 The living world is organized into phenomenological species: recognizable, reidentifiable clusters of organisms. This fact makes the production of bird and butterfly field guides, identification keys for invertebrates, regional floras, and the like, all possible…. There are many routes through which one population can become demographically isolated from, and hence evolutionarily independent of, populations that were once sources and sinks of its own genes. But the fact of isolation and evolutionary independence is of immense importance to the fate of local adaptation in such populations. So the phenomenological species richness of a region is, in an importance sense, a catalogue both of phenotypic variety and of the potential evolutionary resources available in that region. (Maclaurin &amp; Sterelny 2008: 40)