Marcelo Aizen graduated in Biology at the Universidad de Buenos Aires in 1985 and obtained his Ph.D. at the University of Massachusetts in 1992. At present, he is Investigador Superior of CONICET (the National Research Council of Argentina) and Profesor Titular at the Ecology Department of the Universidad Nacional del Comahue in Bariloche. His research has focused on a diversity of basic and applied topics in plant reproductive ecology and plant-pollinator interactions, from the study of pollen tube-pistil interactions to global assessment of pollinator declines and the so-called pollination crisis. He is the author of more than 170 articles. Some of his research has been published in journals such as Science, Nature, PNAS, PloS Biology, and Current Biology. In the last few years, he and his group have been studying the consequences of the invasion of the buff-tailed bumblebee (Bombus terrestris) on the native biota of Patagonia and of invasive bees, in general, on agriculture.