North Korea Bomb Tests, Warming Antarctic Sea Life, the Microbiome, Cuckoo Chuckle

The Democratic People's Republic of Korea claims to have successfully tested a thermonuclear weapon, a hydrogen bomb. Tom Plant, director of Proliferation and Nuclear Policy at the Royal United Services Institute, talks to Adam Rutherford about how the boast might be proved by monitoring technology around the world.

How will marine life respond to warming of the seas around Antarctica this century? Dramatically, according to the results of the most realistic attempt so far to warm the sea bed to temperatures predicted for the coming decades. The British Antarctic Survey installed gently heated panels at 12 metres depth off the West Antarctic coast to mimic rock surfaces and then over 9 months monitored how marine creatures colonised and grew on them. All creatures flourished on panels at 1 degree C above today's chilly waters and in fact grew astonishingly quickly on them. But a 2 degree increase saw some continue to flourish vigorously but many species fail. Experiment mastermind Lloyd Peck tells Adam what the findings may mean, and describes the extraordinary cold water diving skills that made the experiment a success.

'I contain Multitudes' is shortlisted for the Royal Society Insight Investment Science Book Prize this year. Its subject is the microbiome - the trillions of benign , friendly and not so friendly bacteria which inhabit our bodies and those of all other animals.

For 30 years, Cambridge University zoologists have studied the evolutionary arms race between the cuckoo and the reed warbler that rears the cheating bird's offspring. They have figured out many of the deceptions and counter-tactics adopted by the two co-evolving species. The latest revelation concerns the strange chuckling call which the female cuckoo makes after laying her egg in the warbler's nest. Jenny York describes the experiments which show that the cuckoo is mimicking a predatory sparrow hawk which distracts the warblers and makes them much more likely to not recognise her egg as something they should reject from the nest.