Where did horses come from?

Finding when and where the horse was first domesticated is one of those bits of science that doesn't sound important but really is a revolution. Archaeologists in Kazakhstan hope they're on the trail towards an answer. Horses went from being wild terrors, to meat and milk animals, to a new sort of transportation. The milk aspect is especially important, and the team is looking for trace fats from the site as a proof of domestication. After all, no one would milk a wild horse.