Retracing the evolutionary history of Nothofagus in its geo‐climatic context: new developments in the emerging field of phylogeology

• Published in: Geobiology
• Main Authors: Acosta, M. C., Mathiasen, P., Premoli, A. C.
• Other Authors: Agencia de Promoción Científica y Tecnológica, Consejo Nacional de Investigaciones Científicas y Técnicas de Argentina, Universidad Nacional del Comahue
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2014
• Subjects: Antarc*; Antarctica
• Online Access: http://dx.doi.org/10.1111/gbi.12098; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fgbi.12098; https://onlinelibrary.wiley.com/doi/pdf/10.1111/gbi.12098

Abstract Phylogeographic studies have made a significant contribution to the interpretation of genetic lineage distribution in response to climate changes, such as during glaciation events of the Neogene. However, the effects of ancient landscapes associated with global sea level rises, tectonic processes, and climatology driving lineage evolution have been largely overlooked. These effects can be tested in widespread lineages of cold‐tolerant species that have endured cooling, and thus, phylogeographic patterns may reflect large‐scale processes that were not reset by the ice ages. We hereby combine geological evidence from marine sedimentary basins, Andean orogeny, and climatology with molecular dating and statistical phylogeography to infer how geological and climatic processes affected the distribution of lineages in cold‐tolerant N othofagus species during the C enozoic. A total of 239 populations along the entire range of all species within the genus N othofagus ( N . antarctica , N . betuloides , N . dombeyi , N . nitida , and N . pumilio ) were sampled and analyzed by sequencing three non‐coding regions of the chloroplast. We found 30 chloroplast DNA haplotypes that were geographically structured. Molecular dating calibrated with fossils revealed that ancestral lineages appeared in E ocene/ O ligocene, whereas most divergences took place during the M iocene; in turn, B ayesian skyline plots showed that population expansion occurred in the E arly P leistocene (1.5–1 million years ago). Lineage divergence from all wide‐ranging N othofagus was spatially and temporally concordant with episodic marine transgressions and warmer times in P atagonia during E ocene/ M iocene E pochs. Long‐lasting stable raised areas preserved haplotype diversity throughout P atagonia, from where cold‐tolerant taxa expanded their ranges during pre‐ Q uaternary times. The detailed study of such ancient divergences is novel and allows us to infer the effects of geological processes on distribution patterns of ancient lineages, that ...