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Mitochondrial DNA evolution and population history of the Tenerife skink Chalcides viridanus

School of Biological & Earth Sciences, Liverpool John Moores University, UK.
Molecular Ecology (Impact Factor: 6.49). 09/2000; 9(8):1061-7. DOI: 10.1046/j.1365-294x.2000.00962.x
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ABSTRACT Recent studies of island lizards have suggested that historical vicariance as a result of volcanism may have played an important role in shaping patterns of within-island genetic diversity. The skink, Chalcides viridanus, shows variation in morphology within the volcanic island of Tenerife. Two mitochondrial DNA (mtDNA) fragments (from the 12S and 16S rRNA regions) were sequenced in individuals from 17 sites to evaluate the relationship between current phylogeography and the geological history of the island. Three main clades were detected. The two most basal clades were restricted to areas representing the ancient precursor islands of Teno and Anaga in the northwest and northeast of Tenerife, respectively. The third clade showed a widespread geographical distribution and provided evidence of a recent rapid expansion after a bottleneck. Within-island cladogenesis appears to have taken place during a recent period of volcanic activity and long after the ancient islands had been united by the eruptions that led to the formation of the Canadas edifice. Evidence of similar biogeographical histories are found in other species in the Canary archipelago, supporting the volcanism scenario as a potentially widespread cause of within-island differentiation in reptiles.

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    • "Alternatively, Anaga's eastern and western populations may have different origins, with the former populations being formed by the original local individuals and the latter being the result of colonizations from central Tenerife (see following paragraphs). Evidence for phylogeographic structure associated with Tenerife's precursor islands has been found in the gecko Tarentola delalandii (Gübitz et al. 2000), the skink Chalcides viridanus (Brown et al. 2000), the lizard G. galloti (Thorpe et al. 1996), and a species complex within the darkling beetle Pimelia (Juan et al. 1996). For G. galloti and Pimelia, the Anaga populations are the most divergent, whereas the Teno and South populations are closely related or undifferentiated. "
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    • "We used individuals that had been collected for previous research projects (e.g., Pestano and Brown 1999; Brown et al. 2000); see Brown and Pestano (1998) for more information and La Gomera-El Hierro divergence. One individual was used from each site, unless otherwise stated: "
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    • " , 2000 ; Moya et al . , 2004 ) . Thus , it is also possible that later within - island vicariance has caused the pattern . The Gu¨ı´mar valley was massively affected by a landslide approximately 0 . 8 My ago , which is thought to have fragmented the ranges of the Gallotia lizards ( 0 . 8 My ; Brown et al . , 2006 ) , Chalcides skinks ( 1 . 1 My ; Brown et al . , 2000 ) and Eutrichopus beetles ( 0 . 7 My ; Moya et al . , 2004 ) . This would correspond to the pattern found in Arminda , where the branches of the five westernmost taxa have approximately the same length ( note that El Hierro is approximately 1 . 2 My old ) . It is reasonable to suggest that unvegetated young lava flows represent strong b"
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