Historical biogeography: Geography as evolution, evolution as geography

Abstract

Despite a number of advances in method in recent years, biogeography remains a field with a poorly developed philosophical core. As a result, its historical and ecological sides remain as isolated from one another as ever. In this essay I argue that a more unified approach to biogeographic studies will become possible only when workers realise that it is necessary to reject absolute space, “geography as handmaiden” approaches to distribution problems in favour of structuralist models compatible with both probabilistic spatial interaction and deterministic phylogenetic kinds of thinking. Pros and cons of regionalist, vicariance, and panbiogeographic approaches are weighed in this regard; it is shown that the primary objections of the latter schools to the approach of the former are vitiated when one dwells on second-order, rather than first-order, interpretations of regional faunal structure. This approach makes it possible to construct joint taxonomic/spatial models conducive to pattern analysis; the latter permits the genesis of hypotheses that can be tested through independently conceived theories of process (such as vicariance). An example of the kind of pattern study envisioned, involving generalised track depiction, is briefly described. A suggested cycle of research is thus laid out in which systematic revision becomes a function of a joint “natural” spatial and phylogenetic/historical approach to the subject.

Keywords:

• panbiogeography
• biogeography
• vicariance
• Leon Croizat
• Alfred Russel Wallace