That was quite interesting. Demonstrates quite clearly that evolution is a dynamic process and still effects our lives today.
I've also read that one of the reasons western cultures became dominant is that they were exposed to and developed immunity to many diseases as a result of close contact with domesticated animals that were often the originator of the disease.
Many of the communicable diseases - eg measles, influenza, smallpox were diseases that originated from domesticated animals. While they did kill lots of people in the western world at least partial immunity developed over time.
When western culture then interacted with New World cultures the germs did most of the work for them.
The Spanish Conquistadors - while pretty nasty in their own right were nothing compared to the measles and smallpox germs that they brought with them.
So not only did milk confer an advantage for earlier farmers it ultimately led to the conquest of the New World
Gun Germs and Steel by Jared Diamond covers these ideas quite well.