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Re: [Genetics-Psittacine] Natural inbreeding?

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  • Peter Wouters
    Recio and others, The first thing that comes to mind is the story of the cheetah. These are so closely related that they are probably descended from a few
    Message 1 of 15 , Nov 1, 2011
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      Recio and others,
       
      The first thing that comes to mind is the story of the cheetah. These are so closely related that they are probably descended from a few individuals. On a TV documentary they talked about one mother and her young.
      When you are talking about inbreeding in the wild, I think the most important factor is "geographical isolation". In this situation, the likelihood that closely related individuals mate with each other is big. Examples include nature reserves, deforested areas. Certain genetic traits, good or bad, then show themself easily.
      This factor may also help to develop other species.
      Another point is that inbreeding doesn’t necessarily lead to bad traits. It is theoretical possible to have a brother and sister who are 100% unrelated. It depends on which chromosomes the parents passed on to their offspring.
       
      Regards
      Peter
       
      From: XP 2600
      Sent: Tuesday, November 01, 2011 1:18 AM
      Subject: Re: [Genetics-Psittacine] Natural inbreeding?
       
       

      Hello all,
      Well mostly the inbreeding vary from genus to another, some birds or mammals seems does not get affected by inbreeding than others, mostly depend on what is the negative traits could be revealed by inbreeding, so while some birds have it in nature so mostly they are resistant to the bad characteristics of weakness and so on, but i don't think its the right idea in lovebirds, for example once i mated siblings just cause i did not have any other birds, and this couple never have one survived chick! all were drop at about two weeks old, when i split the couple and mate each of it both produced very well!

      Imam

      On Tue, Nov 1, 2011 at 1:55 AM, Pablo Caride <pablo.caride@...> wrote:
       

      Recio,

       
      this subject is very interesting, or at least I find it quite interesting since I have been researching a lot on the theoretical side of inbreeding and linebreeding.
       
      Thank you for sharing your views/knowledge on the subject.
       
      I start to think, more and more, that inbreeding is surrounded by some old wives tales.
      I'm pretty sure there are lots and lots of people that have a lovely pair of cockatiels, lovebirds or budgies that they bought in some random petshop, not knowing that they are brother and sister, and they are breeding healthy chicks.
       
      Also read in poultry articles about people that started breeding a given breed of chickens, partridges or quail from a trio of 3 full siblings. Of course breeding poultry is a whole different game than breeding psittacines, as you can mate 1 cock to several hens and with the use of an incubator you can hatch many more chicks, meaning that you have a bigger population from which you can make a selection (compared to psittacines, that many species don't usually hatch more than 1 batch/year of 2-4 chicks).
       
      Kind regards,
       
      Pablo Caride
      Vigo - Spain
       
       
       
      On Mon, Oct 31, 2011 at 9:07 PM, Recio Joaquin <jrecio99@...> wrote:
       
      Hi everybody;
       
      I use tu put all my young IRN together in the same aviary, and I have noticed that very often couples are made. Curiously these couples are not random: many times (far more often than expected) these couples are made between closely related birds, mainly sister-brother type. I spoke about this with a breeder who confirmed me that this happens also in wild birds: he has been ringing wild birds breeding in his property (swallows, sparrows, goldfinches, ...) for years and he has noticed very often that the couples were made of brother and sister from the last breeding season. Then I read here about the homozygous acqua mutation female IRN that Bala found in wildness, which is quite a rare event if we do not consider a tendency to inbreeding in wild birds. Similar for the first CHCT caught in the wild and for all the other recessive mutations coming from wild birds: the likelyness to happen in a non-restricted area seems to be too low if there is not a tendency to inbreeding in wild birds.
       
      The question: Could be inbreeding a succesfull breeding strategy in wild birds? If it was the case... which are the conditions for this succes to happen?
      Please, forget all antropomorphic consideration in analizing the question.
       
      Thanks
       
      Recio


       



      --
      Imam
      MCSA MCSE
    • Peter Wouters
      Recio, On this subject I forgot to mention the wild IRN populations in various parts of Europe. In 1974, about 50 IRN s were released in the Meli zoo in
      Message 2 of 15 , Nov 1, 2011
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        Recio,
         
        On this subject I forgot to mention the wild IRN populations in various parts of Europe. In 1974, about 50 IRN's were released in the Meli zoo in Brussels. They quickly spread over Brussels and in 2005 their number was estimated at 7000. There are similar cases in the Netherlands and London. See also http://www.youtube.com/watch?v=p4P_NhFlb5w&feature=related
         
        Regards
        Peter
         
        Sent: Tuesday, November 01, 2011 11:06 AM
        Subject: Re: [Genetics-Psittacine] Natural inbreeding?
         
         

        Recio and others,
         
        The first thing that comes to mind is the story of the cheetah. These are so closely related that they are probably descended from a few individuals. On a TV documentary they talked about one mother and her young.
        When you are talking about inbreeding in the wild, I think the most important factor is "geographical isolation". In this situation, the likelihood that closely related individuals mate with each other is big. Examples include nature reserves, deforested areas. Certain genetic traits, good or bad, then show themself easily.
        This factor may also help to develop other species.
        Another point is that inbreeding doesn’t necessarily lead to bad traits. It is theoretical possible to have a brother and sister who are 100% unrelated. It depends on which chromosomes the parents passed on to their offspring.
         
        Regards
        Peter
         
        From: XP 2600
        Sent: Tuesday, November 01, 2011 1:18 AM
        Subject: Re: [Genetics-Psittacine] Natural inbreeding?
         
         

        Hello all,
        Well mostly the inbreeding vary from genus to another, some birds or mammals seems does not get affected by inbreeding than others, mostly depend on what is the negative traits could be revealed by inbreeding, so while some birds have it in nature so mostly they are resistant to the bad characteristics of weakness and so on, but i don't think its the right idea in lovebirds, for example once i mated siblings just cause i did not have any other birds, and this couple never have one survived chick! all were drop at about two weeks old, when i split the couple and mate each of it both produced very well!

        Imam

        On Tue, Nov 1, 2011 at 1:55 AM, Pablo Caride <pablo.caride@...> wrote:
         

        Recio,

         
        this subject is very interesting, or at least I find it quite interesting since I have been researching a lot on the theoretical side of inbreeding and linebreeding.
         
        Thank you for sharing your views/knowledge on the subject.
         
        I start to think, more and more, that inbreeding is surrounded by some old wives tales.
        I'm pretty sure there are lots and lots of people that have a lovely pair of cockatiels, lovebirds or budgies that they bought in some random petshop, not knowing that they are brother and sister, and they are breeding healthy chicks.
         
        Also read in poultry articles about people that started breeding a given breed of chickens, partridges or quail from a trio of 3 full siblings. Of course breeding poultry is a whole different game than breeding psittacines, as you can mate 1 cock to several hens and with the use of an incubator you can hatch many more chicks, meaning that you have a bigger population from which you can make a selection (compared to psittacines, that many species don't usually hatch more than 1 batch/year of 2-4 chicks).
         
        Kind regards,
         
        Pablo Caride
        Vigo - Spain
         
         
         
        On Mon, Oct 31, 2011 at 9:07 PM, Recio Joaquin <jrecio99@...> wrote:
         
        Hi everybody;
         
        I use tu put all my young IRN together in the same aviary, and I have noticed that very often couples are made. Curiously these couples are not random: many times (far more often than expected) these couples are made between closely related birds, mainly sister-brother type. I spoke about this with a breeder who confirmed me that this happens also in wild birds: he has been ringing wild birds breeding in his property (swallows, sparrows, goldfinches, ...) for years and he has noticed very often that the couples were made of brother and sister from the last breeding season. Then I read here about the homozygous acqua mutation female IRN that Bala found in wildness, which is quite a rare event if we do not consider a tendency to inbreeding in wild birds. Similar for the first CHCT caught in the wild and for all the other recessive mutations coming from wild birds: the likelyness to happen in a non-restricted area seems to be too low if there is not a tendency to inbreeding in wild birds.
         
        The question: Could be inbreeding a succesfull breeding strategy in wild birds? If it was the case... which are the conditions for this succes to happen?
        Please, forget all antropomorphic consideration in analizing the question.
         
        Thanks
         
        Recio


         



        --
        Imam
        MCSA MCSE
      • Recio Joaquin
        Hi Pablo, Imam, Peter and everybody,   Budgies breeding in colony usually show a high inbreeding rate since there are 2-3 adult males who become the genetic
        Message 3 of 15 , Nov 1, 2011
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          Hi Pablo, Imam, Peter and everybody,
           
          Budgies breeding in colony usually show a high inbreeding rate since there are 2-3 adult males who become the genetic fathers of all the youngs. Inbreeding seems also occur in european and american populations of IRN which grow apparently without any "weakness" despite that they arise from a very low number of individuals and that they must adapt to an environemental which is not the same than in shouth-est Asia. Even in mammals we can see that inbreeding does not necassarily mean weakness, genetic disorders, and so on: all the golden hamster (Syrian hamster or Mesocricetus auratus) we can find as pets all the world around, with many mutations in color, hair type, ..., all of them come from 3 individuals captured in the wild in the early XX century.
          On the other hand we have the cheetah: they are so closely related that their HLA (histocompatibility system) is almost the same, at a point that you can graft a piece of skin from a cheetah to another without any rejection. They are like tweens, like a clon. This does not mean that they are sick or weak, but their survival on the long term seems hazardous because they do not have the genetic variability to adapt to the changing conditions of the environement (in their population the quantity of different alleles per gen is too low).
           
