AP BIOLOGY

Detailed explanation-1: -In nearly all comparisons of modern versus background extinction rates, the background rate has been assumed to be somewhere between 0.1 and 1 species extinction per 10, 000 species per 100 years (equal to 0.1 to 1 species extinction per million species per year, a widely used metric known as E/MSY).

Detailed explanation-2: -There are two main types of extinction: Mass extinction and background extinction.

Detailed explanation-3: -Extinctions occur continually, generating a “turnover” of the species living on Earth. This normal process is called background extinction. Sometimes, however, extinction rates rise suddenly for a relatively short time-an event known as a mass extinction.

Detailed explanation-4: -The current rates of human-induced extinctions are estimated to be about 1, 000 to 10, 000 times greater than past natural (background) rates of extinction.