Biologist Lewis Wolpert on the collectivity of cells, Lord Paddy Ashdown on the need for joined up thinking from world leaders, and writer Tahmima Anam on the bitter-sweet power of migrant dreams.
Carl Djerassi on the divorce of sex and reproduction in the 21st Century, Mary Beard discusses Roman jokes and their influence on our sense of humour, Harold Varmus on why the public should have free access to all scientific research.