In my limited understanding, the credible version of this story involves the transmission of quite crude information, like a response to famine. Lots of animal

In my limited understanding, the credible version of this story involves the transmission of quite crude information, like a response to famine. Lots of animals starved, since there were animals, and the ability to tune the behavior on a time-scale of a few generations might have been valuable, so it might have evolved. The basics of our hormonal system have not changed much since very simple animals, I think.