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  • Hey there, welcome to Life Noggin!

  • More animal species have gone extinct in the last 500 years than in the last 20 million years combined.

  • And incredible creatures like lions, whales, tigers,

  • oh my, and elephants that used to roam freely in huge numbers are now approaching extinction.

  • The number of wild lions has dropped 95% since only the 1950s.

  • With 75% of all species expected to disappear in the next 300 years.

  • Scientists believe that we're experiencing the sixth mass extinction on Earth.

  • And it's the fastest one ever recorded.

  • Many of the previous extinctions lasted hundreds of thousands and even millions of years.

  • But this one seems to be happening in the blink of an eye.

  • While scientists have found this is due to human activities,

  • the causes for the other five mass extinctions aren't so crystal clear.

  • The most recent K-T extinction wiped out the dinosaurs 65 million years ago.

  • And the general consensus is that an asteroid impact in Mexico is what caused it,

  • but many scientists also point to major volcanic eruptions in India as a likely cause.

  • Both of these catastrophes would've stirred up so much dust and debris that they'd block out sunlight,

  • which is necessary for all kinds of life.

  • But how did dinosaurs die, while creatures like frogs, alligators, birds, and lizards survived?

  • We may never know, but selectiveness is a theme in mass extinctions.

  • During the Triassic-Jurassic extinction about 200 million years ago,

  • there was a mass die off of marine creatures and amphibians, but interestingly, plants weren't really affected.

  • About three quarters of all living species went extinct during this event.

  • It's thought that this was caused by a massive influx of carbon dioxide from major volcanic activity

  • that acidified the oceans and raised air temperatures.

  • Before that, there was the Permian mass extinction, which has ever so pleasantly been nicknamed "The Great Dying,"

  • which is a fantastic name for an emo band, I'm just saying!

  • This was the worst extinction event, wiping out 95% of all species on Earth,

  • including insects, which is very rare.

  • High CO2 levels in the ocean, massive influxes of methane from sea beds and permafrost,

  • and volcanic eruptions are all considered possible causes.

  • Going back even further, we find the Late Devonian extinction about 360 million years ago.

  • This extinction was especially prolonged, lasting about 20 million years,

  • and about 75% of all species were killed off.

  • Marine life were especially affected due to a lack of oxygen in the oceans,

  • but sharks survived though, so that's good, I guess.

  • There are lots of things that could've prompted this,

  • from changing sea levels to new plants altering soil environments.

  • The very first mass extinction that we know of is the Late Ordovician extinction that took place 450 million years ago.

  • Around this time, a huge ice age caused sea levels to drop, ocean currents to reroute,

  • and oxygen levels in the water to drop drastically.

  • At this point, almost all life still lived in the sea

  • and these events caused 85% of all marine plants and animals to go extinct.

  • Some creatures, like trilobites and brachiopods, survived though.

  • But the big question is, will humans die off in this current extinction?

  • The answer really depends on how plants fare in this war.

  • They provide us with food and medicine, and absorb an incredible amount of CO2,

  • keeping global warming a bit more at bay.

  • But it's thought that if plants reach major extinction levels, humans could be next.

  • So, get out there and water those plants like your life depends on it, because it actually does this time.

  • Do you have a favorite animal that went extinct? Is it the dodo? Because I love the dodo.

  • Let me know in the comment section below.

  • Speaking of extinct animals, should humans even try to bring them back?

  • Check out this video where we explored just that!

Hey there, welcome to Life Noggin!

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B1 US extinction extinct mass extinction volcanic marine caused

How Many Mass Extinctions Have Happened On Earth?

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    Evangeline posted on 2021/03/18
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