One of the most puzzling questions in modern human origins has been why the dispersal of modern Homo sapiens out of Africa was so delayed after their first appearance in East African fossil record near ~200 ka (ka, thousands of years ago). Fossil, archaeological, and genetic evidence indicate that Read more about Harvard Climate Seminar
Abstract: We argue for a pervasive link between cold climates and polar ocean stratification. In both the Subarctic North Pacific and the Antarctic Zone of the Southern Ocean, ice ages were marked by low productivity. The accumulated evidence from sediment cores points to an increase in density stratification that reduced the supply of nutrients from the ocean interior into the sunlit surface in both of these regions.The last ice age was associated with stratification of the Antarctic and the Read more about Climate Seminar: "The Polar Oceans during the Ice Ages"