PHYLOGEOLOGY - GENES SPEAK FOR HISTORY: THE CASE OF NOTHOFAGUS

MATHIASEN, P.; ACOSTA, M.C.; PREMOLI, A.C.

Punta Arenas

Congreso; VIII Southern Connection Congress; 2016

The distribution of genetic patterns within a landscape is the result of complex processes occurring at different timescales. Phylogeographic studies have made a significant contribution to the interpretation of genetic lineage distribution in response to recent climate changes (such as glaciation events of theNeogene). However, the effects of ancient tectonic processes and climatology driving lineage evolution have been largely overlooked. Phylogeology is an emerging field, as the study of the geographic distribution of ancient lineages to infer the effects of geological processes. These effects can be tested in widespread lineages of cold-tolerant species that have endured cooling. 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 geneticlineages in cold-tolerant Nothofagus species. Samples of the entire range of all five species within the genus Nothofagus were analyzed by sequencing three cDNA non-coding regions. We found 30 haplotypes that were geographically structured. Fossil calibrated molecular dating revealed that ancestral lineagesappeared by the Eocene/Oligocene, whereas most divergences took place during the Miocene; and posterior population expansion occurred in the Early Pleistocene (1.5?1 Ma). Lineage divergence from all wide-ranging Nothofagus was spatially and temporally concordant with episodic marine transgressions and warmer times in Patagonia during Eocene/Miocene Epochs. Long-lasting stable raised areas preserved haplotype diversity throughout Patagonia, from where cold-tolerant taxa expanded their ranges during preQuaternary times. (Sponsored by PICT 2012-0688, PICT 2013-2404, PIP 2013-646)