A groundbreaking paleogenomic study published this month has mapped the spread of lactose tolerance across Eurasia. By analyzing DNA from over 400 ancient skeletons, researchers found that the genetic mutation allowing adults to digest milk spread rapidly following the migration of Steppe pastoralists into Europe and South Asia.
The study also suggests that the adoption of dairy-based diets was a key driver of population growth and social stratification. This research provides a definitive timeline for the cultural shift from hunting-gathering to specialized pastoralism in early Indo-European societies.