affirming his colleague's hypothesis. A year later, Agassiz raised the hypothesis of a great glacial period that would have had long-reaching general effects. This idea gained him international fame and led to the establishment of the Glacial Theory. In time, thanks to the refinement of geology, it has been demonstrated that there were several periods of glacial advance and retreat and that past temperatures on Earth were very different from today. In particular, the Milankovitch cycles of Milutin Milankovitch are based on the premise that variations in incoming solar radiation are a fundamental factor controlling Earth's climate. During this time, substantial glaciers advanced and retreated over much of North America and Europe, parts of South America and Asia, and all of Antarctica. The Great Lakes formed and giant mammals thrived in parts of North America and Eurasia not covered in ice. These mammals became extinct when the glacial period ended about 11,700 years ago. Modern humans evolved about 315,000 years ago. During the Quaternary Period, mammals, flowering plants, and insects dominated the land. See also List of Quaternary volcanic eruptions Quaternary extinction Quaternary science References External links Subcommission on Quaternary Stratigraphy Stratigraphical charts for the Quaternary Version history of the global Quaternary chronostratigraphical charts (from 2004b) Silva, P.G. C. Zazo, T. Bardají, J. Baena, J. Lario, A. Rosas, J. Van der Made. 2009, "Tabla Cronoestratigrafíca del Cuaternario en la Península Ibérica - V.2". [Versión PDF, 3.6 Mb]. Asociación Española para el Estudio del Cuaternario (AEQUA), Departamento de Geología, Universidad de Salamanca, Spain. (Correlation chart of European Quaternary and cultural stages and fossils) Welcome to the XVIII INQUA-Congress, Bern, 2011 Quaternary (chronostratigraphy scale) Geological periods Physical geography Physical oceanography