That isn't a genetic change either, though. Those species of turtle either lack the typical sex-determining chromosomes entirely, or have sex-determining chromosomes which can be inactivated during development. The genotype doesn't change as a result of what temperature the egg is incubated at; its expression does.

Further reading: https://www.sciencedaily.com/releases/2021/07/210726102148.h...

That's exactly the point. Gene expression can be modified by the environment