Wednesday 11 December 2013

Domestication can change diet in mammals

One of the central arguments for releasing breeding-back results in the former range of their wild type is that they very likely fulfill the same or a very similar ecologic niche, as domestication is thought to affect mainly the morphology and behaviour of the animals but not the internal physiology. A study published this year identified a number of genes in domestic dogs that likely were changed due to domestication of the wolf, including genes that play a key role in starch and fat digestion, suggesting that dogs adapted to a more starch-rich diet relative to wolves: 

The domestication of dogs was an important episode in the development of human civilization. The precise timing and location of this event is debated and little is known about the genetic changes that accompanied the transformation of ancient wolves into domestic dogs. Here we conduct whole-genome resequencing of dogs and wolves to identify 3.8 million genetic variants used to identify 36 genomic regions that probably represent targets for selection during dog domestication. Nineteen of these regions contain genes important in brain function, eight of which belong to nervous system development pathways and potentially underlie behavioural changes central to dog domestication. Ten genes with key roles in starch digestion and fat metabolism also show signals of selection. We identify candidate mutations in key genes and provide functional support for an increased starch digestion in dogs relative to wolves. Our results indicate that novel adaptations allowing the early ancestors of modern dogs to thrive on a diet rich in starch, relative to the carnivorous diet of wolves, constituted a crucial step in the early domestication of dogs.

Paper on nature 

The case of megaherbivores is surely different from the domestication of the wolf, but it is interesting to see that diet can change due to husbandry by man. 



8 comments:

  1. Hi there,
    Other studies regarding dog evolution suggest that the physical, metabolic and behavioral differences between dogs and wolfs exist not because of domestication selection but because dogs are descendants of a different type of wild canid related to the wolf but not the wolf. Those differences might be due to dogs being descendants of a different species that was a generalist not specialized carnivore in opposition to wolfs that are more carnivorous and more specialized hunters including the capacity to digest starch.
    Canis variabilis seams to be the main ancestral of dogs. it coexisted with normal wolfs for thousands of years and they were even more abundant in the same regions of Eurasia. They were virtually identical to primitive dog breeds like the Dingo, the Singing dog, the Canaan dog, or the Carolina dog, what launches immediately in my spirit the idea of a breeding back project for a wild type of dog that is missing in the ecosystems of Eurasia.

    Best regards and thank you for your posts always pleasant to read.

    J. Ferro

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    Replies
    1. Hi,
      thanks for that interesting information, I wasn't aware of that. Could you name some of these studies, please? I couldn't find much in the web. Is Canis (lupus?) variabilis a valid taxon?
      Thanks and best regards!

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    2. Hello, I've read several different new documents regarding this fascinating subject and I will try to find them again and I will send you the links, anyway I believe you can find easily in the net the following document: THE PARIAH CASE: SOME COMMENTS ON THE
      ORIGIN AND EVOLUTION OF PRIMITIVE DOGS
      AND ON THE TAXONOMY OF RELATED SPECIES, By
      Tony Gonzalez
      A thesis submitted for the degree of Doctor of Philosophy
      of the Australian National University.
      I will search for the others and in the first opportunity I will send you.
      Regarding Canis lupus variabilis there is a lot of debate around the subject, scientists still don't know how to call it if Canis lupus variabilis, just Canis variabilis or any other name (because there are other possibility's), the species existed for sure, the oldest records are from China and they date back around 800.000 ybp but samples of this species were collected from Asia to Western Europe and North Africa, but the name and taxon can be misleading since it's almost a dogma for science that dogs are the domesticated form of the wolf. nobody really knows how to name and place an animal that looks like a dog but it's not fitting the assumed dog evolution and domestication chronology.
      Take good care.
      J. Ferro

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  2. Hi there, following is the link to another interesting document regarding primitive dogs:
    http://newguinea-singing-dog-conservation.org/Tidbits/OriginOfTheDog.pdf
    Best regards
    J. Ferro

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    Replies
    1. Hi, thanks for the links, I'll have a look at them. :-)

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  3. And a interesting blog that can lead you to other articles regarding the above mentioned subject: http://darrennaish.blogspot.com/2006/10/controversial-origins-of-domestic-dog.html
    Take good care
    J. Ferro

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    Replies
    1. I just finished reading the two papers and the blog entry by Darren Naish. This re-evaluation of the wolf hypothesis and the alternative hypotheses are really fascinating and mind-expanding, thank you very much for sharing!

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    2. You are welcome!
      If you find some other interesting information regarding this subject please share it.
      Best regards and happy new year!

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