> "They are also bigger, lay larger eggs and have smaller brains than their wild cousins - differences that are also seen in chickens. ...Pets tend to have floppier ears and curlier tails than their wild ancestors. They also have smaller jaws and teeth, white patches on their fur and breed more frequently. This phenomenon is known as 'domestication syndrome'."<p>I am not being glib, but I wonder if this is what happened to humans. allow me to explain. As short as 5,000 years ago, our brains were 10% bigger, our jaws were bigger, and our size was smaller. The former 2 have been associated with diet, but the shrinking brain is still debated. Maybe its simple though. Maybe humans domesticated humans.