The Ancestor’s Tale: A Pilgrimage to the Dawn of Life
by Richard Dawkins
(Weidenfeld & Nicholson)
Evolution is both a process and a narrative; a science and a history. Richard Dawkins has made himself the foremost philosopher of the process, exploring with ruthless and surprising logic how bodies can be best understood as vehicles for the propagation of genes. But until now he has left the history to others such as Stephen Jay Gould and Richard Fortey: the grand narrative of how (some) microbes became men over three billion years. Now, in this extraordinary book, Dawkins turns chronicler.
He does so with a twist that avoids the perennial problem of evolutionary history-telling: how not to make it sound like an inevitable progression towards complexity and us. After all, bacteria and worms did not “fail” to evolve into mammals. You could argue the opposite: that they were so good at being what they were that our ancestors had to invent a different way of living. Dawkins’s twist is to tell the story backwards, starting with us. If you do this, then the ancestors you meet along the way are indeed the clichés of evolutionary narrative — ape-like, monkey-like, shrew-like, lizard-like, fish-like, worm-like, blob-like.
It is not the first time the story has been told backwards, but Dawkins, ingenious as ever, has made it idiosyncratically his own by a clever conceit that he is a pilgrim, meeting the ancestors of all other living forms at the point where their lineages join ours and progressing with them towards a sort of primordial Canterbury.
Surprisingly, there turn out to be just 39 such confluences or 39 “concestors” (Dawkins’s neat neologism for common ancestor). The first is the chimpanzee’s concestor, six million years down the road. Other mammal groups join thick and fast until the duck-billed platypus’s concestor comes in at 180-million years, the 15th rendezvous. There is then a surprising gap of 130-million years during which, subjugated by the dinosaurs, our ancestors spawned no other (living) descendants till we meet the birds and all reptiles in the Carboniferous. A grand rendezvous occurs with concestor 26 at about 590-million years, when all the insects, molluscs and most worms join. Then it is on to meet the fungi, the plants and eventually the bacteria at some indeterminate time in the far-distant past, where all extant life shares the same ancestor.
This march allows Dawkins to do a Chaucer, telling the tale of various pilgrims as they join him. Some of the tales are there purely to wow us with nature’s versatility; others enable him to digress into evolutionary theory and plunder an insight. He is lucky to be doing the book now, when DNA is suddenly confirming or contradicting or amplifying the stories told by fossils to an astonishing extent, a second edition in, say, 10 years’ time, may have the answers to all sorts of questions Dawkins cannot now answer. The book is richly illustrated with photographs and charts, but they support rather than drive the text, so any resemblance to a coffee-table book is illusory.
Dawkins’s focus on ancestors pays dividends. Just as he did in The Selfish Gene, he is writing mainly about discoveries made by other scientists. But just as he did there, he achieves much more than reporting. He mints fresh theoretical ideas. Try this one: “For particular genes, you are more closely related to some chimpanzees than to some humans.” A good example is blood groups: you and a chimp might be group O, while your spouse and the chimp’s mate might be group A. Put like that, it sounds banal, but it is a point that goes deep into our animal ancestry — we can swap hox genes with a fruit fly and still grow the right body — and at the same time it is philosophically unsettling. We each have two kinds of globin genes, but they had a common ancestor in the lamprey’s concestor, so “every gene has its own tree, its own chronicle of splits, its own catalogue of close and distant cousins … individuals are temporary meeting points on the criss-crossing routes that take genes through history”. Sex may unite a species and divide it from others, but the genes, not the species, are the central entities of the evolutionary tale.
Consequently, Dawkins loves continuity, and hates what he calls the “tyranny of the discontinuous mind” with its demand to classify things that cannot be classified. He brings this out best in the “Grasshopper’s Tale”, which turns out to be mainly about human racial differences and the particular absurdity of calling Colin Powell a “black” man. As a contribution to the history of ideas this book is well worthy of Britain’s top public intellectual. The arguments are as sharply honed as we have come to expect from Dawkins. As literature, however, it is not perfect. The prose does not quite rise to his usual high standards of pithiness, perhaps because he must interrupt himself every page or two to greet a new biological cousin. But do join the journey and meet the concestors. — Â