Study: Starch Digestion Adaptation in Dogs

Discussion in 'Dogs - General Dog Chat' started by Shai, Jan 23, 2013.

  1. Saeleofu

    Saeleofu Active Member

    Joined:
    Oct 9, 2009
    Messages:
    9,036
    Likes Received:
    0
    Trophy Points:
    36
    I should have kept up with this thread. Now I'm just lost :rofl1:

    Anyone who questions whether birds are dinosaurs clearly has never seen a Canada goose gosling in their ugly stage :yikes: I also like telling my nephew that back in my day, birds weren't reptiles. We had reptillia and aves and no sauropsida :lol-sign:
     
  2. Romy

    Romy Taxiderpy

    Joined:
    Dec 2, 2006
    Messages:
    10,234
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Olympia, WA
    When my duckling Mahonri was 9 weeks old he chased down a mouse, caught it, and swallowed it whole. It made me really glad ducks are not 9 feet tall. :p

    The classification system has been rearranged so many times in the past 25 years, unless there's DNA behind it I reserve my right to be skeptical.
     
  3. sillysally

    sillysally Obey the Toad.

    Joined:
    Sep 20, 2008
    Messages:
    5,074
    Likes Received:
    0
    Trophy Points:
    0
    Occupation:
    2 dogs, 2 cats, 2 birds, and 1 horse
    Location:
    A hole in the bottom of the sea.
    From what I understand pterosaurs are not considered to be true dinosaurs though they did live at the same time, "Pterosaurs lived among the dinosaurs and became extinct about the same time, but they were not dinosaurs; they were flying reptiles." Source: http://www.livescience.com/24071-pterodactyl-pteranodon-flying-dinosaurs.html


    And no, I have no idea what this has to do with dogs' ability to digest starches :lol-sign:
     
  4. Romy

    Romy Taxiderpy

    Joined:
    Dec 2, 2006
    Messages:
    10,234
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Olympia, WA
    That's what I thought too, but then I consulted the most recent phylogenic chart and it had them listed under dinosauria? :dunno: There seems to be wild variations in cladograms when you get that far back in lineage, and considering how badly we've mucked it up with living species (and proven with DNA testing why assumptions based on phenotype don't work) I'm gonna sit it out until they find DNA for those too. Or figure out some way to turn on and off some combination of genes that makes the ancestral forms of organisms magically manifest. lol.

    Oooooh, then we could reverse engineer whales into ambulocetus and they could roam the countryside, filtering clouds of midge flies from the air. :cool:

    Or even better, we could reverse modern, inferior dogs into their superior extinct form which is the feline wolf. A gentile companion which shares its lineage with the lion. :rofl1:

    ETA: Everything I read about pterosaurs having fur said that it suggested they were warm blooded, which means they weren't technically reptiles. *bangs head against wall*

    Bedtime.
     
  5. Red.Apricot

    Red.Apricot Active Member

    Joined:
    Aug 28, 2011
    Messages:
    2,985
    Likes Received:
    2
    Trophy Points:
    38
    Location:
    Southern California
    Do you have a link about mtDNA being passed by the father?
     
  6. Dekka

    Dekka Just try me..

    Joined:
    May 14, 2007
    Messages:
    19,779
    Likes Received:
    1
    Trophy Points:
    36
    Occupation:
    8 dogs and 6 horses.
    Location:
    Ontario
    Home Page:
    Yes, I would like an example of mtDNA being passed on by males in mammals.

    And many top scientists will argue that dogs ARE wolves. Not just descended from them. I had an argument with my supervisor as I said they are different species (based on behaviour) and he (who has done a lot of work on wolves) says they are the same. It depends on what species model is used.

    Deciding on what is a species is not cut and dry.
     
