Microcosm: E.coli And The New Science Of Life, by Carl Zimmer

From soiled nappies comes a tiny wonder – with a giant role in genetics

One of the things that makes humans different is our curiosity to poke around in the innards of other creatures. When they first got acquainted with zillions of microscopic bacteria, scientists thought their own innards pretty uninteresting. They were dead wrong.

In this satisfying piece of popular science, Carl Zimmer shows how almost the whole of biology can be unfolded from a tiny, rod-shaped organism first found in soiled nappies a bit over a century ago. Escherichia coli – named after the intrepid nappy-scraper Theodor Escherich – is a normally innocuous dweller in the human gut, and many other places it can get a living. But this minute wonder can sense its surroundings, swim around, and co-operate with its bacterial siblings. It has a kind of sex, on occasion, responds to its environment, is shaped by its history, and tries to fight off attacks from bigger bacteria and much smaller viruses.

As Zimmer relates, E. coli is more than a convenient emblem of life's ingenuity. It has been the focus of work in a thousand labs, and given up innumerable secrets about the inner workings of the cell. Thanks to E. coli, we know how genes work, how they are regulated, and how their switches and modulators form subtle networks. The beast has given insight into evolution, behaviour and even ecology. Layer by layer, Zimmer shows how the intricate details of a bacterium relate to problems all organisms face.

His book comes from the US, so has to spend a while debunking creationism's dumber younger brother, intelligent design. This is apt because E. coli's cunningly assembled flagellum is a prime exhibit in the creationists' case: that life is equipped with machines which they cannot believe arose by chance. As usual, look properly and you find lots of intermediate forms, all doing something useful – if not propelling their host along. The flagellum, like antibiotic resistance, undoubtedly evolved.

There follows an excursion into the history and politics of genetic engineering, which may not hold the attention of all those gripped by the unpacking of the bacterium's bag of tricks. There are intriguing scientists there, some beautiful experiments, and medical and industrial developments with high stakes. But the real star of the show remains a tiny, versatile organism which is happily dining off your last meal as you read this.

Jon Turney is writing 'The Rough Guide to the Future'

Heinemann, £20. Order for £18 (free p&p) on 0870 079 8897