The relevance of past mass extinctions to an understanding of current and future extinction processes

Abstract

Since the early beginnings of the scientific investigation of the diversity of the living world, some four hundred years ago, a large number of species have become extinct, in all parts of the world, because of human intervention, and there is widespread concern about a devastating amplification of this trend in the near future. Extinction, however, is of course not a recent phenomenon linked to human activities. The main achievement of early palaeontologists, at the beginning of the nineteenth century, was to demonstrate beyond all doubt the reality of extinction without human intervention, during the geological past (Buffetaut, 1987). The complete extinction of species had long been considered an impossibility, mainly on religious grounds (it contradicted the concept of the plenitude and perfection of divine creation). Accumulating fossil evidence led scientists such as Blumenbach and Cuvier to the inescapable conclusion that countless species had disappeared in the course of geological time, well before the appearance of man. It thus seems that any reflexion on future extinctions should also take the past record of extinctions into account, for the simple reason that it may be impossible to find an analogue to the current wave of extinctions within the time span covered by human history. The philosophical justification of such