The end-Permian mass extinction is considered to be the most devastating biotic event in the history of life on Earth—it caused dramatic losses in global biodiversity, both in water and on land. About 90% of marine and ...
Archaeology & Fossils
22 hours ago
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A team of researchers affiliated with several institutions in China and two in the U.S. has developed a way to use machine learning to get a better look at the past. In their paper published in the journal Science, the group ...
Volcanic activity did not play a direct role in the mass extinction event that killed the dinosaurs, according to an international, Yale-led team of researchers. It was all about the asteroid.
Earth Sciences
Jan 16, 2020
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New evidence gleaned from Antarctic seashells confirms that Earth was already unstable before the asteroid impact that wiped out the dinosaurs.
Earth Sciences
Jan 07, 2020
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Some 250 million years ago, simultaneous mass extinctions of marine and terrestrial life occurred in an event known as the End-Permian. Or so scientists believed.
Archaeology & Fossils
Dec 12, 2019
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New evidence gleaned from Antarctic seashells confirms that Earth was already unstable before the asteroid impact that wiped out the dinosaurs.
Earth Sciences
Dec 11, 2019
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It's well established that unsustainable human activity is damaging the health of the planet. The way we use Earth threatens our future and that of many animals and plants. Species extinction is an inevitable end point.
Ecology
Dec 02, 2019
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When teen climate activist Greta Thunberg, nominated for the Peace Nobel this year, scolded titans of industry in Davos and heads of state at the United Nations, she told them to look at the science.
Environment
Nov 27, 2019
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Nine human species walked the Earth 300,000 years ago. Now there is just one. The Neanderthals, Homo neanderthalensis, were stocky hunters adapted to Europe's cold steppes. The related Denisovans inhabited Asia, while the ...
Archaeology & Fossils
Nov 22, 2019
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For more than 3.5 billion years, living organisms have thrived, multiplied and diversified to occupy every ecosystem on Earth. The flip side to this explosion of new species is that species extinctions have also always been ...
Ecology
Nov 13, 2019
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An extinction event (also known as: mass extinction; extinction-level event, ELE) is a sharp decrease in the number of species in a relatively short period of time. Mass extinctions affect most major taxonomic groups present at the time — birds, mammals, reptiles, amphibians, fish, invertebrates and other simpler life forms. They may be caused by one or both of:
Over 99% of species that ever lived are now extinct, but extinction occurs at an uneven rate. Based on the fossil record, the background rate of extinctions on Earth is about two to five taxonomic families of marine invertebrates and vertebrates every million years. Marine fossils are mostly used to measure extinction rates because they are more plentiful and cover a longer time span than fossils of land organisms.
Since life began on earth, several major mass extinctions have significantly exceeded the background extinction rate. The most recent, the Cretaceous–Tertiary extinction event, occurred 65 million years ago, and has attracted more attention than all others as it marks the extinction of nearly all dinosaur species, which were the dominant animal class of the period. In the past 540 million years there have been five major events when over 50% of animal species died. There probably were mass extinctions in the Archean and Proterozoic Eons, but before the Phanerozoic there were no animals with hard body parts to leave a significant fossil record.
Estimates of the number of major mass extinctions in the last 540 million years range from as few as five to more than twenty. These differences stem from the threshold chosen for describing an extinction event as "major", and the data chosen to measure past diversity.
This text uses material from Wikipedia, licensed under CC BY-SA
