for anyone unaware, this is a book by Stanford professor Robert Sapolsky:

https://en.wikipedia.org/wiki/Why_Zebras_Don%27t_Get_Ulcers

The book is about stress and the impact of glucocorticoids on the body. The chemical stress response used in "the wild" by animals is actually the same as the stress response we have when worrying about losing our job, not being able to complete a paper for school, dealing with poverty, etc. It's a partial explanation for why modern humans have so many chronic diseases that are rarely seen in other animals (or even archeological/anthropological evidence of non-industrial societies but he doesn't really go there much in the book)

I also highly recommend Sapolsky's Human Behavior Biology course which he taught for Stanford but published on YouTube:

https://www.youtube.com/watch?v=NNnIGh9g6fA