The failure of a taxonomic group to produce direct descendants, causing its global disappearance at a given point in time. Extinction may be the result of a number of factors including physical changes in the environment, and competition from other species – in recent times most notably by man. The rate at which extinctions have occurred is very variable. Periods of the earth's history when extinction rates have been high are called mass extinctions.
Related category• ORIGIN AND EVOLUTION OF LIFE
Home • About • Copyright © The Worlds of David Darling • Encyclopedia of Alternative Energy • Contact