  7. Raegan

    Raegan Member

    Joined:
    May 11, 2011
    Messages:
    493
    Likes Received:
    0
    Trophy Points:
    16
    Occupation:
    Giant Miniature Schnauzer & International Toller o
    Location:
    Fond du Lac, WI
    That's because mDNA alone wildly skews the results.

    http://whyevolutionistrue.wordpress...onstructing-evolution-from-mitochondrial-dna/
    http://retrieverman.net/2012/04/20/i-was-wrong-about-polar-bears/comment-page-1/

    And birds are dinosaurs is always relevent, because it's the best science fact ever. :)

    You can never outgrow your ancestry. Everything thing your ancestors were, you still are. So yes, you are an ape (and apes are monkeys). All squares are rectangles, but not all rectangles are squares.

    My understanding is Pterosaurs are dinosaurs, but not the dinosaurs that became birds (theropods). Which is fascinating to me because look at all the different times and ways flight has evoloved! http://www.pterosaur.net/origins.php seems to say "common ancestor with dinosaurs" (which I find to be kind of meaningless, everything has a common ancestor with everything else).

    I have no idea what to do with the word "reptile." The last I heard it was polyphylogenic and wasn't really being used anymore. But I've still seen it used and have never been able to figure out what it meant. I just really don't know/understand.

    In addition, there are multiple accounts of wolves acting like dogs, and dogs acting like wolves.

    (Warning, some of those links have graphic descriptions of hunting)
     
  8. sillysally

    sillysally Obey the Toad.

    Joined:
    Sep 20, 2008
    Messages:
    5,074
    Likes Received:
    0
    Trophy Points:
    0
    Occupation:
    2 dogs, 2 cats, 2 birds, and 1 horse
    Location:
    A hole in the bottom of the sea.
    Solo the Senegal says he is totally related to dinosaurs-he especially claims the velociraptor....:D
     
  9. Oko

    Oko Silence, peasants.

    Joined:
    Sep 10, 2012
    Messages:
    2,138
    Likes Received:
    0
    Trophy Points:
    0
    Occupation:
    Guinea pigs, rabbits, rats, cats, dogs, oh my!
    Location:
    MA, USA
    Read that as 'moose', not 'mouse' :rofl1: :rofl1:
     
  10. sillysally

    sillysally Obey the Toad.

    Joined:
    Sep 20, 2008
    Messages:
    5,074
    Likes Received:
    0
    Trophy Points:
    0
    Occupation:
    2 dogs, 2 cats, 2 birds, and 1 horse
    Location:
    A hole in the bottom of the sea.
    That would be a scary effing duck-lol!

    I know that chickens will hunt and eat mice and small snakes.
     
  11. Romy

    Romy Taxiderpy

    Joined:
    Dec 2, 2006
    Messages:
    10,234
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Olympia, WA
    Not really though, because at some point it just isn't remotely the same. For example, we human mammals aren't in any way prokaryotes.


    Those are interesting links, though I wonder how much has to do with the two lines intermixing through the years vs. one giving rise to the other.

    The gene for solid black in all wild wolves was introduced in a cross breeding between wolves and dogs that took place 12,000 - 121,000 years ago. It's a rather widespread coloration, which makes me wonder what other traits might have been introduced and potentially lay dormant until some human comes along and tests it.

    ETA: To go back to the outgrowing your ancestry thing, it would be more accurate to say dogs are canids then, if humans are apes. We don't say humans are chimpanzees, because they aren't. Just the same, dogs are not wolves. They're both canids with a common ancestor.
     
  12. Raegan

    Raegan Member

    Joined:
    May 11, 2011
    Messages:
    493
    Likes Received:
    0
    Trophy Points:
    16
    Occupation:
    Giant Miniature Schnauzer & International Toller o
    Location:
    Fond du Lac, WI
    But that's exactly the point. Dogs and wolves interbreed freely and easily. Because they are the same species.

    At best, the argument for their seperation is behavioral and cultural - it's artificial. It's because humans keep dogs in fences and kill wolves. In places where those things don't happen, dogs and wolves intermate regularly.
     