          From the above evidences we could think that inbreeding does not necessarily mean weak descendents or genetic disorders, but it seems that it works better in living beings with a high rate of spontaneous mutations to allow them to compensate for the lost of genetic variability when inbreeding.
           
          We all also know that inbreeding is a mechanism acting on speciation when living beings are isolated ... but my question goes further: can inbreeding become a breeding strategy with better results than outbreeding, in wild animals without restrictive conditions?
          Something to think about: some months ago Jaynee said that she was creating mutations (obviously speaking about combination of mutations), big smile, and ... a question: if it was true? can we increase the mutation rate by inbreeding and not only make become apparent mutations which are already in the genetic make up of our birds, but that we can not see? Can inbreeding really create mutations? There is a theoretical mechanism to do so: DNA is constantly under pression to mutate (radiations, pH changes, free radicals, ...), and every day our DNA is broken and repaired. If the system to repair the DNA is affected by inbreeding we should expect more mutations to appear in inbreeding populations. In humans this system can be affected and induce mutations in our skin cells leading to cancers (this illness in humans is called xeroderma pigmentosum). If the same system was affected in the gonads it could explain a higher rate of mutations passing to the offspring.
           
          What I am meaning is that inbreeding, in some groups of animals, could become the origin of an increase in genetic variability instead of the opposite as usually accepted. This could be considered as a feedback system: when the size of a population decreases (decrease of its genetic variability) the system supervising the DNA integrity would work with less of efficacity allowing an increase in the mutation rate in this population. This could explain why in captivity (=inbreeding) we can develop a very big number of mutations in a very short time when comparing to the process of speciation in Nature. I am convinced that we are doing more than a selection of the mutations already presents in the nature, but we are acting like a blind person, without really knowing it.... or may be not : is there any scientific work on this subject, Terry & Inte?
           
          Regards
           
          Recio
           
          From: Recio Joaquin <jrecio99@...>
          To: Genetics-Psittacine@yahoogroups.com
          Sent: Monday, October 31, 2011 9:07 PM
          Subject: [Genetics-Psittacine] Natural inbreeding?

           
          Hi everybody;
           
          I use tu put all my young IRN together in the same aviary, and I have noticed that very often couples are made. Curiously these couples are not random: many times (far more often than expected) these couples are made between closely related birds, mainly sister-brother type. I spoke about this with a breeder who confirmed me that this happens also in wild birds: he has been ringing wild birds breeding in his property (swallows, sparrows, goldfinches, ...) for years and he has noticed very often that the couples were made of brother and sister from the last breeding season. Then I read here about the homozygous acqua mutation female IRN that Bala found in wildness, which is quite a rare event if we do not consider a tendency to inbreeding in wild birds. Similar for the first CHCT caught in the wild and for all the other recessive mutations coming from wild birds: the likelyness to happen in a non-restricted area seems to be too low if there is not a tendency to inbreeding in wild birds.
           
          The question: Could be inbreeding a succesfull breeding strategy in wild birds? If it was the case... which are the conditions for this succes to happen?
          Please, forget all antropomorphic consideration in analizing the question.
           
          Thanks
           
          Recio




        • Peter Wouters
          can inbreeding become a breeding strategy with better results than outbreeding, in wild animals without restrictive conditions? I’ve found 2. 1) It may
          Message 4 of 15 , Nov 1, 2011
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            can inbreeding become a breeding strategy with better results than outbreeding, in wild animals without restrictive conditions?
             
            I’ve found 2.
            1) It may maintain adaptions to local conditions
            2) Combined with natural selection it can purge harmful recessive genes from the genetic pool
             
            Regards
            Peter

             
            Sent: Tuesday, November 01, 2011 8:43 PM
            Subject: Re: [Genetics-Psittacine] Natural inbreeding?
             
             

            Hi Pablo, Imam, Peter and everybody,
             
            Budgies breeding in colony usually show a high inbreeding rate since there are 2-3 adult males who become the genetic fathers of all the youngs. Inbreeding seems also occur in european and american populations of IRN which grow apparently without any "weakness" despite that they arise from a very low number of individuals and that they must adapt to an environemental which is not the same than in shouth-est Asia. Even in mammals we can see that inbreeding does not necassarily mean weakness, genetic disorders, and so on: all the golden hamster (Syrian hamster or Mesocricetus auratus) we can find as pets all the world around, with many mutations in color, hair type, ..., all of them come from 3 individuals captured in the wild in the early XX century.
            On the other hand we have the cheetah: they are so closely related that their HLA (histocompatibility system) is almost the same, at a point that you can graft a piece of skin from a cheetah to another without any rejection. They are like tweens, like a clon. This does not mean that they are sick or weak, but their survival on the long term seems hazardous because they do not have the genetic variability to adapt to the changing conditions of the environement (in their population the quantity of different alleles per gen is too low).
             
            From the above evidences we could think that inbreeding does not necessarily mean weak descendents or genetic disorders, but it seems that it works better in living beings with a high rate of spontaneous mutations to allow them to compensate for the lost of genetic variability when inbreeding.
             
            We all also know that inbreeding is a mechanism acting on speciation when living beings are isolated ... but my question goes further: can inbreeding become a breeding strategy with better results than outbreeding, in wild animals without restrictive conditions?
            Something to think about: some months ago Jaynee said that she was creating mutations (obviously speaking about combination of mutations), big smile, and ... a question: if it was true? can we increase the mutation rate by inbreeding and not only make become apparent mutations which are already in the genetic make up of our birds, but that we can not see? Can inbreeding really create mutations? There is a theoretical mechanism to do so: DNA is constantly under pression to mutate (radiations, pH changes, free radicals, ...), and every day our DNA is broken and repaired. If the system to repair the DNA is affected by inbreeding we should expect more mutations to appear in inbreeding populations. In humans this system can be affected and induce mutations in our skin cells leading to cancers (this illness in humans is called xeroderma pigmentosum). If the same system was affected in the gonads it could explain a higher rate of mutations passing to the offspring.
             
            What I am meaning is that inbreeding, in some groups of animals, could become the origin of an increase in genetic variability instead of the opposite as usually accepted. This could be considered as a feedback system: when the size of a population decreases (decrease of its genetic variability) the system supervising the DNA integrity would work with less of efficacity allowing an increase in the mutation rate in this population. This could explain why in captivity (=inbreeding) we can develop a very big number of mutations in a very short time when comparing to the process of speciation in Nature. I am convinced that we are doing more than a selection of the mutations already presents in the nature, but we are acting like a blind person, without really knowing it.... or may be not : is there any scientific work on this subject, Terry & Inte?
             
            Regards
             
            Recio
             
            From: Recio Joaquin <jrecio99@...>
            To: Genetics-Psittacine@yahoogroups.com
            Sent: Monday, October 31, 2011 9:07 PM
            Subject: [Genetics-Psittacine] Natural inbreeding?

             
            Hi everybody;
             
            I use tu put all my young IRN together in the same aviary, and I have noticed that very often couples are made. Curiously these couples are not random: many times (far more often than expected) these couples are made between closely related birds, mainly sister-brother type. I spoke about this with a breeder who confirmed me that this happens also in wild birds: he has been ringing wild birds breeding in his property (swallows, sparrows, goldfinches, ...) for years and he has noticed very often that the couples were made of brother and sister from the last breeding season. Then I read here about the homozygous acqua mutation female IRN that Bala found in wildness, which is quite a rare event if we do not consider a tendency to inbreeding in wild birds. Similar for the first CHCT caught in the wild and for all the other recessive mutations coming from wild birds: the likelyness to happen in a non-restricted area seems to be too low if there is not a tendency to inbreeding in wild birds.
             
            The question: Could be inbreeding a succesfull breeding strategy in wild birds? If it was the case... which are the conditions for this succes to happen?
            Please, forget all antropomorphic consideration in analizing the question.
             
            Thanks
             
            Recio




          • Terry Martin
            Recio I do not believe inbreeding changes mutation rates, merely increases the rate at which hidden recessive traits will appear. As you all have said,
            Message 5 of 15 , Nov 1, 2011
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              Recio
               
                      I do not believe inbreeding changes mutation rates, merely increases the rate at which hidden recessive traits will appear.
               
                      As you all have said, inbreeding does not necessarily cause problems. In fact all of our breeds of animals have been established through a significant amount of inbreeding to 'fix' certain traits. But the end result of this is that many pure breeds have such limited gene pools that they have certain specific health problems.
               
                      In poultry, some breeds seem to go on for decades with no problems with their vitality. But many of the other rare breeds suffer continually with fertility problems and lack of vigour, meaning they fall over to diseases that might not bother another breed.
               
                      There is no doubt that continual out breeding produces a more vigorous bird. But it depends on the aim of your breeding as to whether this is the best approach.
               
                      Terry
              ----- Original Message -----
              Sent: Wednesday, November 02, 2011 5:43 AM
              Subject: Re: [Genetics-Psittacine] Natural inbreeding?

              Hi Pablo, Imam, Peter and everybody,
               
              Budgies breeding in colony usually show a high inbreeding rate since there are 2-3 adult males who become the genetic fathers of all the youngs. Inbreeding seems also occur in european and american populations of IRN which grow apparently without any "weakness" despite that they arise from a very low number of individuals and that they must adapt to an environemental which is not the same than in shouth-est Asia. Even in mammals we can see that inbreeding does not necassarily mean weakness, genetic disorders, and so on: all the golden hamster (Syrian hamster or Mesocricetus auratus) we can find as pets all the world around, with many mutations in color, hair type, ..., all of them come from 3 individuals captured in the wild in the early XX century.
              On the other hand we have the cheetah: they are so closely related that their HLA (histocompatibility system) is almost the same, at a point that you can graft a piece of skin from a cheetah to another without any rejection. They are like tweens, like a clon. This does not mean that they are sick or weak, but their survival on the long term seems hazardous because they do not have the genetic variability to adapt to the changing conditions of the environement (in their population the quantity of different alleles per gen is too low).
               
