Even to this day, no native Australian animal species and only one plant species-the macadamia nut-have proved suitable for domestication. There still are no domestic kangaroos.

The main thing that gives me hope is the media. We have radio, TV, magazines, and books, so we have the possibility of learning from societies that are remote from us, like Somalia. We turn on the TV and see what blew up in Iraq or we see conditions in Afghanistan.

Recent discoveries about apes suggest, however, that a gorilla or common chimp stands at least as good a chance being murdered as the average human.

No government is here forever. And there are other forces - the most potent force in our society, in fact, big business - doing good for the environment.

Why were there far more species of domesticated animals in Eurasia than in the Americas? The Americas harbor over a thousand native wild mammal species, so you might initially suppose that the Americas offered plenty of starting material for domestication.

With the rise of chiefdoms around 7,500 years ago, people had to learn, for the first time in history, how to encounter strangers regularly without attempting to kill them.

I've always been interested in a lot of things, and a lot of things at the same time, and I always tried to explain them to myself. I ask a lot of questions.