Edward O. Wilson is an entomologist specializing in ants, the recognized leader of biodiversity studies, the founder of sociobiology, and a talented writer. Combining impeccable scientific credentials with the ability to communicate with the lay public, Wilson pleads for the reversal of what he calls “the sixth great extinction spasm,” the destruction of a large fraction of living species within a single human generation.
As a student of ants, Wilson looks at issues of preservation, ecology, and biodiversity in ways different from many people, even different from many biologists. He does not focus only on the possible disappearance of the spotted owl, or large mammals, or majestic birds of prey, although he understands the appeal of such animals to the public. When he speaks of a diverse biosystem, he includes all plants and animals, no matter what their size, aesthetic attraction, or apparent usefulness. He is just as concerned about the thirty species of feather mites that live exclusively on the feathers of a particular species of parrot as he is about that bird or the tree in which the bird lives. From tiny parasite to huge tree, all living things are parts of ecosystems.
The problem he brings before the reader is that 90 percent of all species now living on the earth have never been described by scientists. For all intents and purposes, no one knows they exist. Many may become extinct before they are understood. At first glance, this might seem to be strictly an academic issue, of interest only to biologists. Why should the lay public worry about obscure and undescribed fungi or insects? Wilson’s answer is twofold. First, some of these species may have economic value, either as food sources or sources of medicine. Humanity cannot risk destroying a possible natural cure for cancer out of ignorance. Second, the loss of a species or a number of species may lead to the collapse of an entire ecosystem. The consequences of human actions may be far more widespread than anticipated.
Wilson begins with a discussion of small-scale and large-scale annihilations of life, ranging from the fall of a tree in a rain forest to the destruction of an island by volcanic eruption and finally to the five great extinctions of the last half billion years, extinc- tions in which 90 percent of all species living at the time may have perished. The lesson he wishes the reader to draw from these accounts is that nature easily recovers from localized destruction. It can even rebound from a great extinction. Biodiversity can be restored. The time required for such a restoration on a planetary scale, however, is measured in the tens of millions of years. Unlike localized destruction, which can be restored within a few years, the global destruction that humans could inflict on the planet Earth in a single human lifetime cannot be repaired in millions of lifetimes.
The second section of the book is an excellent popular account of current views of evolution and related theories in biology. To understand the significance of biodiversity, one must first understand taxonomy, classification, evolutionary theory, and ecology. Aided by clear illustrations, Wilson provides a series of lessons in biology worthy of the great teacher he is. In doing so, he also acknowledges the limitations of scientific truth. Sometimes, the best that science can offer is a concept that is provisionally acceptable to a majority of scientists. Wilson makes clear when and if he is presenting the consensus view or his own personal opinion. He also provides the alternative theories. The provisional nature of science is brought out most explicitly in his discussion of the definition of species, the most fundamental concept for bio- diversity and systematic biology. He concedes that the currently accepted working definition of a species as “a population whose members are able to interbreed freely under natural conditions” may be at best a pragmatic compromise that works most of the time....
(The entire section is 1620 words.)