ABSTRACT
When the popular media approach the issue of biodiversity, the subject matter is almost always about charismatic megafauna – tigers, elephants, pandas and the like. We too lament the probable extinction faced by these evocative creatures. The world will surely be diminished as the last wild gorilla is shot by a local warlord beholden to one or another political ideology, or even as a rare but beautiful bird species has its habitat removed to make way for yet another desperately needed row of shops. The irony is gut-wrenching to be sure. However, such concerns are the very small tip of the very large iceberg. If we simply take mammal diversity as an estimate of the number of creatures that are likely to be thought of as charismatic by the general public, we are talking about approximately 4500 known species. By comparison, there are currently about 900,000 known species of insects, and that is almost certainly a gross underestimate of how many actually exist. We have no idea how many species there are, since estimates range from about 2 million to as high as 30 million.1 While the la�er estimate is probably exaggerated, even if there are only 2 million species of insect, we see that a focus on the 4500 species that happen to look more or less like us, is limited to a rather small fraction of the Earth’s biodiversity. And to make the point even more dramatic, consider the biodiversity of bacteria. Microbiologists define two bacterial cells to be in the same species if their DNA overlaps by 70 per cent or higher, which, if applied to mammals, would put all primates (if not all mammals) in the same species. Simply from the point of view of numbers, the world of biodiversity is mainly in the small things, from bacteria to insects, leaving the charismatic megafauna as a rather trivial subplot to the main theme.
