Brief history of extinctions on Earth

“Our planet Earth has extinguished large portions of its inhabitants several times since the dawn of animals. And if science tells us anything, it will surely try to kill us all again. Working in the 19th century, paleontology pioneer Georges Cuvier saw dramatic turnovers of life in the fossil record and likened them to the French Revolution, then still fresh in his memory.

Today, we refer to such events as “mass extinctions,” incidents in which many species of animals and plants died out in a geological instant. They are so profound and have such global reach that geological time itself is sliced up into periods—Permian, Triassic, Cretaceous—that are often defined by these mass extinctions.

RTFA and “enjoy” or at least reflect upon the mortality of this widespread but fragile species.

Thanks, Barry Ritholtz

2 thoughts on “Brief history of extinctions on Earth

  1. Cassandra says:

    “Biological annihilation via the ongoing sixth mass extinction signaled by vertebrate population losses and declines” Proceedings of the National Academy of Sciences of the United States of America (PNAS July 25, 2017 vol. 114 no. 30) http://www.pnas.org/content/114/30/E6089
    See article @ https://www.cbd.int/financial/2017docs/ceballos-sixth2017.pdf “The strong focus on species extinctions, a critical aspect of the contemporary pulse of biological extinction, leads to a common misimpression that Earths biota is not immediately threatened, just slowly entering an episode of major biodiversity loss. This view overlooks the current trends of population declines and extinctions.”

  2. Last call says:

    The ‘Great Dying’ Nearly Erased Life On Earth. Scientists See Similarities To Today” (NPR 6/4/19) https://www.npr.org/2019/06/04/729341362/the-great-dying-nearly-erased-life-on-earth-scientists-see-similarities-to-today “There was a time when life on Earth almost blinked out. The “Great Dying,” the biggest extinction the planet has ever seen, happened some 250 million years ago and was largely caused by greenhouse gases in the atmosphere. Now scientists are beginning to see alarming similarities between the Great Dying and what’s currently happening to our atmosphere.
    …About 250 million years ago or so, an enormous volcanic field erupted in what is now Siberia. It spewed lava that burned though limestone and coal beds and filled the atmosphere with carbon dioxide and pollution, possibly for millions of years. That in turn warmed the planet, made the oceans acidic and robbed them of oxygen. More than 90% of species in the oceans died out as did two-thirds of those on land.
    There have been other mass extinctions, like the one that wiped out the dinosaurs about 65 million years ago, but this one, at the end of the Permian Period, was mostly caused by too much carbon dioxide rising into the atmosphere. And the Smithsonian notes often in its exhibit [at the Smithsonian National Museum of Natural History in Washington, D.C.] that the current warming of the planet is déjà vu all over again.

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