*extinction*

n. [ L. extinctio, exstinction: cf. F. extinction. ] 1. The act of extinguishing or making extinct; a putting an end to; the act of putting out or destroying light, fire, life, activity, influence, etc. [ 1913 Webster ]

2. State of being extinguished or of ceasing to be; destruction; suppression; as, the extinction of life, of a family, of a quarrel, of claim. [ 1913 Webster ]

3. Specifically: The ceasing to exist of a species of living organism, such as a plant or animal, whose numbers declined to the point where the last member of the species died and therefore no new members of the species could ever again be born. [ PJC ]

☞ Extinctions have occurred many times throughout the history of life on Earth, and abundant evidence of the prior existence of animals and plants are found as fossils in rock formations many millions of years old. It is believed by some that due to the influence of man on the environment and destruction of habitat, the rate of extinction of species is now higher than at any previous time on this planet. Extinctions of some animals in recent years have actually been reliably recorded, such as that of the dodo bird. A remarkable example of extinction is that of the passenger pigeon (Ectopistes migratorius) in North America, which once numbered in the billions, and the last living member of which species was recorded as dying in captivity in 1914. [ PJC ]