Lenin expounds in Petrograd the new theory of his April Theses, predicting the possibility of imminent revolution

In Alexander Blok's poem The Twelve, Christ leads his apostles in support of Russia's revolution

H.L. Mencken's The American Language traces the gradual evolution of American from English

A vast crowd, assembling in Berlin, calls for a revolution and begins to seize public buildings

Ten years of violent revolution in Mexico are brought to and end in a successful coup by Alvaro Obregón

The Soviet director Sergei Eisenstein completes his film about the 1905 revolution, The Battleship Potemkin

Biology teacher John Scopes is prosecuted for breaking state law by teaching evolution to his class of children in Dayton, Tennessee

Alvaro Obregón, the leading figure in Mexico's anti-clerical revolution, is shot by a Roman Catholic assassin

Plutarco Calles establishes the National Revolutionary Party that will hold power in Mexico, under different names, for the rest of the century

On his first expedition to the Olduvai Gorge, Louis Leakey finds the oldest object now in the British Museum - the chopping tool from about 1.8 million years ago

Conflicting theories about evolution begin to be brought together by scientists to establish an agreed account, which becomes known as the Modern Evolutionary Synthesis

In To the Finland Station Edmund Wilson discusses the development of socialism and revolution, culminating in Lenin and Trotsky

Aung San and some revolutionary colleagues (the Thirty Comrades) receive military training in Japan, aiming to evict the British from Burma

An uprising in Guatemala brings in a revolutionary junta and a left-wing programme of reform

A left-wing coup brings Paz Estenssoro to power and launches a 12-year revolution in Bolivia

In Syntactic Structures Noam Chomsky proposes the revolutionary theory that humans inherit an innate universal grammar

Mary Leakey finds in the Olduvai Gorge the first specimen of a new hominid species, now known as Australopithecus Boisei

The Quiet Revolution in Quebec begins with the election of Jean Lesage and the Liberals

A gene-centred view of evolution develops – and is brilliantly described in 1976, at a popular level, by Richard Dawkins in his book The Selfish Gene

Communist leaders Liu Shaoqi and Deng Xiaoping are attacked in China's Cultural Revolution as the biggest and worst 'capitalist roaders'

Mao Zedong unleashes China's teenagers as violent Red Guards to spearhead his Great Proletarian Cultural Revolution

Che Guevara arrives in Bolivia in the hope of fomenting a left-wing revolution

Cuban revolutionary Che Guevara is captured and executed in Bolivia

Peter Nzube finds the oldest skull yet discovered in the Olduvai Gorge and names the specimen Twiggy, after the British fashion model of the time

Motoo Kimura proposes the neutral theory of molecular evolution, arguing that molecular changes are caused not by natural selection but by random genetic drift