Why do societies fail? With lessons from the Norse of Iron Age Greenland, deforested Easter Island and present-day Montana, Jared Diamond talks about the signs that collapse.<br /><br /> Civil wars and ethnic conflicts have brought the world incredible suffering, but Stefan Wolff's figures show that, in the last 20 years, their number has steadily decreased..<br /><br /> Strange landscapes, scorching heat and (sometimes) mad crocodiles await scientists seeking clues to evolution's genius. Paleontologist Paul Sereno talks about his surprising.
