Join our zoo community

Domestic Fowl Taxonomy

Discussion in 'General Zoo Discussion' started by Cassidy Casuar, 17 Oct 2014.

  1. Cassidy Casuar

    Cassidy Casuar Well-Known Member

    Joined:
    16 Jul 2014
    Posts:
    68
    Location:
    Wellington
    I am aware of the fact that this is not particularly zoo-related and might not belong here, but it would be good if someone could answer this.
    To my understanding, Domestic Fowl are classified as a subspecies of the Red Junglefowl. If this is true, then does this mean that the evidence of them being the descendants of Red x Green and/or Red x Grey Junglefowl is being ignored? Why are they not instead classified as a hybrid "species"?
    Thanks in advance for any help.
     
  2. Chlidonias

    Chlidonias Moderator Staff Member

    Joined:
    13 Jun 2007
    Posts:
    16,301
    Location:
    omnipresent
    basically, domestic animals are a bit vague taxonomically and there isn't a lot of consistency in how they are treated. They generally waver between being considered the same as their wild ancestors, being considered subspecies, and (especially recently) being completely split off as full species. It depends on author and the trend of the time, and of course each species needs to be considered on its own merits not under an overall "domestic animal" banner. You'd be lucky to find any domestic animal where there is a firm consensus on how to name it. The best you can usually manage is something like "at the current time, most authorities consider x to be called by this scientific name". It is further complicated by situations where even the ancestor species is disputed, and of course by situations where there may be several ancestor species mixed together (as in some of the domestic bovids).

    For domestic chickens the base stock is red junglefowl Gallus gallus. Any additional genetics from other junglefowl species are small, so they are still considered to be domesticated red junglefowl. I can't see there being any case for splitting them into a separate species.
     
  3. Cassidy Casuar

    Cassidy Casuar Well-Known Member

    Joined:
    16 Jul 2014
    Posts:
    68
    Location:
    Wellington
    What about domestic rabbits? I have never seen them being classified differently from wild European rabbits, which are undoubtedly their only wild ancestors.
     
  4. Chlidonias

    Chlidonias Moderator Staff Member

    Joined:
    13 Jun 2007
    Posts:
    16,301
    Location:
    omnipresent
    well there's one then :D Also mice, and rats too I guess. I was thinking more along the lines of farm and working animals, so overlooked the pet ones.
     
  5. billnaylor

    billnaylor Member

    Joined:
    11 Oct 2014
    Posts:
    15
    Location:
    uk
    Subspecies is an exclusive term for a population of a species that differs physically.
    A domestic variety can't be subspecies, as it is not part of the wild population.
    Sub species or race is merely a convenient term for identifying different populations within a species.
    Once a wild species is selectively bred the variations are termed varieties.
    Although interestingly if some of those varieties produced by artificial selection in captivity such as in domestic dogs,poultry and pigeons were found in the wild, they would be classified as distinct species.But being domestic they are termed varieties of one or more wild specie.
    Many zoo animals bred over a number of generations sometimes incorporating genes from different subspecies may no longer resemble the true wild type species.
    And even if they do, their genes may not be pure.
     
  6. Chlidonias

    Chlidonias Moderator Staff Member

    Joined:
    13 Jun 2007
    Posts:
    16,301
    Location:
    omnipresent
    Partly true. The subspecies does not have to differ physically. There are many instances where subspecies are or have been named based solely on geographical separation and cannot be distinguished otherwise.

    They can and they commonly are.

    Exactly. "Subspecies" is a subjective human construct, and hence your preceding statement becomes meaningless ;)

    The different forms within the domesticated animal may be called varieties (or breeds) but the overall animal (say the domestic chicken) is not called a variety.

    Not true at all. A domestic muscovy or domestic pigeon in the wild would quite plainly be considered the same species as its wild ancestor, it is just a domesticated form. A Siamese cat may not look at all like a wild cat but it is easily shown to not be a distinct species in its own right. In some animals the domestic can be shown to be now genetically distinct from the wild ancestor (say, Bactrian camels) but otherwise your statement is completely wrong.

    I'm not sure what this has to do with chickens but it is a fairly obvious thing to say. Many zoo animals are subspecific hybrids and many are horribly inbred.
     
  7. lamna

    lamna Well-Known Member

    Joined:
    21 Jul 2013
    Posts:
    384
    Location:
    West Midlands, UK
    Taxonomy is a real mess, mostly because animals won't follow the rules. Some species separate for millions of years breed and produce fertile a fertile hybrid species, others look very similar but have been genetically distinct for hundreds of thousands of years.

    Hopefully in 20 years things will be sorted out, but for now don't take taxonomy too seriously, the rules are still being rewritten.
     
  8. Jackwow

    Jackwow Well-Known Member

    Joined:
    25 Nov 2012
    Posts:
    448
    Location:
    In Scotland at the moment
    I thought this thread was meant to be about stuffing chickens?!
     
