Species

Abstract

There has been a huge debate over the defi nition of the species concept. In this paper, we take part in this debate and propose a defi nition that we claim is based on the theory of evolution as it is used today. We consider the set of all past, present and future organisms on Earth and call “species” the diverging branches (between two branching events or a branching event and an extinction) as species. Most of them are very diffi cult to discover. However, we claim that this defi nition provides biologists with a sound conceptual ground.