              From the above evidences we could think that inbreeding does not necessarily mean weak descendents or genetic disorders, but it seems that it works better in living beings with a high rate of spontaneous mutations to allow them to compensate for the lost of genetic variability when inbreeding.
               
              We all also know that inbreeding is a mechanism acting on speciation when living beings are isolated ... but my question goes further: can inbreeding become a breeding strategy with better results than outbreeding, in wild animals without restrictive conditions?
              Something to think about: some months ago Jaynee said that she was creating mutations (obviously speaking about combination of mutations), big smile, and ... a question: if it was true? can we increase the mutation rate by inbreeding and not only make become apparent mutations which are already in the genetic make up of our birds, but that we can not see? Can inbreeding really create mutations? There is a theoretical mechanism to do so: DNA is constantly under pression to mutate (radiations, pH changes, free radicals, ...), and every day our DNA is broken and repaired. If the system to repair the DNA is affected by inbreeding we should expect more mutations to appear in inbreeding populations. In humans this system can be affected and induce mutations in our skin cells leading to cancers (this illness in humans is called xeroderma pigmentosum). If the same system was affected in the gonads it could explain a higher rate of mutations passing to the offspring.
               
              What I am meaning is that inbreeding, in some groups of animals, could become the origin of an increase in genetic variability instead of the opposite as usually accepted. This could be considered as a feedback system: when the size of a population decreases (decrease of its genetic variability) the system supervising the DNA integrity would work with less of efficacity allowing an increase in the mutation rate in this population. This could explain why in captivity (=inbreeding) we can develop a very big number of mutations in a very short time when comparing to the process of speciation in Nature. I am convinced that we are doing more than a selection of the mutations already presents in the nature, but we are acting like a blind person, without really knowing it.... or may be not : is there any scientific work on this subject, Terry & Inte?
               
              Regards
               
              Recio
               
              From: Recio Joaquin <jrecio99@...>
              To: Genetics-Psittacine@yahoogroups.com
              Sent: Monday, October 31, 2011 9:07 PM
              Subject: [Genetics-Psittacine] Natural inbreeding?

               
              Hi everybody;
               
              I use tu put all my young IRN together in the same aviary, and I have noticed that very often couples are made. Curiously these couples are not random: many times (far more often than expected) these couples are made between closely related birds, mainly sister-brother type. I spoke about this with a breeder who confirmed me that this happens also in wild birds: he has been ringing wild birds breeding in his property (swallows, sparrows, goldfinches, ...) for years and he has noticed very often that the couples were made of brother and sister from the last breeding season. Then I read here about the homozygous acqua mutation female IRN that Bala found in wildness, which is quite a rare event if we do not consider a tendency to inbreeding in wild birds. Similar for the first CHCT caught in the wild and for all the other recessive mutations coming from wild birds: the likelyness to happen in a non-restricted area seems to be too low if there is not a tendency to inbreeding in wild birds.
               
              The question: Could be inbreeding a succesfull breeding strategy in wild birds? If it was the case... which are the conditions for this succes to happen?
              Please, forget all antropomorphic consideration in analizing the question.
               
              Thanks
               
              Recio




            • Recio Joaquin
              Hi Peter,   You are right. Inbreeding must be studied under the effect of natural selection: Outbreeding will produce a general healthy offspring similar in
              Message 6 of 15 , Nov 2, 2011
              • 0 Attachment
                Hi Peter,
                 
                You are right. Inbreeding must be studied under the effect of natural selection:
                Outbreeding will produce a general healthy offspring similar in phenotype to the parents, but inbreeding wil produce:
                1. Some sick offspring dysplaying illnes not compatible with life.
                2. Some weak individuals with a much lower fitness than their parents.
                3. Some apparent normal birds but with low fertility.
                4. Many "normal" birds
                5. Some birds with a better fitness than their parents for survival (positif recessif traits becoming apparents).
                 
                Birds in 1, 2 and 3 will inducetwo positif consequences for this population: clearing the genetic pool of unadapted traits for 1 (metabolic illness, neurologic diseases, ...), clearing of fertility problems since they (3) do not reproduce and, for 2, becoming easy to catch for predators, the pressure on 4 and 5 will decrease. Far more as they are easy to catch these birds will not help in the selection for the "best predators" and will help in the survival of future generations of better adapted birds.
                 
                The production of very well adapted birds (like 5) is higher in the inbreeding population than in the outbreeding population, and their probability of survival is also greater due to the "sacrifice" of a part of their "siblings". Thus in the inbreeding population the "adaptation rate" to a given environement is higher and speciation appears more quickly. The only problem is that they become highly specialized, with a lower genetic variability, and their capacity to adapt to a new change in environemental conditions is lower. This problem could be overrided if there was a mechanism to induce a higher rate of mutations in these inbred populations (as proposed before), or if these species have enough time after "specialyzing" to recover their genetic variability throug a "normal" mutation rate.
                 
                When inbreeding in captivity we should be able to discard every bird with a genetic problem of our breeding program, keeping only the best fitted. The problem appears when the bird we should "eliminate" carries mutations in which we are interested... and this is the work of the breeder: to isolate the mutations we want from the linked genes of recessive traits we do not want. We become the "natural (?) selection".
                 
                Regards
                 
                Recio
                 
                From: Peter Wouters <wouterscalant@...>
                To: Genetics-Psittacine@yahoogroups.com
                Sent: Tuesday, November 1, 2011 11:48 PM
                Subject: Re: [Genetics-Psittacine] Natural inbreeding?

                 
                can inbreeding become a breeding strategy with better results than outbreeding, in wild animals without restrictive conditions?
                 
                I’ve found 2.
                1) It may maintain adaptions to local conditions
                2) Combined with natural selection it can purge harmful recessive genes from the genetic pool
                 
                Regards
                Peter

                 
                Sent: Tuesday, November 01, 2011 8:43 PM
                Subject: Re: [Genetics-Psittacine] Natural inbreeding?
                 
                 
                Hi Pablo, Imam, Peter and everybody,
                 
                Budgies breeding in colony usually show a high inbreeding rate since there are 2-3 adult males who become the genetic fathers of all the youngs. Inbreeding seems also occur in european and american populations of IRN which grow apparently without any "weakness" despite that they arise from a very low number of individuals and that they must adapt to an environemental which is not the same than in shouth-est Asia. Even in mammals we can see that inbreeding does not necassarily mean weakness, genetic disorders, and so on: all the golden hamster (Syrian hamster or Mesocricetus auratus) we can find as pets all the world around, with many mutations in color, hair type, ..., all of them come from 3 individuals captured in the wild in the early XX century.
                On the other hand we have the cheetah: they are so closely related that their HLA (histocompatibility system) is almost the same, at a point that you can graft a piece of skin from a cheetah to another without any rejection. They are like tweens, like a clon. This does not mean that they are sick or weak, but their survival on the long term seems hazardous because they do not have the genetic variability to adapt to the changing conditions of the environement (in their population the quantity of different alleles per gen is too low).
                 
                From the above evidences we could think that inbreeding does not necessarily mean weak descendents or genetic disorders, but it seems that it works better in living beings with a high rate of spontaneous mutations to allow them to compensate for the lost of genetic variability when inbreeding.
                 
                We all also know that inbreeding is a mechanism acting on speciation when living beings are isolated ... but my question goes further: can inbreeding become a breeding strategy with better results than outbreeding, in wild animals without restrictive conditions?
                Something to think about: some months ago Jaynee said that she was creating mutations (obviously speaking about combination of mutations), big smile, and ... a question: if it was true? can we increase the mutation rate by inbreeding and not only make become apparent mutations which are already in the genetic make up of our birds, but that we can not see? Can inbreeding really create mutations? There is a theoretical mechanism to do so: DNA is constantly under pression to mutate (radiations, pH changes, free radicals, ...), and every day our DNA is broken and repaired. If the system to repair the DNA is affected by inbreeding we should expect more mutations to appear in inbreeding populations. In humans this system can be affected and induce mutations in our skin cells leading to cancers (this illness in humans is called xeroderma pigmentosum). If the same system was affected in the gonads it could explain a higher rate of mutations passing to the offspring.
                 
                What I am meaning is that inbreeding, in some groups of animals, could become the origin of an increase in genetic variability instead of the opposite as usually accepted. This could be considered as a feedback system: when the size of a population decreases (decrease of its genetic variability) the system supervising the DNA integrity would work with less of efficacity allowing an increase in the mutation rate in this population. This could explain why in captivity (=inbreeding) we can develop a very big number of mutations in a very short time when comparing to the process of speciation in Nature. I am convinced that we are doing more than a selection of the mutations already presents in the nature, but we are acting like a blind person, without really knowing it.... or may be not : is there any scientific work on this subject, Terry & Inte?
                 
                Regards
                 
                Recio
                 
                From: Recio Joaquin <jrecio99@...>
                To: Genetics-Psittacine@yahoogroups.com
                Sent: Monday, October 31, 2011 9:07 PM
                Subject: [Genetics-Psittacine] Natural inbreeding?

