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.


  1. Ross Kilgariff April 7, 2013 at 10:40 pm

    haha, furbies…

  2. Christophe L April 9, 2013 at 1:15 am

    I will contest the statement that the furby as a domesticated animal.

  3. Timelord Kitty April 10, 2013 at 9:48 pm

    "…and furbies…" O.O

  4. Ash Hariharan April 10, 2013 at 11:00 pm

    the credits are like a whos who of youtube

  5. Rin S April 11, 2013 at 3:06 pm


  6. JasaanKenneth April 11, 2013 at 4:45 pm

    pet food, science, pets.

  7. JasaanKenneth April 11, 2013 at 4:45 pm

    I've always disliked the idea of pugs and such.

  8. fattybobatty April 11, 2013 at 7:36 pm


  9. typothalamus April 12, 2013 at 6:51 pm

    Have you heard about the Russian fox domestication experiment? There is an article about it on Scientific American called "Man’s new best friend? A forgotten Russian experiment in fox domestication" and there are documentaries that mention the experiment as well. I think you'll find it interesting.

  10. Scene Spyro April 13, 2013 at 3:20 am

    love the portal reference 😛

  11. macmarty2025 April 15, 2013 at 4:29 am

    Another great video.

    I recently read something by Temple Grandin, where she said that wolves do not live in packs. They live in family groups. A mom, a dad and siblings. After about 2 or 3 years the siblings leave the family to mate and form their own family group. meanwhile, each year new wolves are born into the original family. She says that a pack is a group of unrelated animals.

    Thank you for these great videos, I always learn new and interesting stuff.

  12. celeluwhen April 15, 2013 at 5:56 pm

    1:52 Is this Lemon? Hi Lemon!

  13. Khuratokh April 20, 2013 at 12:45 am

    I love how youtube gave me an air-freshener ad for The Brain scoop.

  14. intotheoceanbloo April 26, 2013 at 3:33 am

    Super adorbs Hahahahahahahah!

  15. ShortyStarRose April 26, 2013 at 5:15 pm


  16. MagicTurtle643 April 30, 2013 at 11:12 pm

    That was really fascinating.

  17. Shelby Taylor May 4, 2013 at 6:24 am

    1:53 Hi there, Lemon!

  18. vume5 May 8, 2013 at 5:00 pm

    Well, if you look at the individual creature, then true, but in terms of survival of the species, false. There are many many more pigs alive today than boars because people want to eat pig meat, so people put a lot of effort into breeding and feeding pigs, protecting them from diseases, carnivores, etc.

  19. E Jones May 8, 2013 at 8:58 pm

    She's married to science.

  20. TheVulcanBard May 10, 2013 at 11:46 pm

    Preach Emily!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! 🙂

  21. MisterJimLee May 11, 2013 at 5:46 am

    1:28 The Sandlot, anyone?

  22. TheKillaJoules May 15, 2013 at 1:31 am


  23. Sean Quinn May 24, 2013 at 3:03 am


  24. weirdral May 29, 2013 at 7:45 pm

    For racing.

  25. Keydan June 3, 2013 at 9:40 pm

    For SCIENCE!

  26. DevinJuularValentine June 4, 2013 at 4:17 am

    Poor pugs

  27. Rayram AureanBlue June 4, 2013 at 5:18 pm

    Domesticating furbies was a bad idea. Sure, they look cute, but the problem is, they grow up. Many have gone feral and are competing with our native drop bear population, and the sounds of their fighting keep residents awake at night. Why, there's an area in our woods that overrun with the fuzzy bastards and the local council has issued a cull on their numbers. A furby once stole my lunch money and then proceeded to spend the money on cigarettes. They're an absolute nuisance.

  28. john johnson June 7, 2013 at 1:59 am

    no dude, pet roaches. some people keep exotic species of them, or you can eat them, it's said they taste like what they're fed like apples or bananas

  29. Nought June 11, 2013 at 12:40 pm

    I have a passionate hate for pugs and this is explains why. They're silly things that shouldn't exist.

  30. apoapsisperiapsis June 12, 2013 at 5:33 am

    Vihart is equally as cool

  31. awesomecraftication June 22, 2013 at 3:23 am

    I want to hear about cat domestication

  32. theirishboxer1 June 23, 2013 at 7:19 am

    you assume cats are domesticated

  33. awesomecraftication June 23, 2013 at 8:30 am

    well there is a slight difference between a friendly little house cat and a lion.

