All cells are dependent on what usable energy source

Ever cell uses energy in order to grow. That energy is also used to mange metabolism and to reproduce. For us, humans, we gather energy from food, that's our food source that gives us food molecules. Another example of a food source is the Sun, and through those food sources we get energy rich molecules.

Heyhonestly, probably not. humans have always had a tendency to waste things. whether it's food, cosmetic, infrastructure, or our abandoned constructions,the landscape is littered with the refuseof man. archaeology wouldn't be a developed discipline if humans didn't leave things behind. in a way it makes us human

hope it mark me as brainlieast.