                 
                Hi everybody;
                 
                I use tu put all my young IRN together in the same aviary, and I have noticed that very often couples are made. Curiously these couples are not random: many times (far more often than expected) these couples are made between closely related birds, mainly sister-brother type. I spoke about this with a breeder who confirmed me that this happens also in wild birds: he has been ringing wild birds breeding in his property (swallows, sparrows, goldfinches, ...) for years and he has noticed very often that the couples were made of brother and sister from the last breeding season. Then I read here about the homozygous acqua mutation female IRN that Bala found in wildness, which is quite a rare event if we do not consider a tendency to inbreeding in wild birds. Similar for the first CHCT caught in the wild and for all the other recessive mutations coming from wild birds: the likelyness to happen in a non-restricted area seems to be too low if there is not a tendency to inbreeding in wild birds.
                 
                The question: Could be inbreeding a succesfull breeding strategy in wild birds? If it was the case... which are the conditions for this succes to happen?
                Please, forget all antropomorphic consideration in analizing the question.
                 
                Thanks
                 
                Recio






              • Recio Joaquin
                Hi Terry,   I have found nothing in the web about inbreeding increasing the mutation rate. There are some controversial studies about inbreeding and cancer
                Message 7 of 15 , Nov 2, 2011
                • 0 Attachment
                  Hi Terry,
                   
                  I have found nothing in the web about inbreeding increasing the mutation rate. There are some controversial studies about inbreeding and cancer production. The system helping to repair the DNA protects living beings both against cancers (resulting from mutations in somatic cells) and against hereditary mutations passing to the offspring (by acting on germinal cells). An increase in cancer prevalence among inbred animals would constitute an indirect evidence of a possible increase in the mutation rate in these populations.
                   
                  Something else: how can populations coming from 3 individuals (as the golden hamster), probably related since they were caught in the same area and at the same time, how can they succes reproduction, with a so little genetic variability, and produce a big number of mutations? how could they override inbreeding depression if there was not a system to increase their mutation rate? How can small inbreeding populations isolated in islands succes to adapt and reproduce if there is not an increase in the mutation rate? First Darwin's finches arriving to Galapagos islands could not hold in their genes all the different alleles that were later expressed by their descendants.
                   
                  I do not say that this is a general rule but it could help to explain why some species are able to survive after being restreints to some individuals, and others can not.
                   
                  Recio

                  From: Terry Martin <sbankvet@...>
                  To: Genetics-Psittacine@yahoogroups.com
                  Sent: Wednesday, November 2, 2011 4:53 AM
                  Subject: Re: [Genetics-Psittacine] Natural inbreeding?

                   
                  
                  Recio
                   
                          I do not believe inbreeding changes mutation rates, merely increases the rate at which hidden recessive traits will appear.
                   
                          As you all have said, inbreeding does not necessarily cause problems. In fact all of our breeds of animals have been established through a significant amount of inbreeding to 'fix' certain traits. But the end result of this is that many pure breeds have such limited gene pools that they have certain specific health problems.
                   
                          In poultry, some breeds seem to go on for decades with no problems with their vitality. But many of the other rare breeds suffer continually with fertility problems and lack of vigour, meaning they fall over to diseases that might not bother another breed.
                   
                          There is no doubt that continual out breeding produces a more vigorous bird. But it depends on the aim of your breeding as to whether this is the best approach.
                   
                          Terry
                  ----- Original Message -----
                  Sent: Wednesday, November 02, 2011 5:43 AM
                  Subject: Re: [Genetics-Psittacine] Natural inbreeding?

                  Hi Pablo, Imam, Peter and everybody,
                   
                  Budgies breeding in colony usually show a high inbreeding rate since there are 2-3 adult males who become the genetic fathers of all the youngs. Inbreeding seems also occur in european and american populations of IRN which grow apparently without any "weakness" despite that they arise from a very low number of individuals and that they must adapt to an environemental which is not the same than in shouth-est Asia. Even in mammals we can see that inbreeding does not necassarily mean weakness, genetic disorders, and so on: all the golden hamster (Syrian hamster or Mesocricetus auratus) we can find as pets all the world around, with many mutations in color, hair type, ..., all of them come from 3 individuals captured in the wild in the early XX century.
                  On the other hand we have the cheetah: they are so closely related that their HLA (histocompatibility system) is almost the same, at a point that you can graft a piece of skin from a cheetah to another without any rejection. They are like tweens, like a clon. This does not mean that they are sick or weak, but their survival on the long term seems hazardous because they do not have the genetic variability to adapt to the changing conditions of the environement (in their population the quantity of different alleles per gen is too low).
                   
                  From the above evidences we could think that inbreeding does not necessarily mean weak descendents or genetic disorders, but it seems that it works better in living beings with a high rate of spontaneous mutations to allow them to compensate for the lost of genetic variability when inbreeding.
                   
                  We all also know that inbreeding is a mechanism acting on speciation when living beings are isolated ... but my question goes further: can inbreeding become a breeding strategy with better results than outbreeding, in wild animals without restrictive conditions?
                  Something to think about: some months ago Jaynee said that she was creating mutations (obviously speaking about combination of mutations), big smile, and ... a question: if it was true? can we increase the mutation rate by inbreeding and not only make become apparent mutations which are already in the genetic make up of our birds, but that we can not see? Can inbreeding really create mutations? There is a theoretical mechanism to do so: DNA is constantly under pression to mutate (radiations, pH changes, free radicals, ...), and every day our DNA is broken and repaired. If the system to repair the DNA is affected by inbreeding we should expect more mutations to appear in inbreeding populations. In humans this system can be affected and induce mutations in our skin cells leading to cancers (this illness in humans is called xeroderma pigmentosum). If the same system was affected in the gonads it could explain a higher rate of mutations passing to the offspring.
                   
                  What I am meaning is that inbreeding, in some groups of animals, could become the origin of an increase in genetic variability instead of the opposite as usually accepted. This could be considered as a feedback system: when the size of a population decreases (decrease of its genetic variability) the system supervising the DNA integrity would work with less of efficacity allowing an increase in the mutation rate in this population. This could explain why in captivity (=inbreeding) we can develop a very big number of mutations in a very short time when comparing to the process of speciation in Nature. I am convinced that we are doing more than a selection of the mutations already presents in the nature, but we are acting like a blind person, without really knowing it.... or may be not : is there any scientific work on this subject, Terry & Inte?
                   
                  Regards
                   
                  Recio
                   
                  From: Recio Joaquin <jrecio99@...>
                  To: Genetics-Psittacine@yahoogroups.com
                  Sent: Monday, October 31, 2011 9:07 PM
                  Subject: [Genetics-Psittacine] Natural inbreeding?

                   
                  Hi everybody;
                   
                  I use tu put all my young IRN together in the same aviary, and I have noticed that very often couples are made. Curiously these couples are not random: many times (far more often than expected) these couples are made between closely related birds, mainly sister-brother type. I spoke about this with a breeder who confirmed me that this happens also in wild birds: he has been ringing wild birds breeding in his property (swallows, sparrows, goldfinches, ...) for years and he has noticed very often that the couples were made of brother and sister from the last breeding season. Then I read here about the homozygous acqua mutation female IRN that Bala found in wildness, which is quite a rare event if we do not consider a tendency to inbreeding in wild birds. Similar for the first CHCT caught in the wild and for all the other recessive mutations coming from wild birds: the likelyness to happen in a non-restricted area seems to be too low if there is not a tendency to inbreeding in wild birds.
                   
                  The question: Could be inbreeding a succesfull breeding strategy in wild birds? If it was the case... which are the conditions for this succes to happen?
                  Please, forget all antropomorphic consideration in analizing the question.
                   
                  Thanks
                   
                  Recio






                • Recio Joaquin
                  A lurking australian breeder wrote to me:     In the late 1960’s someone released a dozen or so Rainbow lorikeets in Perth . These birds are not native to
                  Message 8 of 15 , Nov 3, 2011
                  • 0 Attachment
                    A lurking australian breeder wrote to me:
                     
                     "In the late 1960’s someone released a dozen or so Rainbow lorikeets in Perth . These birds are not native to West Australia . That dozen birds grew to the point they were one of Perth ’s most commonly seen wild bird. If you didn’t see them you always heard them. Everyone’s car in Perth has lorikeet crap on them as they defecate while flying. They estimated the population at around 20,000 and culled half of them a couple of years ago. So a dozen birds grew to be 20,000 and while doing so some of them mutated to produce 2 Fallow mutations. I was successful in establishing one of them and while I had probably the only one in existence the second one died before I could get it going. One year I collected 5 wild Fallows from people who found them and turned them in to bird dealers or animal rescue centres. They were all young fledglings abandoned by their parents and from all corners of Perth so there had to be several split/split pairs around. What is strange was that the appearance of these Fallow birds only lasted a few years before disappearing. Nobody finds them anymore. Both birds are in Terry’s book labelled ‘Anon’."
                     
                    What he says about rainbow lorikeets confirms the theory that when inbreeding there is a first phase in which recessive mutations become apparent (like the fallows he has found) and then they are cleared from the population, so that in a second phase those mutations are extremely rare (at present he can not find these mutations in the wild). It does not allow to conclude that the mutation rate increases in inbreeding populations, but it is a good exemple of succes in inbred population clearing recessive traits under the effect of natural selection.
                     
                    Regards
                     
                    Recio
                     

                    From: Recio Joaquin <jrecio99@...>
                    To: "Genetics-Psittacine@yahoogroups.com" <Genetics-Psittacine@yahoogroups.com>
                    Sent: Wednesday, November 2, 2011 10:13 PM
                    Subject: Re: [Genetics-Psittacine] Natural inbreeding?

