LiveScience: he modern ecosystem of icy Antarctica is some 33.6 million years old, new research finds, with a system dating back to the formation of the polar ice caps. The date is revealed by fossilized remnants of plankton found in Antarctic sediments, which show how plankton diversity plummeted when a big chill came along at the end of the Eocene Epoch and the beginning of the Oligocene Epoch. Before the transition, Earth was a toastier place, and a wide array of plankton survived even at the poles. The...