The superior performance of Sherpa guides on Mountain Everest is legendary. New findings reveal how their bodies make the most of low oxygen levels at high altitude.

Presenter Gareth Mitchell also talks to the Mexican biologist heading a last ditch attempt to save the world's most endangered marine mammal - a small porpoise called vaquita. There are fewer than 30 animals left, all of them in the Gulf of California. The plan is to capture up to half of them and move them to a safe haven in the Gulf, away from the illegal fishing nets that have been trapping and drowning them. Key players in the plan are US Navy dolphins, trained to find and follow the vaquitas so the scientists can catch and move them. The idea is to keep the porpoises in a protected bay until the illegal fishing threat has been tackled.

Also in the programme, white hot lavas and reporter Roland Pease asks whether quantum computing is finally coming of age.