                     
                    Hi Peter,
                     
                    You are right. Inbreeding must be studied under the effect of natural selection:
                    Outbreeding will produce a general healthy offspring similar in phenotype to the parents, but inbreeding wil produce:
                    1. Some sick offspring dysplaying illnes not compatible with life.
                    2. Some weak individuals with a much lower fitness than their parents.
                    3. Some apparent normal birds but with low fertility.
                    4. Many "normal" birds
                    5. Some birds with a better fitness than their parents for survival (positif recessif traits becoming apparents).
                     
                    Birds in 1, 2 and 3 will inducetwo positif consequences for this population: clearing the genetic pool of unadapted traits for 1 (metabolic illness, neurologic diseases, ...), clearing of fertility problems since they (3) do not reproduce and, for 2, becoming easy to catch for predators, the pressure on 4 and 5 will decrease. Far more as they are easy to catch these birds will not help in the selection for the "best predators" and will help in the survival of future generations of better adapted birds.
                     
                    The production of very well adapted birds (like 5) is higher in the inbreeding population than in the outbreeding population, and their probability of survival is also greater due to the "sacrifice" of a part of their "siblings". Thus in the inbreeding population the "adaptation rate" to a given environement is higher and speciation appears more quickly. The only problem is that they become highly specialized, with a lower genetic variability, and their capacity to adapt to a new change in environemental conditions is lower. This problem could be overrided if there was a mechanism to induce a higher rate of mutations in these inbred populations (as proposed before), or if these species have enough time after "specialyzing" to recover their genetic variability throug a "normal" mutation rate.
                     
                    When inbreeding in captivity we should be able to discard every bird with a genetic problem of our breeding program, keeping only the best fitted. The problem appears when the bird we should "eliminate" carries mutations in which we are interested... and this is the work of the breeder: to isolate the mutations we want from the linked genes of recessive traits we do not want. We become the "natural (?) selection".
                     
                    Regards
                     
                    Recio
                     
                    From: Peter Wouters <wouterscalant@...>
                    To: Genetics-Psittacine@yahoogroups.com
                    Sent: Tuesday, November 1, 2011 11:48 PM
                    Subject: Re: [Genetics-Psittacine] Natural inbreeding?

                     
                    can inbreeding become a breeding strategy with better results than outbreeding, in wild animals without restrictive conditions?
                     
                    I’ve found 2.
                    1) It may maintain adaptions to local conditions
                    2) Combined with natural selection it can purge harmful recessive genes from the genetic pool
                     
                    Regards
                    Peter

                     
                    Sent: Tuesday, November 01, 2011 8:43 PM
                    Subject: Re: [Genetics-Psittacine] Natural inbreeding?
                     
                     
                    Hi Pablo, Imam, Peter and everybody,
                     
                    Budgies breeding in colony usually show a high inbreeding rate since there are 2-3 adult males who become the genetic fathers of all the youngs. Inbreeding seems also occur in european and american populations of IRN which grow apparently without any "weakness" despite that they arise from a very low number of individuals and that they must adapt to an environemental which is not the same than in shouth-est Asia. Even in mammals we can see that inbreeding does not necassarily mean weakness, genetic disorders, and so on: all the golden hamster (Syrian hamster or Mesocricetus auratus) we can find as pets all the world around, with many mutations in color, hair type, ..., all of them come from 3 individuals captured in the wild in the early XX century.
                    On the other hand we have the cheetah: they are so closely related that their HLA (histocompatibility system) is almost the same, at a point that you can graft a piece of skin from a cheetah to another without any rejection. They are like tweens, like a clon. This does not mean that they are sick or weak, but their survival on the long term seems hazardous because they do not have the genetic variability to adapt to the changing conditions of the environement (in their population the quantity of different alleles per gen is too low).
                     
                    From the above evidences we could think that inbreeding does not necessarily mean weak descendents or genetic disorders, but it seems that it works better in living beings with a high rate of spontaneous mutations to allow them to compensate for the lost of genetic variability when inbreeding.
                     
                    We all also know that inbreeding is a mechanism acting on speciation when living beings are isolated ... but my question goes further: can inbreeding become a breeding strategy with better results than outbreeding, in wild animals without restrictive conditions?
                    Something to think about: some months ago Jaynee said that she was creating mutations (obviously speaking about combination of mutations), big smile, and ... a question: if it was true? can we increase the mutation rate by inbreeding and not only make become apparent mutations which are already in the genetic make up of our birds, but that we can not see? Can inbreeding really create mutations? There is a theoretical mechanism to do so: DNA is constantly under pression to mutate (radiations, pH changes, free radicals, ...), and every day our DNA is broken and repaired. If the system to repair the DNA is affected by inbreeding we should expect more mutations to appear in inbreeding populations. In humans this system can be affected and induce mutations in our skin cells leading to cancers (this illness in humans is called xeroderma pigmentosum). If the same system was affected in the gonads it could explain a higher rate of mutations passing to the offspring.
                     
                    What I am meaning is that inbreeding, in some groups of animals, could become the origin of an increase in genetic variability instead of the opposite as usually accepted. This could be considered as a feedback system: when the size of a population decreases (decrease of its genetic variability) the system supervising the DNA integrity would work with less of efficacity allowing an increase in the mutation rate in this population. This could explain why in captivity (=inbreeding) we can develop a very big number of mutations in a very short time when comparing to the process of speciation in Nature. I am convinced that we are doing more than a selection of the mutations already presents in the nature, but we are acting like a blind person, without really knowing it.... or may be not : is there any scientific work on this subject, Terry & Inte?
                     
                    Regards
                     
                    Recio
                     
                    From: Recio Joaquin <jrecio99@...>
                    To: Genetics-Psittacine@yahoogroups.com
                    Sent: Monday, October 31, 2011 9:07 PM
                    Subject: [Genetics-Psittacine] Natural inbreeding?

                     
                    Hi everybody;
                     
                    I use tu put all my young IRN together in the same aviary, and I have noticed that very often couples are made. Curiously these couples are not random: many times (far more often than expected) these couples are made between closely related birds, mainly sister-brother type. I spoke about this with a breeder who confirmed me that this happens also in wild birds: he has been ringing wild birds breeding in his property (swallows, sparrows, goldfinches, ...) for years and he has noticed very often that the couples were made of brother and sister from the last breeding season. Then I read here about the homozygous acqua mutation female IRN that Bala found in wildness, which is quite a rare event if we do not consider a tendency to inbreeding in wild birds. Similar for the first CHCT caught in the wild and for all the other recessive mutations coming from wild birds: the likelyness to happen in a non-restricted area seems to be too low if there is not a tendency to inbreeding in wild birds.
                     
                    The question: Could be inbreeding a succesfull breeding strategy in wild birds? If it was the case... which are the conditions for this succes to happen?
                    Please, forget all antropomorphic consideration in analizing the question.
                     
                    Thanks
                     
                    Recio








                  • Peter Wouters
                    Hello Recio, Something else: how can populations coming from 3 individuals (as the golden hamster), probably related since they were caught in the same area
                    Message 9 of 15 , Nov 3, 2011
                    • 0 Attachment
                      Hello Recio,
                       
                      Something else: how can populations coming from 3 individuals (as the golden hamster), probably related since they were caught in the same area and at the same time, how can they succes reproduction, with a so little genetic variability, and produce a big number of mutations?
                       
                      I think the answer to your question is already mentioned. There is no doubt that inbreeding among individuals with high genetic variability results in inbreeding depression. It seems to be that the more inbreeding occurs in subsequent generations  the lower the inbreeding depression. After all, only individuals with the best set of genes survive. Logically, they can no longer pass on bad genes. What remains are individuals with little or no genetic variability. So we can conclude that species with little genetic variability are more successful in inbreeding.
                       
                      Regards
                      Peter
                       
                       
                      Sent: Wednesday, November 02, 2011 10:15 PM
                      Subject: Re: [Genetics-Psittacine] Natural inbreeding?
                       
                       

                      Hi Terry,
                       
                      I have found nothing in the web about inbreeding increasing the mutation rate. There are some controversial studies about inbreeding and cancer production. The system helping to repair the DNA protects living beings both against cancers (resulting from mutations in somatic cells) and against hereditary mutations passing to the offspring (by acting on germinal cells). An increase in cancer prevalence among inbred animals would constitute an indirect evidence of a possible increase in the mutation rate in these populations.
                       
                      Something else: how can populations coming from 3 individuals (as the golden hamster), probably related since they were caught in the same area and at the same time, how can they succes reproduction, with a so little genetic variability, and produce a big number of mutations? how could they override inbreeding depression if there was not a system to increase their mutation rate? How can small inbreeding populations isolated in islands succes to adapt and reproduce if there is not an increase in the mutation rate? First Darwin's finches arriving to Galapagos islands could not hold in their genes all the different alleles that were later expressed by their descendants.
                       
                      I do not say that this is a general rule but it could help to explain why some species are able to survive after being restreints to some individuals, and others can not.
                       
                      Recio
                       
                      From: Terry Martin <sbankvet@...>
                      To: Genetics-Psittacine@yahoogroups.com
                      Sent: Wednesday, November 2, 2011 4:53 AM
                      Subject: Re: [Genetics-Psittacine] Natural inbreeding?

                       
                      
                      Recio
                       
                              I do not believe inbreeding changes mutation rates, merely increases the rate at which hidden recessive traits will appear.
                       
                              As you all have said, inbreeding does not necessarily cause problems. In fact all of our breeds of animals have been established through a significant amount of inbreeding to 'fix' certain traits. But the end result of this is that many pure breeds have such limited gene pools that they have certain specific health problems.
                       
