The title of this week’s new Nature installment is anything but hyperbole. Sudan, pictured here, is the very last male Northern White Rhinoceros known to exist on the planet. (There’s a mother-daughter pair, but neither can raise young.) Sudan is 43 years old, with an ancestry that goes back five million years – and teams of biologists, zoologists and other scientists are searching frantically for a way to prolong the species while caring for Sudan. Check local listings.