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    Why Dogs Can Be Tamed But Wolves Cannot
    By News Staff | January 18th 2013 10:13 AM | 9 comments | Print | E-mail | Track Comments

    Wolves and dogs are genetically very similar, so why did dogs become "man's best friend" while wolves remain wild?

    Kathryn Lord at the University of Massachusetts Amherst suggests the different behaviors are related to the animals' earliest sensory experiences and the critical period of socialization.  Not much is known about sensory development in wolf pups and assumptions are usually extrapolated from what is known for dogs - but there are significant differences in early development between wolf and dog pups, chief among them timing of the ability to walk. 

    Lord studied responses of seven wolf pups and 43 dogs to both familiar and new smells, sounds and visual stimuli, tested them weekly, and found they did develop their senses at the same time. But she found new information about how the two subspecies of Canis lupus experience their environment during a four-week developmental window called the critical period of socialization, and the new facts may change understanding of wolf and dog development.

    When the socialization window is open, wolf and dog pups begin walking and exploring without fear and will retain familiarity throughout their lives with those things they contact. Domestic dogs can be introduced to humans, horses and even cats at this stage and be comfortable with them forever. But as the period progresses, fear increases and after the window closes, new sights, sounds and smells will elicit a fear response.

    Through observations, Lord found that both wolf pups and dogs develop the sense of smell at age two weeks, hearing at four weeks and vision by age six weeks on average. However, these two subspecies enter the critical period of socialization at different ages.

    Dogs begin the socialization period at four weeks, while wolves begin at two weeks. Therefore, how each subspecies experiences the world during that all-important month is extremely different, and likely leads to different developmental paths, she says. 




    Differences in timing of sensory development during the critical period of socialization in wolf and dog pups may help to explain why wolves are difficult to tame while dogs are not. Credit: Kathryn Lord

    Lord reports for the first time that wolf pups are still blind and deaf when they begin to walk and explore their environment at age two weeks. "No one knew this about wolves, that when they begin exploring they're blind and deaf and rely primarily on smell at this stage, so this is very exciting," she notes. "When wolf pups first start to hear, they are frightened of the new sounds initially, and when they first start to see they are also initially afraid of new visual stimuli. As each sense engages, wolf pups experience a new round of sensory shocks that dog puppies do not."

    Meanwhile, dog pups only begin to explore and walk after all three senses, smell, hearing and sight, are functioning. Overall, "It's quite startling how different dogs and wolves are from each other at that early age, given how close they are genetically. A litter of dog puppies at two weeks are just basically little puddles, unable to get up or walk around. But wolf pups are exploring actively, walking strongly with good coordination and starting to be able to climb up little steps and hills."

    These significant, development-related differences in dog and wolf pups' experiences put them on distinctly different trajectories in relation to the ability to form interspecies social attachments, notably with humans, Lord says. This new information has implications for managing wild and captive wolf populations, but it's not a good idea to have a wolf in your house. A whole lot of genetic modification went into making dogs a house pet and even then they are still sometimes dangerous to their own families.

    The experiments analyzed the behavior of three groups of young animals: 11 wolves from three litters and 43 dogs total. Of the dogs, 33 border collies and German shepherds were raised by their mothers and a control group of 10 German shepherd pups were hand-raised, meaning a human was introduced soon after birth.

    At the gene level, Lord adds, "the difference may not be in the gene itself, but in when the gene is turned on. The data help to explain why, if you want to socialize a dog with a human or a horse, all you need is 90 minutes to introduce them between the ages of four and eight weeks. After that, a dog will not be afraid of humans or whatever else you introduced. Of course, to build a real relationship takes more time. But with a wolf pup, achieving even close to the same fear reduction requires 24-hour contact starting before age three weeks, and even then you won't get the same attachment or lack of fear."


    Published in Ethology


    Comments

    Gerhard Adam
    Wolves and dogs are genetically very similar, so why did dogs become "man's best friend" while wolves remain wild?
    What?!?!  The statement makes no sense, since dogs are domesticated versions of the Gray Wolf.  Dogs are the proof that wolves can be tamed.  If the point is to examine the divergence between the domesticated and wild animals, then that is a different question.

    There's no question that there will be behavioral differences between the two species, especially after thousands of years, but this tells us what exactly?  That animals reared on vastly different circumstances will evolve differently?

