We investigated the population dynamics of a highly clonal marine angiosperm, Cymodocea nodosa, in the eastern Mediterranean Sea, to identify the historical dy-namics, demography, and connectivity of the species in the area. Eighteen microsatel-lite loci were used in conjunction with coalescent methods to investigate the genetic structure and demographic history of C. nodosa meadows. Approximate Bayesian computation (ABC) modeling was used to examine the pattern of divergence over time in the context of environmental change over the course of the Quaternary period. ABC analysis revealed an initial split of the C. nodosa populations between the north-western, northern, and north-eastern Aegean Sea during the Pleistocene epoch, followed by a more recent divergence of the north-western population and the central-western part of the Aegean Sea. According to the results, the most parsimo-nious historical scenario is that of a pervasive genetic signature of the effects of the drop in sea level during the Pleistocene epoch. This scenario supports the isolation of the north-western, north, and north-eastern area, and the subsequent recolonization after post- glaciation sea level rise that may explain the north-western differentiation as well present-day detected dispersion of C. nodosa.
This research has been co-financed by the European Union (European Social Fund – ESF) and Greek national funds through the Operational Program "Education and Lifelong Learning" of the National Strategic Reference Framework (NSRF) - Research Funding Program: THALES. The authors would like to thank M. Malandrakis and A. Lolas for their contribution to sampling.
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- Mediterranean Sea
- Population structure
- Cymodocea nodosa
- sea level rise