  9. billnaylor

    billnaylor Member

    Joined:
    11 Oct 2014
    Posts:
    15
    Location:
    uk
    Reply to Childonias from Bill Naylor

    The term Domestic fowl taxonomy is a misnomer.
    As zoological taxonomy is not applied to domestic animals.

    Your quote:
    The subspecies does not have to differ physically.
    There are many instances where subspecies have been named based on geographical separation.

    Not true. The classic definition of subspecies repeated through many zoology textbooks is ‘a subspecies is population that can be morphologically distinguished’ (Morphological, shape and form) Hence the time spent by zoologists measuring and weighing wild caught animals.
    When a population is distinct from other members of the species it can be considered a subspecies or race. If there were no variation why would it be termed a race?

    Your quote: A domestic variety can be a subspecies and they commonly are.

    No they are not. Total misconception of the term subspecies.

    Your quote: subspecies is a subjective human construct.
    Man made you mean?
    Well so are species, genus and all other taxonomic ranks.
    Which I need to emphasise are used as biological classification for exclusively wild species, not domestic varieties of species.
    But the point I was making was that subspecies is a convenient way of categorising a variant population within a species, produced by natural selection. It isn’t applied to domestic varieties produced by artificial selection.
    My statement: If some of those varieties produced by artificial selection in captivity such as domestic dogs poultry and pigeons were found in the wild, they would be classified as distinct species. I was referring to domestic varieties which have become changed dramatically from the wild ancestor through selective breeding, such as in the Chihuahua. Or Aylesbury duck, totally unlike it’s wild ancestor the European Mallard.
    I’m not the first to make this point. Darwin wrote about the diversity of domestic pigeons breeds, all originating from their common ancestor the Rock dove.which he observed, if occurring in the wild would be distinct species
    Your reply that a domestic pigeon or domestic muscovy in the wild would be considered the same species, is stating the obvious, and missing the point that Darwin and I were speaking hypothetically, to make the point that
    the diversity of domestic breeds has parallels with the evolution of
    wild species.
    I apologise if my point about zoo animals incorporating genes from different subspecies was obvious. I was just trying to emphasise that a wild species bred in captivity like domestic species, is no longer shaped by natural selection.
    And even with the best intentions the captive environment will impact on it
    physically and mentally. And over time it will become a wild type domestic animal.
    My quote: Once a wild species is selectively bred the variations are called varieties.
    Your reply:
    The over all animal (say the domestic chicken) is not a variety.

    The domestic chicken is obviously a variety as it is does not in anyway resemble its ancestor the Red Jungle fowl. If a domestic animal resembles its wild ancestor it’s termed wild type.
     
  10. Chlidonias

    Chlidonias Moderator Staff Member

    Joined:
    13 Jun 2007
    Posts:
    16,301
    Location:
    omnipresent
    I haven't got time really to constuct a detailed reply to billnaylor because you have many misconceptions and personal opinions in there, as well as outdated notions (e.g. the one referencing how species were considered at the time of Darwin - you know, before anyone even knew what a gene was!), not to mention the misquoting of what I wrote. Suffice to say, I leave my original reply to you as it stands.
     
  11. billnaylor

    billnaylor Member

    Joined:
    11 Oct 2014
    Posts:
    15
    Location:
    uk
    Which out dated notions? The discovery of how genes worked by Mendel and subsequent discovery of DNA by Crick and Watson supports and confirms Darwin’s theory of evolution and common ancestry by means of natural selection. A theory that included data from captive breeding. some of which Darwin acquired personally from his own experiments mainly with varieties of pigeons and fowls.
    (Note variety, not subspecies) Like all plant and animal breeders in the 1800’s Darwin was aware of inherited (dominant ) and passive (recessive traits), but was unaware
    genes were responsible.
    Members will be able to draw their own conclusion from the postings as to whether you were misquoted.
     
  12. DDcorvus

    DDcorvus Well-Known Member

    Joined:
    18 Aug 2008
    Posts:
    1,167
    Location:
    everywhere and nowhere
    We moved quite bit beyond that, there is are discussion going on what to do with species that look the same but are genetically very distinct the main debate varies between classifying these as different subspecies or different species, but there is quite a lot of agreement that genetic difference should be recognized.

    Actually they are, not individual races but the domestic form of a species is in most cases classified as a separate subspecies see canis lupus familiaris, bos taurus taurus, felis silvestris catus. Only case of very recent domesticated species this is not the case like in Melopsittacus undulatus. You might disagree with this but then I propose you start working on a peer-reviewd article on the taxonomy of domesticated varieties.


    Actually populations in captivity are influenced by things like genetic drift, but as well by natural selection (please note that natural does not have to mean to be shaped by being in the wild) only the selection pressures are very different from the populations in the wild. How do individuals cope with human pressence or being fed different food etc etc. We do agree on the end result that this makes that over time captive populations start to differ quite a lot from the wild populations. In some bird species there are indications this can happen already in a couple of generations. A solution would be to ensure that there is an exchange between the captive and wild populations to limit these effects although this will make management more challenging.
     
