To those suggesting above that it's okay to let things die out naturally, "unless it was because of mankind", do you view yourselves as somehow super-natural?
I've always considered myself a part of nature. If I cut down a tree and it contained the last "purple Wiznook", the purple wiznook has died out as naturally as if it was eaten by a Lion.
I watched "Last Chance to See" on Sunday and, whilst beatifully shot, the complete bollocks about the deforestation of Madagascar was maddening. We deforested Britain and most of mainland Europe. Why the hell are we stopping them having a great quality of life just to save a few ugly little primates who haven't evolved to survive without a dwindling natural resource?
Eventually, some day, we might use up all the resources and, unless we evolve, spread out to other planets etc, we'll die out and Earth will get along just fine without us. 65 Million years from now some species will be digging up our fossils and making films about how we have been recreated from the last batch of frozen embryos....
"Conservationists" annoy me almost as much as religious fanatics and strike me as appallingly similar in their view of humans as somehow superior.