Evolution along the time has not followed a linear increase. The diversity and number of species and individuals increase and decrease depending on the environment of each historical moment and sometimes abruptly. Evolution has had many ups and downs and as at some times, the Earth could be proud of the number of animals that lived in the past in this life has been about to disappear altogether. We are talking about the great extinctions. Surely you know the extinction that ended the hegemony of big lizards, which ended with the T-Rex or Triceratops, perhaps because the nearest extinction and we have seen in many documentaries. This extinction which is popularly known as the extinction of the dinosaurs, and occurred in the Cretaceous 65 million years ago, exterminated 40% of life on Earth. Maybe we think a lot, 40% of human life on Earth would end up with almost 3,000 million people, with for example, all people living in the southern hemisphere, but if we look at the mass extinctions that have occurred , there is a very important extinction: the mass extinction of Permian-Triassic. This was the extinction that nearly destroyed of life on Earth.

The Permian extinction wiped out more than 70% of life on earth, and 95% of marine life. To continue with absurd comparisons, it is as if they disappeared all people in the world, except those who live in Mexico ... for example.
Disease, starvation, earthquakes, catastrophic weather events were the survivors had to endure 250,000,000 years ago.

And what were the largest causes of extinctions on Earth?

There are several theories about the causes of extinction, and as we discuss all take a long time, we discuss only the experts think that possible: Meteorite and Volcanism Theory.

250 million years ago, there were on Earth, exactly in which today is Siberia a continuing series of Mega volcanoes spewing material from the bowels of the planet for thousands and thousands of years (80,000 years). These surface megavolcanes threw 4 million km3 of lava. About 40,000 times the Krakatoa.

The CO2, lava, pyroclastic flows from volcanoes and other gases could increase the temperature of the Earth, it is estimated that in 5th.

Now comes the second part of the theory ... rather the first. A few years ago discovered a large crater on Antarctica, exactly what is known as Wilkes Land. This crater has a diameter of 450 km and it is estimated that the meteorite that caused it could measure almost 50 km (nearly 5 times more than the meteor that killed the dinosaurs.)

The meteorite discovered, made ​​a great impact on our planet, for example, separated Australia from Antarctica when they were together and formed the Gondwana continent 250 million years ago ... 250 million years, precisely the date on which occurred the volvanes. That's why many experts geologists attribute the origin of these supervolcanoes the ripple effect that could produce the meteorite on Earth.

Of course, along with supervolcanoes, the effect of the meteorite caused further increase in global temperature. It is thought that up to 12 degrees to increase the temperature of sea water, produced from melting methane hydrate deposits, which by pressure and cold were in solid state. Following this event was intoxicated marine life slowly almost to extermination.

This is summarized and anyone interested will easily find more information about it. Finally, say that the Permian extinction wiped out some prehistoric animals known as Scutosaurus, the DIMETRODON or Inostrancevia or insects as Meganeuropsis.

But thanks to what is perhaps the fate, life continued and developed further evolution to what we know today: the human species ... the last great extinction.
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