  13. Pertinax

    Pertinax Well-Known Member

    Joined:
    5 Dec 2006
    Posts:
    16,417
    Location:
    england
    Some domestic fowl do resemble Red Jungle fowl. The ancestral 'black/red'/ wild-type colouration is found as either predominant in e.g the Welsummer, or as one of several colours (varieties) in a number of breeds, -the cockerels that is, while the hens follow the 'partridge' colouration of the female ancestor.

    I would reserve the term 'variety' for the offshoots- in type, colour, appearance etc- of an already domesticated species, for which I think the most accurate term may be 'breed'- as in 'domesticated breed'.
     
  14. billnaylor

    billnaylor Member

    Joined:
    11 Oct 2014
    Posts:
    15
    Location:
    uk
    BN:
    Sorry but captive animals are not subject to natural selection no matter how much you stretch the definition. They are totally isolated from their ecosystem which includes weather, flora and fauna which they interact with. And it’s one of the main challenges zoos have to meet, to simulate and compensate. And they’ll always fall short.
     
  15. billnaylor

    billnaylor Member

    Joined:
    11 Oct 2014
    Posts:
    15
    Location:
    uk
    Domestic chicken and red jungle fowl indistinguishable

    Okay, there is some similar plumage, but c'mon a domestic chicken alongside any species of Jungle fowl would be picked out of a line up.
    Lifes complicated enough as they say on the adds, variety is synonymous with breed, why change it?
     
  16. Chlidonias

    Chlidonias Moderator Staff Member

    Joined:
    13 Jun 2007
    Posts:
    16,301
    Location:
    omnipresent
    nobody said the discovery of DNA disproved evolution. What you said was that varieties of domestic animals would be considered distinct species if found in the wild, and used Darwin's opinion as such as evidence. It means nothing because at the time of Darwin, species limits were generally determined by outward appearance because they didn't have the benefit of genetic analyses. That Darwin may have thought that a, say, pekingese would be considered a different species to a wolf is completely irrelevant today.

    With regards to "experiments mainly with varieties of pigeons and fowls. (Note variety, not subspecies)" -- yes, varieties. Nobody has disputed that domestic animals are composed of many individual varieties. But the whole animal itself is not a variety (as Pertinax earlier noted but you do not seem to agree with).

    yes, they will. By reading what you wrote ;)


    I'll leave your replies to DDCorvus for him to reply to your misinterpretations and mistakes.
     
  17. Pertinax

    Pertinax Well-Known Member

    Joined:
    5 Dec 2006
    Posts:
    16,417
    Location:
    england
    1. The 'black/red' plumage is the same as the wild bird from which it derives. I said that birds with this plumage colour resembled Jungle Fowl- I did not say they were indistinguishable as per your subheading above- the two things are quite different. Obviously most domestic chickens do differ in shape, size etc from Jungle Fowl, as well as having many other colour forms.

    2. Variety is not quite synonymous with breed. A 'breed' can sometimes have many 'varieties'.
     
    Last edited: 22 Oct 2014
  18. DDcorvus

    DDcorvus Well-Known Member

    Joined:
    18 Aug 2008
    Posts:
    1,167
    Location:
    everywhere and nowhere
    Here I go then

    I was actually referring to vertebrate species as well. You might wanna have a closer look into Crocodylus suchus. Als research from 2011 showed that in Argentina there are 3 genetically different populations of Burrowing parrots out which 2 of them look exactly similar but there has been no exchange of genes later then 9.000 years ago. And you also might be aware of the genetic distinctiveness of the Bryde's whale population in the golf of Mexico.


    There is inherent inconsistency in the naming of non-domestic species as well. Put 3 Taxonomists in a room and you will get 5 different proposals. This makes the discussion around classifying domestic animals as subspecies very similar to the debates around species with wild population.


    Firstly animals in captivity are under selection, there are always individuals that seem to fit more than others and leave us with more offspring. You can call it natural or not but in the end it is the same process is the animal suitable for the habitat it is living in. Only in the case the habitat is a man-created one in captivity. And it is one that always will differ from the natural one.
     
  19. billnaylor

    billnaylor Member

    Joined:
    11 Oct 2014
    Posts:
    15
    Location:
    uk
    Another distorted reply,

    No bias there then. You have already decided my replies will be full of mistakes and misinterpretations.
    I must say you have an amusing knack for confidently grasping the wrong end of the stick. Then issuing an illogical comment such as:
    "The whole animal is not a variety." What does that mean? The entire domestic population? If a domestic animal doesn't resemble
    the wild type, yes it is a variety. DDCorvus, your spokesperson, well chosen. The same guy who believes captive animals are subject to natural selection.It's been entertaining but life's too short to continue.
     
  20. DDcorvus

    DDcorvus Well-Known Member

    Joined:
    18 Aug 2008
    Posts:
    1,167
    Location:
    everywhere and nowhere

    A shame Bill that you stopped responding on content and in case of of my believe I would recommend Frankham's 2008 paper: Genetic adaptation to captivity in species conservation programs

    If you feel that is not enough I also have another paper that deals more with a particular group of animals.