There are hundreds of dog breeds around the world, all thanks to centuries of selective breeding by humans. With such a wide range of canine sizes and temperaments, it's no surprise that, in the process, we have reshaped their brains as well as their bodies. Here are the main findings of a new study of 33 different dog breeds, published in the journal Neurosci by study leader, Erin E. Hecht, an evolutionary neuroscientist at Harvard University. Via: Science News