  13. Romy

    Romy Taxiderpy

    Joined:
    Dec 2, 2006
    Messages:
    10,234
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Olympia, WA
    Actually, in places where those things don't happen wolves eat dogs (see Alaska). Coyotes and wolves have interbred occasionally as well, but it's not a normal occurrence despite them cohabiting the same land because coyotes are a food source for wolves.
     
  14. sillysally

    sillysally Obey the Toad.

    Joined:
    Sep 20, 2008
    Messages:
    5,074
    Likes Received:
    0
    Trophy Points:
    0
    Occupation:
    2 dogs, 2 cats, 2 birds, and 1 horse
    Location:
    A hole in the bottom of the sea.
    Horses, donkeys, and zebras can and do interbreed as well...
     
  15. Shai

    Shai & the Muttly Crew

    Joined:
    Dec 14, 2009
    Messages:
    6,216
    Likes Received:
    0
    Trophy Points:
    0
    To be fair, however, their offspring is generally sterile.
     
  16. Romy

    Romy Taxiderpy

    Joined:
    Dec 2, 2006
    Messages:
    10,234
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Olympia, WA
    Elaphe gutatta (corn snake) can hybridize with many species of king snake and produce fertile offspring. They aren't even classified in the same genus. They do not cross ever in the wild because king snakes eat other snakes. Even in captivity you have to bait and switch, with two king snakes together and then yank out the female and stick a corn snake in her place at the last second, and then you have to remove her as soon as the deed is done or the male will eat her after the fact.

    Corn
    [​IMG]

    California King
    [​IMG]

    Here's an F2 hybrid, produced by breeding sibling F1 corn snake/california king snakes.
    [​IMG]

    Servals and house cats produce fertile offspring, and I'm pretty dang sure that housecats are not servals. Both felids yes, but they're not the same species nor are house cats derived from servals.
    [​IMG]

    Pretty much every species of cattle is fertile with each other. American bison, Asian yaks, European cattle, etc. all readily hybridize and produce fertile offspring.
    Beefalo
    [​IMG]

    Yakalo had some problems, only females were fertile.
    [​IMG]


    Sulimov dogs were made from crossing golden jackals and dogs. The jackals had to be raised exclusively with dogs so that they would mate. Jackal DNA has never been found in domestic dog DNA except for possibly in Africaans and Azawakhs. I've read that it has been found in them, but haven't actually seen a published paper saying so. If anybody knows of one, I'd love to see it.

    Grizzly bears and polar bears readily hybridize, in captivity and the wild. In captivity it was found that both genders of F1 hybrids were fertile with their parent species and with each other.
    [​IMG]

    Servals X Caracals produce fertile hybrids.

    Tigers x Lions produce ligers. I know for sure at least the females are fertile because I met a pair of Ti-ligons, which were F2 from breeding a liger to a tiger.

    Bobcats and Canadian lynx freely hybridize in the wild and produce fertile offspring as well.
     
  17. sillysally

    sillysally Obey the Toad.

    Joined:
    Sep 20, 2008
    Messages:
    5,074
    Likes Received:
    0
    Trophy Points:
    0
    Occupation:
    2 dogs, 2 cats, 2 birds, and 1 horse
    Location:
    A hole in the bottom of the sea.
  18. sciatrix

    sciatrix New Member

    Joined:
    Oct 6, 2012
    Messages:
    10
    Likes Received:
    0
    Trophy Points:
    1
    I'm just delurking here because evolutionary biology is my field and there are a couple of misconceptions that are bugging me a bit.

    Basically, the definition of a species has to do with barriers to gene flow. Postzygotic isolation--that is, never being able to produce offspring together--is the gold standard, yeah, but there are also good biological species that can theoretically create offspring in really unusual conditions--like captivity!--but never or almost never do in the wild. Your king snake idea is an awesome example of this! No genes are being passed back and forth in the wild because king snakes generally eat corn snakes instead of mating with them, so you have reproductive isolation as a consequence of behavioral traits. So they're still good species even though you can, with careful finagling, get a fertile F1 hybrid, because in the wild they never reproduce together and gene flow between corn and king snakes is nonexistent.

