Today we’re gonna talk about domestication. Domestication is the process in which humans selectively breed for a certain characteristic in a plant or animal. In the last 40,000 years or so, we’ve domesticated horses and cows and sheep and goats and pigs and guinea pigs and ferrets and Furbies and honey bees and cockroaches and skunks and over a hundred other species. It’s not just limited to animals either. We’ve domesticated plants and fungi for food and cultivation of crops and for also giving flowers to your mother. One of the first animals to be domesticated, as you may know, was the dog, about 30,000 years ago. According to an article by National Geographic, some wolves figured out that if they were friendly to humans, they would have a much better chance of survival than their aggressive and hostile pack mates. Food was scarce and being on the same team as humans proved to be an advantage. Friendlier wolves were much more likely to be tolerated and accepted by humans as pets. I guess if you think about it, dogs kind of domesticated themselves. What’s interesting is that as this group of wolves became more docile over time, their physical appearances began to change as well. They got upright wagging tails and floppy ears and spotted coats. They eventually became distinct enough from wolves (canis lupus), that we now classify them as their own subspecies: canis lupus familiaris. Fast forward to present day and you can see that we went really super crazy with this whole selective breeding thing Especially within the last few hundred years or so, we’ve bred dogs for very specific cognitive or aesthetic traits, resulting in dogs as big as ponies and small enough to fit inside of Paris Hilton’s purse. This is kind of interesting, it’s a portrait of a man and his pug from 1745. And here’s one of an angry woman and her pug from 255 years later. And finally, this is what pugs look like today. So we have this thing called the cranial index, which we use to categorize animals. It’s the ratio of a skull’s maximum width to its maximum length. An example of a dog breed with low cranial index is a greyhound with their long snouts and their low foreheads. A pug, on the other hand, has a high cranial index. Animals with high cranial indexes are called brachycephalic and have high foreheads, shortened snouts and enlarged eyes. With certain dog breeds, we’ve ended up heavily exaggerating these features, either consciously or not, ending up with dogs that look suspiciously human-like. And while they might look super adorbs, animals with high cranial indexes are subject to a multitude of health problems. They have a difficult time regulating their body temperature, because smaller mouths means less surface area for water to evaporate, resulting in less effective panting. Their exaggerated ocular orbitals put them at risk for their eyes literally popping right out of their heads should they accidentally sustain any trauma to the back of the skull. And because their skulls have been so dramatically shortened, it’s resulted in a bunch of skin bunching on their faces which can get really dirty and nasty and result in bacterial infections and all kinds of pretty gross stuff. All because we wanted to have a wolf that looked like this. It kind of makes you think about the depth of impact that we humans have when we go around messing with nature. Thanks for watching, this has been an episode of The Brain Scoop, this has been a Brain Scoop T-shirt and I’ll see you next time.