Explanation:
As far as I can think of, we're dependent on other species. If we can't be carnivores, then literally, the only other option I can think of is being a herbivore, and that still an organism. We need sufficient life essence to keep living. We CANNOT live without harming another organism.
In short of my babbling, human survival is not independent of other species.
Answer:
Solar Energy
The sun radiates solar energy to the earth and it is used for other things.
