There could be as many as 30m species of insects in tropical rainforests alone, calculated Erwin. The finding drew controversy, but Erwin defended his method against those in the latest study. The reason it is predictable is that humans are predictable, especially in the scientific field.
What they are measuring really is human activity. It is not real activity out in the wild. He went on: "I was the first to use real critters, not some kind of limp arithmetic. I had to make some assumptions and came out with 30m. What it started was a kind of cottage industry of estimating everything on the planet. However, Nigel Stork, a professor of environmental science at Griffith University, south-east Queensland, believes the current study appears to be closer towards an accurate count.
The authors note that identifying and describing new life forms is expensive and slow, especially when set against the magnitude of species yet to be found or catalogued. And, according to David Kavanaugh, a beetle expert at the California Academy of Science, funding and other resources fall short of the task as research institutions are cutting back, and governments are more preoccupied with finding life on Mars than on Earth.
Most of those species waiting to be discovered will be small, and they are likely to be concentrated in remote areas or the depths of the ocean. But the authors said: "Many could be found literally in our own backyards. But at the current pace, it would take , specialists 1, years to go through the laborious process of describing the new discoveries in scientific journals, and then entering them in electronic databases. Many of those species will be extinct before scientists have even registered their presence.
Scientists and conservationists are regularly updating the inventory of life with the discovery of new species. Last week, scientists at the Smithsonian Institution reported the discovery of a primitive eel in a reef off the coast of the South Pacific island nation of Palau. The new species, Protoanguilla palau , bore little relation to 19 other forms of eel currently in existence and some of its characteristics — such as a second upper jaw — were more in line with fossils from 65m years ago.
Other recent highlights, as compiled by the International Institute for Species Exploration IISE at Arizona State University, include the eternal light mushroom, or Mycena luxaeterna , which emits bright yellowish light.
The trick this team used was to look at the relationship between species and the broader groupings to which they belong. In , Swedish biologist Carl Linnaeus developed a comprehensive system of taxonomy, as the field is known, which is still - with modifications - in use today. Groups of closely related species belong to the same genus, which in turn are clustered into families, then orders, then classes, then phyla, and finally into kingdoms such as the animal kingdom.
The higher up this hierarchical tree of life you look, the rarer new discoveries become - hardly surprising, as a discovery of a new species will be much more common than the discovery of a totally new phylum or class.
The researchers quantified the relationship between the discovery of new species and the discovery of new higher groups such as phyla and orders, and then used it to predict how many species there are likely to be.
And the number came out as 8. At current rates of discovery, completing the catalogue would take over 1, years - but new techniques such as DNA bar-coding could speed things up. The scientists say they do not expect their calculations to mark the end of this line of inquiry, and are looking to peers to refine methods and conclusions.
Follow Richard on Twitter. Species heading faster to poles. The economic benefits of nature. That's a relatively easy task, since the number of new examples in these categories has leveled off in recent decades. Using complex statistics, Worm and colleagues used the number of genera, families, and so on to predict Earth's number of unknown species, and their calculations gave them a number: 8.
The new study "takes a hugely clever approach, and I think it's going to turn out to be a pretty important study," said Lucas Joppa , a conservation ecologist at Microsoft Research, the research branch of the software giant. But Dan Bebber , an ecologist at the environmental group Earthwatch Institute, said the study relies on improper statistical methods.
The study team used a method called linear regression to calculate the number of Earth's species. But Bebber thinks this method is the wrong one for the data, and that the team should have used a technique known as ordinal regression.
Overall, formally categorizing a new organism is a lot more complicated than discovering one, study co-author Worm said. Scientists must compare their specimen to museum samples, analyze its DNA, and complete reams of paperwork. Most scientists "will describe dozens of species in their lifetime, if they're really lucky. Unfortunately, extinction rates have accelerated to ten to a hundred times their natural level, Worm added. See "Extinctions Overestimated by Percent?
The information to be gained when new species are discovered "is nature's library, and we've only begun to decipher the first ten books," Worm said. All rights reserved. By contrast, the number of newly discovered species continues to rise sharply. As a result, the true number of species could be much higher or lower than 8. Nature's Library Disappearing Overall, formally categorizing a new organism is a lot more complicated than discovering one, study co-author Worm said.
Share Tweet Email. Read This Next Wild parakeets have taken a liking to London. Animals Wild Cities Wild parakeets have taken a liking to London Love them or hate them, there's no denying their growing numbers have added an explosion of color to the city's streets. India bets its energy future on solar—in ways both small and big.
Environment Planet Possible India bets its energy future on solar—in ways both small and big Grassroots efforts are bringing solar panels to rural villages without electricity, while massive solar arrays are being built across the country.
0コメント