I've been reading this book and I'm trying to figure out some stuff. I would like to know if customs such as animal sacrifice and circumcision were practiced in the fertile crescent before the Chaldeans settled there. I'm not even sure who was there first, I'm a little confused.

If it wasn't practiced there beforehand, is there evidence that the Chaldeans carried such customs with them? Also I've read that Egypt and Ethiopia had such customs, and I'm wondering if anyone in those areas practiced those customs before the 3rd dynasty of Egypt. Thank you for your help.