Process, pattern and scale in biogeography

Abstract

Patterns of distribution of organisms over the surface of the globe can be demonstrated to be non-random. Once defined, this non-randomicity requires explanation in terms of process or processes, before a reconstruction of the events of biotic history that led to present day species distributions can be achieved. Biogeography has evolved along the two avenues of pattern definition and process identification, principally from systematics, ecology and palaeontology. Biogeography is not, however, a unified subject and this is due in part to these diverse origins. Publications in biogeography occur in rather different journals, each with its own clientele, further aggravating the lack of overlap between disciplines. Biogeographers will always have different interests born out of their different backgrounds. They include botanists, ecologists, geneticists, geographers, geologists, palaeontologists, taxonomists and zoologists. It is not surprising, therefore, that researchers in these diverse fields tend often to talk past, rather than to each other. This interdisciplinary nature has led to fragmentation rather than cooperation which has been to the detriment of the subject as a whole. To progress, biogeography must attempt to integrate these divergent interests and determine how speciation, adaptation, extinction and ecological processes interact with one another and with geology and climate to produce distributional patterns in the world’s biota through time.