“Rat bites are almost certainly under reported because only the most serious cases attract attention, but even using the most conservative figures, at least fourteen thousand people in the United States are attacked by rats each year.”

“Incidentally, the long-held idea that spices were used to mask rotting food doesn't stand up to much scrutiny. The only people who could afford most spices were the ones least likely to have bad meat, and anyway spices were too valuable to be used as a mask.”

“Columbus's real achievement was managing to cross the ocean successfully in both directions. Though an accomplished enough mariner, he was not terribly good at a great deal else, especially geography, the skill that would seem most vital in an explorer. It would be hard to name any figure in history who has achieved more lasting fame with less competence. He spent large parts of eight years bouncing around Caribbean islands and coastal South America convinced that he was in the heart of the Orient and that Japan and China were at the edge of every sunset. He never worked out that Cuba is an island and never once set foot on, or even suspected the existence of, the landmass to the north that everyone thinks he discovered: the United States.”

“I have long known that it is part of God's plan for me to spend a little time with each of the most stupid people on earth, and Mary Ellen was proof that even in the Appalachian woods I would not be spared. It became evident that she was a rarity.”

“Most people when they nod off look as if they could do with a blanket; I look as if I could do with medical attention. I sleep as if injected with a powerful experimental muscle relaxant.”

“But that's the glory of foreign travel, as far as I am concerned. I don't want to know what people are talking about. I can't think of anything that excites a greater sense of childlike wonder than to be in a country where you are ignorant of almost everything. Suddenly you are five years old again. You can't read anything, you have only the most rudimentary sense of how things work, you can't even reliably cross a street without endangering your life. Your whole existence becomes a series of interesting guesses.”

“I mention all this to make the point that if you were designing an organism to look after life in our lonely cosmos, to monitor where it is going and keep a record of where it has been, you wouldn't choose human beings for the job.But here's an extremely salient point: we have been chosen, by fate or Providence or whatever you wish to call it. It's an unnerving thought that we may be living the universe's supreme achievement and its worst nightmare simultaneously.Because we are so remarkably careless about looking after things, both when alive and when not, we have no idea-- really none at all-- about how many things have died off permanently, or may soon, or may never, and what role we have played in any part of the process. In 1979, in the book The Sinking Ark, the author Norman Myers suggested that human activities were causing about two extinctions a week on the planet. By the early 1990s he had raised the figure to about some six hundred per week. (That's extinctions of all types-- plants, insects, and so on as well as animals.) Others have put the figure ever higher-- to well over a thousand a week. A United Nations report of 1995, on the other hand, put the total number of known extinctions in the last four hundred years at slightly under 500 for animals and slightly over 650 for plants-- while allowing that this was "almost certainly an underestimate," particularly with regard to tropical species. A few interpreters think most extinction figures are grossly inflated.The fact is, we don't know. Don't have any idea. We don't know when we started doing many of the things we've done. We don't know what we are doing right now or how our present actions will affect the future. What we do know is that there is only one planet to do it on, and only one species of being capable of making a considered difference. Edward O. Wilson expressed it with unimprovable brevity in The Diversity of Life: "One planet, one experiment."If this book has a lesson, it is that we are awfully lucky to be here-- and by "we" i mean every living thing. To attain any kind of life in this universe of ours appears to be quite an achievement. As humans we are doubly lucky, of course: We enjoy not only the privilege of existence but also the singular ability to appreciate it and even, in a multitude of ways, to make it better. It is a talent we have only barely begun to grasp.We have arrived at this position of eminence in a stunningly short time. Behaviorally modern human beings-- that is, people who can speak and make art and organize complex activities-- have existed for only about 0.0001 percent of Earth's history. But surviving for even that little while has required a nearly endless string of good fortune.We really are at the beginning of it all. The trick, of course, is to make sure we never find the end. And that, almost certainly, will require a good deal more than lucky breaks.”