Monday, March 3, 2014

SALVI,D.,SCHEMBRI ,P.J., SCIBERRAS,A &HARRIS,J.D.(2014)Evolutionary history of the Maltese wall lizard Podarcis filfolensis: insights on the ‘Expansion–Contraction’ model of Pleistocene biogeography. Molecular Ecology 23: 1167–1187.

Evolutionary history of the Maltese wall lizard Podarcis
filfolensis: insights on the ‘ExpansionContraction’ model
of Pleistocene biogeography

*CIBIO, Centro de Investigac_~ao em Biodiversidade e Recursos Gen_eticos, Campus Agr_ario de Vair~ao, 4485-661 Vair~ao, Portugal,
Department of Biology, University of Malta, Msida MSD2080 Malta, 133, Arnest, Arcade Str., Paola, Malta

The expansioncontraction (EC) model predicts demographic and range contraction of
temperate species during Pleistocene glaciations as a consequence of climate-related
habitat changes, and provides a paradigm for explaining the high intraspecific diversity
found in refugia in terms of long-term demographic stability. However, recent evidence
has revealed a weak predictive power of this model for terrestrial species in
insular and coastal settings. We investigated the Pleistocene EC dynamics and their
evolutionary consequences on temperate species using the Maltese archipelago and its
endemic lizard Podarcis filfolensis as a model system. The evolutionary and demographic
history of P. filfolensis as inferred from mitochondrial and nuclear sequences
data does not conform to the EC model predictions, supporting (i) demographic and
spatial stability or expansion, rather than contraction, of the northern and southern lineages
during the last glacial period; and (ii) a major role for allopatric differentiation
primed by sea-level dynamics, rather than prolonged demographic stability, in the formation
of the observed genetic diversity. When combined with evidence from other
Mediterranean refugia, this study shows how the incorporation of Pleistocene sea-level
variations in the EC model accounts for a reverse demographic and range response of
insular and coastal temperate biotas relative to continental ones. Furthermore, this
cross-archipelago pattern in which allopatric diversity is formed and shaped by EC
cycles resembles that seen between isolated populations within mainland refugia and
suggests that the EC model, originally developed to explain population fluctuations
into and out-of refugia, may be appropriate for describing the demographic and evolutionary
dynamics driving the high genetic diversity observed in these areas.
Keywords: Allopatric divergence, genetic diversity, glacial expansion, historical demography,
Mediterranean islands, phylogeography
Received 31 August 2012; revision received 30 December 2013; accepted 9 January 2014

Because of copyright issues the whole work could not be uploaded in this blog. For further info contact me on