15 PHOTOS 6th extinction See Gallery Study finds Earth is on verge of 'the 6th extinction' GOLDEN LION TAMARIN, LEONTOPITHECUS ROSALIA, ENDANGERED. NATIONAL ZOO Golden lion tamarin Leontopithecus rosalia A golden lion tamarin (Leontopithecus rosalia rosalia) sits on a tree in the zoological gardens in Hong Kong on October 11, 2009. The golden lion tamarin, an endangered species, is native to the forests of Brazil. AFP PHOTO / Antony DICKSON (Photo credit should read ANTONY DICKSON/AFP/Getty Images) Small monkeys known as the Golden Lion Tamarin (Leontopithecus rosalia) are seen in a cage at the Hamamatsu Zoo in Shizuoka Prefecture on November 1, 2010. AFP PHOTO/Kazuhiro NOGI (Photo credit should read KAZUHIRO NOGI/AFP/Getty Images) (FILES) This file picture taken on April 26, 2012 shows a visitor taking pictures with a smartphone of a whitetip reef shark at the Aquarium of the Pacific in Long Beach, California. Japan and other pro-shark fishing nations on March 14 lost a bid to overturn a landmark deal to offer international trade protection for several species of the ocean's oldest predator. The decision to restrict exports in the oceanic whitetip shark, the porbeagle, three types of hammerheads and the manta ray won final approval by the 178-member Convention on International Trade in Endangered Species (CITES). AFP PHOTO /JOE KLAMAR (Photo credit should read JOE KLAMAR/AFP/Getty Images) BAMAHAS - MAY 5: ***EXCLUSIVE*** Juvenile oceanic whitetip shark, on May 5, 2007 in Bahamas. Shark shepherd Jim Abernathy has spent an incredible 35 years interacting with sharks underwater and BONDED with some of the largest and most fearsome predators ion the seas. The 52-year-old, from Florida, has won the trust of many individual sharks - so much so that they follow him around like meek puppy dogs. He loves the animals so much - spending 320 days a year with them for two decades - that he has even shunned the idea of finding true love with a GIRLFRIEND or WIFE. Using his incredible relationship with sharks he has managed to capture extraordinary close up pictures of the wild predatory fish in their natural habitats in the Bahamas, Mexico and South Africa. During his career he has dived with schools of up to 20 tiger sharks - a species known as one of few man eaters - 24 basking sharks, 70 lemon sharks and a massive 350 Caribbean reef sharks. Other images show him up-close-and-personal with 15foot tiger shark Emma. His new book 'Sharks Up Close' tells the story of the larger sharks of the world and aims to educate about the importance of the animals' conservation from fishing and is available on hardback for Â£15.75 from Amazon or www.scuba-adventures.com (Photo by Jim Abernethy / Barcroft Media / Getty Images) SHARM EL SHEIKH, EGYPT - UNDATED: File picture of a juvenile female Oceanic whitetip shark swimming close to the surface in Sharm El Sheikh, Red Sea, Egypt. British tourists have been warned by the Foreign Office to avoid cheap dive tour operators after a spate of violent shark attacks at the popular Egyptian tourist resort of Sharm El Sheikh. One attack left a 70-year-old German woman dead after having her arm ripped off by one of the killer beasts. Egypt's tourism minister Zuhair Garana insists diving will continue because 'sharks will not attack divers'. (Photo by Mark Doherty / Specialist Stock / Barcroft Media / Getty Images) SHARM EL SHEIKH, EGYPT - UNDATED: File picture of a juvenile female Oceanic whitetip shark swimming close to tourists in Sharm El Sheikh, Red Sea, Egypt. British tourists have been warned by the Foreign Office to avoid cheap dive tour operators after a spate of violent shark attacks at the popular Egyptian tourist resort of Sharm El Sheikh. One attack left a 70-year-old German woman dead after having her arm ripped off by one of the killer beasts. Egypt's tourism minister Zuhair Garana insists diving will continue because 'sharks will not attack divers'. (Photo by Mark Doherty / Specialist Stock / Barcroft Media / Getty Images) SHARM EL SHEIKH, EGYPT - UNDATED: File picture of a juvenile female Oceanic whitetip shark swimming close to tourists in a pedalo in Sharm El Sheikh, Red Sea, Egypt. British tourists have been warned by the Foreign Office to avoid cheap dive tour operators after a spate of violent shark attacks at the popular Egyptian tourist resort of Sharm El Sheikh. One attack left a 70-year-old German woman dead after having her arm ripped off by one of the killer beasts. Egypt's tourism minister Zuhair Garana insists diving will continue because 'sharks will not attack divers'. (Photo by Mark Doherty / Specialist Stock / Barcroft Media / Getty Images) SHARM EL SHEIKH, EGYPT - UNDATED: File picture of a juvenile female Oceanic whitetip shark swimming close to tourists in Sharm El Sheikh, Red Sea, Egypt. British tourists have been warned by the Foreign Office to avoid cheap dive tour operators after a spate of violent shark attacks at the popular Egyptian tourist resort of Sharm El Sheikh. One attack left a 70-year-old German woman dead after having her arm ripped off by one of the killer beasts. Egypt's tourism minister Zuhair Garana insists diving will continue because 'sharks will not attack divers'. (Photo by Mark Doherty / Specialist Stock / Barcroft Media / Getty Images) SHARM EL SHEIKH, EGYPT - UNDATED: File picture of a juvenile female Oceanic whitetip shark swimming close to the surface in Sharm El Sheikh, Red Sea, Egypt. British tourists have been warned by the Foreign Office to avoid cheap dive tour operators after a spate of violent shark attacks at the popular Egyptian tourist resort of Sharm El Sheikh. One attack left a 70-year-old German woman dead after having her arm ripped off by one of the killer beasts. Egypt's tourism minister Zuhair Garana insists diving will continue because 'sharks will not attack divers'. (Photo by Mark Doherty / Specialist Stock / Barcroft Media / Getty Images) SHARM EL SHEIKH, EGYPT - UNDATED: File picture of a juvenile female Oceanic whitetip shark swimming close to tourists in Sharm El Sheikh, Red Sea, Egypt. British tourists have been warned by the Foreign Office to avoid cheap dive tour operators after a spate of violent shark attacks at the popular Egyptian tourist resort of Sharm El Sheikh. One attack left a 70-year-old German woman dead after having her arm ripped off by one of the killer beasts. Egypt's tourism minister Zuhair Garana insists diving will continue because 'sharks will not attack divers'. (Photo by Mark Doherty / Specialist Stock / Barcroft Media / Getty Images) SHARM EL SHEIKH, EGYPT - UNDATED: File picture of a juvenile female Oceanic whitetip shark swimming close to tourists in Sharm El Sheikh, Red Sea, Egypt. British tourists have been warned by the Foreign Office to avoid cheap dive tour operators after a spate of violent shark attacks at the popular Egyptian tourist resort of Sharm El Sheikh. One attack left a 70-year-old German woman dead after having her arm ripped off by one of the killer beasts. Egypt's tourism minister Zuhair Garana insists diving will continue because 'sharks will not attack divers'. (Photo by Mark Doherty / Specialist Stock / Barcroft Media / Getty Images) SHARM EL SHEIKH, EGYPT - UNDATED: File picture of a juvenile female Oceanic whitetip shark swimming close to tourists in Sharm El Sheikh, Red Sea, Egypt. British tourists have been warned by the Foreign Office to avoid cheap dive tour operators after a spate of violent shark attacks at the popular Egyptian tourist resort of Sharm El Sheikh. One attack left a 70-year-old German woman dead after having her arm ripped off by one of the killer beasts. Egypt's tourism minister Zuhair Garana insists diving will continue because 'sharks will not attack divers'. (Photo by Mark Doherty / Specialist Stock / Barcroft Media / Getty Images) SHARM EL SHEIKH, EGYPT - UNDATED: File picture of a juvenile female Oceanic whitetip shark swimming close to the surface in Sharm El Sheikh, Red Sea, Egypt. British tourists have been warned by the Foreign Office to avoid cheap dive tour operators after a spate of violent shark attacks at the popular Egyptian tourist resort of Sharm El Sheikh. One attack left a 70-year-old German woman dead after having her arm ripped off by one of the killer beasts. Egypt's tourism minister Zuhair Garana insists diving will continue because 'sharks will not attack divers'. (Photo by Mark Doherty / Specialist Stock / Barcroft Media / Getty Images) Up Next See Gallery Discover More Like This HIDE CAPTION SHOW CAPTION of SEE ALL BACK TO SLIDE

