Darwin's Island: The Galapagos in the Garden of England

No one but Steve Jones could have written this book. That deep, resonant voice echoes from every page, not only with characteristic insights but also with phrases to make them memorable, such as "the habits of mites would astonish any pornographer"; or "the expression of a Scotsman with a grievance is easy to distinguish from a ray of sunshine" (Jones is presumably Welsh); and, most memorably, "fatness runs in families but so do frying pans".

His purpose, in the 150th year since the publication of On the Origin of Species, is to remind us that Charles Darwin wrote other books. Moreover, although the five weeks he spent in the Galapagos Islands were important in setting Darwin's mind in motion, his work there was brief and far from systematic. The studies he undertook in Britain during the remaining 46 years of his life not only generated the material that underpinned the arguments of his most famous work but also led to other books that virtually created the modern science of biology. Jones then proceeds to demonstrate how the ideas that Darwin discussed in these works have been confirmed by later scientists, for example through understanding what vitamins do and how DNA works. He also shows, often alarmingly, the consequences of evolutionary ideas for humankind in the 21st century.

Thus the domestication of early man and his adoption of a settled life are shown to have led to a more restricted diet than that of early hunter-gatherers whose diet varied with the seasons and gave them a variety of foods that provided adequate nutrients. By contrast, "the taming of the hamburger" and the promotion of cheap food have meant that poor families in the developed world have been seduced into diets that are high in calories and low in nutrients. This reader will never again be able to view a field of maize without a shudder.

Other themes that emerge from this fascinating book, almost incidentally, concern Darwin's patience, modesty and determination. His study of the effects of worms in creating vegetable mould are well known, but how many knew that, having begun the experiment by scattering chalk over a field near his home, he waited 29 years before digging a trench to find out how deeply the worms had buried it? The resulting volume Darwin described as "a curious little book" that "may appear insignificant", but it remains definitive - and if it had been heeded by those who tilled the American prairies, then the dust bowls of the 1930s would never have occurred.

Darwin showed determination and ingenuity in his research. Having married his cousin Emma Wedgwood, he wished to test the prevalent theory that such marriages could produce sickly children. He pointed out that "supposed injurious consequences" rested upon "no firm evidence" and advocated the inclusion of a question on the subject in the 1871 Census to test the supposition. This was rejected by Parliament, possibly because Queen Victoria had married her cousin Albert. Undeterred, Darwin's son George put the "cousin" question to boat-racing crews of Oxford and Cambridge colleges, ascertaining that cousin marriages were unusual among these fine specimens of athletic humanity - although he felt that the sample was too small to draw definitive conclusions. Darwin, ingeniously, then tested the concept on orchids and inferred that "marriage between near relatives is in some way injurious", a conclusion now widely accepted.

The last word on Darwin's books must go to their author, who wrote to Thomas Huxley in 1865: "I think that general and popular treatises are almost as important for the progress of science as original work." Jones has written one himself, and it is one for which we should be grateful.