  34. Inaveve June 24, 2013 at 2:57 am

    Amazing! Thanks for explaining brachycephalic in it's scientific context. I'm going to look for the National Geographic article on Canidae domestication, but I was wondering if you knew much about tandem repeats in genetics? Dogs have a lot of tandem repeats in their genetics which is what allows for sudden changes, both physiological and behavioral, over just a few generations. I've been wanting to learn more about this. Do you have any knowledge on the subject or direction for me?

  35. diceman199 July 1, 2013 at 3:41 pm

    There was a good documentary re dogs. The secret life of the dog I think it was.

    They showed the breeding program that was run on silver foxes. They selected for the ones that were less aggressive towards humans and the results were amazing, physical changes in just a few generations and that was only selecting for a behavioral trait.

  36. Bryan Sanchez July 13, 2013 at 8:48 am

    She's sexy

  37. K Goldstein July 19, 2013 at 2:56 pm

    Lemon! 🙂

  38. littlebumgorf July 26, 2013 at 8:57 pm

    I believe it was for studying insecticide effect

  39. silverfuturist August 4, 2013 at 11:16 am

    brachycephalic! Could you spell that correctly off the top of your head? (bad pun hidden in there somewhere)

  40. Shunga4 August 5, 2013 at 1:28 pm

    Love the t-shirt!!! (Ecerything is dead)

  41. ShatteredDawn August 14, 2013 at 6:50 pm

    Did we? I thought they just got used to living in close prximity to us .-. kind of like them adapting to some sort of microclimate we create.(with like the shelters we make and our waste are a constant to them if they live near us)

  42. Brandie Mercer August 15, 2013 at 5:35 pm

    Furbys. We domesticated the spawns of Satan

  43. Crashtopher September 5, 2013 at 4:08 am

    In love.

  44. whooleein nava September 17, 2013 at 2:01 am

    fear factor

  45. Searonix September 27, 2013 at 4:23 am

    Hey Emily, what do you think of the domesticated foxes we have now that are taking on characteristics of domesticated dogs like loss of musk smell, wagging tails and spotted coats?

  46. Leo Dea Larriko October 6, 2013 at 6:08 pm

    Im officially under the spell of Emily Graslie. I am now apart of the Legion of Graslie! Graslegion geeks unite!

  47. JacenJacen October 7, 2013 at 1:24 pm

    According to the site below, the photo of the gigantic dog used in this episode appears to be a hoax:
    There are links to the actual tallest and heaviest dogs below that article for anyone interested.
    Have fun!

  48. Sean Norris October 22, 2013 at 3:18 am

    Is it sad that I come to this video just to hear Emily say "DOMESTICATION"

  49. Hinrik Stefnir Ævarsson October 26, 2013 at 10:26 am

    My cousin Ben over in XXXX told me that the drop bears' increasing difficulty in finding food has caused them to drop even on armed full grown mounted men.

  50. Hadar Milner December 2, 2013 at 8:09 am

    A million internets to you! Now I'me gonna giggle the whole day through.

  51. Damian Shaw December 4, 2013 at 5:49 am

    For all those watching thebrainscoop for the first time, there's an Easter egg in every episode. "Soon Raccoon", a taxidermy Raccoon that appears in at least 1 scene per episode (not counting introduction). See if you can spot Soon this episode!

  52. Matt Privett December 5, 2013 at 4:39 pm

    yeah, breeding an animal to look a certain way and actually causing it considerable health problems as a result is a pretty good reason why people should just stay out of nature's way.  

  53. Summer127 December 20, 2013 at 1:56 am

    I have a friend who knows someone who has a pug who's eyes pop out sometime.

  54. Erin Howarth December 26, 2013 at 7:22 am

    I was hoping to hear a little about the difference between domestication and taming of animals.  Elephants, cheetahs and zebras have been tamed on occasion, but human attempts to domesticate these animals have failed for various reasons.

  55. Zasta Droid March 6, 2014 at 10:16 pm

    The pug pictures BLEEWW MY MIND!

