Banca de DEFESA: FLÁVIA MÓL LANNA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : FLÁVIA MÓL LANNA
DATA : 21/02/2017
HORA: 08:00
LOCAL: Departamento de Ecologia da UFRN
TÍTULO:

Evolutionary history of dwarf-geckos (Lygodactylus, Gekkonidae) in South American continent


PALAVRAS-CHAVES:

Caatinga, Chaco, Pleistocenic Arc Hypothesis, riverine hypothesis, São Francisco River, SDTF, species complex.


PÁGINAS: 96
GRANDE ÁREA: Ciências Biológicas
ÁREA: Ecologia
RESUMO:

What processes and mechanisms are responsible for species diversification? This old question has been revolutionized with technological and methodological advancements, and is now being understood in a way that was previously not possible. Phylogeography is a multidiscipline that uses tools derived from biogeography, molecular phylogeny, and population genetics to understand the context of gene distribution in time and space. The present study uses phylogenetic and phylogeografic analyses to infer the determinant processes in the diversification of the lizard genus Lygodactylus in the Seasonally Dry Tropical Forests (SDTF) in South America. In the first chapter we investigate the relationships among South American Lygodactylus species, seeking to understand the influence of the Pleistocenic Arc on its diversification and whether these species represent a monophyletic group. Through phylogenetics and species delimitation analyses we recovered the group's monophyly when compared with African species and recognized L. klugei as a complex o cryptic species. We suggest an increase from two to five species of Lygodactylus in South America. The divergence time among L. klugei and candidates species endemic from SDTFs was not congruent with the Pleistocenic Arc Hypothesis. However, we suggest the fragmentation of SDTFs likely influenced the divergence of L. wetzeli and a candidate species endemic from a SDTF enclave within Cerrado biome (São Domingos, Vale do Paranã region). In the second chapter we investigate the diversification within the Caatinga, testing the role of the São Francisco River (SFR) as a prominent geographic barrier. We used a lizard endemic from this region (L. klugei) as study model. We delimited the existent lineages, investigated the genetic relationships between them, the spatio-temporal diffusion history and to test the riverine hypothesis (barrier to gene flow) we used a migration analysis. We recovered two lineages structured to respect to SFR: one northern and other southern. The lineage divergence occurred 295 kya, congruent with the change of course of the SFR to the current position. We found no influence of the paleo-SFR on L. klugei structure.


MEMBROS DA BANCA:
Presidente - 1678338 - ADRIAN ANTONIO GARDA
Externo à Instituição - FABRÍCIUS MAIA CHAVES BICALHO DOMINGOS - UnB
Externo à Instituição - SIMONE NUNES BRANDÃO - UFRN
Notícia cadastrada em: 09/02/2017 14:33
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