Humans are a part of nature. Bacteria, fungi, soil, skies are us and we are them. The mystics and outsider philosophies were right. Humans are nature and we can't live without the healthy complexity of a natural ecosystem. Something created by humans in a laboratory cannot be the same as nature. Industrial pollution is an example that disconnecting ourselves from the green web simply causes problems.
See http://en.wikipedia.org/wiki/Man_and_the_Natural_World:_Changing_Attitudes_in_England_1500–1800
The above link shows where certain dominion attitudes towards nature originated.
Interesting, how our ancestors were given such a bountiful world, but took it for granted and ended up squandering it.