Speciation, macroecology, and patterns of diversityDiego Fontaneto
My research interests include speciation, macroecology, and patterns of diversity, mostly using as a test case microscopic invertebrates like rotifers. Speciation: The evolution of distinct species in animals has often been considered a property solely of sexually reproducing organisms. I am working on a famous group of asexual (=parthenogenetic) animals, the bdelloid rotifers, which has diversified into distinct species, with patterns equivalent to those found in sexual groups. With new statistical methods for the combined analysis of morphology and DNA sequence data, independent evolution of species in bdelloids was confirmed. Moreover, the most important process in driving such divergence, namely ecological divergence by natural selection could be inferred. The results show that sex is not the sole and necessary condition for speciation. Diversity: I am interested in obtaining reliable estimates of diversity, and I am investigating the discrepancies between traditional and DNA taxonomy at the species, population and community level using rotifers as a test-case. Moreover, with morphological and phylogenetic combined approach, I am currently revising species diversity in some genera of rotifers. Macroecology: Patterns of diversity in microscopic organisms are hypothesised to differ from macroscopic ones, as small size, desiccation tolerance, and dispersal capability should allow micro-organisms to achieve global distributions. The so-called ‘everything is everywhere´ hypothesis, based on patterns in protists is controversial, and I am testing its predictions for alpha-, beta- and gamma-diversity in bdelloids — similar size and biology of protists. My results support the hypothesis using species identified from traditional taxonomy, while using a DNA taxonomy approach support for a significant relationship between geographic and genetic distances is found. This demonstrates that also geographic isolation, other than selection, may act in shaping diversity in asexual microscopic animals. Publication list on Researcher-ID: http://www.researcherid.com/rid/B-9710-2008
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