Banca de QUALIFICAÇÃO: EMANUEL MASIERO DA FONSECA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : EMANUEL MASIERO DA FONSECA
DATA : 04/11/2016
HORA: 14:00
LOCAL: Sala Didático I do Departamento de Ecologia da UFRN
TÍTULO:

Phylogeography, evolutionary hotspots and conservation throughout South American open vegetation formations

PALAVRAS-CHAVES:

ABC, Caatinga, Cerrado, genetic diversity, herpetofauna, lizard, phylogeography, Polchrus acutirostris

PÁGINAS: 76
GRANDE ÁREA: Ciências Biológicas
ÁREA: Ecologia
RESUMO:

One of the main goals of biogeography is to unveil the processes and mechanisms involved on generation and maintaining of the observed patterns of biodiversity distribution over time and space. Phylogeography, a discipline of biogeography, has revolutionized the comprehension of microevolutionary processes by enabling the reconstruction and testing of evolutionary scenarios from the information stored in genes. Taken together, the conceptual, methodological and computational advances have provided hypotheses tests that once were unfeasible. A diagonal of open formations stretches from southwest to northeast in South America, encompassing three biomes: Caatinga, Cerrado and Chaco. Historically considered species-poor biomes and with no evolutionary identity, these regions have witnessed a change in paradigm and, currently, are recognized as holding high levels of richness, endemism, and unique evolutionary history.  However, the tempo and mode of diversification of the fauna throughout this region still poorly known and the debate remains largely open. This study is composed of two chapters. First, using a phylogeography approach, we tested the effects of historical, geological and environmental events on the diversification throughout the diagonal of open formation using the lizard Polychrus acutirostris as model. We recovered three non-overlapped lineages spatially structured that corresponded to Caatinga, northeast Cerrado, and southwest Cerrado. Diversification among lineages took place during the transition between Miocene and Pliocene and was associated to a complex scenario involving simultaneous divergence, early stages of diffusion, asymmetric patterns of migration, distinct effects of physical and environmental barriers. (ii) The second chapter aimed to identify areas in the Caatinga biome where the genetic diversity is spatially restricted (Evolutionary Hotspots) and propose areas that should be protected in order to maintain the evolutionary history of those regions. We used 23 Evolutionary Significant Units (ESU) which encompassed 17 formally described species of amphibians and reptiles. We calculated two metrics of genetic diversity and, concomitantly, estimated the geographic distribution of the ESUs through environmental niche modeling. Next, the genetic diversity of each ESU was spatially divided given its geographic distribution and the genetic diversity in the Caatinga was calculated by summing each species layer, corrected by species richness. Southern Caatinga was the most genetic diverse region. Such areas are composed of ESU with narrow geographic distributions and hold the highest levels of diversity, but are poorly represented within protected areas. Our results highlight the complex evolutionary history of species within the diagonal of open formations and help identify regions genetically diverse and therefore of utmost importance to conservation.

MEMBROS DA BANCA:
Presidente - 1678338 - ADRIAN ANTONIO GARDA
Externo à Instituição - ELIANA FARIA DE OLIVEIRA - UFMS
Interno - 1715227 - GABRIEL CORREA COSTA