The Variety of Life: A Survey and a Celebration of All the Creatures that Have Ever Lived
It takes a brave writer to tackle the truly Herculean task of describingThe Variety of Lifewith the astronomical numbers of organisms living today, let alone all those that have fallen by the wayside over the billions of years of life on Earth. No one is quite sure how many living species there are, but it is estimated to be somewhere between 10 million and 100 million. Fortunately, since the days of the great Swedish naturalist Linnaeus, around 250 years ago, life has been grouped and classified into hierarchical schemes. As a result, it is possible to encompass this enormous variety of life by describing the relatively few groups into which it can be clustered. And, since the mid-19th century and the Darwin-Wallace theory of evolution by natural selection, classification has taken on an extra, evolutionary dimension.Colin Tudge, a well-known British science writer, has training in whole animal biology and a self-proclaimed love for the natural-historical foray among our fellow creatures. The first part of this big book (all of 90 pages) deals with the thorny problems of what Tudge rightly calls the craft and science of classification. Since the 1950s, the wordcladisticshas terrorized many traditional naturalists and biologists. But it is here to stay, and Tudge provides a very welcome guide that will be invaluable to both lay people and students.The bulk of the text, nearly 500 pages, forms part II and includes the descriptions of the main groups, from the most primitive (alpha proteobacteria) prokaryotes toEupatorium, a large genus of 1,800 or so species of plant. In between these two groups, at either end of the biological spectrum, lie all the more familiar bugs and beasts, including ourselves. Inevitably, given so many millions of organisms, difficult choices have to be made. Some groups are only dealt with at phylum level (for example, brachiopods), while others are detailed down to family level (for example, primates). Some extinct groups (not surprisingly, the dinosaurs) get a look, but not many overall. The short epilogue concerns conservation and is followed by a useful reference list of sources and an index. Altogether, the 600-odd pages are enlivened with a large number of excellent black-and-white drawings of individual organisms and diagrams illustrating evolutionary relationships. For all natural historians and anyone interested in biology, theThe Variety of Lifeis a must.--Douglas Palmer, Amazon.co.uk