In an article called "Dear Fellow Improbable", Dick Cavett writes:

"Back to Monterey. A genial, humorous and brilliant geologist, and the kind of professor too few ever experience, is onstage. His name: Walter Alvarez, of the University of California, Berkeley. He and his Nobel-prized father, the late physicist Luis Alvarez, gave the world the Òimpact theoryÓ that explained the demise of the dinosaurs.

Near the end of his talk, he refers to you and me as belonging to a species called Òastronomically improbables.Ó

HasnÕt almost everyone, sooner or later, hit upon the realization that because you have two parents, four grandparents, eight great-grandparents and so on into near-infinity, you are related to practically everyone on earth?

Here, for now, are just a few of AlvarezÕs astonishers regarding this, which made everyone gasp.

(Fundamentalists may wish, at this point, to switch to some other reading material to avoid distress.)

He pointed out that we each have millions of ancestors and that, at conception, your sex is determined randomly. If any single one of that galaxy of ancestors had chanced to have a different sex, you would not be here to read this. (Presumably, someone else would. Unless of course one of my millions of ancestors met with a mishap.)

Keep that word ÒgalaxyÓ in mind.


NASA
Do we have more ÒancestorsÓ than there are atoms in several galaxies?
Just how many of your forebears were there, that the wrong gender accident could have happened to, thereby snuffing any chance of your existence? Brace yourself.

Alvarez led us gently to the wowing fact: An imaginary space ship travels through our galaxy. Each of the millions of heavenly bodies in our galaxy represents one ancestor. But it gets better. (Or worse.)

The ship leaves our galaxy and journeys through the next. And the next.

And É

Even typing this next bit makes me glad IÕm sitting down. Not only does each planet, star, Milky Way and what-have-you in every galaxy represent numerically a member of your family tree, so does each atom in all those galaxies. Every one representing a chance for each of us not to exist.

Had any one of those parents died before maturing, or been sterile, or not met the wife by chance in handing her a dropped glove, or shared a woolly mammoth bone with her on a date leading to bed, or been carried off in the plague or killed by some forerunner of a New York bicycle rider on the sidewalk . . . the mind boggles. (Not to mention the near-infinite number of people who might have been born down through the end of time but werenÕt Ñ because your particular chain went on unbroken.)

Can any mind this side of EinsteinÕs accommodate this thought?

How many ancestors, going back millions and millions of years Ñ each of whose specific wiggly was in each case the only one among millions that got through to make you . . . how many of those ancestors are there?

Help me, math guys and gals. WhatÕs the answer? What to the 10th power?

ThereÕs more good stuff on this.

But for now, I have to lie down."


(NYT)