Symbiosis

Some cultures need cows and their cows could not survive without their
shepharding. Same with sheep. Speaking of which, Amerikans too.

Cats needs people to live to e.g., the 17 years that my domestic shorthair has lived. People need cats if people are to accumulate wealth in the form of grains (before they get industrial tech). That is in fact how folks got friendly with cats: the grain guards got friendly, and gave the Prez. some nice friendly specimens.

Who didn't poop or pee on their Pharoah's clothes, unlike mine.

Symbiosis: lichen: algae (primitive plant) + fungi (plant or animal that's lost its ability to eat by itself). They could colonize Mars.

Humans are also symbiotic with gut bacteria (Est. coli), skin flora & fauna, and their various domesticated animals, cats dogs sheep pigs cows llamas etc. Read
Guns Germs and Steel, and then read Collapse or any of Chalmers Johnsons' books on the specific collapse of US civ.