Environmental and evolutionary stability in bivalve mollusks.

There is no relationship between environmental stability [as indicated by infaunal (stable) versus epifaunal (unstable) habits] and the generic duration of extinct marine bivalve mollusks when the effects of cosmopolitanism (which is associated with long generic durations) and other paleontological "noise" are excluded. This is contrary to the "depauperate gene pool" hypothesis of extinctions.