Richard Dawkins: The Ancestor's tale

We have all grown up now with the theory of evolution. But it is such an extraordinary story that it deserves telling over and over, and no one is better placed to tell it for our generation than Richard Dawkins.

The author of The Selfish Gene and The Blind Watchmaker knows how to get people talking with controversial new theories to explain how evolution may have unfolded.

In this 528-page magnum opus, he uses the skills of the controversialist to set out the straight facts as we understand them in the light of the amazing new science of genetics that is unfolding exponentially in our own time.

It is a remarkable fact, for example, that our alpha and beta blood groups are also found in the blood of every other backboned species on the land, in the air and in the sea. Although it is possible that these blood groups evolved separately in each of the 50,000-plus vertebrate species, it seems more likely that the blood-
making gene mutated into alpha- and beta-making groups just once, in ancient species that were the ancestors of us all.

Even more remarkably, scientists studying the genetic differences between species, and observing the average rate at which genetic differences arise in each species, can now estimate how long it is since that common ancestor of all backboned animals lived (about 530 million years, Dawkins says).

Similar common ancestors can be pinned down for all modern humans perhaps as recently as just 30,000 years ago, for all
mammals at around 180 million years ago, for all living cells with a distinct nucleus perhaps 2 billion years ago, and ultimately for all of life itself perhaps twice that long ago.

In all, Dawkins identifies 39 of these common ancestors of ever-widening groups of living things.

He chooses to tell the tale from us, modern humans, backwards in a "pilgrimage" to find our ancestors, modelled on the medieval pilgrimage to Canterbury in Chaucer's Canterbury Tales.

He imagines pilgrims from all modern species setting off at the same time, and as we humans go back in time we gradually meet them all — first the chimps and bonobos, and so on back through the land mammals to the fish and ultimately to single-cell bacteria. At each
"rendezvous" we greet a new, slightly more distant set of modern "cousins".

It is told like a whodunnit, constantly whetting the reader's appetite for the next instalment.

The further back you go, the more you marvel at the processes of evolution that created the wonderful complexity of life on this planet from such simple beginnings.

Unfortunately, the book is expensive, and you might want to wait for a cheaper paperback version to appear in a year or two.

But if you can afford it, this is an exciting story for any adult or teenager. I loved it; I think you will, too.

* Simon Collins is the Herald science reporter.

* Weidenfeld & Nicholson, $79.99