I had in mind a message, although I hope it doesn't intrude too badly, persuading Americans, and especially Southerners, of the critical importance of land and our vanishing natural environment and wildlife.

I turned to the teeming small creatures that can be held between the thumb and forefinger: the little things that compose the foundation of our ecosystems, the little things, as I like to say, who run the world.

We don't even know what species are out there, for the most part, particularly when you get down to the microbes and very small invertebrates. They make up the mass of the organisms around us, including the soil we depend on, the soil of cornfields as well as hardwood forests. We haven't taken ecology to the point where we can even make a crude prediction of what's going to happen when we've reduced the living world down to a certain level.

No one knows the diversity in the world, not even to the nearest order of magnitude. ... We don't know for sure how many species there are, where they can be found or how fast they're disappearing. It's like having astronomy without knowing where the stars are.

Overall, the human brain is the most complex object known in the universe - known, that is, to itself.

Evolution by natural selection is not an idle hypothesis. The genetic variation on which selection acts is well understood in principle all the way down to the molecular level.

We should preserve every scrap of biodiversity as priceless while we learn to use it and come to understand what it means to humanity.