WASHINGTON (AP) -- Species of plants and animals are becoming extinct at least 1,000 times faster than they did before humans arrived on the scene, and the world is on the brink of a sixth great extinction, a new study says.

The study looks at past and present rates of extinction and finds a lower rate in the past than scientists had thought. Species are now disappearing from Earth about 10 times faster than biologists had believed, said study lead author noted biologist Stuart Pimm of Duke University.

"We are on the verge of the sixth extinction," Pimm said from research at the Dry Tortugas. "Whether we avoid it or not will depend on our actions."

The work, published Thursday by the journal Science, was hailed as a landmark study by outside experts.

Pimm's study focused on the rate, not the number, of species disappearing from Earth. It calculated a "death rate" of how many species become extinct each year out of 1 million species.

In 1995, Pimm found that the pre-human rate of extinctions on Earth was about 1. But taking into account new research, Pimm and his colleagues refined that background rate to about 0.1.

Now, that death rate is about 100 to 1,000, Pimm said.

Numerous factors are combining to make species disappear much faster than before, said Pimm and co-author Clinton Jenkins of the Institute of Ecological Research in Brazil. But the No. 1 issue is habitat loss. Species are finding no place to live as more places are built up and altered by humans.

Add to that invasive species crowding out native species, climate change affecting where species can survive, and overfishing, Pimm said.

The buffy-tufted-ear marmoset is a good example, Jenkins said. Its habitat has shrunk because of development in Brazil, and a competing marmoset has taken over where it lives. Now ,it's on the international vulnerable list.

The oceanic white-tip shark used to be one of the most abundant predators on Earth and they have been hunted so much they are now rarely seen, said Dalhousie University marine biologist Boris Worm, who wasn't part of the study but praised it. "If we don't do anything, this will go the way of the dinosaurs."

Five times, a vast majority of the world's life has been snuffed out in what have been called mass extinctions, often associated with giant meteor strikes. About 66 million years ago, one such extinction killed off the dinosaurs and three out of four species on Earth. Around 252 million years ago, the Great Dying snuffed out about 90 percent of the world's species.

Pimm and Jenkins said there is hope. Both said the use of smartphones and applications such as iNaturalist will help ordinary people and biologists find species in trouble, they said. Once biologists know where endangered species are they can try to save habitats and use captive breeding and other techniques to save the species, they said.

One success story is the golden lion tamarin. Decades ago the tiny primates were thought to be extinct because of habitat loss, but they were then found in remote parts of Brazil, bred in captivity and biologists helped set aside new forests for them to live in, Jenkins said.

"Now there are more tamarins than there are places to put them," he said.

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