Dogs have long been dependable companions by our sides. But it wasn’t always that way, and a look at their closest living relative, the wolf, makes it clear why. Research into dog domestication and intelligence offers clues into the human-dog relationship. And analyzing dogs’ brain activity and genes may even help answer whether dogs are in it for the food—or if they really love us.。想看更多的相关作品，请收藏我们的网站：winecool.net（三酉影视）