In the Pyrenees, we also observe numerous species with more than one genetic
lineage within these mountains. However, the most often observed number of
different lineages in animals and plants found here is two (e.g. Kropf et al. 2002,
2003; Schmitt et al. 2006; Lauga et al. 2009), translating into only two glacial
refugia (and differentiation centres) in close proximity to the Pyrenees and not four
as in the much bigger Alps. Higher numbers of different lineages in the Pyrenees
Fig. 3.2 Genetic structures in the Alps. a The most common pattern of genetic differentiation in
the Alps is one of the four different lineages. b However, a reduction of this pattern, e.g. to just two
lineages, is frequently observed. Maps based on Google Maps
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T. Schmitt