Fog of Ignorance
Exactly how much life is there on earth?
Mathematician Bob May would like to find out. He calculates that there may be 30 million insect species but we've identified fewer than two million. As tropical forests burn, how many species will we lose before we find them?
Spare Parts
Transplant surgery is a modern-day medical miracle. But, as the recent British 'kidneys for sale' scandal revealed, there is a shortage of donated organs. Zach Richter , a journalist and kidney patient, tracks the international trade - from the European organ broker offering to buy kidneys from living donors to prisoners in the Philippines willing to offer him their kidneys in return for the hope of reduced sentences. Is transplant technology running ahead of our ability to control it? Producers Martin Freeth and Ilan Ziv
Editor Jana Bennett (R)