                              In poultry, some breeds seem to go on for decades with no problems with their vitality. But many of the other rare breeds suffer continually with fertility problems and lack of vigour, meaning they fall over to diseases that might not bother another breed.
                       
                              There is no doubt that continual out breeding produces a more vigorous bird. But it depends on the aim of your breeding as to whether this is the best approach.
                       
                              Terry
                      ----- Original Message -----
                      Sent: Wednesday, November 02, 2011 5:43 AM
                      Subject: Re: [Genetics-Psittacine] Natural inbreeding?
                       
                      Hi Pablo, Imam, Peter and everybody,
                       
                      Budgies breeding in colony usually show a high inbreeding rate since there are 2-3 adult males who become the genetic fathers of all the youngs. Inbreeding seems also occur in european and american populations of IRN which grow apparently without any "weakness" despite that they arise from a very low number of individuals and that they must adapt to an environemental which is not the same than in shouth-est Asia. Even in mammals we can see that inbreeding does not necassarily mean weakness, genetic disorders, and so on: all the golden hamster (Syrian hamster or Mesocricetus auratus) we can find as pets all the world around, with many mutations in color, hair type, ..., all of them come from 3 individuals captured in the wild in the early XX century.
                      On the other hand we have the cheetah: they are so closely related that their HLA (histocompatibility system) is almost the same, at a point that you can graft a piece of skin from a cheetah to another without any rejection. They are like tweens, like a clon. This does not mean that they are sick or weak, but their survival on the long term seems hazardous because they do not have the genetic variability to adapt to the changing conditions of the environement (in their population the quantity of different alleles per gen is too low).
                       
                      From the above evidences we could think that inbreeding does not necessarily mean weak descendents or genetic disorders, but it seems that it works better in living beings with a high rate of spontaneous mutations to allow them to compensate for the lost of genetic variability when inbreeding.
                       
                      We all also know that inbreeding is a mechanism acting on speciation when living beings are isolated ... but my question goes further: can inbreeding become a breeding strategy with better results than outbreeding, in wild animals without restrictive conditions?
                      Something to think about: some months ago Jaynee said that she was creating mutations (obviously speaking about combination of mutations), big smile, and ... a question: if it was true? can we increase the mutation rate by inbreeding and not only make become apparent mutations which are already in the genetic make up of our birds, but that we can not see? Can inbreeding really create mutations? There is a theoretical mechanism to do so: DNA is constantly under pression to mutate (radiations, pH changes, free radicals, ...), and every day our DNA is broken and repaired. If the system to repair the DNA is affected by inbreeding we should expect more mutations to appear in inbreeding populations. In humans this system can be affected and induce mutations in our skin cells leading to cancers (this illness in humans is called xeroderma pigmentosum). If the same system was affected in the gonads it could explain a higher rate of mutations passing to the offspring.
                       
                      What I am meaning is that inbreeding, in some groups of animals, could become the origin of an increase in genetic variability instead of the opposite as usually accepted. This could be considered as a feedback system: when the size of a population decreases (decrease of its genetic variability) the system supervising the DNA integrity would work with less of efficacity allowing an increase in the mutation rate in this population. This could explain why in captivity (=inbreeding) we can develop a very big number of mutations in a very short time when comparing to the process of speciation in Nature. I am convinced that we are doing more than a selection of the mutations already presents in the nature, but we are acting like a blind person, without really knowing it.... or may be not : is there any scientific work on this subject, Terry & Inte?
                       
                      Regards
                       
                      Recio
                       
                      From: Recio Joaquin <jrecio99@...>
                      To: Genetics-Psittacine@yahoogroups.com
                      Sent: Monday, October 31, 2011 9:07 PM
                      Subject: [Genetics-Psittacine] Natural inbreeding?

                       
                      Hi everybody;
                       
                      I use tu put all my young IRN together in the same aviary, and I have noticed that very often couples are made. Curiously these couples are not random: many times (far more often than expected) these couples are made between closely related birds, mainly sister-brother type. I spoke about this with a breeder who confirmed me that this happens also in wild birds: he has been ringing wild birds breeding in his property (swallows, sparrows, goldfinches, ...) for years and he has noticed very often that the couples were made of brother and sister from the last breeding season. Then I read here about the homozygous acqua mutation female IRN that Bala found in wildness, which is quite a rare event if we do not consider a tendency to inbreeding in wild birds. Similar for the first CHCT caught in the wild and for all the other recessive mutations coming from wild birds: the likelyness to happen in a non-restricted area seems to be too low if there is not a tendency to inbreeding in wild birds.
                       
                      The question: Could be inbreeding a succesfull breeding strategy in wild birds? If it was the case... which are the conditions for this succes to happen?
                      Please, forget all antropomorphic consideration in analizing the question.
                       
                      Thanks
                       
                      Recio






                    • Recio Joaquin
                      Hi Peter,   Some precisions: There is no doubt thatinbreeding among individuals with high genetic variability results ininbreeding depression .... I agree
                      Message 10 of 15 , Nov 4, 2011
                      • 0 Attachment
                        Hi Peter,
                         
                        Some precisions:
                        " There is no doubt that inbreeding among individuals with high genetic variability results in inbreeding depression" .... I agree
                        " the more inbreeding occurs in subsequent generations  the lower the inbreeding depression" ... I do not agree: subsequent inbreeding will lead to more and more inbreeding depresion, and if it continues finally it leads to "clonal" individuals (like the cheetah we wrote about).
                        "we can conclude that species with little genetic variability are more successful in inbreeding." I think that you are confusing cause and effects. I think that succesful inbreeding leads to little genetic variability with a good adaptation to local conditions but a loss of capacity to adapt to a drastic change in environement, since many different alleles were lost in the process of inbreeding.
                         
                        And about my question : how can populations coming from 3 individuals (as the golden hamster), probably related since they were caught in the same area and at the same time, how can they succes reproduction, with a so little genetic variability, and produce a big number of mutations? The problem here is that a population with a theoric low genetic variability  (it has been produced by inbreeding) show a great array of mutations even after the initial period of inbreeding during which mutations are expected to appear before being cleared by the natural selection. Thre are many possible explanations: the most probable is that "natural selection" was not there; it was man selection doing the opposite than nature: keeping for reproduction all the "strange phenotyes"... but the idea of inbreeding as a way to increase mutation rates could be another explanation.
                         
                        Best regards
                         
                        Recio

                        From: Peter Wouters <wouterscalant@...>
                        To: Genetics-Psittacine@yahoogroups.com
                        Sent: Thursday, November 3, 2011 11:55 PM
                        Subject: Re: [Genetics-Psittacine] Natural inbreeding?

                         
                        Hello Recio,
                         
                        Something else: how can populations coming from 3 individuals (as the golden hamster), probably related since they were caught in the same area and at the same time, how can they succes reproduction, with a so little genetic variability, and produce a big number of mutations?
                         
                        I think the answer to your question is already mentioned. There is no doubt that inbreeding among individuals with high genetic variability results in inbreeding depression. It seems to be that the more inbreeding occurs in subsequent generations  the lower the inbreeding depression. After all, only individuals with the best set of genes survive. Logically, they can no longer pass on bad genes. What remains are individuals with little or no genetic variability. So we can conclude that species with little genetic variability are more successful in inbreeding.
                         
                        Regards
                        Peter
                         
                         
                        Sent: Wednesday, November 02, 2011 10:15 PM
                        Subject: Re: [Genetics-Psittacine] Natural inbreeding?
                         
                         
                        Hi Terry,
                         
                        I have found nothing in the web about inbreeding increasing the mutation rate. There are some controversial studies about inbreeding and cancer production. The system helping to repair the DNA protects living beings both against cancers (resulting from mutations in somatic cells) and against hereditary mutations passing to the offspring (by acting on germinal cells). An increase in cancer prevalence among inbred animals would constitute an indirect evidence of a possible increase in the mutation rate in these populations.
                         
                        Something else: how can populations coming from 3 individuals (as the golden hamster), probably related since they were caught in the same area and at the same time, how can they succes reproduction, with a so little genetic variability, and produce a big number of mutations? how could they override inbreeding depression if there was not a system to increase their mutation rate? How can small inbreeding populations isolated in islands succes to adapt and reproduce if there is not an increase in the mutation rate? First Darwin's finches arriving to Galapagos islands could not hold in their genes all the different alleles that were later expressed by their descendants.
                         
                        I do not say that this is a general rule but it could help to explain why some species are able to survive after being restreints to some individuals, and others can not.
                         
                        Recio
                         
                        From: Terry Martin <sbankvet@...>
                        To: Genetics-Psittacine@yahoogroups.com
                        Sent: Wednesday, November 2, 2011 4:53 AM
                        Subject: Re: [Genetics-Psittacine] Natural inbreeding?

                         
                        
                        Recio
                         
                                I do not believe inbreeding changes mutation rates, merely increases the rate at which hidden recessive traits will appear.
                         
                                As you all have said, inbreeding does not necessarily cause problems. In fact all of our breeds of animals have been established through a significant amount of inbreeding to 'fix' certain traits. But the end result of this is that many pure breeds have such limited gene pools that they have certain specific health problems.
                         
                                In poultry, some breeds seem to go on for decades with no problems with their vitality. But many of the other rare breeds suffer continually with fertility problems and lack of vigour, meaning they fall over to diseases that might not bother another breed.
                         
                                There is no doubt that continual out breeding produces a more vigorous bird. But it depends on the aim of your breeding as to whether this is the best approach.
                         
                                Terry
                        ----- Original Message -----
                        Sent: Wednesday, November 02, 2011 5:43 AM
                        Subject: Re: [Genetics-Psittacine] Natural inbreeding?
                         
