INVESTIGADORES
PONSSA maria laura
congresos y reuniones científicas
Título:
Phylogenetic Analysis of the genus Leptodactylus (Anura, Leptodactylidae). Project
Autor/es:
PONSSA, M. L. DE SÁ, R. Y HEYER, R. W.
Lugar:
Austin. Estados Unidos.
Reunión:
Workshop; Iº AmphibiaTree Workshop; 2004
Institución organizadora:
University of Texas
Resumen:
The genus Leptodactylus is predominantly Neotropical. Considerable life-history variation in the genus includes foam nest placement either on top of temporary pond water, in terrestrial burrows, or terrestrial chambers and differences in females attendance of eggs and larvae. There are about 62 recognized species of Leptodactylus. On the basis of morphology and behavior, Heyer (1969) divided the genus into four species groups (fuscus, melanonotus, ocellatus, pentadactylus). The previous analyses show the necessity to test the monophyly of the genus Leptodactylus and to corroborate the recognized species groups. These analyses were done considering only a few species of each group, and the characters were too few to resolve the relationships of the number of analyzed species. Further the different kinds of characters were separately analyzed. For this it is necessary to complete the morphologycal, molecular and advertisement call data in order to test the monophyly of the genus and to propose a hypothesis of phylogenetic relationship. This goal lead at other accessories objectives, by example: To obtain polarizations that allow us to detect heterochronic pattern. To test traditional hypothesis of evolution, specially in characters associated with a tendency for a more terrestrial mode of life and burrowing habits, on base of polarizations of these characters. To elucidate differentiation pattern that allow us to take systematic decisions (differentiation at specific level). As initial point of this project we have: (1) Tissue samples of 51 species of the genus and eight outgroup genera (mtrDNA 12S y 16S, nr28S, ND1, RAG1 genes). (2) External morphology data of adults of 50 species, internal morphology of 29 species, larval morphology, advertisement call and other behavior characters. (3) Analysis that suggest that Vanzolinius belongs to Leptodactylus (4) Data suggesting that of the 4 traditionally recognized species groups of Leptodactylus, the pentadactylus group is polyphyletic, the melanonotus group is paraphyletic relative to the ocellatus group and the fuscus group is monophyletic (5) Analyses of relationships in sibling species, by example L. didymus – L. mystaceus, which according morphologycal data, are sister taxa, but according sequence data never cluster as sister taxa. Phylogenetic reconstructions will be done using maximum parsimony, maximum likelihood and Bayesian. Maximum parsimony is our prefered method based on our conceptual model of evolution. Initially the following data partitions will be analized separately: (1) 12S sequence data, (2) 16s sequence data, (3) adult morphology and (4) larval morphology. Also a simultaneous analysis of all the available evidences will be done to obtain the most resolved phylogeny.