[ben_w]

Regarding gender ratios: https://en.wikipedia.org/wiki/Fisher's_principle

There's exceptions, but they tend to be colonial animals in the broadest sense e.g. how clownfish males are famously able to become female but each group has one breeding male and one breeding female at any given time*, or bees where the males (drones) are functionally flying sperm and there's only one fertile female in any given colony; or some reptiles which have a temperature-dependent sex determination that may have been 50/50 before we started causing rapid climate change but in many cases isn't now: https://en.wikipedia.org/wiki/Temperature-dependent_sex_dete...

* Wolves, despite being where nomenclature of "alpha" comes from, are not this. The researcher who coined the term realised they made a mistake and what he thought of as the "alpha" pair were simply the parents of the others in that specific situation: https://davemech.org/wolf-news-and-information/

[bonzini]

Temperature-dependent sex determination may not be at equilibrium now but is not an exception to Fisher's principle. The temperature at which sex determination switches is variable based on the parent's genes, and it will try to re-equilibrate with the environment temperature to obtain 1:1 ratios just like in other animals.

[ben_w]

Indeed, that is why I wrote "may have been 50/50 before we started causing rapid climate change".

[bonzini]

It's still not a violation of Fisher's principle, long term we would see natural selection move the threshold temperature upwards.