19/05/2011 (The Epoch Times) - Extinction rates may have been overestimated by more than 160 percent based on current scientific methods, according to a new study published in Nature on May 18.

"The methods currently in use to estimate extinction rates are erroneous, but we are losing habitat faster than at any time over the last 65 million years," said co-author Stephen Hubbell, a theoretical ecologist at the University of California, Los Angeles, in a university press release.

"The good news is that we are not in quite as serious trouble right now as people had thought, but that is no reason for complacency,” Hubbell added.

“I don't want this research to be misconstrued as saying we don't have anything to worry about when nothing is further from the truth."

Currently, an indirect method for assessing extinction is used, because it is too difficult to tell when a species has actually gone extinct. Using this “species-area relationship,” the number of species in a given area is employed to calculate how the number of species increases as the area increases.

By reversing the calculations, scientists have estimated how many fewer species will exist as habitat loss reduces area.

"There is a forward version when we add species and a backward version when we lose species," Hubbell said, adding that the Nature paper shows this measure is “fundamentally flawed.”

“The species-area curve has been around for more than a century, but you can't just turn it around to calculate how many species should be left when the area is reduced; the area you need to sample to first locate a species is always less than the area you have to sample to eliminate the last member of the species.

"The overestimates can be very substantial,” he said. “The way people have defined 'extinction debt' (species that face certain extinction) by running the species-area curve backwards is incorrect, but we are not saying an extinction debt does not exist."

Hubbell is “100 percent” confident of the mathematical proof in the paper. "We have bought a little more time with this discovery, but not a lot," he concluded.