Relict species: a relict concept?

Relict species have always beguiled evolutionary biologists and biogeographers, who often view them as fascinating 'living fossils' or remnants of old times. Consequently, they are believed to provide interesting and important information on a vanished past and are used to understand the evolution of clades and biotas. The information that relicts provide can, however, be misleading and overemphasised when it is not remembered that they belong to groups or biotas that are mostly extinct. For example, relict species imply regional extinctions and, for this reason, they cannot simultaneously provide evidence of local biota permanence. Here we consider carefully misconceptions about relict species and highlight more clearly their evolutionary and biogeographical significance.