Refugia in Patagonian fjords and the eastern Andes during the Last Glacial Maximum revealed by huemul (Hippocamelus bisulcus) phylogeographical patterns and genetic diversity

Abstract

Aim Our aim was to determine the combined impacts of Pleistocene climatic oscillations and glacial periods with recognized biogeographical barriers on the evolutionary history of huemul deer (Hippocamelus bisulcus). Location Southern Chile and Argentina's Andean forest, and Patagonian fjords. Methods We examined the phylogeography of huemul using 772 bp of the mitochondrial DNA control region sequence from 275 samples (29 locations) collected throughout the distributional range of the species. We grouped samples into clusters based on Bayesian genetic and spatial structure analyses and reconstructed the species' phylogeographical and demographic history. Results We observed 63 haplotypes that grouped into three clusters (Central Chile, North Patagonia and South Patagonia). All but five haplotypes in North and South Patagonia were distributed locally. Bayesian skyline plots showed that population sizes remained fairly constant until an increase during and after the Last Glacial Maximum. Genetic diversity was generally low, except in three populations in the eastern Andes and on Wellington Island (Patagonian fjords). Main conclusions Our results suggest that the biogeographical separation of huemul into phylogeographical groups has been heavily influenced by Pleistocene glacial stages, and more recently by habitat fragmentation and isolation. This provides the first evidence that the region west of the Cordilleran ice field was a refugium for at least one species of large mammal during the Pleistocene in southern South America. These results have direct implications for the conservation and management of this endangered deer species.

Tabula rasa in the Patagonian Channels II: The cushion peat bog species Astelia pumila (Asteliaceae) and Donatia fascicularis (Stylidiaceae) survived the last glacial in south‐central Chile

“…If several independent refugia had existed, distinct geographical patterns for individual alleles and genetic clusters would likely result. This is the case for several (but not all) previously studied taxa from West and Andean Patagonia ( Hippocamelus bisulcus , Marín et al., ; Oreobolus obtusangulus , Pfanzelt et al., ) and the Patagonian steppe (Patagonian‐Fueguian rodents, Lessa et al., ; Anarthrophyllum desideratum , Cosacov et al., ). Often, phylogeographic discontinuities are shared among taxa.…”

“…An endemic frog species of West Patagonian Nothofagus forests, Eupsophus calcaratus, persisted the last glacial on Guafo Island, also located at the outermost margin of the ice, off the southwestern coast of Chiloé (Nuñez, Wood, Rabanal, Fontanella, & Sites, 2011). Cold-stage survival within the Patagonian Channels was postulated for otter (Vianna et al, 2011) and deer (Marín et al, 2013) and, in continental northern Patagonia, for the freshwater crab Aegla alacalufi, whose persistence was facilitated by geothermal activity (Xu, Pérez-Losada, Jara, & Crandall, 2009). Other authors discussed the possibility of forest refugia along the western coast, based on rapid forest expansion following deglaciation (Haberle & Bennett, 2004) and the presence of flightless forest beetles in the basalmost strata of peat cores (Ashworth, Markgraf, & Villagrán, 1991).…”

Tabula rasa in the Patagonian Channels? The phylogeography of Oreobolus obtusangulus (Cyperaceae)

“…Considering the large amount of data and the very low frequency of weak candidate alleles, in situ survival of the Estero Bachem population seems highly unlikely. Note, however, that similar molecular data from deer and otter in that region were interpreted as evidence for refugia (Marín et al., ; Vianna et al., ).…”

“…For the South Andean deer species Hippocamelus bisulcus Molina, 1782, Marín et al. () postulated two major refugia, one of them in the central Patagonian Channel region. In summary, the existing evidence points towards in situ survival of some organisms but the picture is far from being resolved, especially for plants.…”

Interpretation of Plasma Selenium Data in Huemul: Response to Flueck et al

“…It is important to consider that the data provided by Chihuailaf et al (2014) only suggest a condition that should be further investigated. After all, huemul have survived since the Pleistocene (Marín et al 2013) in habitats dominated by volcanic soils lacking in Se (reviewed by Chihuailaf et al 2014).…”