Asst. Curator, Analysis Unit, Center for Conservation and Sustainable Development, MBG
• Understanding the determinants of the abundance and distribution of organisms at a variety of spatial scales, ranging from the small extents on which foraging theory focuses, to the broad geographic extents characteristic of macroecology
Web Pages: MBG, The R Project for Statistical Computing
Project: Species delimitation based on continuous morphological characters. Delimiting species is essential for elucidating the processes driving the origin and maintenance of biological diversity, as well as for basic and applied research in many areas of biology. Yet, how one goes about delimiting species has been a controversial issue in systematics. A broad consensus seems to be growing around the notion of recognizing species as separately evolving segments of metapopulation-level lineages (de Queiroz 1998, 2005). This notion provides a context for integrating information from different sources for inferring lineage separation and thus for evaluating hypotheses about species boundaries. It also fosters the use and development of a wide range of methods for inferring species limits (de Queiroz 2007). However, approaches to delimit species using morphological variation have received little attention recently (Wiens 2007, but see Wiens and Servedio 2000, Erard et al. 2010, Zapata and Jiménez 2011). This is surprising because many, perhaps most, species are still delimited based on statements made by museum/herbarium-based systematists about patterns of morphological variation (Luckow 1995; Wiens and Servedio 2000). Even when other kinds of data are used (such as environmental, geographic and molecular genetic data) morphological variation plays a major role in species delimitation (e.g., Bond and Stockman 2008). This project focuses on examining the performance of methods recently proposed by Erard et al. (2010) to delimit species based on continuous morphological characters. The student(s) participating in this project would use measurements of continuous morphological characters previously published to examine the performance of various statistical approaches to delimit species. The student(s) would use the R environment to implement statistical methods used in species delimitation. No previous experience with statistics or the R environment is needed; but if the student is not familiar with the R language or basic statistics, disposition to learn a computer language and statistics is required.
- Bond J.E., Stockman A.K. 2008. An integrative method for delimiting cohesion species: finding the population-species interface in a group of Californian trapdoor spiders with extreme genetic divergence and geographic structuring. Syst. Biol. 57:628-646.
- de Queiroz K. 1998. The general lineage concept of species, species criteria, and the process of speciation: a conceptual unification and terminological recommendations. In: Howard DJ, Berlocher SH, editors. Endless forms: species and speciation. New York: Oxford University Press. p. 57-75.
- de Queiroz K. 2005. A unified concept of species and its consequences for the future of taxonomy. Proc. Calif. Acad. Sci. 56:196-215.
- de Queiroz K. 2007. Species concepts and species delimitation. Syst. Biol.56:879-886.
- Erard T.H.G, Pearson PN, Purvis A. 2010. Algorithmic approaches to aid species’ delimitation in multidimensional morphospace. BMC Evolutionary Biology 10:175.
- Luckow M. 1995. Species concepts: assumptions, methods and applications. Syst. Bot. 20:589-605.
- Wiens J.J.. 2007. Species delimitation: new approaches for discovering diversity. Syst. Biol. 56:875-878.
- Wiens J.J., Penkrot T.A. 2002. Delimiting species using DNA and morphological variation and discordant species limits in spiny lizards (Sceloporus). Syst. Biol. 51:69-91.
- Wiens J.J., Servedio M.R. 2000. Species delimitation in systematics: inferring diagnostic differences between species. Proc. R. Soc. Lond. B. 267:631-636.
- Zapata F, Jiménez I. 2012. Species Delimitation: Inferring Gaps in Morphology across Geography. Systematic Biology 61: 179-194.