Free Darwin's Island by Steve Jones

nitrogen in their flesh. The trade is one-way, for the plants kill the animals. Sometimes, in contrast, the treaty seems positive, for both parties appear to gain. In fact, even the several apparently amicable associations in the nitrogen market are based on greed and expedience. The fight for the crucial chemical is fierce and has led to shared adaptations that straddle the whole of life.
    All animals fall prey to the vegetable world in the end as their dust returns to dust, but in the starved landscape of the Lost World the vegetation cuts out the middleman and devours the local wildlife directly. Natural selection has tinkered with leaves, roots and other parts to come up with the equivalents of teeth, gullets, stomachs and intestines, to draw the machinery of the botanical world close to that of animals.
    Charles Darwin’s book on the insect-eaters sold less well than had Conan Doyle’s fictional lizards but such creatures behave in a way beyond the imagination of the most fanciful novelist. Insectivorous Plants raised biological questions that resonate beyond the universe of the carnivores. At first Darwin doubted the value of his own experiments and wrote to a colleague that ‘I must consult you some time whether my “twaddle” is worth communicating’, but he soon became an enthusiast. His book is a masterful narrative of the ingenuity of existence.
    Plants that eat flesh attracted curiosity and hyperbole long before Darwin’s day. They still do, even if the Australian version that feeds on rabbits has yet to be confirmed by science. The sundews of Ashdown Forest have a natural flypaper that holds its victims with a syrupy glue. The leaves curl round to entangle them before they meet a sticky end in its sinister digestive globules. Their secretions give the plant its name; as Henry Lyte wrote in 1578 in his Nievve Herbal : ‘This herbe is of a very strange nature and marvelous: for although that the Sonne do shine hoate, and a long time thereon, yet you shall finde it always moyst and bedewed.’ Insectivorous Plants also includes experiments on the Venus flytrap, which modified some of its leaves into a ‘horrid prison’, and on many other kinds forwarded to Down House from afar.
    The insectivore habit has evolved in around a dozen distinct lineages, and Darwin saw most of them. They represent but a small fraction of the quarter of a million kinds of plants with flowers, but their habits, and their origins, are varied indeed. Some of the flesh-eaters are relatives as close as the anteater and the pangolin (long-nosed predators of ants from the Americas and the Old World respectively, the former kin to armadillos and the latter to dogs and cats) but others are as different as an anteater is from an insect-eating lizard or a bird such as the swallow.
    The sundew belongs to a group of a hundred or so species whose centre of diversity is in Australia. It has a relative called the butterwort that hunts in the same way. The flypaper habit has evolved on at least five independent occasions, to produce the Australian ‘rainbow plants’, so called because of the sinister sheen of their leaves, and many more. Some kinds are three metres high and some tiny, and they are found across much of the globe, from Alaska to New Zealand. Europe has just three of the hundreds of species known. DNA shows that even the sundew and a very similar species from Portugal have evolved insectivory of their own accord, as each can trace affinity to closer relatives that do not indulge in the pastime.
    A second trick remarked on by Darwin is to swing a door shut upon the prey. The most familiar jailer is the Venus flytrap, brought to attention in 1768 as the ‘fly trap sensitive’ by Arthur Dobbs, Governor of North Carolina, who sent the first specimen back to Britain (and was in addition the first person to record the movement of pollen by bees). The botanist William Bartram saw the ‘ludicrous’ plant on his travels through the