Researchers have identified 1.4 million animal species so far—and millions remain to be discovered, named, and scientifically described. So how much would it actually cost to identify every animal on Earth? A pair of Brazilian scientists has crunched the numbers and come up with an answer: $263 billion.
That's way more than the $5 billion that famed Harvard University ant biologist Edward O. Wilson estimated back in 2000—and that was for every species on Earth, not just animals. But even $263 billion would be a small price to pay to understand the creatures that enable such essentials as agriculture, fisheries, new drugs, and energy sources, says ornithologist Joel Cracraft of the American Museum of Natural History in New York City. "Literally, the world economy runs on biodiversity," he says. "People don't understand really, deeply how much we depend on biodiversity."
Most biologists agree that with extinction rates soaring and climate change looming, the effort to document the planet's biodiversity—or biota—is urgent, especially considering the essential role these life forms play in crop pollination, clean air, and other aspects of human well-being. "We are losing species by extinction faster than we are describing new species" according to some estimates, says biologist Antonio Marques, who coauthored the new paper with Fernando Carbayo, both at of the University of São Paulo in Brazil. "We have to know the biota to preserve and conserve the biota," he says.
Marques, a jellyfish specialist, and Carbayo, who studies flatworms, surveyed 44 Brazilian taxonomists (about 9% of the country's working taxonomists) to determine their rate of describing new species and the cost of their education, lifetime salaries, laboratory equipment, and expeditions. They argue that these data can be reasonably extrapolated worldwide because Brazil is home to 1/10th of the world's known animal species and has a very active community of taxonomists who earn close to the global average. They found that on average, each taxonomist describes just shy of 25 new species during his or her career, at a cost of $97,000 a year.
Not all species are created equal, however. Marques and Carbayo found that all told, it costs about $122,000 to describe a new Brazilian vertebrate, such as a bird—twice the price of a new noninsect invertebrate, such as a worm. New insects are a bargain at $39,000. And working in different habitats entails different costs. Marques and Carbayo applied those numbers to an estimated 5.4 million yet-to-be-discovered animal species to get their $263 billion price tag, which was published online last month in Trends in Ecology and Evolution. Of course, that money wouldn't have to be paid all at once.
Besides the money, another huge obstacle to a complete understanding of the animal kingdom is a global shortage of taxonomists, experts say. At the current pace of 16,000 new animal species cataloged annually, Marques and Carbayo estimate it will take 360 years to complete the job.
So why is the cost estimate so much higher than Wilson's? Wilson says two factors may account for the disparity. For one, whereas Marques and Carbayo base their number on the output of currently practicing taxonomists, technological advances in areas such as image-matching software, electronic publishing, and photography are quickly bringing down costs. Moreover, many taxonomists describe far more new species than the researchers assume. He himself has logged some 450, and that was using laborious, old-fashioned techniques such as illustrating thousands of anatomical drawings by hand.
On the flip side, Wilson says he has a hunch that the final tally of Earth's species will far exceed the 6.8 million animals that the present paper conservatively assumes—even though this number roughly aligns with the 10 million life forms that his own estimate rests on. An original champion of biodiversity, Wilson wholeheartedly agrees that more resources must be devoted to studying life on Earth and more taxonomists brought on board. "This is a starveling field," he says.
But given the expense of producing and supporting Ph.D.s, the pool of professional taxonomists is unlikely to expand, says tiger beetle specialist David Pearson of Arizona State University in Tempe. "There are not going to be more taxonomists in the future. It's just a pipe dream as far as I'm concerned," he says. Marques and Carbayo's $263 billion would be much lower if they had considered relying more on amateurs, Pearson says. In a January BioScience paper, he and two co-authors called for the inclusion of more amateurs and laypeople, who are already making substantial taxonomic contributions but whose work is often marginalized by turf-jealous academics. If you own a pair of binoculars or a microscope, there are at least 5 million species out there awaiting your gaze.