Secondary products revolution

Andrew Sherratt's model of a secondary products revolution involved a widespread and broadly contemporaneous set of innovations in Old World farming. The use of domestic animals for primary carcass products (meat) was broadened from the 4th-3rd millennia BCE to include exploitation for renewable 'secondary' products: milk, wool, traction (the use of animals to drag ploughs in agriculture), riding and pack transport.

The SPR model incorporates two key elements:

Many of these innovations first appeared in the Near East during the fourth millennium BCE and spread to Europe and the rest of Asia soon afterwards. They appeared in Europe by the beginning of the third millennium BCE. These innovations became available in Europe due to the westwards diffusion of new species (horse, donkey), breeds (e.g. woolly sheep), technology (wheel, ard) and technological knowledge (e.g. ploughing). Their adoption can be understood in terms of pastoralism, plough agriculture and animal-based transport facilitating marginal agricultural colonisation and settlement nucleation. Ultimately it was revolutionary in terms of both origins and consequences.

However, both the dating and significance of the archaeological evidence cited by Sherratt (and thus the validity of the model) have been questioned by several archaeologists. The dangers of dating the innovations on the basis of evidence such as iconography and waterlogged organic remains with restricted chronological and geographical availability have been pointed out. Sherratt has himself acknowledged that such dates provide a terminus ante quem for the invention of milking and ploughing.

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