article_snippet.sent: A study of ancient human bones has revealed how Early Europeans had difficulties digesting milk around 5,000 years after the introduction of farming.
article_snippet.sent: A study of ancient human bones took at least that long for hunter gatherers living on the site of Motala, southern Sweden genes to evolve until their genes were no longer intolerant to lactose, the natural sugar in mammalian milk, scientists suggests.
article_snippet.sent: This means that these ancient Europeans would have had domesticated animals like cows, goats and sheep, but these ancient Europeans would not yet have genetically developed a tolerance for drinking large quantities of milk from mammals.'