  56. Skywalker April 17, 2014 at 9:11 pm

    neoteny, or the tendency to retain youthful behaviors and features throughout adulthood, or the reason why the internet loves animals with high cranial index – grumpy cat, doge (and assorted lap dog breeds) and occasionally gollum. :-)

  57. SciJoy April 30, 2014 at 3:46 pm

    Sometimes I think you can read my mind. When I saw the last pug I thought, I wonder why the latest ones are wrinkled.

  58. ୲ 𐙼 𐚮 ୲ July 14, 2014 at 9:04 pm

    Oh yes, try to make me feel responsible for other humans, making dogs be absolutely worthles, look retarded and super easy to die from a disease. They look "cute"?!!!! Poor dogs.

  59. Lolp Cake July 30, 2014 at 9:49 pm

    We have been messing with nature in so many ways for so long and for so many reasons, some of them really good (like medicine to prevent disease) that I don't really think you can say it is ethical either way. Perhaps it is even 'natural' to mess with nature. 

  60. 6TheLastBroadcaster6 August 6, 2014 at 12:36 pm

    It's good that you mentioned the adverse health effects instead of pretending there's nothing wrong with this practice to make the video cheery.

  61. R.B. October 14, 2014 at 10:25 am

    That dog next to the horse was a photoshopped image of a neopolitan mastiff, it is no where near that size in reality, and the record for biggest dog is held by a great dane, which is still smaller than the dog in that picture.

  62. R.B. October 14, 2014 at 10:27 am

    Hem Em, don't forget the breathing problems!

  63. rachel November 12, 2014 at 8:36 pm

    Yay for pugs. They come with their drawbacks but they're still amazing dogs. 

  64. ddawn23 January 14, 2015 at 4:08 pm

    The first pug is from 1745 and the second pug is from 255 years later?  So 2000?  Surely you meant 1900.

  65. here2watch08 January 18, 2015 at 4:46 pm

    Some Pugs just have a seizure and die, just because they're Pugs.

  66. allie March 11, 2015 at 2:55 am

    I thought that looked like Lemon!  Haven't watched Vlogbrothers in ages (shameful, I know), but I still recognize Hank's dog.

    Hi Lemon!

  67. curiosity keeper May 18, 2015 at 5:17 pm

    Very interesting. Thank you.

  68. Itza Ushernaem May 26, 2015 at 2:52 pm

    Consider this, human understanding of "cuteness" stems directly from our instincts which entise us to protect and care for our young, babies.

    Therefor, in an attempt to create animals which we could call cute, we slowly bread wolves over thousands of years until they resembled babies…

    Fuch the what!


  69. Anne Foley August 28, 2015 at 1:29 am


  70. Wayne Miller October 30, 2015 at 5:44 am

    Hi Emily, I really like what you do. That said thank you for this video, because you said yourself that "man through selective breeding in the last 400 years"… although you ended you paragraph differently than I'm about to. You statement proved mine is true. That's important because people I talk to keep insisting that evolution takes millions of years. That is not true and "selective breeding" is a human assisted form of evolution that takes only generations. Therefore reducing evolution to years, rather that millions of years *~

    You're intelligence is evident. I'd like to meet you someday and have lunch or dinner, just talk. I like the way you look at things… it is very refreshing *~

    Say "Hi" sometimes *~

  71. Trevor Duarte December 24, 2015 at 4:16 pm

    Furbies, oh my gosh, I died xD

  72. daydodog January 6, 2016 at 1:09 am

    Was that Lemon?

  73. Nicholas Kam February 16, 2016 at 7:06 am

    I bet that shirt is your favorite shirt when primary students visits the museum!

  74. stephen madl April 14, 2016 at 3:04 am

    I must have one.

  75. Miky ॐ June 5, 2016 at 10:01 pm

    mi sono innamorato di Emily !!!!     aaaaahhhhhhhh

  76. Michael Block July 9, 2016 at 10:47 pm

    We should just stop with the pugs. It's getting unhealthy.

  77. R.Instro September 29, 2016 at 11:18 am

    Pretty impressive how you managed to get that episode filmed before the Sun could peek out from behind the slat & totally blind all of us unsuspecting viewers! XD

  78. Susannah Ayres-Thomas October 29, 2016 at 1:18 am

    I have a real dislike of breeding animals for traits that are counter-survival–like pug dogs. If a given breed of animal would not survive in the wild, ell, that's my point.

