Current perspectives in phylogeography and the significance of South European refugia in the creation and maintenance of European biodiversity

Abstract

This contribution briefly summarizes the current state of phylogeography and its significance in evolutionary research, particularly involving organisms existing in southern European refugia. These refugia, characterized by a highly heterogeneous landscape, harbor a large percentage of Europe's organismal diversity. They are also shown to offer model systems where the long-term dynamics of particular evolutionary phenomena can be fruitfully explored within well-defined phylogeographic contexts. It is suggested, for example, that the dynamics of gene-flow and natural selection in hybrid zones within long-term glacial refugia are much more complex than those in previously glaciated regions. Emphasis in this review is also given to the breadth of available analytical approaches to phylogeographic analysis, including current controversies and ongoing developments such as the aim to better integrate coalescent theory and both large(geographic) and small scale (landscape) environmental variables. Despite different schools of thought on how to approach phylogeographic analysis, a plea is made to maintain pluralism when dealing with such complex, multi-disciplinary and stochastically influenced data sets. In summary, phylogeography is shown to be a highly successful and popular field of inquiry with a high potential for growth, especially as cutting edge analytical and genomic-oriented techniques, often developed within the field of human genetics, are applied across broader taxonomic scales.