Morphological, behavioural and molecular characters are of interest in evolutionary biology because they evidence lineage divergence and are contingent properties of species. With the incorporation of molecular biology into taxonomy, taxonomists realized that species diversity could not be completely deciphered using morphology alone. Nonetheless, the incorporation of multiple biological properties into taxonomic practice has been controversial. This proposal aims to test how the combined use of different suites of characters may converge toward more stable taxonomies, less likely to be affected by the discovery of new taxa or by the advance on the knowledge. Stable taxonomies would obviously benefit other scientists and society. To explore this, we test to which extent do species described on qualitative morphological coincide with the results of DNA barcoding analyses, and divergences in prezygotic reproductive barriers. We further aim to analyze how characters evolve during the process of speciation to provide a better basis for the selection of character when describing and naming species. This research will be performed at the Department of Evolutionary Biology of the Evolutionary Biology Centre at Uppsala University, under the supervision of Dr. Carles Vilà. His expertise in the use of molecular genetics approaches for the study of organismal and molecular evolution will perfectly complement the expertise of the applicant. During his PhD research the applicant has acquired an extensive experience on taxonomy (morphology) and bioacoustics (analyses of reproductive barriers through mating calls) analyses of amphibians and reptiles. Hence, the applicant could obtain solid formation on molecular techniques and concepts while transferring his taxonomic knowledge to molecular biologists. The combination of these different areas of expertise will allow the development of truly integrative approaches to taxonomy.