Mammalian biogeography of Patagonia and Tierra del Fuego

LESSA, E.; D'ELÍA, G.; PARDIÑAS, U.F.J.

Bones, clones, and biomes: The History and Geography of Recent Neotropical mammals

The University of Chicago Press

Año: 2012; p. 379 - 398

The Patagonian-Fuegian region, located in southern South America roughly south of 40¡ÆS,comprises areas of Argentinean Monte, Patagonian Steppe and Grasslands, and Valdiviantemperate and Magellanic subpolar forests. Although the area was aff ected by the glacialcycles of the Neogene, glacial sheets were typically much more limited in South Americathan in northern continents. In this context, we review distributional, phylogenetic, phylogeographic,and population genetic information on the composition and historical biogeographyof mammals in the region. Although many species are likely relatively recentcolonizers of the region, distributional and phylogenetic data provide several examples ofendemic species and others that likely resulted from local diversifi cation. Phylogeographicanalyses provide additional indications of diff erentiation within the region. Phylogeographicbreaks divide species distributions by latitude rather than between major habitats.Population genetic analyses reveal several cases of demographic expansion, all of whichcan be assigned to the late Pleistocene (i.e., the last 500,000 years). However, very fewof these can be attributed to events postdating the Last Glacial Maximum (¡21,000 BP). Overall, the current mammalian fauna of Patagonia and Tierra del Fuego is the resultof a complex mix of local fragmentation, diff erentiation, and colonization from lowerlatitudes.