Biography:

Beatriz Aguirre-Urreta got her degree in Biology in 1978 and her Ph.D. in 1982, both at the Faculty of Exact and Natural Sciences, University of Buenos Aires. She spent a year as a postdoctoral fellow at the South African Museum in Cape Town, South Africa in 1983. She also stayed as an external researcher at University College London, United Kingdom in 1988. Her main research is focused on Cretaceous ammonoid systematics, biostratigraphy, and paleobiogeography. Her interest on Darwin was born while working in the High Cordillera of Mendoza, following Darwins footsteps across the Andes. She is author of numerous articles specially focused in the ammonoids of the Cretaceous basins of southern South America. She has just edited a special issue of the Revista de la Asociacin Geolgica Argentina devoted to Darwin research in Argentina that has been released on February 12, 2009 honoring Darwins 200 anniversary. Her present position is Full Professor in Paleontology, Department of Geological Sciences, University of Buenos Aires and Principal researcher at CONICET (Argentine National Agency for Scientific Research).

Abstract:

Darwins research in Argentina: its influence in the building of his scientific theory

During the famous voyage around the world on board HMS Beagle, Charles Darwin spent nearly three years, between August 1832 and April 1835, visiting and studying different regions of the Argentine territory. In several opportunities Darwin spent considerable time on land, riding across the Pampas, exploring upstream the Ro Santa Cruz in Patagonia and crossing the Andes by two different passes. He also had many occasions to land at selected points along the Atlantic coast for days or even for a few hours. Darwin saw certain facts in the distribution of the inhabitants of southern South America that throw some light on the origin of species. One of these facts was the replacement of extinct species by modern ones. This was based on his collection of large extinct animals as the giant glyptodonts obviously closely similar to the living armadillos. Both groups are edentate mammals which are only found in America. Another piece of evidence was that closely similar species tend to replace each other over broad expanses of mainland South America. Darwin was puzzled by the distribution of two different species of Rhea, a kind of American ostrich, the replacement of the common rhea (and) by the lesser rhea (and petiso) in more southerly stretches of Argentina. His observations on the faunas, the geology and paleontology of the diverse regions of Argentina where he stayed, were the germ of his ideas on the transmutation of the species, well in advance of his few weeks visit to the Galpagos Islands.