                        Hi Pablo, Imam, Peter and everybody,
                         
                        Budgies breeding in colony usually show a high inbreeding rate since there are 2-3 adult males who become the genetic fathers of all the youngs. Inbreeding seems also occur in european and american populations of IRN which grow apparently without any "weakness" despite that they arise from a very low number of individuals and that they must adapt to an environemental which is not the same than in shouth-est Asia. Even in mammals we can see that inbreeding does not necassarily mean weakness, genetic disorders, and so on: all the golden hamster (Syrian hamster or Mesocricetus auratus) we can find as pets all the world around, with many mutations in color, hair type, ..., all of them come from 3 individuals captured in the wild in the early XX century.
                        On the other hand we have the cheetah: they are so closely related that their HLA (histocompatibility system) is almost the same, at a point that you can graft a piece of skin from a cheetah to another without any rejection. They are like tweens, like a clon. This does not mean that they are sick or weak, but their survival on the long term seems hazardous because they do not have the genetic variability to adapt to the changing conditions of the environement (in their population the quantity of different alleles per gen is too low).
                         
                        From the above evidences we could think that inbreeding does not necessarily mean weak descendents or genetic disorders, but it seems that it works better in living beings with a high rate of spontaneous mutations to allow them to compensate for the lost of genetic variability when inbreeding.
                         
                        We all also know that inbreeding is a mechanism acting on speciation when living beings are isolated ... but my question goes further: can inbreeding become a breeding strategy with better results than outbreeding, in wild animals without restrictive conditions?
                        Something to think about: some months ago Jaynee said that she was creating mutations (obviously speaking about combination of mutations), big smile, and ... a question: if it was true? can we increase the mutation rate by inbreeding and not only make become apparent mutations which are already in the genetic make up of our birds, but that we can not see? Can inbreeding really create mutations? There is a theoretical mechanism to do so: DNA is constantly under pression to mutate (radiations, pH changes, free radicals, ...), and every day our DNA is broken and repaired. If the system to repair the DNA is affected by inbreeding we should expect more mutations to appear in inbreeding populations. In humans this system can be affected and induce mutations in our skin cells leading to cancers (this illness in humans is called xeroderma pigmentosum). If the same system was affected in the gonads it could explain a higher rate of mutations passing to the offspring.
                         
                        What I am meaning is that inbreeding, in some groups of animals, could become the origin of an increase in genetic variability instead of the opposite as usually accepted. This could be considered as a feedback system: when the size of a population decreases (decrease of its genetic variability) the system supervising the DNA integrity would work with less of efficacity allowing an increase in the mutation rate in this population. This could explain why in captivity (=inbreeding) we can develop a very big number of mutations in a very short time when comparing to the process of speciation in Nature. I am convinced that we are doing more than a selection of the mutations already presents in the nature, but we are acting like a blind person, without really knowing it.... or may be not : is there any scientific work on this subject, Terry & Inte?
                         
                        Regards
                         
                        Recio
                         
                        From: Recio Joaquin <jrecio99@...>
                        To: Genetics-Psittacine@yahoogroups.com
                        Sent: Monday, October 31, 2011 9:07 PM
                        Subject: [Genetics-Psittacine] Natural inbreeding?

                         
                        Hi everybody;
                         
                        I use tu put all my young IRN together in the same aviary, and I have noticed that very often couples are made. Curiously these couples are not random: many times (far more often than expected) these couples are made between closely related birds, mainly sister-brother type. I spoke about this with a breeder who confirmed me that this happens also in wild birds: he has been ringing wild birds breeding in his property (swallows, sparrows, goldfinches, ...) for years and he has noticed very often that the couples were made of brother and sister from the last breeding season. Then I read here about the homozygous acqua mutation female IRN that Bala found in wildness, which is quite a rare event if we do not consider a tendency to inbreeding in wild birds. Similar for the first CHCT caught in the wild and for all the other recessive mutations coming from wild birds: the likelyness to happen in a non-restricted area seems to be too low if there is not a tendency to inbreeding in wild birds.
                         
                        The question: Could be inbreeding a succesfull breeding strategy in wild birds? If it was the case... which are the conditions for this succes to happen?
                        Please, forget all antropomorphic consideration in analizing the question.
                         
                        Thanks
                         
                        Recio








                      • Peter Wouters
                        Maybe I expressed myself wrong. What I wanted to say is that populations that experience high levels of inbreeding and subsequent inbreeding depression may in
                        Message 11 of 15 , Nov 4, 2011
                        • 0 Attachment
                          Maybe I expressed myself wrong. What I wanted to say is that populations that experience high levels of inbreeding and subsequent inbreeding depression may in future generations have significantly lower levels of inbreeding depression even if closely inbred, because of the purging of deleterious recessive alleles expressed during inbreeding. Maybe the Golden hamsters that were caught in Syria had already a history of high levels of inbreeding. Little genetic variability but adapted to inbreeding. Just the same as when you take 2 specimen(male and female) of the Chillingham white cattle and breed with them for several generations. They are already genetically uniform.
                           
                          Regards
                          Peter
                           
                          Sent: Friday, November 04, 2011 11:12 AM
                          Subject: Re: [Genetics-Psittacine] Natural inbreeding?
                           
                           

                          Hi Peter,
                           
                          Some precisions:
                          " There is no doubt that inbreeding among individuals with high genetic variability results in inbreeding depression" .... I agree
                          " the more inbreeding occurs in subsequent generations  the lower the inbreeding depression" ... I do not agree: subsequent inbreeding will lead to more and more inbreeding depresion, and if it continues finally it leads to "clonal" individuals (like the cheetah we wrote about).
                          "we can conclude that species with little genetic variability are more successful in inbreeding." I think that you are confusing cause and effects. I think that succesful inbreeding leads to little genetic variability with a good adaptation to local conditions but a loss of capacity to adapt to a drastic change in environement, since many different alleles were lost in the process of inbreeding.
                           
                          And about my question : how can populations coming from 3 individuals (as the golden hamster), probably related since they were caught in the same area and at the same time, how can they succes reproduction, with a so little genetic variability, and produce a big number of mutations? The problem here is that a population with a theoric low genetic variability  (it has been produced by inbreeding) show a great array of mutations even after the initial period of inbreeding during which mutations are expected to appear before being cleared by the natural selection. Thre are many possible explanations: the most probable is that "natural selection" was not there; it was man selection doing the opposite than nature: keeping for reproduction all the "strange phenotyes"... but the idea of inbreeding as a way to increase mutation rates could be another explanation.
                           
                          Best regards
                           
                          Recio
                           
                          From: Peter Wouters <wouterscalant@...>
                          To: Genetics-Psittacine@yahoogroups.com
                          Sent: Thursday, November 3, 2011 11:55 PM
                          Subject: Re: [Genetics-Psittacine] Natural inbreeding?

                           
                          Hello Recio,
                           
                          Something else: how can populations coming from 3 individuals (as the golden hamster), probably related since they were caught in the same area and at the same time, how can they succes reproduction, with a so little genetic variability, and produce a big number of mutations?
                           
                          I think the answer to your question is already mentioned. There is no doubt that inbreeding among individuals with high genetic variability results in inbreeding depression. It seems to be that the more inbreeding occurs in subsequent generations  the lower the inbreeding depression. After all, only individuals with the best set of genes survive. Logically, they can no longer pass on bad genes. What remains are individuals with little or no genetic variability. So we can conclude that species with little genetic variability are more successful in inbreeding.
                           
                          Regards
                          Peter
                           
                           
                          Sent: Wednesday, November 02, 2011 10:15 PM
                          Subject: Re: [Genetics-Psittacine] Natural inbreeding?
                           
                           
                          Hi Terry,
                           
                          I have found nothing in the web about inbreeding increasing the mutation rate. There are some controversial studies about inbreeding and cancer production. The system helping to repair the DNA protects living beings both against cancers (resulting from mutations in somatic cells) and against hereditary mutations passing to the offspring (by acting on germinal cells). An increase in cancer prevalence among inbred animals would constitute an indirect evidence of a possible increase in the mutation rate in these populations.
                           
                          Something else: how can populations coming from 3 individuals (as the golden hamster), probably related since they were caught in the same area and at the same time, how can they succes reproduction, with a so little genetic variability, and produce a big number of mutations? how could they override inbreeding depression if there was not a system to increase their mutation rate? How can small inbreeding populations isolated in islands succes to adapt and reproduce if there is not an increase in the mutation rate? First Darwin's finches arriving to Galapagos islands could not hold in their genes all the different alleles that were later expressed by their descendants.
                           
                          I do not say that this is a general rule but it could help to explain why some species are able to survive after being restreints to some individuals, and others can not.
                           
                          Recio
                           
                          From: Terry Martin <sbankvet@...>
                          To: Genetics-Psittacine@yahoogroups.com
                          Sent: Wednesday, November 2, 2011 4:53 AM
                          Subject: Re: [Genetics-Psittacine] Natural inbreeding?

                           
                          
                          Recio
                           
                                  I do not believe inbreeding changes mutation rates, merely increases the rate at which hidden recessive traits will appear.
                           
                                  As you all have said, inbreeding does not necessarily cause problems. In fact all of our breeds of animals have been established through a significant amount of inbreeding to 'fix' certain traits. But the end result of this is that many pure breeds have such limited gene pools that they have certain specific health problems.
                           
                                  In poultry, some breeds seem to go on for decades with no problems with their vitality. But many of the other rare breeds suffer continually with fertility problems and lack of vigour, meaning they fall over to diseases that might not bother another breed.
                           
