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Normal extinction rates are often used as a comparison to present day extinction rates, to illustrate the higher frequency of extinction today than in all periods of non-extinction events before it. [1] Background extinction rates have not remained constant, although changes are measured over geological time, covering millions of years. [2] [3] [4]
Extinction Date Probable causes [2] Quaternary: Holocene extinction: c. 10,000 BC – Ongoing: Humans [3] Quaternary extinction event: 640,000, 74,000, and 13,000 years ago: Unknown; may include climate changes, massive volcanic eruptions and Humans (largely by human overhunting) [4] [5] [6] Neogene: Pliocene–Pleistocene boundary extinction: 2 Ma
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]
This is much faster than the expected “background” extinction rate, or the rate at which species would naturally die off without outside influence — in the absence of human beings, these 73 ...
These papers utilized the compendium to track origination rates (the rate that new species appear or speciate) parallel to extinction rates in the context of geological stages or substages. [60] A review and re-analysis of Sepkoski's data by Bambach (2006) identified 18 distinct mass extinction intervals, including 4 large extinctions in the ...
In a 2019 review, David Wagner noted that currently the Holocene extinction is seeing animal species loss at about 100–1,000 times the planet's normal background rate, and that various studies found a similar, or possibly even faster extinction rate for insects.
Global biodiversity is affected by extinction and speciation. The background extinction rate varies among taxa but it is estimated that there is approximately one extinction per million species years. Mammal species, for example, typically persist for 1 million years.
Scientists estimate that the current species extinction rate, or the rate of the Holocene extinction, is 1,000 to 10,000 times higher than the normal, background rate. [ 9 ] [ 10 ] [ 11 ] Habitat loss is a leading cause of species extinctions [ 11 ] and ecosystem service decline. [ 12 ]