Banca de DEFESA: CECIL PERGENTINO FAZOLATO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : CECIL PERGENTINO FAZOLATO
DATE: 20/12/2023
TIME: 08:30
LOCAL: https://conferenciaweb.rnp.br/sala/henrique-batalha-filho-2
TITLE:

Evolution and biogeography of endemic lizards from the white sand dunes of the northeastern coastal region of Brazil

KEY WORDS:

Restinga, ddRADseq, Cryptic diversity, Morphology, Phylogeography, Conservation

PAGES: 122
BIG AREA: Ciências Biológicas
AREA: Zoologia
SUMMARY:

Geological changes through the Quaternary have impacted watercourses, climate, and coastal areas, which drove the evolutionary diversification of many organisms. In coastal landscapes during the Pleistocene and Holocene, these transformations caused notable impacts due to sea level variation and the dynamics of these recent habitats. The study of fauna in these environments allows to comprehend how historical factors have shaped the current species diversity. In this dissertation we analyzed the genetic and phenotypic variation in populations of the lizards Tropidurus hygomi, Glaucomastix abaetensis, and Glaucomastix itabaianensis that are endemic and sympatric species inhabiting a short sandy coastal range in the northern coastal region of Bahia and the coast of Sergipe. The dissertation encompasses two chapters. In the first chapter we employed an integrated approach using different biotic and abiotic data sources to better understand the diversification of these species. We explored the phenotype variation using linear morphological characters from the limbs and body and geometric morphometrics of the head of individuals. We compared these data with climatic information to identify correlations between morphological variation and climate. We addressed gaps in the spatial sampling from previous studiesof these lizards to assess population structure. Our results identified five and three well-supported lineages for T. hygomi and G. abaetensis/itabaianensis, respectively. We found morphological suport for different mitochondrial lineages in both lizards’ groups, as well as correlation of morphological variation with climatic data. Our findings revealed cryptic diversity and a complex evolutionary history associated with the formation of these restinga environments. In the second chapter, we obtained subgenomic data of these species through the ddRADseq approach to infer spatial-temporal diversification in these restinga formations. Our data revealed a high level of population structure with the presence of eight genetic groups in each taxon (T. hygomi and G. abaetensis/itabaianensis). Historical demographic analyses indicated synchronous population decline in all groups in the last 10,000 to 50,000 years ago. We observed a possible association of these patterns with the elements of the restinga landscapes where these species are restricted. The presence of mangrove regions at river mouths fragments the continuous distribution of white sand dunes and exhibits spatial concordance with the observed genetic groups. Late Quaternary climate changes are linked to the population decline of these species, with the influence of rising sea levels reducing available habitats and increased wind incidence promoting blowout dune remodeling. Finally, the results of this dissertation revealed hidden diversity and a complex evolutionary history in a short range of dunes along the Brazilian coast. Our findings also have direct implications for future management and conservation plans for these threatened species, aiming to mitigate anthropogenic disturbances that jeopardize these lizards.

COMMITTEE MEMBERS:
Presidente - 2048980 - HENRIQUE BATALHA FILHO
Interna - 1299193 - ALESSANDRA SELBACH SCHNADELBACH
Externa à Instituição - TAMÍ MOTT - UFAL
Externo à Instituição - FABRICIUS MAIA CHAVES BICALHO DOMINGOS - UFPR
Externo à Instituição - RICARDO MARQUES DA SILVA