As humans, we’ve always been omnivores, eating a combination of plant and animal foods. Since the introduction of agriculture and domestication of livestock, we’ve been raising ruminants for meat and milk products for thousands of years. The kind of animal raised depends on climate and terrain. In India and Pakistan, milk is more likely to be from buffalos. In arid zones, milk is more likely to be from camels. In mountainous areas, milk is more likely to be from goats and sheep. In North America, milk is more likely to be from dairy cows.
Our ability to make use of the foods in our environment and to consume a varied and nutritious diet has helped us adapt and evolve as humans. While we don’t need to drink milk to survive, people all over the world depend on milk as an important and easy source of many nutrients. They always have, and chances are, they always will.