a certain extent its own sexual destiny," Wei-Guo told AFP. From the Chinese Academy of Sciences.
The team had previously demonstrated that reptile embryos could move within their ovum for thermoregulation, and wanted to know if this behavior had a significant impact in determining the sex of the reptile.
Scientists placed freshwater turtle eggs in a range of different temperatures and noticed that a single embryo could experience temperature changes of 4.7 degrees in its egg.
"This could explain how reptile species whose sex determination depends on temperature have survived previous periods of Earth's history when temperatures were much higher than today," said Richard Shine. , professor at Macquarie University of Australia and one of the co-authors of the study.
But the control of the sex of the embryos has its limits: when the average temperatures in the nests are very hot or very cold, the effort of the embryo does not have an impact on the sex of the offspring.
"It may not be enough to protect it from the much faster climate change that is currently caused by human activities," Wei-Guo Du told AFP.
But, he added, the species can resort to means not yet discovered to offset the impact of global warming, such as egg-laying earlier in the season or in shaded nests, which will the subject of his future studies.
© 2019 AFP