In the field of conservation, success stories about saving individual species abound. Bald eagles have recovered from their bout with the pesticide DDT; from fewer than 500 breeding pairs in 1963, the population in the lower 48 states has grown to nearly 10,000 breeding pairs, such that they are no longer listed even as threatened under the Endangered Species Act. Gray wolves have returned to Yellowstone National Park, as well as to the Italian and French Alps. The California condor has been brought back from the absolute brink of extinction, after the last surviving birds were rounded up and bred in the San Diego and Los Angeles zoos. And so on.
When human ingenuity and resources are trained on a particular species, usually a charismatic one, it makes a difference—but it does not change the global pattern, which is a steady drumbeat of extinction and of the permanent loss of biodiversity that goes with it. In a recent global assessment, Stuart Butchart and his colleagues at BirdLife International in England concluded that between 1994 and 2004 conservation efforts had saved 16 species of bird from extinction, at least temporarily. During that same decade, however, another 164 bird species listed as threatened by the International Union for Conservation of Nature (IUCN) had slipped a notch closer to extinction.
Conservationists have many priorities and many strategies. But for the past two decades, a leading priority has been to preserve as much biodiversity as possible, and the most prominent strategy has been to focus on “hotspots”—regions of the world, such as tropical rain forests, that are rich in species and yet losing them fast. The strategy has been arguably successful, yet it has also been controversial.
“The most difficult challenge we face as conservationists today is to answer the question, Why does biodiversity matter?” says Mike Hoffmann, an ecologist based at Conservation International (CI), an organization that has made hotspots the centerpiece of its efforts. All conservationists oppose extinction, it seems, in the same way that they favor apple pie. But not all agree that saving the maximum number of species worldwide should be the number-one priority—or that preserving hotspots on our increasingly crowded planet leads to the best of all possible worlds.
The word “biodiversity” first appeared in print in 1988, as the title of a National Research Council report edited by Harvard University entomologist E. O. Wilson. In the opening chapter Wilson guessed that the earth held between five million and 30 million species, more than half of them living in tropical rain forests. “From a single leguminous tree in the Tambopata Reserve of Peru,” he wrote, “I recently recovered 43 species of ants belonging to 26 genera, about equal to the entire ant fauna of the British Isles.” He went on to make an equally rough estimate of how many species the earth was losing to extinction: about one every half an hour. Most were undescribed tropical insects vanishing without witness.
Wilson’s calculation was based on his theory of “island biogeography,” which predicts how many species can survive in a given area of isolated or fragmented habitat, and on estimates of how much rain forest was being cut down. An area the size of West Virginia, Wilson said, was being lost every year—confirming predictions made a decade earlier by a British researcher named Norman Myers. Those predictions had been dismissed by some of his peers as alarmist, but it became clear they were not: human beings were causing a mass extinction unparalleled since the demise of the dinosaurs 65 million years ago.
Over in species-poor Britain, Myers was also coining a new term in 1988—new at least to conservation biology—and it would soon become a buzzword, too: “hotspots.” Myers is an independent environmental consultant, an adjunct academic, notably at the University of Oxford, and a self-described “lone wolf.” After previous lives as a schoolteacher in colonial Kenya and then as a photographer of African wildlife, he had earned a Ph.D. at the University of California, Berkeley, in the early 1970s and moved into conservation work. By the late 1980s he was frustrated. “It struck me that because of sheer shortage of funds, scientific expertise and government attention, we were not helping many species all that much,” Myers recalls. “We were spreading ourselves far too thinly.”