What are extinct events?

extinct events or events at the level of extinction (ELE) are caused by global environmental disruption, which results in a large percentage of sea and ground species that disappear. On the other hand, extinct events lead to a drastic decline in the species after a "short" geological period.

The most famous evaluation event was the chalking-Tercaříří 65.5 million years ago (MyA), which erased 50 % of all species, including families of dinosaurs. This extinct event was also referred to as the eventual event kt , from the German spelling of the geological time period, which is caused by an asteroid impact on what is now a Mexican Gulf. This resulted in a cascade of environmental impacts that lasted for a long time and smoked animals that ruled the sovereign for more than 150 million years.

Although the event KT is the best known extinction, it is almost a non-deceit compared to the event permian-triassic triassicSmooths. It was also called a great dying, erased 95% of all life on Earth and at sea. It is assumed that the volcanism that created the Siberian trapezes has led to global warming that could so increase the temperatures of the ocean, or release methane gases from the frozen state in the sea, which could increase the temperatures of the ocean. This would complicate global warming, and this temperature, if sufficient, could kill most of their lives and contributed to the stagnation of thermohalin or global streams around the supercontinent of Pang. Then the mushrooms for several million years were dominant in the form of ground life, so Permian-Triassic Ele was the worst mass of history.

However, there were several events of mass extinction that date up to 650 mya, when the stromatolites - structures consisting of cyanobacteria - were eliminated 70% of the dominant Precambrian forms. Another extinction is:

488 Mya: Cambrian-ordovic period has recorded a number of bulkExtinction of many brachiopods or molluscs of similar creatures and Conodonts, which were marine beings that resembled worms with a cone -shaped teeth. Trilobites - small mud animals - was dramatically reduced.

440 - 450 Mya: There were two extinct events of Ordoviků, which were the second most devastating demise of marine life with more than 100 invertebrate families. It is suspicious to heard the Gondwana, which eventually formed part of the supercontinent of Pange.

360 MyA: Devonian carbon extinction event - about 70% of marine species were eliminated. This included plankton, reef builders, all jaw fish and invertebrates. There are some evidence that associates it with another glacial period. The impacts of the meteorite could also contribute.

252 Mya: The event of Permian-Triassic, the worst mass extinction of the country eliminates 95% of all species. Evidence suggests mixed causes, including Pang's formation in combination with Siberian volcanism, greenhouse effect and methane gasificationIncreasing the gases of the greenhouse.

200 Mya: The Triassic-Jurassic EXTICTION event has reduced 20% of all naval families, as well as most of the Corocodilian Archosaurs, most therapies or reptiles similar to Savb and the remaining large amphibs. It is assumed that this extinct event has similar causes to the previous event, with massive volcanic eruptions of the central Atlantic of the magmatic province (camp) leading to possible methane gasification.

65 Mya: Křída-Terciář (KT) Extreme event that spoiled dinosaurs due to the impact of the asteroid.

Midošlo also for extinction events and marine species are more often affected than earthly species. Studies have submitted Raup and Sepkoski, which indicates that the event of a certain size has been extinct, approximately 26 million years, leading to some speculation about an unknown planet whose eccentric orbit passes through Oort Cloud every 26 million years, causing increased probability of asteroid effects. Others claim that cycles of 26 million years uveThey are inaccurate in the study.

According to recent studies, most biologists believe that we are currently going through another great extinction event, because natural habitats are erased at an alarming pace. In the book the future of life , author E.O. Wilson of the University of Harvard predicts that 50% of all species will be extinct in 100 years. In 1998, the US Museum of Natural History conducted a survey and found that most biologists agreed with this evaluation. A study conducted since then Union for Conservation of Nature and Natural Resources (IUCN) supports Wilson's forecast, resulting in an international consensus among scientists.