  79. charmaine hansen November 18, 2016 at 8:46 pm

    And this is why we need to stop breeding dogs to just be cute. Now we end up having so many dogs with health problems

  80. Qupid VOneOhOne December 15, 2016 at 4:34 pm

    But what can cranial index tell us about personality? 🤔 puts on his victorian smoking jacket

  81. Sophie Ciaglia January 15, 2017 at 12:19 pm

    the got had red eyes… satan is unleashed

  82. Jack Butler May 26, 2017 at 10:25 pm

    There is really strong research to suggest that wolves were domesticated within a few generations because of a protein that affects aggressiveness, coat color, and ear floppiness. If you selectively breed the docile animals you will get very domesticated dogs in a couple generations. Also because natural selection is dead for them most dogs have terrible cancer and tumors because they have been bred only for their looks.

  83. Leopard-King June 9, 2017 at 10:36 pm

    How do you domesticate a roach? What, like Charlie Sheen on house arrest? Mel Gibson with a feed bag? Chris Brown with positive reinforcement and clicker training?

  84. Wynter Panther June 13, 2017 at 9:58 pm

    I like how you just slipped in ferbies.

  85. Theodore Rule of Law August 1, 2017 at 1:36 am

    Who domesticated whom?

  86. Jimmy Jimmy August 14, 2017 at 10:42 pm

    This is being a brain scoop of brain scoop.

  87. you must not know dick about starkid August 17, 2017 at 6:32 am

    That's why I like feral mutts, they somehow rediversify their features to be the best and most functional for street life. Pedrigree female bulldogs and chihuahuas will have issues out in the wild where giving birth could mean death, the bulldog's puppies have too large heads and the chihuahuas have too small vulvas.

  88. Sky1arks September 16, 2017 at 5:35 am

    I think sometimes we go too far, and the bulldog is one of them. Not because its ugly (but it is), but because it is so anatomically deformed that it cannot reproduce without human intervention. You don't even need to do anything, just stop actively breeding them, and they'll naturally thin out as they reach the full length of their lives without repopulating.

    That being said, I'm a lover of naturally proportioned (resembles wolf anatomy) dogs like the like german shepherd's, labradors, or the Japanese shiba inu.

  89. Nara Feralina October 17, 2017 at 12:56 pm

    Well, at least we haven't had them grow legs out of their faces. So that's a good thing…

  90. Jaycee Allen October 24, 2017 at 3:14 am

    1:40 is where we should have stopped with short faced breeds

  91. Eric Taylor November 11, 2017 at 10:46 pm

    Humans did not domesticate cats, cats domesticated humans.

  92. David Reddy November 12, 2017 at 1:07 am

    Whoa, I never realized, but yeah, pugs kinda look like people. Like little derpy babies. I think I prefer the ones from centuries ago.

  93. gigglechan15 November 29, 2017 at 12:54 am

    NEEEEEED that shirt

  94. m I o . o I m February 3, 2018 at 9:17 am

    Domestication is why I have a kind wolf at home that I walk every day

  95. Daniel Hay February 8, 2018 at 2:08 am


  96. Jean Myers March 29, 2018 at 11:14 pm

    i want one of those brain scoop t shirts

  97. Amadon Faul July 5, 2018 at 4:31 pm

    This is a very old video so I'm sure I won't get a reply, but Emily are you wearing a Danzig belt buckle? Or a rams head or something?

  98. bad1dobby January 31, 2019 at 8:38 am

    I was confused because I thought brachy meant arm, as in brachiosaurus (arm-lizard). Turns out brachio = arm, whereas brachy = short.
    So brachy (short) + cephalic (of the head) = brachycephalic (short-headed).

    You’re very welcome.

  99. pim1234 March 2, 2019 at 1:51 am

    Great T-shirt !!

  100. Firebrand May 13, 2019 at 3:12 pm

    The majority of dog breeds are examples of human cruelty on nature and should not be allowed to reproduce, they live tortured lives purely for our selfishness. Some breeds could never survive in nature with their short snouts and legs while others cant even give birth without human intervention. Let's not forget 90% of dogs aren't walked even 10% of what they require for mental and physical health.

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