Federal elections happen every two years in this country. Presidential elections every four years. And four years just isn't long enough to dismantle all the environmental laws we've got in this country.

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.

It invites a search for ultimate causes: why were Europeans, rather than Africans or Native Americans, the ones to end up with guns, the nastiest germs, and steel?

Perhaps our greatest distinction as a species is our capacity, unique among animals, to make counter-evolutionary choices.

Take air quality in the United States today: It's about 30 percent better than it was 25 years ago, even though there are now more people driving more cars.

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.

Civilization originates in conquest abroad and repression at home.