The brain and its satellite glands have now been probed to the point where no particular site remains that can reasonably be supposed to harbour a nonphysical mind.

That's what the best global conservation organisations and the American government (and other environmentally inclined governments, such as Sweden and the Netherlands) are doing: protecting the remaining wild environment. This is the equivalent of getting a patient to the emergency room - keep them alive and then figure out how to save them.

The big question that scientists haven't even begun to get an answer for is how many species of microorganisms are there? Now, this is not stamp collecting. What we need is experts totally devoting their research to everything they can find out about every species, in a community of scientists who appreciate that every fact counts...everything new you learn about any species in any group is worth publishing somewhere.

Every native species, however humble in appearance...has its place in the nation's heritage. It is a masterpiece of evolution, an ancient, multifaceted entity that shares the land with us.

And pigs may fly. And we may be able to terraform and send surface populations to Mars. And Jesus may come next week anyway, so it doesn't matter one way or the other. All these crazy things run through people's minds.

Most people are surprised when they hear my somber figures: we know of 2 million species of plants, animals and microorganisms, and we can give them each a scientific name and a diagnostic description. We know, perhaps generously, more than just a little bit of the anatomy in no more than 10 percent. We have done thorough studies in fewer than one-tenth of 1 percent. And the total number of species on Earth is unknown to the nearest order of magnitude.

The history of life on earth has been a history of interaction between living things and their surroundings.