The sixth mass extinction that scientists recently predicted may be upon us faster than previously thought, according to new predictions. A new study, which appeared in the journal Conservation Biology, shows species are disappearing 1,000 times faster than they did in pre-human times – instead of 100 times faster as was previously thought. And that number is expected to increase as time goes on.
The researchers established the faster extinction rate by coming up with a more accurate pre-human or background rate for comparison, according to Phys.org. “Being able to look at a pre-human or background rate of extinction is important,” University of Georgia ecologist who participated in the study, John Gittelman told Phys.org. “We know that the current rate of extinction is worse than we thought because the background rate is an order of magnitude slower than the original estimate. Having a real rate of extinction will allow us to look at causal mechanisms much more carefully.”
They came up with their numbers by comparing the number of species that died out with the number of new species that emerged. The previous pre-human rate of extinction was about 0.1 extinctions per million species years – or that one out of ever 10 million species on Earth went extinct every year during that time – making the rate 100 times faster than current. But new data allowed the researchers to not only bump that number up a decimal point to 1,000 but also extrapolate that future rates are likely to be as great as 10,000 times higher.
The revised estimate took advantage of new techniques and databases that weren’t available when the previous estimate was made, as well as novel analytical computer models used to estimate extinction rates from phylogenetic, or evolutionary trees that essentially provide maps of the genetic history of a group of organisms.
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