Edward O. Wilson, The Diversity of Life

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[Image: © The Folio Society, 2019]

Edward O. Wilson (b. 1929), University Research Professor Emeritus at Harvard University, is one of the world’s leading biologists. Damage to his eyesight during childhood led him to study insects, which is why he became a myrmecologist (a scientist specialising in ants). His research led to breakthroughs in understanding of the social structures of ants and wildlife more widely. He has taught and written on entomology and biology and won numerous awards and prizes during his distinguished career. It is his book BioDiversity (1988) that is credited with introducing the phrase “biodiversity” into scientific and general usage.

The Diversity of Life was first published in 1992. This Folio edition is a republication of the second edition (2010), with a new foreword by Bill McKibben, renowned environmentalist author. This issue – as is usual with Folio Society books – contains unique visual elements, discussed at the end of this review.

Wilson’s thesis is that although life is vigorous and multifarious, it is also delicate. Ecosystems are dynamic but depend upon multiple factors, with relatively small changes to a few species causing a great knock-on impact. Wilson starts by outlining the rich diversity of life in the tropical rainforest, before outlining the impact of the eruption of Krakatau (Krakatoa), in the Indonesia archipelago. The famous eruption – more properly volcanic explosion – in 1883 destroyed all life on the small island. The event destroyed most of the island and left the remainder desolate. Naturalists realised this was a test bed for biological study: as flora and fauna returned to the land, observations could be made about the evolution of ecosystems. New species arrived – to thrive or die off and sometimes old species never returned to the island. Forest regrew on the island but to this day none of the species of rainforest giant trees have arrived on the island.

Wilson explains the thorny issue of inter-subspecies hybridisation. It is possible to interbreed lions and tigers in captivity. That being so, why do we not see natural hybridisation? In other words, why do we have two distinct groups at all? One reason is that the subspecies are separated geographically (though this has not always been the case) and the second is that in terms of social structure and preferred climate, the subspecies are dissimilar and therefore would have little in common and thus rarely mix. Plants in temperate regions hybridise more than those in tropical regions.

Division into subspecies can come about by the environment changing (leading to a local population diverging by developing unique deviations from its original form), isolation (a population being suddenly separated by a flood, earthquake or volcanic activity) or by colonisation (waifs being translocated to islands and subsequently evolving). (“The 10,000 known endemic species of insects in Hawaii are believed to have evolved from only about 400 immigrant species.”) The use of subspecies as a taxonomical classification is tricky. Wilson points out that these classifications can be relatively arbitrary, only denoting how much scientific attention a widely distributed species has attracted, for many such species could be broken down into numerous subspecies. Exactly what markers denote a population to be worthy of assuming the status of a subspecies is flexible.

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[Image: © The Folio Society, 2019]

Some species develop distinct characteristics faster than others, with insects of short lifespans evolving fastest. In Lake Victoria, a family of freshwater fish called cichlids evolved into a variety of unique species with specialised physiognomies, diets and behaviour in only 200,000 years. “If evolution can occur rapidly, with the number of species quickly restored, why should we worry about species extinction? The answer is that new species are usually cheap species. […] Great biological diversity takes long stretches of geological time and the accumulation of large reservoirs of unique genes. The richest ecosystems build slowly, over millions of years.” In the case of the chichlids, they are rapidly approaching extinction because of the predation of the Nile perch, a non-native species introduced by man as a sport fish. This giant predator has adapted well to Lake Victoria and could well outcompete the specialised and isolated chichlid species.

The author introduces technical discussions where necessary but does this sparingly, allowing the non-scientist to follow is discussions easily and pleasurably. He finds apt examples to demonstrate points. The explain how absence of competition can lead to parallel evolutions in separate species, he chooses Hawaii. The honeycreeper is a family of bird species native to the islands of Hawaii. They have developed beaks and behaviour that resemble woodpeckers, albeit in inefficient forms. Wilson points out that had woodpeckers migrated to the islands, honeycreepers would never have developed their woodpecker-type features because they would have been competing with a much more efficient family that would have exploited the ecological niche already, outcompeting for associated resources. The absence of woodpeckers allowed the honeycreeper space to evolve woodpecker-style behaviour and physiological forms.

The sheer variety of life forms defies scientific understanding, with potentially millions of species, ranging from microbes to viruses, fungi, lichen, advanced plants, insects and mammals. The precautionary principle suggests we should beware of destroying species and environments of which we are not even aware, in case their removal leads to significant consequences for the ecosystem. When the sea otter was hunted to near extinction in the Aleutian Island, the sea urchins they preyed upon – now largely unpredated – decimated the kelp forests. The subsequent barrenness severely reduced the biodiversity of the environment. Thus, a single apex predator can shape an ecosystem.

Wilson is honest about the impact of human migration on reduction of biodiversity – as many non-indigenous apex predators have upon ecosystems. He discusses the extinction of the moa (a giant flightless bird in New Zealand) at the hands of the Maori and the damage done by species introduced by Western colonists. He shows sharp declines in numbers of species in recent eras match the expansion of Homo sapiens. An alarming map of reducing forest in Ecuador gives a graphic warning of the impact of man-made habitat change. The case is put for the practical benefits species preservation has for humanity, in the form of medicines or crop hybridisation derived from life forms not yet studied. A couple of fascinating lists give native species that could be reared as potential crops and animals for human consumption, all of which might prove superior in their native environs the imported Western staples. The book ends with some positive steps that are being taken and avenues for future activity to prevent loss of biodiversity.

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[Image: © The Folio Society, 2019]

Edward O. Wilson is a gifted communicator, full of enthusiasm. The clarity and vigour of Wilson’s prose is a great pleasure to read. The importance of his warnings is as relevant now as when The Diversity of Life was originally published. Wilson’s personal encounters (sometimes as part of field experiments) add touches of personal experience – elegiac but lacking false sentimentality. The book contains footnotes, a glossary and an index.

The Folio Society edition boasts a full-colour iridescent hardback cover, protected by a slipcase. The cover was designed by Jamie Keenan. The complex, demanding and precise process that was used to apply the special holographic film over the cover is described in a Folio Society blog post here. This edition includes maps, charts and graphs with attractive ornamentation. The line and stipple ink drawings by Amy Bartlett Wright are concise and attractive, acting as visual aides and enriching the reading experience. There are plate sections of 24 colour wildlife photographs, featuring close-ups that showcase the beautiful variety of flora and fauna. The simple textured board used to make the protective slipcase has a pleasing eco-friendly feel to it.

The Folio Society edition of The Diversity of Life is an ideal gift for a child over 14 or young adult interested by science and for anyone delighted by the natural world. The visual touches enhance the message and the content in a sympathetic and considered manner. Highly recommended.


The Folio Society edition of Edward O. Wilson’s The Diversity of Life, with foreword by Bill McKibben and preface by the author, with extensive Folio Society picture research, is available exclusively from The Folio Society.

Edward O. Wilson, Bill McKibben (foreword), The Diversity of Life, The Folio Society, 2019, hardback, 448pp, 24 col./47 mono illus., slipcase, £49.95


© Alexander Adams 2020

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