"The Human Revolution" is a term used by archaeologists, anthropologists and other specialists in human origins; it refers to the spectacular and relatively sudden – apparently revolutionary – emergence of language, consciousness and culture in our species. The term came into fashion following a conference on human origins held in the late 1980s, resulting in a 1989 edited volume entitled The Human Revolution, edited by archaeologist Paul Mellars and palaeontologist Chris Stringer. In this early version, the rapid process of change was identified as the so-called 'Upper Palaeolithic Revolution' which occurred in Ice Age Europe around 40,000 years ago, resulting in the displacement of the local Neanderthals by anatomically modern Homo sapiens, with their sophisticated ivory tools, carved figurines and cave paintings. More recently, archaeologists have come to realise that if we can speak of a 'human revolution' at all, it happened tens of thousands of years earlier, in sub-Saharan Africa rather than Europe. This means that the revolution was inseparable from the emergence of modern Homo sapiens in Africa between 150,000 and 200,000 years ago.
From the mid-1990s and as of 2010, archaeological revelations from the African Middle Stone Age have transformed our picture of the timing of symbolic culture's emergence. Until the early 1990s, the prevailing view of the "human revolution" was concerned with Europe and focused on the Upper Palaeolithic Revolution, which was seen as humanity's "Great Leap Forward". Recent discoveries from Africa have made some researchers controversially claim symbolic activity before 40,000 years ago. Researchers diverge in their positions concerning the timeline for symbolic culture's emergence, for example:
1. Francesco D'Errico. Multispecies transition across Africa and Eurasia. Symbolic capacities already in place with Homo heidelbergensis 300,000 – 400,000 years ago. Sporadic behavioural expressions of symbolism among ancestors of both Neanderthals and ourselves.
2. Sally McBrearty and Alison Brooks. African ancestors of modern humans undergo gradual, sporadic build-up of modern cognition and behaviour spanning 300,000 years. Symbolism presents no special theoretical difficulties, emerging as part of the package of modern, flexible, creative behaviours within Africa.
3. Christopher Henshilwood and Ian Watts. The human revolution occurred as part of modern human speciation in Africa. Evidence for symbolism in the form of cosmetics and personal ornamentation is the archaeological signature of this transition. Symbolism was not an optional extra – life following the transition became fundamentally organized through symbols.
4. Richard Klein. Recent interpretations of the African Middle Stone Age record are not conclusive; the original "human revolution" theory remains correct. Middle Stone Age humans evolving in Africa may appear anatomically modern, but did not become cognitively modern until the Later Stone Age/Upper Palaeolithic. Symbolic culture emerged some 50,000 years ago, caused by a genetic mutation that re-wired the brain.