Some of these species that are now no longer with us were killed off by a fungal disease that was moved around the planet by people.

You're an animal that needs to move across the landscape, you can't anymore, and that's another way we're just changing the surface of the Earth in very dramatic ways.

What are the Chinese doing, what are we doing, what are - so we need, both the developed world and the developing world, really need to be moving, once again, getting all your arrows in the same direction if you want to have any impact.

Some of these species that are now no longer with us were killed off by a fungal disease that was moved around the planet by people.

There's this idea of shifting baselines. It was coined by a guy named Jeremy Jackson. It's the idea that every generation takes what it sees, and says, "Okay, well, that's the norm."

We have all this Paleolithic art that suggests that our ancestors really venerated animals and that they depended on wild animals to survive - as opposed to domesticated animals that we depend on. Would it radically change things if we had more rhinos in our midst? I kind of suspect it would.

Though it might be nice to imagine there once was a time when man lived in harmony with nature, it’s not clear that he ever really did.