What is the oldest branch of biological sciences?

Question

What is the oldest branch of biological sciences?

Answer 1

Without doing a lot of research, probably the oldest branch is taxonomy!  Primitive hunter-gatherers had to be able to recognize the right kinds of plants and animals to survive.  But that was not formal science.  Aristotle was one of the first "scientists" to systematically carry out dissections of animals of all kinds.  His anatomy of the Barbary ape was used for centuries since many considered dissection of humans desecration.  Theophratus was one of the first to systematically describe plants.

Answer 2

Probably a tie between zoology and medicine.