That's a great point, though I surmise that there is no waste in the human body. Human's constituents are entirely composed of cells or organelles, and those a

That's a great point, though I surmise that there is no waste in the human body. Human's constituents are entirely composed of cells or organelles, and those all consume energy. If there were any cells/organelles that did not contribute at all to the human, he would have a lower performance than humans without the waste, and so evolution would select them out.