At 27.9 °C, roughly equal numbers of female and male turtles will emerge from the nests of the Chinese pond turtle Mauremys reevesii. Slightly warmer, and more females will hatch; a little cooler, and there will be more males.
Developing reptile embryos that have temperature-dependent sex determination were long thought to passively accept their weather-based fate. But now, new research suggests that at least in M. reevesii, embryos can move around to find slightly cooler or warmer regions within their eggs, and thereby have some control over the sex they develop into. The authors propose that this ability may help offset drastic, population-wide shifts in sex ratios that are occurring due to climate change. The findings appear today (August 1) in Current Biology.
“I find it fascinating that [embryonic movements] may be an important contributor to the production of equal numbers of males and females at intermediate conditions in the ...
