Here's an intriguing - and if you are male, worrying - thought. Is global warming a dastardly scheme cooked up by females so they can take over the planet?
A new study of reproduction in one creature affected by rising temperatures and sea levels - the Caribbean hawksbill turtle - has raised the sinister possibility. (Sort of.) As with other animals, such as lizards and snakes, the sex of a turtle's hatchling will depend on the temperature its eggs are kept during incubation. In general, the cooler the egg is kept, the more likely the baby is to be male. The hotter the egg, the more likely it is to be female. With this in mind, the hawksbill turtles chooses different incubation grounds for male and female eggs, dividing eggs roughly equally among the two sites to maintain a balanced population. To produce males they lay their eggs above the high tide marks on beaches where, in the past, at least, the shade of the natural forests have kept temperatures cooler. However, rising sea levels and temperatures - as well as deforestation by humans - has reduced the number of cool spots for the turtles to lay their eggs. As a result, or so the survey reported in Science magazine concludes, the hawksbill population is becoming more and more dominated by females. If things carry on like this, the poor male turtle will soon be completely over-run by his female counterparts. We have yet to see evidence of how lizard and snake populations are changing, but it's a safe guess they may well be experiencing the same female bias. Where will it end? And is there a female hand at work in all this? Don't human mums produce more CFCs?