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Background extinction rate, also known as the normal extinction rate, refers to the standard rate of extinction in Earth's geological and biological history, excluding major extinction events, including the current human-induced Holocene extinction. There have been five mass extinction events throughout Earth's history.
Permian–Triassic extinction event 252 Ma Large igneous province (LIP) eruptions [ 23 ] from the Siberian Traps , [ 24 ] an impact event (the Wilkes Land Crater ), [ 25 ] an Anoxic event , [ 26 ] an Ice age , [ 27 ] or other possible causes
Subtracting background extinctions from extinction tallies had the effect of reducing the estimated severity of the six sampled mass extinction events. This effect was stronger for mass extinctions which occurred in periods with high rates of background extinction, like the Devonian. [14]
More significantly, the current rate of global species extinctions is estimated as 100 to 1,000 times "background" rates (the average extinction rates in the evolutionary time scale of planet Earth), [71] [72] faster than at any other time in human history, [73] [74] while future rates are likely 10,000 times higher. [72]
The contemporary rate of extinction is estimated at 100 to 1,000 times higher than the natural background extinction rate—the typical rate of species loss through natural evolutionary processes. [ 11 ] [ 12 ] [ 13 ] [ 63 ] One estimation suggested the rate could be as high as 10,000 times the background extinction rate , though this figure ...
Since the mid-1980s the actual rates of extinction have exceeded 211 times rates measured from the fossil record. [148] However, "The current amphibian extinction rate may range from 25,039 to 45,474 times the background extinction rate for amphibians." [148] The global extinction trend occurs in every major vertebrate group that is being ...
Among benthic organisms the extinction event multiplied background extinction rates, and therefore caused maximum species loss to taxa that had a high background extinction rate (by implication, taxa with a high turnover). [102] [103] The extinction rate of marine organisms was catastrophic.
[2] [11] Plankton diversity dropped suddenly, [12] but it was relatively mildly impacted at the Triassic-Jurassic boundary, although extinction rates among radiolarians rose significantly. [13] Early Hettangian radiolarian communities became depauperate as a result of the TJME and consisted mainly of spumellarians and entactiniids. [14]