INVESTIGADORES
ACOSTA Maria Cristina
congresos y reuniones científicas
Título:
Paleolandscape reconstruction based on DNA sequences of widespread Nothofagus
Autor/es:
ACOSTA M. C.; MATHIASEN, P.; PREMOLI, A. C.
Lugar:
Concepción
Reunión:
Congreso; IUFRO Landscape Ecology Conference; 2012
Institución organizadora:
International Union of Forest Research Organizations (IUFRO)
Resumen:
Phylogeographic analysis of widespread South American Nothofagus species in combination with molecular dating and geological data provide the natural setting to reconstruct paleolandscape features and species? distribution patterns, including past population expansions. A total of 156 populations along the entire distribution range of four species of subgenus Nothofagus (N. antarctica, N. betuloides, N. dombeyi, and N. nitida) which grow predominantly in lowland Patagonia were sampled and analyzed by DNA sequences of three non-coding regions of the chloroplast. Twenty eight chloroplast DNA (cpDNA) haplotypes were found that were significantly correlated with geographic distance. Molecular dating on the haplotype phylogeny revealed that most chloroplast variants were shared by all species which date back to Eocene-Miocene and long-lasting paleobasins and marine ingressions impeded transoceanic dispersal. Bayesian skyline plot showed that the lineages of all species suffered a last bottleneck in the limit of Pliocene-Pleistocene, and they expanded after the Great Patagonian Glaciation. These results show that species of subgenus Nothofagus consist of ancient lineages that evolved during Tertiary times and that survived in situ throughout Patagonia.