She Has Her Mother’s Laugh

by Carl Zimmer Picador 672pp £25 The Week Bookshop £20

In this long but “fascinating” book, the American science writer Carl Zimmer explores the “glorious complexities of human heredity”, said Robin Mckie in The Observer. It is tempting to see this as a matter of particular genes (for height, hair colour etc.) being passed to us by our parents. But, as Zimmer shows, that picture is too simple. For one thing, a trait such as height isn’t determined by “one or two” genes, but by “at least 800”. For another, how tall we are also depends on environmental factors, such as diet and health. Zimmer argues that the “DNA revolution” of recent decades has caused the pendulum to swing too far from nurture to nature, said Robert Plomin in the London Evening Standard. Society today, he writes, “practically worships DNA”. As an antidote, he wants us to acknowledge “non-genetic forms of heredity”, which include “microbes, cultural inheritance and even technology”. A book on this subject might have been “heavy going”, but Zimmer – one of the best science journalists in the US – has the ability to make “complex topics accessible”.

He also reminds us of the “horrors perpetrated” by those who oversimplified heredity in the past, said Bryan Appleyard in The Sunday Times. In the late 19th century, eugenicists used “bad science” to argue that it was possible to eradicate undesirable traits from humanity. Another form of “genetic essentialism”, also embraced by the Nazis, was the belief – since proved to be quite false – that race has a “basis in genetics”. Now, thanks to the rise of gene editing, we may soon have the power to “short-circuit the whole system of genetic heredity” entirely. It is unclear as yet whether this will be a good or a bad thing, but on the evidence of history, Zimmer suggests, “we shouldn’t get our hopes up”.