My life comes from the study of nature. When we were born, we become participate in the circle of life. But only humans don't take part in that cycle. Normally, insects, mammals, reptiles, etc., eats or get eaten, and they return to the earth when they die, consumed by bacteria. Thus the cycle begins again. The only thing humans do is consume these organisms and no more.
Philosophically, let's say we this earth was a body of a organism. We are made of different cells, tissues and bacteria. We are saved by these small organisms and helped us live. Like this link between us and cells, earth is the same way. The plants and animals help us live. Therefore, the earth is supporting animals and humans alike. The marine animals, land animals, insects and other organisms have lived on this earth far longer then we have and supported each other with great care. If time were to be measured using meter stick, humans have lived less than 1 millimetre if converted to time. Through mutations through our gene pool, during these 100 years, we have overpopulated and destroyed this planet in a wink. Animals, without question, have preformed their task of maintaining this earth. With our selfish hearts, we try again and again to control this cycle. Do you realise what we are? A destructive cancer on this earth, eating away the nutrients like parasites.