杏吧原创

WHO doubts that of any science, evolution is the best at combining curiosity with admiration? Who can fail to be impressed by the realisation that the human body is a walking, talking monument to evolution; a palimpsest of all our ancestors from bacteria to fish to ape? Yet what should be an epic story has somehow failed to capture the popular imagination. Why else does a significant proportion of the world鈥檚 population 鈥� by no means all of whom live in the US 鈥� flatly disbelieve in evolution?

In a book that unpacks the history in our bones, , takes up the baton. As he seizes it, his hand, transformed from what was once a fishy fin, provides a powerful example of what evolution is capable of. At the same time Shubin lifts up his nose, swivels his eyes, appreciates music, ponders on the contortions of the male reproductive system, even addresses hiccups, and in each case he tells a compelling evolutionary story.

As Shubin points out, we could as easily have begun this epic as a yeast or a jellyfish, but by using the fish he focuses on how an aquatic torpedo transformed first into a sprawling amphibian then ultimately into ourselves: fins to fingers, gills to ears, scales to teeth.

He walks the tightrope between mind-numbing complexity and patronising oversimplification with an agreeably light touch. By and large he gets the balance spot on, and the result is a deft synthesis of palaeontology, embryology and developmental biology. It is enlivened by personal stories, such as sharing a room with 25 corpses, and carrying out field work under threat of attack by polar bears, rip-roaring tides or territorial colleagues guarding their patch of fossil-rich desert. Shubin also brings the experimental method alive, explaining, for example, how to obtain DNA (and here I paraphrase) using liver, washing-up liquid and gin. Only occasionally does the style creak: labelling statocysts, organs of balance, as 鈥渢iny rocks鈥� is not that helpful.

In treating humans as integral to the tree of life, rather than the tired trope of us being a tiny and insignificant twig, Shubin revitalises our evolutionary pedigree. In doing so he stresses how evolutionary differences are largely skin-deep, with developmental pathways that are strikingly conserved across species. Thus a sea anemone is more like a sister than a remote cousin.

But here perhaps the book might have pondered matters a bit more deeply. After all, chimps and humans are nearly identical as far as our genomes are concerned, but who makes the dry Martinis? The answer reveals a paradox, because despite these conserved pathways, evolution is as much driven by its extraordinary sensitivities, where seemingly trivial changes at the molecular level can have profound consequences.

In every organism there is a sort of evolutionary Russian doll, hiding echo upon echo of vanished body plans. Evolution got us to where we are, but is that the end of the story? When Shubin dwells on the case of the protein collagen, of which your Achilles tendon is largely made, he lets slip that 鈥渕olecules like these had to be invented鈥�. Yet suppose such inevitability was generally true? If so, we might suggest that just as we have our inner fish, so conversely the fish also had our future written into its body.

鈥淓very organism hides echoes of vanished body plans鈥�

Shubin writes as well as anyone on evolution, and doesn鈥檛 waste time tangling with the intelligent-design brigade. But beneath the fluent narrative I sense a deeper uncertainty. As he describes how he was almost moved to tears on seeing a space capsule used on a moon mission, Shubin tries to articulate how he sees such scientific adventure as our future source of wonder. But will rockets, or indeed any technological paraphernalia, re-enchant our world? Shubin dismisses the idea of eyes as 鈥渨indows into the soul鈥� and urges us to abandon any such romantic vision in favour of 鈥渕olecules, genes and tissues鈥�. Maybe, but when I look into my lover鈥檚 eyes and murmur, 鈥淚 adore your crystallins; I鈥檝e never seen a Pax6 like yours,鈥� she is strangely unimpressed. Let us celebrate evolution, but not by mapping a world that becomes increasingly arid and meaningless.

Evolution 鈥� Learn more about the struggle to survive in our comprehensive special report.