Geologic and Climate Factors Affecting Fish Speciation, Lauca River, South American Altiplano

Dr. Barry Keller

Dr. Barry Keller, PG, CHG
Wednesday, November 16th, 2016
CSL – 422, 1 pm


The South America Altiplano is a flat, internally drained area at 3500 m elevation and higher. In late Pleistocene, large lakes filled much of the area, but have since dried, leaving isolated lakes and playas. Endemic fish species, particularly the killifish Orestias, have been isolated during this drying and due to geologic influences, and have developed into new species.  Lauca River drains the highest part of this area, with headwaters on the flank of Parinacota Volcano (6342 m). A catastrophic collapse of Parinacota at 8.8 Ka formed avalanche deposits that fragmented a previously existing lake into separated surface water bodies, connected by groundwater, in which new species have developed.