A short history of nearly everything - Bill Bryson [182]
In principle you ought to be able to go to experts in each area of specialization, ask how many species there are in their fields, then add the totals. Many people have in fact done so. The problem is that seldom do any two come up with matching figures. Some sources put the number of known types of fungi at 70,000, others at 100,000—nearly half as many again. You can find confident assertions that the number of described earthworm species is 4,000 and equally confident assertions that the figure is 12,000. For insects, the numbers run from 750,000 to 950,000 species. These are, you understand, supposedly the known number of species. For plants, the commonly accepted numbers range from 248,000 to 265,000. That may not seem too vast a discrepancy, but it's more than twenty times the number of flowering plants in the whole of North America.
Putting things in order is not the easiest of tasks. In the early 1960s, Colin Groves of the Australian National University began a systematic survey of the 250-plus known species of primate. Oftentimes it turned out that the same species had been described more than once—sometimes several times—without any of the discoverers realizing that they were dealing with an animal that was already known to science. It took Groves four decades to untangle everything, and that was with a comparatively small group of easily distinguished, generally noncontroversial creatures. Goodness knows what the results would be if anyone attempted a similar exercise with the planet's estimated 20,000 types of lichens, 50,000 species of mollusk, or 400,000-plus beetles.
What is certain is that there is a great deal of life out there, though the actual quantities are necessarily estimates based on extrapolations—sometimes exceedingly expansive extrapolations. In a well-known exercise in the 1980s, Terry Erwin of the Smithsonian Institution saturated a stand of nineteen rain forest trees in Panama with an insecticide fog, then collected everything that fell into his nets from the canopy. Among his haul (actually hauls, since he repeated the experiment seasonally to make sure he caught migrant species) were 1,200 types of beetle. Based on the distribution of beetles elsewhere, the number of other tree species in the forest, the number of forests in the world, the number of other insect types, and so on up a long chain of variables, he estimated a figure of 30 million species of insects for the entire planet—a figure he later said was too conservative. Others using the same or similar data have come up with figures of 13 million, 80 million, or 100 million insect types, underlining the conclusion that however carefully arrived at, such figures inevitably owe at least as much to supposition as to science.
According to the Wall Street Journal, the world has “about 10,000 active taxonomists”—not a great number when you consider how much there is to be recorded. But, the Journal adds, because of the cost (about $2,000 per species) and paperwork, only about fifteen thousand new species of all types are logged per year.
“It's not a biodiversity crisis, it's a taxonomist crisis!” barks Koen Maes, Belgian-born head of invertebrates at the Kenyan National Museum in Nairobi, whom I met briefly on a visit to the country in the autumn of 2002. There were no specialized taxonomists in the whole of Africa, he told me. “There was one in the Ivory Coast, but I think he has retired,” he said. It takes eight to ten years to train a taxonomist, but none are coming along in Africa. “They are the real fossils,” Maes added. He himself was to be let go at the end of the year, he said. After seven years in Kenya, his contract was not being renewed. “No funds,” Maes explained.
Writing in the journal Nature last year, the British biologist G. H. Godfray noted that there is a chronic “lack of prestige and resources” for taxonomists everywhere. In consequence, “many species are being described poorly in isolated publications, with no attempt to relate