background extinction

The current background extinction rate is estimated to be one species every few years.

Background extinction rates are typically measured three different ways.

Since life began on Earth, several major mass extinctions have significantly exceeded the background extinction rate.

Background extinction rates have not remained constant, although changes are measured over geological time, covering millions of years.

The global extinction rate may be approximately 100,000 times higher than the natural background extinction rate.

One scientist estimates the current extinction rate may be 10,000 times the background extinction rate.

Extinctions are a normal part of the evolutionary process, and the background extinction rate is a measurement of "how often" they naturally occur.

Background extinction rate, also known as 'normal extinction rate', refers to the standard rate of extinction in earth's geological and biological history before humans became a primary contributor to extinctions.

Almost all scientists acknowledge that the rate of species loss is greater now than at any time in human history, with extinctions occurring at rates hundreds of times higher than background extinction rates.

Calculations based on extinction rates suggest that the current extinction rate of amphibians could be 211 times the background extinction rate and the estimate goes up to 25,039-45,474 times if endangered species are also included in the computation.

"In short, Gould's case for the importance of mass extinction depends on the view that there is a qualitative difference between mass extinction and background extinction, and that major groups have disappeared that would otherwise have survived".

Among benthic organisms, the extinction event multiplied background extinction rates, and therefore caused most damage to taxa that had a high background extinction rate (by implication, taxa with a high turnover).