Humans are not unitary individuals but superorganisms
This is a sort of pattern. (1) We create categories and concepts that rely on categories: molecules, organisms, species, galaxies; water, rebecca, potatoes, multiple personality disorder. (2) We use those categories to describe and understand things, engineer and theorize using them. We have evolution and chemistry and potato salad recipes. (3) Then we discover that these categories aren't really real. They're real, like, but not really real, you know what I mean. Tasmanian devils are being decimated by a contagious cancer. A mutated cell in some devil reproduced until it was lumps, then the devils bit another delve in the face (they're not nice animals) and some of that cancer jumped into another one and spread. Now, that cancer has outlived his maker and is going around spreading in the world with complete disregard for the concepts of organism or species and behaving like a bacteria, virus or somesuch. Instead of spreading normally like the rest of the devil by sexy with other devils it jumps into the other devil's face (sometimes during sex, they are not nice animals). Maybe one day it will evolve into our replacement. Maybe it will find symbioses with sheep and become a beneficial gut fauna (it is a taste devil after all).We make up these categories for convenience. They are not obligated to comply.