Lee Evans (pictured), Yuan Longping, Bill McCall, Alix Dobkin

Matthew Bannister on Lee Evans, the world-record-breaking American sprinter who took part in black power protests at the 1968 Mexico Olympics.Yuan Longping, the plant scientist who developed hybrid varieties of rice that increased yields dramatically and so saved millions from hunger.Bill McCall, the General Secretary of the Institution of Professional Civil Servants who challenged Margaret Thatcher over union recognition at GCHQ.Alix Dobkin, the folk singer and lesbian activist who performed to women-only audiences. Producer: Neil GeorgeInterviewed guest: Tommie Smith Interviewed guest: Professor Douglas Hartmann Interviewed guest: Keith Bradsher Interviewed guest: Charles Harvey Interviewed guest: Liza CowanArchive clips used: Athletics_400 Metres Final: BBC One, TX 18.10.1968; A Classless Civil Service: Radio 3, TX 10.7.1968; BBC News: BBC One, TX 28.2.1984