JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. Ecological Society of America is collaborating with JSTOR to digitize, preserve and extend access to Ecological Applications.Abstract. Environmental assessments of regional development projects have been used in Mexico to determine where conflicts between conservation of biodiversity and resource extraction are likely to occur. Species-rich areas have been acknowledged as a priority for conservation. However, biological information is incomplete and biased toward accessible sites, so species-rich areas cannot be depicted directly from current biological knowledge.An alternative approach to predicting species-rich areas is presented in this article. It is based on the gap analysis technique and involves the use of ordination analysis and generalized linear models integrated with a geographic information system. This approach was used for locating species-rich areas in the Mexican states of Guerrero and Oaxaca, where a regional forestry development project was proposed. Baseline information consisted of geo-referenced collection sites of terrestrial vertebrates. Thirty-two species assemblages were identified by the ordination analysis, as well as by 25 generalized linear models. Validation of six of these models showed no significant differences between observed and predicted species frequencies.Results demonstrated that species-rich areas could be depicted even under the constraints of environmental assessment in Mexico. A large number of species could be used in this analysis due to the minimal information required for each species record. This predictive approach optimized available biological information for the integration of conservation into regional development planning. Abramsky, Z., and M. L. Rosenzweig. 1984. Tilman's predicted productivity-diversity relationships shown by desert rodents. Nature 309:150-15 1. Atkin, M., D. Anderson, B. Francis, and J. Hinde. 1990. Statistical modeling in GLIM. Clarendon, Oxford, England. Austin, M. P., R. B. Cunningham, and P. M. Flemming. 1984. New approaches to direct gradient analysis using environmental scalars and statistical curve-fitting procedures. Vegetatio 55:11-27.

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Phenotypes, DNA, and measures of ecological differences are widely used in species delimitation. Although rarely defined in such studies, ecological divergence is almost always approximated using multivariate climatic data associated with sets of specimens (i.e., the “climatic niche”); the justification for this approach is that species-specific climatic envelopes act as surrogates for physiological tolerances. Using identical statistical procedures, we evaluated the usefulness and validity of the climate-as-proxy assumption by comparing performance of genetic (nDNA SNPs and mitochondrial DNA), phenotypic, and climatic data for objective species delimitation in the speckled rattlesnake (Crotalus mitchellii) complex. Ordination and clustering patterns were largely congruent among intrinsic (heritable) traits (nDNA, mtDNA, phenotype), and discordance is explained by biological processes (e.g., ontogeny, hybridization). In contrast, climatic data did not produce biologically meaningful clusters that were congruent with any intrinsic dataset, but rather corresponded to regional differences in atmospheric circulation and climate, indicating an absence of inherent taxonomic signal in these data. Surrogating climate for physiological tolerances adds artificial weight to evidence of species boundaries, as these data are irrelevant for that purpose. Based on the evidence from congruent clustering of intrinsic datasets, we recommend that three subspecies of C. mitchellii be recognized as species: C. angelensis, C. mitchellii, and C. Pyrrhus.

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The colubrid snake genus Conopsis is distributed in mainland Mexico. The taxonomic history of this genus is complex and recently organisms under the genus Toluca have been synonimized with Conopsis. Here we present the nomenclatural history, morphological variation, distribution and a dichotomous key for the genus Conopsis. Species characterizations are based on a previous cladistic analysis of molecular and morphological characters. We recognize six valid species: C. acuta n. comb., C. amphisticha, C. biserialis, C. lineata, C. megalodon and C. nasus.

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