“We may be only one of millions of advanced civilizations. Unfortunately, space being spacious, the average distance between any two of these civilizations is reckoned to be at least two hundred light-years, which is a great deal more than merely saying it makes it sound. It means for a start that even if these beings know we are here and are somehow able to see us in their telescopes, they're watching light that left Earth two hundred years ago. So, they're not seeing you and me. They're watching the French Revolution and Thomas Jefferson and people in silk stockings and powdered wigs--people who don't know what an atom is, or a gene, and who make their electricity by rubbing a rod of amber with a piece of fur and think that's quite a trick. Any message we receive from them is likely to begin "Dear Sire," and congratulate us on the handsomness of our horses and our mastery of whale oil. Two hundred light-years is a distance so far beyond us as to be, well, just beyond us.”

“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.”

“Every atom you possess has almost certainly passed through several stars and been part of millions of organisms on its way to becoming you. We are each so atomically numerous and so vigorously recycled at death that a significant number of our atoms - up to a billion for each of us, it has been suggested - probably once belonged to Shakespeare. A billion more each came from Buddha and Genghis Khan and Beethoven, and any other historical figure you care to name. So we are all reincarnations - though short-lived ones. When we die, our atoms will disassemble and move off to find new uses elsewhere - as part of a leaf or other human being or drop of dew.”

“There’s something satisfying, I think,’ Evans said, ‘about the idea of light travelling for millions of years through space and just at the right moment as it reaches Earth someone looks at the right bit of sky and sees it. It just seems right that an event of that magnitude should be witnessed.”

“Beulah has a husband?'I know. It's a miracle. There can't be more than two people on the planet who'd be willing to sleep with her, and here we are both in the same town.”

“People don't talk like this, theytalklikethis. Syllables, words, sentences run together like a watercolor left in the rain. To understand what anyone is saying to us we must separate these noises into words and the words into sentences so that we might in our turn issue a stream of mixed sounds in response. If what we say is suitably apt and amusing, the listener will show his delight by emitting a series of uncontrolled high-pitched noises, accompanied by sharp intakes of breath of the sort normally associated with a seizure or heart failure. And by these means we converse. Talking, when you think about it, is a very strange business indeed.”

“I know this goes without saying, but Stonehenge really was the most incredible accomplishment. It took five hundred men just to pull each sarsen, plus a hundred more to dash around positioning the rollers. Just think about it for a minute. Can you imagine trying to talk six hundred people into helping you drag a fifty-ton stone eighteen miles across the countryside and muscle it into an upright position, and then saying, 'Right, lads! Another twenty like that, plus some lintels and maybe a couple of dozen nice bluestones from Wales, and we can party!' Whoever was the person behind Stonehenge was one dickens of a motivator, I'll tell you that.”