Extinction event


Extinctions have occurred at over 1000 times the background extinction rate since 1900.


Mass extinctions seem to be a mainly Phanerozoic phenomenon, with extinction rates low before large complex organisms arose. ==Major extinction events== In a landmark paper published in 1982, Jack Sepkoski and David M.

A quantification of the rock exposure of Western Europe indicates that many of the minor events for which a biological explanation has been sought are most readily explained by sampling bias. Research completed after the seminal 1982 paper (Sepkoski and Raup) has concluded that a sixth mass extinction event is ongoing: 6.


But sea-level falls are very probably the result of other events, such as sustained global cooling or the sinking of the mid-ocean ridges. Sea-level falls are associated with most of the mass extinctions, including all of the "Big Five"—End-Ordovician, Late Devonian, End-Permian, End-Triassic, and End-Cretaceous. A 2008 study, published in the journal Nature, established a relationship between the speed of mass extinction events and changes in sea level and sediment.


A study published in May 2017 in Proceedings of the National Academy of Sciences argued that a “biological annihilation” akin to a sixth mass extinction event is underway as a result of anthropogenic causes, such as over-population and over-consumption.


In May 2020, studies suggested the cause of the mass extinction was due to global warming, related to volcanism, and anoxia, and not due, as considered earlier, to cooling and glaciation. Late Devonian extinction: 375–360 Ma near the Devonian–Carboniferous transition.

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