Certainly the first true humans were unique by virtue of their large brains. It was because the human brain is so large when compared with that of a chimpanzee that paleontologists for years hunted for a half-ape, half-human skeleton that would provide a fossil link between the human and the ape.

It's not that humans and non-humans are identical... but the lack of understanding that led to the slave trade is the same lack of understanding many people have about animals today. When slaves were brought over from Africa, many people believed they were not humans, that they didn't have feelings. Many people believe that primates and other animals don't have feelings, too, but they do.

Our brain is almost the same as the chimps', but we have language, we have electronic communications, we've put people on the moon - we are immensely more intelligent. And yet: how come the being with the most extraordinary intellect ever is destroying its only planet?

And always I have this feeling--which may not be true at all--that I am being used as a messenger.

Chimps are brutal, and it is so deliberate. The males go out and get near the boundary of their territory. And they walk very silently trying hard not to make any noise. They will climb into a tree and stare out over hostile territory for hours. They are waiting for the right opportunity. And then they attack.

Animals were my passion from even before I could speak apparently. When I was about 10, 11 I fell in love with Tarzan.

I've always felt you don't have to be completely detached, emotionally uninvolved to make precise observations. There's nothing wrong with feeling great empathy for your subjects.