Continuing the Synthesis Between Panbiogeography, Phylogenetic Systematics and Geology as Illustrated by Empirical Studies on the biogeography of New Zealand and the Chatham Islands

Abstract

-Panbiogeographic and vicariance cladistic methods are compared and contrasted through applications to two aspects of New Zealand biogeography involving the inter-relationships of endemic rich and poor areas, and of the Chatham Islands biota. Biological area cladogram methods are utilized and for the first time the construction of a geological area cladogram based on cladistic analysis of geological characters is demonstrated. A new method of track analysis based on compatibility and clique approaches to graph analysis is outlined and applied to distributional data sets for taxa distributed in New Zealand and the Chatham Islands. This track analysis provides the basis for a novel parallel arcs model for the origin of the Chatham Islands biota. This model exemplifies reciprocal illumination between panbiogeography, phylogenetic systematics and [Biogeography; Chatham Islands; compatibility analysis; geology; New Zealand; panbiogeography; phylogenetic systematics; vicariance biogeography.] All of tree logic is a logic of tracing and reproduction.... It is a question of method: the tracing should always be put back on the map [Deleuze and Guattari, 1987:12-13]. ... the rigorous cladistic core of cladistic vicariance biogeography and the important primary spatial base of panbiogeography form essential groundplan for interpretation of the space-time evolutionary framework of historical biogeography [Myers and Giller, 1988:310]. Panbiogeography was described by Croizat (1958:title page) as an introductory synthesis of phytogeography, zoogeography and geology. To facilitate this synthesis Croizat developed a system of classification of biogeographic regions that could interact with geology at the conceptual level, rather than being tied to any particular geological model (Craw and Weston, 1984; Craw, 1988a; Craw and Page, 1988). His classification was genetic (i.e., reflecting the origin and causes of biogeographic patterns) rather than being merely a convenient summary of the products of biogeographic history. This parallels HenInvited paper presented at the symposium Vicariance Biogeography: Theory, Methods and Applications, 27 December 1987; Annual Meeting of the Society of Systematic Zoology/American Society of Zoologists, New Orleans, Louisiana, U.S.A. nig's (1966) insistence on phylogeny as the basis for classifying taxa, rather than a system based on overall similarity. The empirical bases for Croizat's classification were his graphical track analyses of the distribution patterns of hundreds of animal and plant groups (Croizat, 1952, 1958, 1964). Croizat's method was to plot distributions of organisms on maps and connect the disjunct distribution areas or collection localities together with lines he called tracks. Individual tracks were then superimposed and if they coincided the resulting summary line was termed a generalized or standard track. A generalized track was interpreted by Croizat as indicating the pre-existence of a widespread ancestral biota that had subsequently become fragmented by tectonic, climatic or sea-level changes. In a series of seminal papers Donn Rosen (1974,1976,1978) and Platnick and Nelson (1978) united aspects of Croizat's track method with Hennig's phylogenetic systematics. Rosen (1978:187) also drew attention to the need to develop a common language for geology and biogeography: ... I ... recognize that geology and biogeography are both parts of natural history and, if they