Biogeography of New Zealand : a Methodological and Conceptual Approach

Abstract

In a series of nine separate papers historical, methodological and theoretical issues in the study of biogeography are extensively reviewed and discussed, with particular reference to the panbiogeographic methodology and synthesis of Leon Croizat (1894-1982). Conceptual differences between Croizat's panbiogeography, and the Darwinian theories of vicariance cladistic and centres of origin/migration biogeography are emphasized. Croizat's refutation of Alfred Wegener's (1929, in The Origin of Continents and Oceans) drift solution to the problem of disjunctively distributed organisms is discussed in relation to: 1) Lakatos' demarcation criterion for science/nonscience of progressive versus degenerating research programmes and 2) recent geological work which falsifies Wegener's concept of an original, single Permian supercontinent Pangaea; and corroborates Croizat's novel predictions concerning the composite geological nature of several continents and islands based on his biogeographic analyses. The panbiogeographic method is applied to the analysis of the classic problems of New Zealand and Southern Hemisphere biogeography such as the disjunct distribution of leiopelmatid – ascaphid frogs, ratite birds and the southern beeches Nothofagus. A new synthesis of New Zealand biogeography is proposed following this analysis. The equivalent of a concept of homology in biogeography, the problem of biogeographical classification, and the relationship between geology and biogeography are discussed with reference to this new sythesis, formulated around Croizat's, novel concept that the natural biogeographic regions for terrestrial and freshwater organisms are the present day sea and ocean basins.