                                  There is no doubt that continual out breeding produces a more vigorous bird. But it depends on the aim of your breeding as to whether this is the best approach.
                           
                                  Terry
                          ----- Original Message -----
                          Sent: Wednesday, November 02, 2011 5:43 AM
                          Subject: Re: [Genetics-Psittacine] Natural inbreeding?
                           
                          Hi Pablo, Imam, Peter and everybody,
                           
                          Budgies breeding in colony usually show a high inbreeding rate since there are 2-3 adult males who become the genetic fathers of all the youngs. Inbreeding seems also occur in european and american populations of IRN which grow apparently without any "weakness" despite that they arise from a very low number of individuals and that they must adapt to an environemental which is not the same than in shouth-est Asia. Even in mammals we can see that inbreeding does not necassarily mean weakness, genetic disorders, and so on: all the golden hamster (Syrian hamster or Mesocricetus auratus) we can find as pets all the world around, with many mutations in color, hair type, ..., all of them come from 3 individuals captured in the wild in the early XX century.
                          On the other hand we have the cheetah: they are so closely related that their HLA (histocompatibility system) is almost the same, at a point that you can graft a piece of skin from a cheetah to another without any rejection. They are like tweens, like a clon. This does not mean that they are sick or weak, but their survival on the long term seems hazardous because they do not have the genetic variability to adapt to the changing conditions of the environement (in their population the quantity of different alleles per gen is too low).
                           
                          From the above evidences we could think that inbreeding does not necessarily mean weak descendents or genetic disorders, but it seems that it works better in living beings with a high rate of spontaneous mutations to allow them to compensate for the lost of genetic variability when inbreeding.
                           
                          We all also know that inbreeding is a mechanism acting on speciation when living beings are isolated ... but my question goes further: can inbreeding become a breeding strategy with better results than outbreeding, in wild animals without restrictive conditions?
                          Something to think about: some months ago Jaynee said that she was creating mutations (obviously speaking about combination of mutations), big smile, and ... a question: if it was true? can we increase the mutation rate by inbreeding and not only make become apparent mutations which are already in the genetic make up of our birds, but that we can not see? Can inbreeding really create mutations? There is a theoretical mechanism to do so: DNA is constantly under pression to mutate (radiations, pH changes, free radicals, ...), and every day our DNA is broken and repaired. If the system to repair the DNA is affected by inbreeding we should expect more mutations to appear in inbreeding populations. In humans this system can be affected and induce mutations in our skin cells leading to cancers (this illness in humans is called xeroderma pigmentosum). If the same system was affected in the gonads it could explain a higher rate of mutations passing to the offspring.
                           
                          What I am meaning is that inbreeding, in some groups of animals, could become the origin of an increase in genetic variability instead of the opposite as usually accepted. This could be considered as a feedback system: when the size of a population decreases (decrease of its genetic variability) the system supervising the DNA integrity would work with less of efficacity allowing an increase in the mutation rate in this population. This could explain why in captivity (=inbreeding) we can develop a very big number of mutations in a very short time when comparing to the process of speciation in Nature. I am convinced that we are doing more than a selection of the mutations already presents in the nature, but we are acting like a blind person, without really knowing it.... or may be not : is there any scientific work on this subject, Terry & Inte?
                           
                          Regards
                           
                          Recio
                           
                          From: Recio Joaquin <jrecio99@...>
                          To: Genetics-Psittacine@yahoogroups.com
                          Sent: Monday, October 31, 2011 9:07 PM
                          Subject: [Genetics-Psittacine] Natural inbreeding?

                           
                          Hi everybody;
                           
                          I use tu put all my young IRN together in the same aviary, and I have noticed that very often couples are made. Curiously these couples are not random: many times (far more often than expected) these couples are made between closely related birds, mainly sister-brother type. I spoke about this with a breeder who confirmed me that this happens also in wild birds: he has been ringing wild birds breeding in his property (swallows, sparrows, goldfinches, ...) for years and he has noticed very often that the couples were made of brother and sister from the last breeding season. Then I read here about the homozygous acqua mutation female IRN that Bala found in wildness, which is quite a rare event if we do not consider a tendency to inbreeding in wild birds. Similar for the first CHCT caught in the wild and for all the other recessive mutations coming from wild birds: the likelyness to happen in a non-restricted area seems to be too low if there is not a tendency to inbreeding in wild birds.
                           
                          The question: Could be inbreeding a succesfull breeding strategy in wild birds? If it was the case... which are the conditions for this succes to happen?
                          Please, forget all antropomorphic consideration in analizing the question.
                           
                          Thanks
                           
                          Recio








                        • Hector Raigosa
                          Peter / Recio Include Los Angeles, Ca. USA I seen flocks that darken the sky, In Blue Lutino IRN, Canary Wings, Amazon s etc., that have mass produced.
                          Message 12 of 15 , Nov 4, 2011
                          • 0 Attachment
                            Peter / Recio
                            Include Los Angeles, Ca. USA
                            I seen flocks that darken the sky, In Blue Lutino IRN, Canary Wings, Amazon's etc., that have mass produced.


                            From: Peter Wouters <wouterscalant@...>
                            To: Genetics-Psittacine@yahoogroups.com
                            Sent: Tue, November 1, 2011 5:47:50 AM
                            Subject: Re: [Genetics-Psittacine] Natural inbreeding?

                             

                            Recio,
                             
                            On this subject I forgot to mention the wild IRN populations in various parts of Europe. In 1974, about 50 IRN's were released in the Meli zoo in Brussels. They quickly spread over Brussels and in 2005 their number was estimated at 7000. There are similar cases in the Netherlands and London. See also http://www.youtube.com/watch?v=p4P_NhFlb5w&feature=related
                             
                            Regards
                            Peter
                             
                            Sent: Tuesday, November 01, 2011 11:06 AM
                            Subject: Re: [Genetics-Psittacine] Natural inbreeding?
                             
                             

                            Recio and others,
                             
                            The first thing that comes to mind is the story of the cheetah. These are so closely related that they are probably descended from a few individuals. On a TV documentary they talked about one mother and her young.
                            When you are talking about inbreeding in the wild, I think the most important factor is "geographical isolation". In this situation, the likelihood that closely related individuals mate with each other is big. Examples include nature reserves, deforested areas. Certain genetic traits, good or bad, then show themself easily.
                            This factor may also help to develop other species.
                            Another point is that inbreeding doesn’t necessarily lead to bad traits. It is theoretical possible to have a brother and sister who are 100% unrelated. It depends on which chromosomes the parents passed on to their offspring.
                             
                            Regards
                            Peter
                             
                            From: XP 2600
                            Sent: Tuesday, November 01, 2011 1:18 AM
                            Subject: Re: [Genetics-Psittacine] Natural inbreeding?
                             
                             

                            Hello all,
                            Well mostly the inbreeding vary from genus to another, some birds or mammals seems does not get affected by inbreeding than others, mostly depend on what is the negative traits could be revealed by inbreeding, so while some birds have it in nature so mostly they are resistant to the bad characteristics of weakness and so on, but i don't think its the right idea in lovebirds, for example once i mated siblings just cause i did not have any other birds, and this couple never have one survived chick! all were drop at about two weeks old, when i split the couple and mate each of it both produced very well!

                            Imam

                            On Tue, Nov 1, 2011 at 1:55 AM, Pablo Caride <pablo.caride@...> wrote:
                             

                            Recio,

                             
                            this subject is very interesting, or at least I find it quite interesting since I have been researching a lot on the theoretical side of inbreeding and linebreeding.
                             
                            Thank you for sharing your views/knowledge on the subject.
                             
                            I start to think, more and more, that inbreeding is surrounded by some old wives tales.
                            I'm pretty sure there are lots and lots of people that have a lovely pair of cockatiels, lovebirds or budgies that they bought in some random petshop, not knowing that they are brother and sister, and they are breeding healthy chicks.
                             
                            Also read in poultry articles about people that started breeding a given breed of chickens, partridges or quail from a trio of 3 full siblings. Of course breeding poultry is a whole different game than breeding psittacines, as you can mate 1 cock to several hens and with the use of an incubator you can hatch many more chicks, meaning that you have a bigger population from which you can make a selection (compared to psittacines, that many species don't usually hatch more than 1 batch/year of 2-4 chicks).
                             
                            Kind regards,
                             
                            Pablo Caride
                            Vigo - Spain
                             
                             
                             
                            On Mon, Oct 31, 2011 at 9:07 PM, Recio Joaquin <jrecio99@...> wrote:
                             
                            Hi everybody;
                             
                            I use tu put all my young IRN together in the same aviary, and I have noticed that very often couples are made. Curiously these couples are not random: many times (far more often than expected) these couples are made between closely related birds, mainly sister-brother type. I spoke about this with a breeder who confirmed me that this happens also in wild birds: he has been ringing wild birds breeding in his property (swallows, sparrows, goldfinches, ...) for years and he has noticed very often that the couples were made of brother and sister from the last breeding season. Then I read here about the homozygous acqua mutation female IRN that Bala found in wildness, which is quite a rare event if we do not consider a tendency to inbreeding in wild birds. Similar for the first CHCT caught in the wild and for all the other recessive mutations coming from wild birds: the likelyness to happen in a non-restricted area seems to be too low if there is not a tendency to inbreeding in wild birds.
                             
                            The question: Could be inbreeding a succesfull breeding strategy in wild birds? If it was the case... which are the conditions for this succes to happen?
                            Please, forget all antropomorphic consideration in analizing the question.
                             
                            Thanks
                             
                            Recio


                             



                            --
                            Imam
                            MCSA MCSE
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