This result is right in line with the observations of people studying the evolution of lactose tolerance [1].
Lactose-tolerant middle-easterners (who had long been eating lactose-free fermented milk, until they developed lactose tolerance) moved in to Europe and took over, and rarely mixed with the native hunter gatherers. Instead, they simply outcompeted them and largely wiped them out. It is estimated that lactose tolerance gave them "up to 19% more fertile offspring" than the indigenous hunter-gatherers.
That makes me muse: Maybe the two groups didn't mix because the hunter-gatherers couldn't survive on the high-milk (and high starch?) diet of the agricultural people. Lactose intolerance can be quite violent!
Lactose-tolerant middle-easterners (who had long been eating lactose-free fermented milk, until they developed lactose tolerance) moved in to Europe and took over, and rarely mixed with the native hunter gatherers. Instead, they simply outcompeted them and largely wiped them out. It is estimated that lactose tolerance gave them "up to 19% more fertile offspring" than the indigenous hunter-gatherers.
That makes me muse: Maybe the two groups didn't mix because the hunter-gatherers couldn't survive on the high-milk (and high starch?) diet of the agricultural people. Lactose intolerance can be quite violent!
[1] http://www.nature.com/news/archaeology-the-milk-revolution-1...