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  • in reply to: science question — atavism, reversion and pariah morphs #7056
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    kathryn lord
    Participant

    Hi Jennifer,

    Thanks for your thoughtful question. I think this idea comes from a misunderstanding of what a pariah/ village dog is. There is this idea that all dogs come from our pet population dogs and that all dogs are mixes of breeds. In reality a vast majority of the world’s dogs are free-living animals that were never any breed. Those dogs as you mention have a certain look to them, (we have a nice blog article on this entitled “What is a dog breed”). This look is due to natural selection as well as some random events, for example if the founder of a new population has spots or floppy ears and they are not deleterious those will occur at a high rate. If a pure bred dog strays into the village dog population, it’s traits tend to be less well adapted to this environment and will be selected against and quickly swamped out by those of the better adapted local village dogs. There is actually a village in Venezuela that the Coppinger’s write about in their recent book “What is a dog” where they let St. Bernard’s breed with their village dogs, to try to make them look more like the famous war dog Nevado. Of course, the St. Bernard is much too large to be well adapted to surviving as a village dog in this area and while a few of their village dogs have some St. Bernard traits for a time, they do not survive as well and do not produce as many pups as the regular village dogs, so without continued reintroduction of St. Bernards their village dogs look like the normal village dogs from anywhere else in that climate.

    in reply to: Genetics and dog vocalization #6185
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    kathryn lord
    Participant

    Hi David,

    This is a very interesting question, and it turns out the answer is complicated. You are right that Dr. Miklosi’s work suggests that specific barks are associated with particular contexts. He has concluded from this that a diversity and increased prevalence of barks has evolved specifically in dogs to communicate with us. You are also right that this would suggest that we should find some strong genetic signal associated with variation among dogs in the prevalence of barking and also, perhaps, the diversity of their barks. However, my work suggests that barking occurs in times of conflict not only in dogs, but in all other members of the genus Canis. It also occurs in many other mammals and birds. Given that barking occurs in times of conflict throughout the genus Canis, another possibility is that dogs bark more often simply because they are in conflicting situations more often than wolves. This is where we get into the differences in “emotions” that you brought up, in addition to another variable: the environment.

    Wolves rarely experience conflict in their natural habitat, for example, the approach of a potential predator at a den site. By contrast, dogs experience conflict frequently. They are often unable to flee from frightening things, because dogs are inside a house, or behind a fence, on a leash, etc. Dogs also are often unable to approach things they would like for the same reason, resulting in just as much conflict, indicated by a higher pitched, more tonal bark. In part, then, dogs’ barks maybe more frequent and more diverse simply because dogs experience frequent and variable reasons to bark.

    But this difference in environment is not the only reason for increased barking in dogs. Dogs also have a shorter flight distance than wolves, and this does likely have a genetic component to it. Because dogs let scary things get closer they are more likely to get into situations where the scary thing has gotten too close for them to run away. If they turn away, they could get grabbed from behind. This is most often the situation in which you see free-living dogs bark. Dogs that live in our homes also learn to bark. For example, if you have a house-trained dog and you forget to let it outside, there is a good chance it will bark, because it is conflicted over not being able to go outside when it has the urge to urinate. You, hearing this bark, remember you have neglected to let the dog out and open the door. Your dog quickly learns that this sound (which previously had no particular meaning) causes you to open the door.

    While there are genetic components that contribute to these things being possible in dogs and less possible in wolves, these may or may not be why different dogs have differences in their bark prevalence, or type. To make things even more complicated, the size of the dog greatly affect the sound of their bark. So, while I am sure there are genetics involved in differences in dog barks, why a dog barks in a particular situation and how it barks is extremely complex and would thus require a finely tuned questionnaire to get at the trait of interest. We have yet to develop such a questionnaire, but we are always eager to hear participants ideas for questionnaires and we will certainly keep this interesting topic in mind for the future.

    in reply to: Your newest survey & DNA intentions #5790
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    kathryn lord
    Participant

    Hi Car2ner,

    You bring up two interesting points.
    1) There is variation within breeds. You are absolutely right! If we look at individuals within a breed we see different pups progressing towards the end of the critical period at different rates. Differences in experiences during the critical period can further exacerbate later behavioral differences. Even littermates growing up in the same place can have different early experiences. But if we look at a group of labradors for example and compare them to a group of German shepherds, we see that on average labradors are progressing to the end of their critical period of socialization more slowly than German shepherds.

    2) Something is going on in adolescence/early adulthood. The critical period we are focused on presently is the primary critical period of socialization, which happens in the first months of life. However, there has long been talk of the possibility of a secondary critical period of socialization toward the end of adolescence/ beginning of adulthood. Such a period has been found in mice, and while behavior is not as flexible during this period as it is during the primary critical period, it is still important in the development of adult behavior in mice. We currently do not know what or if there is an equivalent period in dogs, but I think it is likely and have long been interested in studying this hypothesis.

    in reply to: Your newest survey & DNA intentions #5788
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    kathryn lord
    Participant

    Hi car2ner,

    Thank you for your interest. We are not going to be looking directly at the amounts or types of socialization during the critical period in this particular study. Instead we are confirming the timing of the critical period of socialization in different breeds of dogs and wolves and trying to understand how these differences are controlled. This variation in timing changes how different breeds of dogs and wolves experience the same environment, during this very sensitive developmental period, and consequently, for the rest of their lives. For example, regardless of early environment, the shorter the critical period is the less time there is for the dog to encounter new things and the more likely they are to show fear of novelty as adults. The longer the critical period the more likely they are to experience more things and be less fearful of novelty as adults.

    in reply to: Your newest survey & DNA intentions #5786
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    kathryn lord
    Participant

    Hi Linda,

    Thank you for your questions. My main research interest is in the development and evolution of behavior. In the past I have focused on differences during development that explain the changes in adult behavior between wolves and dogs and between breeds of dogs. As a member of the Karlsson lab I am now starting a new project to see if we can determine the genetic and epigenetic mechanisms that may cause these changes in development.

    We are particularly interested in differences during the critical period of socialization, a time early in the development of mammals when their developing brains are extremely sensitive to environmental input. In other words, what a young mammal sees, hears, smells and touches during this time period can change how their brain grows and ultimately how they interact with the world as adults. During this time young mammals form social bonds, and positive experiences with new things render them familiar.

    I have found that while dogs’ critical period is shifted two weeks later than wolves, they both still develop their senses at the same time. This means that dogs and wolves have very different early experiences during this important developmental period. I have also found that different dog breeds have different length critical periods of socialization, allowing them more or less time to encounter new things and form social bonds.

    We will be doing some more direct measures of critical period length in dogs and wolves and looking at the variation of social behavior between dogs and wolves and dog/wolf hybrids. This questionnaire is an attempt to see what the variation in social behavior is across the population of pet dogs and to see if they are associated with the same genes we find in these other studies.

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