Humans were drinking animal milk long before they could digest it
Milk consumption was widespread in Europe from the Neolithic period (7000 BCE) onwards, and is likely to be a response to famine.
A study just published in Nature shows that humans were drinking milk from domesticated animals long before they evolved the gene required to digest it. Nine thousand years ago, to be exact. This somewhat surprising findings offer new insights into the evolution of lactose tolerance.
Analysis of ancient human DNA, dairy fat and protein residues by archaeological biochemist Richard Evershed and colleagues shows that the consumption of animal milk began in Anatolia (modern Turkey) in the seventh millennium BCE, and by 5000 BCE the practice was widespread in Europe, the Eurasian steppe, and northern Africa. Adult lactose tolerance was not common until around 1000 BCE.
The researchers find no strong link between milk use and lactose tolerance in their modelling of genetic and archaeological data, but instead find that indicators of famine and pathogen exposure better explain its evolution. Adult milk consumption appears to be a response to food shortages and environmental stress, and it was this that drove the evolution of lactose tolerance. Humans with the ability to ingest large amounts of fresh milk would have fared much better nutritionally than those who lacked it.