Research group suggests modern extinction rate may be higher than thought

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(Phys.org)—A team of researchers from a wide variety of institutions in France has concluded that it appears likely that approximately seven percent of all modern invertebrates have gone extinct. In their paper published in Proceedings of the National Academy of Sciences, the team outlines the research they conducted on land snail extinctions and how they extrapolated what they found to apply to non-marine invertebrates extinctions worldwide in the modern age.

For thirty years or more, scientists have been theorizing that planet Earth is undergoing a sixth , this one during the so-called Anthropocene—a time dominated by the impact of modern human beings. The problem has been that the theories have been based on a sense of what is likely happening due to destruction of natural habitats, pollution, etc. rather than raw data that shows actual examples of species that have gone extinct. Furthermore, scientists have been noting that most modern extinctions are occurring with , which make up approximately 99 percent of all species on the planet. To add some credence to such theories the team in France set their sights on land snails—a group of invertebrates that has been relatively well studied which means there exists data on their numbers. Scientists believe there were approximately 200 species of the snails originally in modern times, but after an extensive review of the literature, the team concluded that approximately ten percent of all of them have now gone extinct.

The researchers then used the data from the snails to make estimates of how many extinctions are occurring in all other non-marine invertebrates—some in the science community have suggested that such animals species are disappearing at a rate of a hundred every day, but hard proof has been limited—thus far only 800 species have been documented as going extinct, out of almost two million that have been named. Complicating the problem is that estimates of total numbers of actual varies from a few million to hundreds of millions—thus coming up with a figure representing the total number of extinctions is not feasible at this time, but the team believes that it likely represents approximately seven percent of the total, which would represent the largest mass since the dinosaurs disappeared.


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More information: Mass extinction in poorly known taxa, Claire Régnier, PNAS, DOI: 10.1073/pnas.1502350112

Abstract
Since the 1980s, many have suggested we are in the midst of a massive extinction crisis, yet only 799 (0.04%) of the 1.9 million known recent species are recorded as extinct, questioning the reality of the crisis. This low figure is due to the fact that the status of very few invertebrates, which represent the bulk of biodiversity, have been evaluated. Here we show, based on extrapolation from a random sample of land snail species via two independent approaches, that we may already have lost 7% (130,000 extinctions) of the species on Earth. However, this loss is masked by the emphasis on terrestrial vertebrates, the target of most conservation actions. Projections of species extinction rates are controversial because invertebrates are essentially excluded from these scenarios. Invertebrates can and must be assessed if we are to obtain a more realistic picture of the sixth extinction crisis.

© 2015 Phys.org

Citation: Research group suggests modern extinction rate may be higher than thought (2015, June 9) retrieved 15 September 2019 from https://phys.org/news/2015-06-group-modern-extinction-higher-thought.html
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Jun 09, 2015
Do Big Money folk care?

We will be among those species lost to environmental degradation.

Jun 09, 2015
Interesting....hasn't a die off been happening since global warming ended the last Ice Age?

Also, what of new species and genotypes?

Finally, these people are extrapolating and ignoring that species can be thought to be extinct for millennia only to pop up somewhere "unexpectedly."

Jun 09, 2015
"Finally, these people are extrapolating and ignoring that species can be thought to be extinct for millennia only to pop up somewhere "unexpectedly."

That's like throwing snowballs in congress to disprove global warming.

If you want to learn something instead of spout drivel, try looking up the length of time the previous die-offs spanned vs the current one. (thousands or hundreds of thousands of years, vs a couple hundred.)

Jun 09, 2015
Do Big Money folk care?

We will be among those species lost to environmental degradation.

Sorry, G - too dire...

Jun 13, 2015
"Finally, these people are extrapolating and ignoring that species can be thought to be extinct for millennia only to pop up somewhere "unexpectedly."

That's like throwing snowballs in congress to disprove global warming.

If you want to learn something instead of spout drivel, try looking up the length of time the previous die-offs spanned vs the current one. (thousands or hundreds of thousands of years, vs a couple hundred.)


wrong, idjit.

Megafauna have been in decline for tens of thousands of years, both in the numbers of species and the number of individuals within a species, but this is not caused by pollution. It was caused by human beings directly hunting the animals to extinction. Another example of this would be the alligator garfish in Louisiana and other southern states, as there are fewer of them and they grow to half historical sizes now.

Guess what is most likely killing snails? That rubber tire on your 70mph automobile, NOT the CO2 exhaust.


Jun 13, 2015
The idjit white people slaughtered buffalo and left the carcasses to rot.

That's what causes species to decline, not a few PPM worth of CO2.

Idjit people killed off mountain lions and bobcats, and bears through direct hunting, not pollution.

Tasmanian devil? Hunted to the extinction, not pollution. Niche replaced by foreign wild dogs.

It seems colonists never comprehend you don't have to kill the local predator, you can just scare it away. Noooo, they just shoot them on sight and ask questions later.

Jun 13, 2015
But there were other megafauna extinctions within the past several million years involving giant pig species, terror birds, different horse and camel species, etc, which happened before human beings could possibly have been the cause for their deaths. Recall that Horses are actually native to N. America, then they went extinct here long before humans set foot here, then they were repopulated by the Spanish a few hundred years ago.

Get it in your thick skull that this planet has been to hell and back again several times, and the events of life are often far greater than human beings.

Jun 13, 2015
"Get it in your thick skull "
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Excuse me, . . who the hell are you?

Jun 13, 2015
"Get it in your thick skull "
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Excuse me, . . who the hell are you?


I'm a person who's sick of seeing how naive you people are.

These people can't even tell you within an order of magnitude how many "species" there actually are, but they claim to know what percentage of said species are going extinct. They ignore the fact they are supposed to know about the topic of extinctions, but insinuate that man-made pollution is the culprit.

I have never seen so much as one bird kill caused by CO2. I've seen plenty of fish kills caused by all-natural algal blooms, and I've seen plenty of dead animals that got run over on the street, but never a die-off caused by CO2. The CO2's more sinister cousin, CO, is sometimes seen in mass kills associated with volcanism, but not CO2.

Even if there is a mass extinction happening, it's been happening for millions of years, NOT just the past few hundred.

Jun 13, 2015
"I'm a person who's sick of seeing how naive you people are."
-----------------------------------------

Then, start looking elsewhere.


Jun 14, 2015
Guess what is most likely killing snails? That rubber tire on your 70mph automobile, NOT the CO2 exhaust.
I can't find anything in the article on CO2, and you are the one bringing it up in the comments. Why?

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