Abstract.A major challenge confronting many contemporary systematists is how to integrate standard taxonomic research with conservation outcomes. With a biodiversity crisis looming and ongoing impediments to taxonomy, how can systematic research continue to document species and infer the 'Tree of Life', and still maintain its significance to conservation science and to protecting the very species it strives to understand? Here we advocate a systematic research program dedicated to documenting short-range endemic taxa, which are species with naturally small distributions and, by their very nature, most likely to be threatened by habitat loss, habitat degradation and climate change. This research can dovetail with the needs of industry and government to obtain high-quality data to inform the assessment of impacts of major development projects that affect landscapes and their biological heritage. We highlight how these projects are assessed using criteria mandated by Western Australian legislation and informed by guidance statements issued by the Environmental Protection Authority (Western Australia). To illustrate slightly different biological scenarios, we also provide three case studies from the Pilbara region of Western Australia, which include examples demonstrating a rapid rise in the collection and documentation of diverse and previously unknown subterranean and surface faunas, as well as how biological surveys can clarify the status of species thought to be rare or potentially threatened. We argue that 'whole of biota' surveys (that include all invertebrates) are rarely fundable and are logistically impossible, and that concentrated research on some of the most vulnerable elements in the landscape -short-range endemics, including troglofauna and stygofauna -can help to enhance conservation and research outcomes.

In the Dampier Archipelago of Western Australia's Pilbara Region, several locally endemic, morphologically distinctive species of Rhagada land snails occur, contrasting with the morphologically conservative species with wider distributions on the adjacent mainland. To test alternative origins of this unusual local diversity in a continental archipelago, we examined sequences of the cytochrome oxidase subunit 1 and 16S mitochondrial genes in 22 described species and eight undescribed forms, including all known morphospecies from the Pilbara Region's Dampier Archipelago and adjacent mainland. Phylogenetic analyses consistently resolved four, deep clades within the Pilbara Region, with a mean sequence divergence of 15–18%. All but one of the species from the Dampier Archipelago formed one of the major clades, indicating that the morphological radiation in the archipelago evolved locally, rather than through multiple, relictual mainland lineages. Morphological divergence spanning almost that of the entire genus was within a subclade with sequence divergence < 4%, highlighting the disconnection between morphological diversification and levels of molecular genetic divergence. This in situ morphological radiation in the Dampier Archipelago, which transcends variation seen over much larger distances on the mainland, is unusual for a continental archipelago, and may relate to local heterogeneity of land forms. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 106, 316–327.

Mainland species of the camaenid genus Rhagada, endemic to northern Western Australia, have relatively large, non-overlapping geographic ranges. In contrast, over much smaller distances in the Dampier Archipelago, several locally endemic, morphologically distinctive species occur with intermingled ranges. To test alternative origins of the unusual local diversity, we compared allozymes at 21 loci in 12 archipelago populations and 14 mainland populations, representing 14 species. Genetic distances were consistently low, averaging 0.019 (range 0.000–0.051) within species, and only 0.043 (range 0.001–0.133) between species. In the Dampier Archipelago, the average genetic distance between species was even smaller (0.023). This result was indistinguishable from the within-species comparisons, highlighting the disconnection between morphological diversification and levels of molecular genetic divergence. A pattern of isolation by distance among all comparisons within the archipelago also suggests a historic cohesiveness of the species in the Dampier Archipelago. Although providing no resolution of relationships among mainland populations, a neighbour-joining tree provided further support for an in situ morphological radiation in the Dampier Archipelago, transcending variation seen over much larger distances on the mainland.

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