The Neglected Side of the Coin: Non-adaptive Radiations in Spring Snails (Bythinella spp.)

Abstract

Recently, there has been increased scientific interest among evolutionary biologists in both causes and consequences of radiations. Whereas one form of radiation – adaptive radiation – has been studied extensively, another form – non-adaptive radiation – is discussed controversially and is poorly understood. In fact, the concept of non-adaptive radiation (i.e., rapid diversification of species not accompanied by adaptation into various niches and resulting in a group of allopatric taxa) is rejected by some workers.