    This study might have provided some useful information had it compared the differences between feral and domesticated dogs, especially in terms of socialization, etc.  However, in fairness to the study, if the point was merely to illustrate why wild animals should not be presumed to have the same characteristics as their domestic corollaries, then I would agree.  Wild horses do not behave the same as domesticated horses.  Wild cats do not behave the same as domesticated cats.

    There are clearly major psychological differences between these groups, just as there are for domesticated animals going feral.  After all, even feral animals do not necessarily behave the same as their "wild" counterparts.
    Mundus vult decipi
    damonisherwood
    Agree with Gerhard above. Dogs are simply a domesticated, and therefore 'juvenilized' version of wolves, therefore the comment does not make sense. 
    Dr Belyaev's fascinating experiments with foxes show how quickly selection against aggression has associated effects on morphology, physiology and behaviour - presumably the ability to be tamed. See for example, http://vimeo.com/22734940 

    But again as Gerhard says, the report is interesting if it is read within the context that domestic dogs are just juvenilized wolves. 



    damonish
    Hank
    It's certainly an interesting claim on Lord's part.  She has done a lot of work with dog barks too, and made some conclusions that enraged dog owners, like that dogs are not actually communicating anything. She certainly seems to know a lot about the evolution of dogs but Gerhard is right that there is little known about how dogs can from a wolf ancestor.  She was in a National Geographic special on that topic a short while ago.
    Gerhard Adam
     She has done a lot of work with dog barks too, and made some conclusions that enraged dog owners...
    Don't know about enraged, but from what I saw, she's simply incorrect.  It's obvious that dogs aren't attempting to articulate specific messages by barking, but to attribute it only to conflict and mobbing behavior misses a rather significant aspect of it.

    I always viewed barking as something comparable to humans use of the word "Hey!".  I also find it interesting when non-specific explanations are provided.
    It’s true, but in our view it’s going too far to suggest the animal is intentionally referring to a specific activity. Rather, it has just learned cues, as it does when it learns to sit or beg for a treat.”
    http://www.sciencedaily.com/releases/2009/07/090714210137.htm
    What exactly is a "learned cue" and why is this somehow conveyed as dismissive in a dog's ability to attain an objective [i.e. feeding, going out, etc.].
    Lord says. “Dogs do quickly learn the simple cause-and-effect relationship between their bark at 10 p.m. and the fact that you’ll get right up and take them outdoors. It’s true, but in our view it’s going too far to suggest the animal is intentionally referring to a specific activity.
    This just sounds confused.  Dogs don't refer to a specific activity, and yet they learn the cause-and-effect relationship to use their bark to signal a desire for a specific activity.

    Certainly there are elements of these explanations that are true, but my problem is in trying to applying a general "one-size fits all" explanation to something that is clearly a bit more compliex.
    Mundus vult decipi
    UvaE
    It's obvious that dogs aren't attempting to articulate specific messages by barking,

    Ours does. He's trained by Mira (they raise guide dogs in Quebec) , so i don't know if that has anything to do with it, but Blues has a characteristic bark that he only uses in the middle of the night if he's sick and desperately has to go out to do his business. If my son accidentally steps on one of his paws, that vocalization(not really a bark) is very unique as well. There's another sound he makes when he eagerly awaits food. And the few times he loses it indoors with an annoying and intense bark, he's invariably set off by a car door shutting within about a 10 meter radius.
    Gerhard Adam
    I should have been more clear.  My point was that barking is not a language.  Interpretation is context dependent on the owner recognizing the circumstances under which it occurs.  So, it does provide a means of communication, but if one were to play a recording of a bark to another dog, it wouldn't convey any information.

    I agree that it is used in a specific context which renders some degree of meaning.  We have an old Pomeranian that barks only when she has to go out or when she's hungry.  It's very specific, and to lend credence to this claim, if you try to let her out and she hasn't barked, she'll simply ignore you.  In addition, since she spends almost all her days in our bedroom, you can readily see that there's no "excitement" in her barking, because she'll simply sit on her bed and engage in it until it draws your attention.  Then she'll come walking over to the door to go out, or sit expecting her food [she doesn't appreciate dallying in that regard at all].

    However, I don't believe that the bark, specifically, means anything special.  Dogs can provide some degree of inflection in the bark which allows us to distinguish something as being more general, versus a serious concern, versus whatever.
    Mundus vult decipi
    Then why does my husky talk to the husky across the way. She does not do this to barking dogs.

    Hank
    What do they discuss?
    Can you come up and play?
    No I'm tied up. Can you come down?
    No I'm tied up. I'll try to get the boss to bring me over.
    OK.