Two of the great feel-good fallacies promoted by vegetarians and vegans today is that eating less meat will stop climate change and that ancient man did it their way.

In reality, ancient man loved meat, it was just hard to kill.  So ancient scientists domesticated livestock - and then they found more uses for it, like milk, butter and cheese. It wasn't just Europeans, researchers have identified the chemical signature of dairy fats inside the surfaces of pottery from 7,200 years ago in North Africa.

Archaeologist Julie Dunne and biomolecular archaeologist Richard Evershed from the University of Bristol in England used mass spectrometry to identify different forms of carbon in small, ground-up samples taken from 81 pottery fragments previously found at a Libyan rock shelter and mostly dating to between 7,200 and 5,800 years ago. 29 of the samples had fats and at least half contained fats came from dairy foods.

Further chemical comparisons to milk fats from grazing animals now living in Africa showed that ancient Saharans milked cattle - but not goats or sheep.Some African groups possess genetic mutations that enable milk drinking without nausea and other unpleasant reactions to lactose, a sugar found in milk. These mutations commonly appear in Europeans, whose farming ancestors used milk at least 6,000 years ago, notes Bruce Bower at ScienceNews.

Carbon isotopes from milk fat can also point to the sorts of food the dairy animals ate, as different plants incorporate varying amounts of carbon-13 relative to carbon-12, writes Ewen Callaway at Nature. 

Citation: Julie Dunne, Richard P. Evershed, Mélanie Salque, Lucy Cramp, Silvia Bruni, Kathleen Ryan, Stefano Biagetti&Savino di Lernia, 'First dairying in green Saharan Africa in the fifth millennium bc', Nature 486, 390–394 (21 June 2012) doi:10.1038/nature11186