Learning from a multidisciplinary approach: the evolution of a widely introduced Mediterranean Gecko.

The Moorish gecko Tarentola mauritanica has a widespread circum-Mediterranean distribution. Because it is frequently associated with humanized infrastructures, accidental introductions into new areas have been reported, such as into most Mediterranean islands, Madeira, South America, the United States, and the Azores archipelago. Surprisingly, all introduced individuals belong to the same mitochondrial clade, known as the European clade, suggesting that the animals from this group are more prone to be introduced and also more successful in colonizing distinct environments. Following a multidisciplinary approach under genetic, ecophysiological and niche evolution frameworks, we intend to uncover the phenotypic attributes of this species that allows them to be such a successful colonizer. The lack of morphologically diagnosable characters typical of cryptic species poses a particular problem to taxonomists. Phylogenetic studies on the Moorish gecko uncovered extremely high levels of mtDNA diversity with six identified clades. Because of the conserved morphology of this species and lack of monophyly relative to T. angustimentalis, it has been suggested that T. mauritanica is a cryptic species complex that originated around 6 Mya. The recent addition of novel genetic markers and Bayesian coalescent species delimitation analysis support all six mitochondrial clades as “unconfirmed candidate species”, pending morphological data to define them. The quantification of realized niche overlap and the integration of species distribution models (SDMs) with calibrated phylogenies to study niche evolution are becoming powerful tools to understand speciation events. Our results suggest that diversification within T. mauritanica during the Miocene and Pleistocene is associated with both niche divergence and niche conservatism, related to temperature and humidity. Specifically, our ecophysiological experimental studies suggest that individuals from European populations display a trend for higher water loss, but higher variance compared with the Iberian populations. The detection of a phylogenetic signal suggests divergent evolutionary responses to the environment, which may account for the differences in their range expansion