Evolutionary radiations and extinctions.

Abstract

Biologic groups may remain static for long time intervals, suffer a sudden increase in standing diversity, radiation, or become extinct. The factors and processes affecting these different responses are discussed. Mass extinctions are an especially high profile event, and have for this reason previously been chosen as stratigraphical markers; but there are differences between mass and background extinctions which have been poorly researched. It is suggested that extensive information about radiations and extinctions is still required including data on taxonomic distribution, with much tighter time resolution. Rigorous statistical analysis could then be extremely informative. - T.Kennard