comparison with animals
The study of the history of life, the evolutionary process, and the nature of the other beings who ride this planet with us has begun to cast a little light on those past links in the chain. We have not met our forgotten ancestors, but we begin to sense their presence in the dark. We recognize their shadows here and there. They were once as real as we are. We would not be here if not for them. Our natures and theirs are indissolubly linked despite the aeons that may separate us. The key to who we are is waiting in those shadows.
——
When we began this search into our origins, using the methods and findings of science, it was almost with a sense of dread. We were afraid of what we might find. We found instead not just room but reason for hope, as we begin to explain in this book.
The real orphan’s file is long. We humans have uncovered bits and pieces, occasionally a few consecutive pages, nothing as elaborate as a complete chapter. Many of the words are blurred Most have been lost. 7
Here then is one version of some of the early pages of the orphan’s file, the missing note that should have accompanied the foundling on the doorstep, something of our beginnings and the forgotten ancestors that are central to the outcome of our story. Like most family stories, it begins in the dark—so long ago and far away, in circumstances so unpromising, that no one could have guessed where it all would lead.
We are about to trace the history of life, and the path that led to us—how we got to be the way we are. It is fitting that we begin at the beginning. Or a little earlier.
Chapter 1
ON EARTH AS IT IS IN HEAVEN
How long the stars
Have been fading,
Lamplight dimming …
NANSEN
(748–834, China) 1
For the forming of the earth they said “Earth.” It arose suddenly, just like a cloud, like a mist, now forming, unfolding …
Popol Vuh: The Mayan Book of the Dawn of Life
2
N othing lives forever, in Heaven as it is on Earth. Even the stars grow old, decay, and die. They die, and they are born. There was once a time before the Sun and Earth existed, a time before there was day or night, long, long before there was anyone to record the Beginning for those who might come after.
Nevertheless, imagine you were a witness to that time:
An immense mass of gas and dust is swiftly collapsing under its own weight, spinning ever faster, transforming itself from a turbulent, chaotic cloud into what seems to be a distinct, orderly, thin disk. Its exact center smolders a dull, cherry red. Watch from on high, above the disk, for a hundred million years and you will see the central mass grow whiter and more brilliant, until, after a couple of abortive and incomplete attempts, it bursts into radiance, a sustained thermonuclear fire. The Sun is born. Faithfully, it will shine over the next five billion years—when the matter in the disk will have evolved into beings able to reconstruct the circumstances of its origin, and theirs.
Only the innermost provinces of the disk are illuminated. Farther out, the sunlight fails to penetrate. You plunge into the recesses of the cloud to see what wonders are unfolding. You discover a million small worlds milling about the great central fire. A few thousand sizable ones here and there, most circling near the Sun but some at great distances away, are destined to find each other, merge, and become the Earth.
This spinning disk out of which worlds are forming has fallen together from the sparse matter that punctuates a vast region of interstellar vacuum within the Milky Way galaxy. The atoms and grains that make it up are the flotsam and jetsam of galactic evolution—here, an oxygen atom generated from helium in the interior inferno of some long-dead red giant star; there, a carbon atom expelled from the atmosphere of a carbon-rich star in some quite different galactic sector; and now an iron atom freed for world-making by a mightysupernova