Alan Solem's work on the diversity of Australasian land snails: an unfinished project of global significance

WA Museum Records and Supplements | Updated 7 years ago

ABSTRACT – Alan Solem's systematic work focused on Pacific island Endodontoidea and on Australian Camaenidae. His many papers on these taxa deal with 647 species (329 new) and 136 genera. His descriptions and identification criteria are detailed and clear. Though not a formal cladist, his interpretation of characters shows that his approach was intuitively cladistic, and his phylogenies are likely to survive formal analysis. His comprehensive revisions, and his cataloguing of whole faunas enabled him to analyse patterns of distribution, and to relate them to evolutionary, biogeographic and ecological theory. For the Pacific Islands, he exposed the limitations of the equilibrium theory of MacArthur and Wilson, drawing attention to its neglect of in situ speciation. In Australia, he identified many cases of remarkable allopatric distributions amongst camaenid genera and species, many of which have minute geographical ranges. Because he studied the whole fauna, and achieved remarkable geographical coverage, he could contrast these patterns with those seen in other families, and in the much richer faunas he studied in New Zealand, where many congeners coexist. He used his experience as a basis for a global review of land snail diversity. Some of the questions and ideas he raised are discussed here and elsewhere in the symposium. At the time of his death, Solem was working on the description of more material (8-10 genera and c. 100 species), and had started to explore the evolutionary events underlying these contrasts. Both his described and undescribed materials are available in WAM and FMNH, and offer the opportunity for cladistic and molecular analysis, answering questions of theoretical and conservation concern. His work has already informed conservation planning in Western Australia. Snail faunas are good general indicators of conservation value, and the completion of his work will further aid conservation planning.