mass extinction teriminin İngilizce İngilizce sözlükte anlamı
A sharp decrease in the total number of species in a relatively short period of time
A catastrophic, widespread perturbation where major groups of species become extinct in a relatively short time compared to normal background extinctions
The dying-out of several plant and/or animal groups over a brief period of geological time
An event in which a large number of organisms in many different clades are eliminated
An event in which large numbers of species die out in a very short time across the whole of the Earth The K-T event was one of the 'Big Five', the five largest mass extinctions
The sudden disappearance in the fossil record of a large number of species of life, to be replaced by new species in subsequent layers Mass extinctions are indications of catastrophic changes in the environment, such as might be produced by a large impact on the Earth
n: A catastrophic, widespread -- often global -- event in which major groups of species are wiped out over a relatively short period when compared to normal ( background ) extinction rates There have been five major mass extinctions, of natural causes (in at least one case due to an asteroid impacting the earth), in the earth's history We are now entering a sixth great mass extinction, this time of unnatural causes human activities