Radio 4 tonight at 9pm. You can hear it again by going to BBC Radio 4 website and downloading it. Great stuff - guy in Siberia is restocking huge area with herbivores and predators. Uses a tank to smash down trees to replicate the disturbance formerly done by mammoths in order to provide churned soil for plant growth. He has access to many frozen mammoth bodies and hopes to bring them (and wooly rhinos) back from their DNA!
