It's coming home to roost over the next 50 years or so. It's not just climate change; it's sheer space, places to grow food for this enormous horde. Either we limit our population growth or the natural world will do it for us, and the natural world is doing it for us right now.

The only way to save a rhinoceros is to save the environment in which it lives, because there's a mutual dependency between it and millions of other species of both animals and plants.

There's a small worm called Loa Loa Filariasis. This parasite can survive in one environment exclusively- namely, underneath the skin and inside the eyes of human beings. Children and the elderly in tropical regions (usually the poorest) are the most widely affected. A painful, slow death is virtually certain. The worm can actually live in the host for 17 years before the host finally dies.

It's like saying that two and two equals four, but if you wish to believe it, it could also be five ... Evolution is not a theory; it is a fact, every bit as much as the historical fact that William the Conqueror landed in 1066.

The process of making natural history films is to try to prevent the animal knowing you are there, so you get glimpses of a non-human world, and that is a transporting thing.

Nothing in the natural world makes sense - except when seen in the light of evolution

The whole of science, and one is tempted to think the whole of the life of any thinking man, is trying to come to terms with the relationship between yourself and the natural world. Why are you here, and how do you fit in, and what's it all about.