More than a million species are at risk of extinction according to a new report on biodiversity. But even some species that aren't considered endangered may be less safe than people think. A new study published in the Journal ...
Ecology
May 15, 2019
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7
Humans are causing the Earth's sixth mass extinction event, with an estimated one million species at risk of extinction.
Ecology
May 10, 2019
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9
Diplomats and scientists from 132 nations wrapped up six days of negotiations in Paris Saturday over the wording of a landmark report on the dire state of Nature and its impact on humanity, a UN official told AFP.
Environment
May 04, 2019
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15
Most scientists agree that a "mass extinction" event is underway on Earth, with species disappearing hundreds of time quicker under the influence of human activity.
Ecology
Apr 25, 2019
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49
Researchers say mercury buried in ancient rock provides the strongest evidence yet that volcanoes caused the biggest mass extinction in the history of the Earth.
Earth Sciences
Apr 15, 2019
9
411
It takes at least 10 million years for life to fully recover after a mass extinction, a speed limit for the recovery of species diversity that is well known among scientists. Explanations for this apparent rule have usually ...
Ecology
Apr 08, 2019
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658
The Sydney Opera House and the Harbour Bridge were plunged into darkness for an hour Saturday to raise awareness about climate change and its impact on the planet's vanishing biodiversity.
Environment
Mar 30, 2019
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42
Global landmarks from the Sydney Opera House to Dubai's Burj Khalifa are set to dim their lights on Saturday to raise awareness about energy use and our planet's vanishing biodiversity.
Earth Sciences
Mar 29, 2019
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47
"Why did the dinosaurs die out?" The consensus, among palaeontologists and dinosaur crazy seven-year-olds alike, seems to be that about 66m years ago a 10km diameter asteroid crashed into what is now Central America. It raised ...
Archaeology & Fossils
Mar 29, 2019
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88
Ancient sea-floor dwellers are providing new clues about how mass extinctions steer life's evolutionary history, according to scientists.
Plants & Animals
Mar 29, 2019
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127
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
