SHE HAS HER MOTHER’S LAUGH

THE POWERS, PERVERSIONS AND POTENTIAL OF HEREDITY

CARL ZIMMER Picador, 672pp, £25, Oldie price £16.27 inc p&p

If you are European you are a descendant of Charlemagne. Some of your ancestors mated with Neanderthals, so your genome is also 1 to 2 per cent Neanderthal – genes which survived as a useful addition to our DNA. You have millions of ancestors, but, as Bryan Appleyard wrote in the Sunday Times, DNA is so ‘sliced and diced down the generations’ that you cannot inherit all their genes and are simply ‘a bewildering genetic salad’. Genetic diversity within populations is far greater than between populations – a white Brit may be more closely related, in genetic terms, to an African or Asian person than another white Brit.

Tom Whipple in the Times lauded a ‘grand and sweeping book ... beautifully written’. Appleyard described the prose as ‘workmanlike and his storytelling excellent if, at times, long-winded... it feels at least 100 pages too long’. Robin Mckie in the Guardian agreed that the book was a ‘fascinating – though overlong – exploration of the glorious complexities of human heredity’.

Francis Galton was an early proponent of the theory that genetic traits, such as intellect, were inherited: the eugenics movement was born. Morons beget morons and could be eliminated by breeding out inferior stock. Cue the Nazis. ‘Bad science costs lives, millions of them,’ Appleyard commented.

We now know that other – cultural – factors are at work. There is a genetic component to tallness, for instance, but better food and housing mean that entire populations grew taller in the 20th century. Now we have the ability to ‘edit’ genes.

The book offers hope, Whipple decided: ‘Because once you understand the full story, it becomes clear that there is no such concept as death or extinction. Instead, we all live on in our genes, and all things – plants, animals, and men – are already in eternity, travelling across the face of time.’