People who lived in those regions began to see cattle as a convienent way of feeding themselves. I learned that those people are referred to as gauchos (kind of like cowboys), and that the way that in which would prepare asado has shaped the way that people continue to prepare it today.
The food also continues to be connected to the environment here in Argentina because most of the charcoal used to make asado is made from trees that are native to the country. Some of the Argentine people that I have met have said, "todo el mundo come carne," meaning "everyone here eats meat." It is a tradition that will probably last forever.