BACKGROUND EXTINCTION Background Extinction is a process of natural and low-level extinction that goes on continuously due to changes in the environmental conditions; such changes may be small or big, gradual or sudden. When such changes occur, the local species
must adapt itself, move to a more favorable area or become extinct.
The background extinction has always been happening and biologists say that 99.9% of all species that
ever lived are extinct. The rate of background extinction has been generally uniform over
long geological periods. At some points in time, however, mass extinctions have occurred on earth.
