How lizards survived blizzards: phylogeography of the Liolaemus lineomaculatus group (Liolaemidae) reveals multiple breaks and refugia in southern Patagonia, and their concordance with other co-distributed taxa

BREITMAN, M.F.; AVILA, L.J.; SITES, J.W., JR.; MORANDO, M.

MOLECULAR ECOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2012 vol. 21 p. 6068 - 6085

0962-1083

Patagonia was shaped by a complex geological history, including the Miocene uplift of theAndes, followed by volcanism, marine introgressions, and extreme climatic oscillations during Pliocene-Pleistocene glaciation?deglaciation cycles. The distributional patterns and phylogenetic relationships of southern patagonian animals and plants were affected in different ways, and those imprints are reflected in the seven phylogeographic breaks and eight refugia that have been previously proposed. In this study we estimated time-calibrated phylogenetic/phylogeographic patterns in lizards of the Liolaemus lineomaculatus group, and relate them to historical Miocene-to-Pleistocene events of Patagonia and the previously proposed phylogeographic patterns. Individuals from 51 localities were sequenced for the mitochondrial marker (cyt-b) and a sub-sample of individuals from each mitochondrial lineage was sequenced for one nuclear (LDA12D) and one slow evolving mitochondrial gene (12S). Our analyses revealed strong phylogeographic structure among lineages and, in most cases, no signal of demographic changes through time. The lineomaculatus group is composed of three strongly supported clades (lineomaculatus, hatcheri and (kolengh+silvanae), and divergence estimates suggested their origins associated with the oldest known Patagonian glaciation (7-5 Ma); subsequent diversification within the lineomaculatus clade coincided with the large Pliocene glaciations (~3.5 Ma). The lineomaculatus clade includes nine strongly genetically and geographically structured lineages, five of which are interpreted as candidate species. Our findings suggest that some Liolaemus lineages have persisted in situ, each of them in a different refugium, through several glaciation-deglaciation cycles without demographic fluctuations. We also summarize and update qualitative evidence of some shared phylogeographic breaks and  refugia among plants, rodents and lizards.