Hitting the Books: The genetic fluke that enabled us to drink milk

It may not contain our recommended daily allowance of Vitamin R but milk -- or "cow juice" as it's known on the streets -- is among the oldest known animal products repurposed for human consumption. Milk has been a staple of our diets since the 9th century BC but it wasn't until a fortuitous mutation to the human genome that we were able to properly digest that delicious bovine-based beverage. In her latest book, Life as We Made It: How 50,000 Years of Human Innovation Refined -- and Redefined -...