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The natural world. Looking pretty for 3.5b years.

the 6th Extinction

Author: Hugh Bollinger/Monday, June 22, 2015/Categories: natural history, wildlife conservation, sustainability, environment, climate change

Fossilized bones inform us that the Earth has undergone multiple  mass extinction events . The most well known saw the demise of the dinosaurs at the end of the Cretaceous era but other mass events have occurred. From the  Ordovician extinctions nearly 460 million years ago through the Cretaceous 66 million years ago, five major events are recognized. Research is now beginning to indicate a new one is in progress now. 

Publishing in  Science Advances  researchers from Mexico, Stanford, Princeton, and elsewhere, say we are now entering a new mass extinction phase. Their study,
Accelerated modern human–induced species losses: Entering the sixth mass extinction, shows that even with extremely conservative estimates, species are disappearing about 100 times faster than the normal background rate between mass extinctions.

The researchers used "a 2 vertebrate species extinctions/per 10,000 species/per 100 year period as their background rate. By that estimate, the number of species that have gone extinct in the last century would have taken between 800 and 10,000 years to disappear. These estimates reveal an exceptionally rapid loss of biodiversity over the last few centuries, indicating that a sixth mass extinction is already under way."

                                               Species Extinctions 1500-2010  (credit: IUCN  records)

The lead author of the new study, Gerardo Ceballos of the Autonomous University of Mexico, said:

"If this
(extinction rate) is allowed to continue, life would take many millions of years to recover, and our species itself would likely disappear."

As species disappear, so do crucial ecosystem services such as honeybees' crop pollination and wetlands' water purification, among many others. At this new rate of species loss, people will lose biodiversity and ecosystem benefits within three generations noted Paul
Ehrlich, another of the new study's authors. Estimates kept by the International Union fo the Conservation of Nature (IUCN) show the specter of extinction hangs over nearly 41% of all amphibian species and 26% of all mammals. Ehrlich continued:

"There are examples of species all over the world that are essentially the walking dead."

He provided more of his perspective in this short video released by Stanford:

The last mass extinction allowed a small surviving mammal to evolve into every possible mammalian form we know today, including ourselves. The dodo is used as the poster child for extinction but the bird's position may be taken up by many new species in this century. Hopefully, we will act wisely to prevent that happening, for our own sake.


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