Shadows of Forgotten Ancestors

This book is written for a wide readership. For clarity, we have sometimes stressed the same point more than once, or in more than one context. We have tried to indicate qualifications and exceptions. The pronoun “we” is used sometimes to mean the authors of this book, but usually to mean the human species; the context should make clear which is meant. For those who wish to dig deeper, references to other works, popular and technical—keyed to superscripts in the text—are in the back of the book. Also to be found there are additional comments, notes, and clarifications. Although the two works have little else in common, the haunting 1964 film by Sergei Parajanov gave us our title.

As for essential inspiration and a heightened sense of urgency, it was during the years of preparation of this book that we became the parents of Alexandra Rachel and Samuel Democritus—beloved namesakes of unforgettable ancestors.

CARL SAGAN

ANN DRUYAN

June 1, 1992

Ithaca, N.Y.

Prologue

THE

ORPHAN’S

FILE

Having seen a small part of life, swift to die,

men rise and fly away like smoke, persuaded

only of what each has met with … Who then

claims to find the whole?

EMPEDOCLES

On Nature¹

Who are we? The answer to this question is not

only one of the tasks, but the task of science.

ERWIN SCHRÖDINGER

Science and Humanism²

The immense, overpowering blackness is relieved here and there by a faint point of light—which, upon closer approach, is revealed to be a mighty sun, blazing with thermonuclear fire and warming a small surrounding volume of space. The Universe is, almost entirely, black emptiness, and yet the number of suns is staggering. The neighborhoods immediately encompassing these suns represent an insignificant fraction of the vastness of the Cosmos, but many, perhaps most, of those cheerful, bright, clement circumstellar regions are occupied by worlds. In the Milky Way galaxy alone there may be a hundred billion of them—neither too close by, nor too distant from, the local sun, around which they orbit in silent gravitational homage.

This is a story about one such world, perhaps not very different from many others—a story, especially, about the beings that evolved upon it, and one kind in particular.

Just to be alive billions of years after the origin of life, a being must be tough, resourceful, and lucky: There have been so many hazards along the way. Lifeforms endure by being patient, say, or ravenous, or solitary and camouflaged, or profligate with offspring, or fearsome hunters, or able to fly away to safety, or sleek swimmers, or burrowers, or sprayers of noxious, disorienting liquids, or masters at infiltrating into the very genetic material of other, unsuspecting, beings; or by accidentally being elsewhere when the predators stalk or the river is poisoned or the food supply dwindles. The creatures with which we are particularly concerned were, not so long ago, gregarious to a fault, noisy, quarrelsome, arboreal, bossy, sexy, clever, tool-using, with prolonged childhoods and tender regard for their young. One thing led to another, and in a twinkling their descendants had multiplied all over the planet, killed off all their rivals, devised world-transforming technologies, and posed a mortal danger to themselves and the many other beings with whom they shared their small home. At the same time, they set off to visit the planets and the stars.

——

Who are we? Where do we come from? Why are we this way and not some other? What does it mean to be human? Are we capable, if need be, of fundamental change, or do the dead hands of forgotten ancestors impel us in some direction, indiscriminately for good or ill, and beyond our control? Can we alter our character? Can we improve our societies? Can we leave our children a world better than the one that was left to us? Can we free them from the demons that torment us and haunt our civilization? In the long run, are we wise enough to know what changes to make? Can we be trusted with our own future?

Many thoughtful people fear that our problems have become too big for us, that we are for reasons at the heart of human nature unable to deal with them, that we have lost our way, that the dominant political and religious ideologies are unable to halt an ominous, long-term drift in human affairs—indeed, that they have helped cause that drift through rigidity, incompetence, and the inevitable corruption of power. Is this true, and if it is, can we do anything about it?