From tail to tale on the path of pilgrims in life

IT IS a conceit of hindsight to see evolution as aimed towards some particular end point, such as ourselves.

We are not elephants, we are people. It is humanly natural to reserve a special warmth and curiosity for whichever otherwise ordinary species in an ancient landscape is our ancestor (it is an intriguingly unfamiliar thought that there is always one such species). It is hard to deny our human temptation to see this one species as "on the main line" of evolution, the others as supporting cast, walk-on parts, sidelined cameos. Without succumbing to that error, there is one way to indulge a legitimate human-centrism while respecting historical propriety. That way is to do our history backwards, and it is the way of my book, The Ancestor’s Tale, which is cast in the form of an epic pilgrimage from the present to the past. All roads lead to the origin of life. But because we are human, the path we follow is a human pilgrimage to discover human ancestors. As we go, we greet other pilgrims who join us at a series of rendezvous points, as we encounter the common ancestor we share with each of them.

The first fellow pilgrims we greet, at Rendezvous 1, some five million years ago, deep in Africa where Stanley memorably shook hands with Livingstone, are the chimpanzees. A million years further into the past, the gorillas join us at Rendezvous 2, then the orang-utans at Rendezvous 3. Next, the gibbons, then monkeys ... and so on until we finally greet the bacteria at Rendezvous 39, after which all the pilgrims march together in one single backward quest for the origin of life itself, life’s "Canterbury".

Following Chaucer’s lead, my pilgrims, which are all the different species of living creature, have the opportunity to tell tales along the way. Incidentally, I decided it would be twee to let them tell their tales in the first person singular. And, as with Chaucer’s tales, they are not necessarily about the teller but they carry a message about life, or evolution, in general. The Flounder’s Tale, told at Rendezvous 20, is an example of one of the shortest of the tales.

An endearing quality of Chaucer is the nave perfectionism of his General Prologue. It wasn’t enough to have a Doctour of Physik on the pilgrimage: he had to be the finest doctor in the land:

"In all this world ne was ther noon hym lik,

To speke of physik and of surgerye."

The "verray, parfit gentil knyght" was, it seemed, unmatched in Christendom for bravery, loyalty and even temper. As for his squire and son, he was "A lovere and a lusty bacheler . . . wonderly delyvere, and of greet strengthe." To top it all, he was "as fressh as is the month of May". Even the knight’s yeoman knew all there was to know of woodcraft. The reader comes to take it for granted that, if a profession is mentioned, its practitioner will automatically turn out to be unrivalled in all of England.

Perfectionism is a tempting vice of evolutionists. We are so used to the wonders of Darwinian adaptation, it is tempting to believe there could be nothing better. But imagine how imperfect a jet engine would be if, instead of being designed on a clean drawing board, it had to be changed one step at a time, screw by screw and rivet by rivet, from a propeller engine.

A skate is a flat fish that might have been designed on a drawing board to be flat, resting on the belly, with wide "wings" reaching symmetrically out to both sides. Flounders and their kind do it in a different way. They rest on one side, but this means that one eye is permanently looking down into the sand. Fascinatingly, the shape of the whole skull is distorted so that the eye on the lower side can move over to the upper side, where it can see. Picasso would have loved them. But, by the standards of any drawing board, they are revealingly imperfect. They have precisely the kind of imperfection you would expect from being evolved rather than designed.

The genial host, having guided Chaucer and the other pilgrims from London to Canterbury and stood impresario to their tales, turned around and led them back to London. If I, as returning host, reflect on the much longer pilgrimage of which I have been a grateful part, my overwhelming reaction is one of amazement. Amazement not only at the extravaganza of details that we have seen; amazement, too, at the very fact that there are any such details to be had at all, on any planet. The universe could so easily have remained lifeless and simple - just physics and chemistry, just the scattered dust of the cosmic explosion that gave birth to time and space. The fact that it did not - the fact that life evolved out of nearly nothing, some ten billion years after the universe evolved out of literally nothing - is a fact so staggering that I would be mad to attempt words to do it justice. And even that is not the end of the matter. Not only did evolution happen: it eventually led to beings capable of comprehending the process, and even of comprehending the process by which they comprehend it.

Although The Ancestor’s Tale has been written from a human point of view, another book could have been written in parallel for any of ten million starting pilgrims. Not only is life on this planet amazing, and deeply satisfying, to all whose senses have not become dulled by familiarity: the very fact that we have evolved the brain power to understand our evolutionary genesis redoubles the amazement and compounds the satisfaction.

Richard Dawkins is the author of The Selfish Gene and The Ancestor’s Tale and will appear at the Edinburgh Science Festival tonight, in conversation with New Scientist editor-in-chief Alun Anderson, at the Royal Museum of Scotland, Chambers Street, between 8pm and 9pm