    Speciation is also a process, not an all/nothing boundary--there are honestly almost none of those in biology. You start with two populations of the same species, with no barriers to gene flow, and you end with two species where no genes can flow back and forth, but there are some intermediate steps along the way. Behavioral isolation like the king snake example and other forms of isolation that happen before mating can take place usually happen first, which is why we have so many examples of good species that can produce occasional hybrids under unusual conditions, like captivity.

    Dogs and wolves, if allowed to live in proximity to each other, will still freely interbreed without human intervention. Therefore they are not good species. (For example, feral dogs and wolves interbreed very commonly in Italian garbage dumps, where both are known to live without much in the way of human intervention.) This is not true of, say, dogs and coyotes--yes, rare hybrids exist, but there are enough natural behavioral barriers that they stay very rare even though coyotes and dogs often do live in close proximity to each other.

    With respect to animals in different genuses being able to produce offspring together, well, while species are a natural unit of biodiversity (sort of the way that days, months and years are a natural unit of time), taxonomic classifications above that like genuses, families, and orders actually aren't (sort of like weeks). We sometimes use them as a shorthand to help us conceptualize the evolutionary tree of the species we're talking about, but they're largely a holdover from an older, Linnean school of classifying life. Most biologists today think primarily in terms of species.

    Does that help to clarify anything?
     
  19. Romy

    Romy Taxiderpy

    Joined:
    Dec 2, 2006
    Messages:
    10,234
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Olympia, WA
    It does, although I disagree that wolves and dogs hybridize freely in the wild when they do encounter each other without human intervention. Most wild wolves will happily eat a dog.

    http://onlinelibrary.wiley.com/doi/10.1046/j.1523-1739.1999.97425.x/abstract

    http://link.springer.com/article/10.1023%2FA%3A1014229610646?LI=true

    And actually coydogs aren't that uncommon. Coyotes eat dogs, but their more fluid social structure and close proximity to people allows for a lot of coyote/dog interaction. There's a coydog in the local coyote pack, a whole litter of them (feral) were collected on the Tohono o'Odham reservation and were turned into a rescue in Tucson, AZ when I was living there. There's even a member on this board who has one.

    http://onlinelibrary.wiley.com/doi/10.1046/j.1365-294X.2003.01708.x/abstract?deniedAccessCustomisedMessage=&userIsAuthenticated=false

    The Canadian lynx X bobcat occur pretty frequently in the wild, enough that there are serious concerns about hybridization impeding the recovery of the wild lynx population.

    http://www.nrri.umn.edu/lynx/information/hybrid.html

    The spotted owl's greatest threat to recovery now is hybridization with the common barred owl. And that polar bear/grizzly hybrid I posted the picture of was of a wild animal. Several have also been shot by hunters but I don't want to post pics because they're kind of gory.
     
  20. Pops2

    Pops2 New Member

    Joined:
    Sep 21, 2008
    Messages:
    3,072
    Likes Received:
    0
    Trophy Points:
    0
    Occupation:
    none
    Location:
    UT
    No actually the theory is not comfortably established within the second law of thermodynamics. According to the second law, a subsystem within a system can only experience negative entropy (movement from chaos to order or order to greater order) by the ENTROPY of ANOTHER SUBSYSTEM. Applied to evolution, one species (subsystem) can only evolve (negative entropy) by feeding off the devolution (entropy) of another species (subsystem). Evolution theory says that negative entropy in one subsystem causes negative entropy in another. That is absolutely contrary to the second law.
    According to the theory a portion of a foundation species changes its DNA in response to external factors and becomes a new species. Medical science has shown unequivocally that adding or taking away a chromosome to/from a normal DNA sequence almost universally results in defects that are survival disadvantages.
    That's something that stayed in my brain from an article about ten years ago. Current searches showed ranges from 98.8 to 99.07 %.
     

Share This Page