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Editor, Senior Moderator
Study: 6th mass extinction already underway -- and we're the cause
Katharine Lackey, USA TODAY 5:16 p.m. EDT June 20, 2015
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"Recent extinction rates are unprecedented in human history and highly unusual in Earth's history," according to a study published Friday in the journal Science Advances. "Our global society has started to destroy species of other organisms at an accelerating rate, initiating a mass extinction episode unparalleled for 65 million years."
Researchers used "extremely conservative assumptions" to determine extinction rates that prevailed in the past five annihilation events. Still, they found the average rate of vertebrate species lost over the past century was up to 114 times higher than normal.
...
"The number of species that have gone extinct in the last century would have taken ... between 800 and 10,000 years to disappear," the study reported. "These estimates reveal an exceptionally rapid loss of biodiversity over the last few centuries, indicating that a sixth mass extinction is already underway."
The previous five mass extinctions happened well before mankind walked the Earth, and are believed to have been mainly caused by natural disasters, such as asteroid impacts and volcanic eruptions.
The last mass extinction happened some 65 million years ago, killing off the dinosaurs. Overall, each mass extinction event has rid the planet of up to 96% of its species each time.
...
http://www.usatoday.com/story/news/nation/2015/06/20/sixth-mass-extinction-study/29028887/
Katharine Lackey, USA TODAY 5:16 p.m. EDT June 20, 2015
...
"Recent extinction rates are unprecedented in human history and highly unusual in Earth's history," according to a study published Friday in the journal Science Advances. "Our global society has started to destroy species of other organisms at an accelerating rate, initiating a mass extinction episode unparalleled for 65 million years."
Researchers used "extremely conservative assumptions" to determine extinction rates that prevailed in the past five annihilation events. Still, they found the average rate of vertebrate species lost over the past century was up to 114 times higher than normal.
...
"The number of species that have gone extinct in the last century would have taken ... between 800 and 10,000 years to disappear," the study reported. "These estimates reveal an exceptionally rapid loss of biodiversity over the last few centuries, indicating that a sixth mass extinction is already underway."
The previous five mass extinctions happened well before mankind walked the Earth, and are believed to have been mainly caused by natural disasters, such as asteroid impacts and volcanic eruptions.
The last mass extinction happened some 65 million years ago, killing off the dinosaurs. Overall, each mass extinction event has rid the planet of up to 96% of its species each time.
...
http://www.usatoday.com/story/news/nation/2015/06/20/sixth-mass-extinction-study/29028887/