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Universidade do Porto (2016)

Combining ecological niche modeling and phylogeographic analyses to address climatic stability and persistence in four Tarentola species across the West Sahara

Brojo de Melo José Pedro

Titre : Combining ecological niche modeling and phylogeographic analyses to address climatic stability and persistence in four Tarentola species across the West Sahara

Auteur : Brojo de Melo José Pedro

Université de soutenance : Universidade do Porto

Grade : Mestrado em Biodiversidade, Genética e Evolução 2016

Résumé
Past climatic changes influenced the patterns of biodiversity distribution. Research is lacking for remote parts of the world, such as West Africa, where current biodiversity patterns are likely to have been influenced by oscillations between wet and dry climatic periods. In the region, the Sahara desert acts as a barrier to species not adapted to arid conditions, but in the past many corridors are thought to have existed during wet periods. Some may even have persisted through time, as the Atlantic Sahara. This study used four species of the genus Tarentola (T. annularis, T. chazaliae, T. hoggarensis and T. parvicarinata), and a combination of ecological niche-based models and phylogeographic analyses to infer the climatic stability of the region. A total of 140 samples were sequenced for a 12S fragment of 388bp. ENMs were constructed using Maxent. The genetic results show concordance with the morphological species identification, and a high level of geographic substructuration in T. hoggarensis and T. parvicarinata. Tarentola annularis shows no signs of differentiation throughout most of its range, while T. chazaliae has genetic diversity but it is not geographically structured. ENMs reveal stable areas for all species in more coastal regions with the exception of T. parvicarinata, which had stable areas in the Mauritanian mountains. For T. chazaliae the stable area identified is a small coastal patch in the border between Morocco and Western Sahara. Despite not being completely concordant, genetic and ecological results complement each other and provide a more complete visualization of evolutionary processes in the Sahara-Sahel.

Mots clés  : Tarentola, past climate, ecological niche-based models, integrative approach, North Africa, Sahara, Sahel, ecological corridor, climatically stable areas.

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