From Ben Haller, Ithaca, New York, US
Cooling turtle nests with a bit of cold seawater, in order to shift the temperature-dependent sex ratio of the resulting hatchlings, is an intriguingly simple solution to the misalignment of this system due to climate change (29 July, p 16).
However, there is a risk to this strategy that isn’t mentioned: it would make the turtles utterly dependent upon our continuing intervention for their survival. It would be far better to help their sex-determination system evolve in response to climate change, perhaps with assisted breeding or even genetic engineering; they would then be self-sufficient.
