What is the original source of the energy that flows through most ecosystems? what would happen without this source?

Solar energy is the original source of energy in most ecosystems. There must be a continual supply, due to energy only flowing in one direction in an ecosystem. Energy that is lost to heat must be replaced by more energy.

fumikage isn't really a bird, and tsuyu does have teeth. tsuyu has a transformation quirk which still allows her to be partially human. otherwise we'd have a large frog running around. fumikage has teeth because again, he isn't a bird. his head was a quirk mixture if i'm correct.

answer; benefit; harmed;