Browsing by Author "Barata, M."
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- Comparative phylogeography of northwest African Natrix maura (Serpentes: Colubridae) inferred from mtDNA sequencesPublication . Barata, M.; Harris, D. J.; Castilho, RitaWhile the comparative phylogeography of European fauna is relatively well understood, with Pleistocene climatic oscillations leading to ‘southern refugia’ for many species, the equivalent pattern has not been determined for North Africa. In this context variation within North African populations of the riverine snake Natrix maura were assessed using mitochondrial DNA sequences. Recent literature regarding North African phylogeographic studies of reptiles was compiled, and several surprising patterns emerged. The most interesting was the extensive movement of species across the Strait of Gibraltar during the Pleistocene. Another is the general pattern of deep genetic divergences between Tunisian and Moroccan populations, often at a level implying the existence of cryptic species. Natrix maura has three distinct lineages in North Africa, however, it apparently did not cross the Strait of Gibraltar during the Pleistocene, but probably did so during the Messinian salinity crisis.
- Impact of mountain chains, sea straits and peripheral populations on genetic and taxonomic structure of a freshwater turtle, Mauremys leprosa (Reptilia, Testudines, Geoemydidae)Publication . Fritz, U.; Barata, M.; Busack, S. D.; Fritzsch, G.; Castilho, RitaMauremys leprosa, distributed in Iberia and North-west Africa, contains two major clades of mtDNA haplotypes. Clade A occurs in Portugal, Spain and Morocco north of the Atlas Mountains. Clade B occurs south of the Atlas Mountains in Morocco and north of the Atlas Mountains in eastern Algeria and Tunisia. However, we recorded a single individual containing a clade B haplotype in Morocco from north of the Atlas Mountains. This could indicate gene flow between both clades. The phylogenetically most distinct clade A haplotypes are confined to Morocco, suggesting both clades originated in North Africa. Extensive diversity within clade A in south-western Iberia argues for a glacial refuge located there. Other regions of the Iberian Peninsula, displaying distinctly lower haplotype diversities, were recolonized from within south-western Iberia. Most populations in Portugal, Spain and northern Morocco contain the most common clade A haplotype, indicating dispersal from the south-western Iberian refuge, gene flow across the Strait of Gibraltar, and reinvasion of Morocco by terrapins originating in south-western Iberia. This hypothesis is consistent with demographic analyses, suggesting rapid clade A population increase while clade B is represented by stationary, fragmented populations. We recommend the eight, morphologically weakly diagnosable, subspecies of M. leprosa be reduced to two, reflecting major mtDNA clades: Mauremys l. leprosa (Iberian Peninsula and northern Morocco) and M. l. saharica (southern Morocco, eastern Algeria and Tunisia). Peripheral populations could play an important role in evolution of M. leprosa because we found endemic haplotypes in populations along the northern and southern range borders. Previous investigations in another western Palearctic freshwater turtle (Emys orbicularis) discovered similar differentiation of peripheral populations, and phylogeographies of Emys orbicularis and Mauremys rivulata underline the barrier status of mountain chains, in contrast to sea straits, suggesting common patterns for western Palearctic freshwater turtles.
- Variation within North African natrix maura (Serpentes: Colubridae) inferred from mtDNA sequences: comparative phylogeography of Magrehbian reptilesPublication . Barata, M.; Harris, D. J.; Castilho, RitaWhile the comparative phylogeography of European fauna is relatively well understood, with Pleistocene climatic oscillations leading to ‘southern refugia’ for many species, the equivalent pattern has not been determined for North Africa. In this context variation within North African populations of the riverine snake Natrix maura were assessed using mitochondrial DNA sequences. Recent literature regarding North African phylogeographic studies of reptiles was compiled, and several surprising patterns emerged. The most interesting was the extensive movement of species across the Strait of Gibraltar during the Pleistocene. Another is the general pattern of deep genetic divergences between Tunisian and Moroccan populations, often at a level implying the existence of cryptic species. Natrix maura has three distinct lineages in North Africa, however, it apparently did not cross the Strait of Gibraltar during the Pleistocene, but probably did so during the Messinian salinity crisis.