Name: Sousa F

Biodeserts supervisors: Boratyński Z, Brito JC

Title: Biogeography and phylogenetic position of a Sahara-Sahel mountain endemic, Felovia vae (Ctenodactylidae)

Institution: University of Porto

Status: Completed

 

Abstract

The Sahara-Sahel is composed of a mosaic of habitats, mountains, seasonal rivers, sandy and rocky areas, that can define both species distribution and within species genetic structure. These variables were strongly shaped by the Pleistocene climatic oscillations, and such effects can be often assessed through species genetic variation patterns. Rodents of the Ctenodactylidae family are typical inhabitants of the mountains ranges and rocky outcrops across North Africa, and therefore a suitable model for testing these climatic effects. We use an endemic species from North West Africa, Felovia vae, in combination with all four extant Ctenodactylidae family members, to conduct a detailed biogeographical study by combining genetic structure and ecological niche-based modeling. Sequences obtained for the partial cytochrome b (mtDNA) and growth hormone factor receptor genes (nDNA) were analyzed using phylogenetic and population genetic methods. Topoclimatic factors related to the occurrence of Felovia vae were identified for the present conditions and projected into the past (Mid-Holocene, Last Glacial Maximum and Last Interglacial). Results showed: 1) diversification events of the family occurred during Miocene, with Pectinator genus being a basal clade for the family, while Massoutiera being more closely related with Ctenodactylus than with Felovia, opposite to what have previous morphological studies suggested; 2) five Felovia vae genetic clades were identified, corresponding mostly to distinct mountain massifs, suggesting an important role of external geographical barriers, associated with Pleistocene climatic fluctuations, in explaining the phylogeographical patterns observed; 3) Dry and wide sandy valleys and permanent rivers are important barriers, during dry and humid periods respectively, but savannah like habitats might have dissolved these barriers during particular climatic periods; 4) species demographic expansions seems to be related with more humid periods (Last Interglacial), while arid phases (Present, Mid-Holocene and Last Glacial Maximum) restricted the species distribution to mountains; 5) the observed pattern for Felovia vae is congruent with limited biogeographical knowledge of other vertebrates from the region. This study highlight past connectivity between putatively isolated contemporary populations, suggesting dynamic history of the regional biota shaped by Sahara-Sahel climatic fluctuations. Moreover, information about this species biology is still very limited (IUCN DD status) making it potentially vulnerable to habitat alteration, given its strict habitat specialization to rocky patches with higher inclinations and the presence of gueltas.