Breeder Misconceptions
The Pedigree
A pedigree is a piece of paper that shows the lineage of an animal, a "family tree". Many breeders place emphasis on a dog that appear multiple times in the 5th, 6th, or even 7th generation of a dog's pedigree. With such interest placed on these dogs that brings up the question, Is the pedigree more important that the dog itself? The answer is NO. There are 256 ancestors in 8 generations of a dog's pedigree. Dogs only carry 78 chromosomes, so unless there was heavy inbreeding in those past generations, and a minute segment of a chromosome has been passed on, it is unlikely that these dogs contributed any genetic influence let alone even are related to the first generation dog of the pedigree. Dogs in the first 3 generations are the ones that have the most genetic influence, the parents each passing 50% of those genes. A pedigree is a good reference, but one of the many misconceptions breeders make is that they put too much emphasis on a pedigree. The term used for that is "Kitchen Table Breeding". Breeders look at the names of dogs in the pedigree, when they should be looking at the phenotype and genotype of the individual dogs that they are planning on mating.
It is important though to use the pedigree as a perspective and remember that the top titled dog has the same pedigree as its litter mates that may have not been trained or titled. The individual dog itself is always more important than the pedigree when predicting the dog's breeding value for passing on desired traits. The same goes for just breeding dogs based on the titles they and their ancestors have. This is referred to as how much "Red Ink" there is in a pedigree. As discussed about placing emphasis on a pedigree, it doesn't matter how many titled dogs are in the pedigree. A highly trained and titled dog could very well be an inferior producer and it's non titled litter-mate could be the superior producer. The progeny are the "report cards" of whether the dogs being used in a breeding are good producers regardless of how many titles the breeding dogs have acquired. On occasions, a mediocre dog can come from a great pedigree and a great dog can come from a mediocre pedigree. A great dog from a mediocre pedigree is like getting dealt a lucky hand in cards. This may be due to a random lucky combination of genes being passed on. Since the dog would only pass on 50% of its genes, it very well might be a disappointing producer.
To sum things up, a pedigree is a general guide and that the information on the individual dog is more critical than information on its ancestors. Most importantly the outcome of the offspring will give us the best clues to the breed value of a specific dog and the quality of how good of a producer it is.
Inferior offspring = inferior producer, Superior offspring = Superior producer.
Some other misconceptions most breeders have......
1. Galton's Law
Inheritance of genes; 50% from Parents, 25% from Grandparents, 12.5% from Great grandparents and so on, cut by 1/2 with each generation.
Geneticists have learned that the only definite % of inheritance come from the parents, 50% from sire and dam. Distribution during crossover, what is inherited from grandparents, is random and tends to be unequal. There is no guarantee that each grandparent will pass on 25% of its genes.
2.Tail male/ Tail female theory.
This theory was originally developed by Bruce Lowe, an Australian that worked with racehorses. The principles of this theory is that the main players in a pedigree were the sire's sire line and the dam's dam line (top and bottom lines) of the pedigree. There is no scientific proof that the tail male/female lines are any more important then any other line in the pedigree.
The closest relatives in a pedigree are the most influential with regards to genetic inheritance.
3. Pedigree Ancestors
It is believed by some breeders that a dog inherits genes from ALL its ancestors.
It's possible, however, for a dog to have certain ancestors in its pedigree from which it has received no genetic inheritance and to which it is not biologically related.
To be related to a particular ancestor a dog must carry one or more of its genes.
M.B.Willis
The German Shepherd Dog: A Genetic History
Practical Genetics for Dog Breeders
Genetics of the Dog
A pedigree is a piece of paper that shows the lineage of an animal, a "family tree". Many breeders place emphasis on a dog that appear multiple times in the 5th, 6th, or even 7th generation of a dog's pedigree. With such interest placed on these dogs that brings up the question, Is the pedigree more important that the dog itself? The answer is NO. There are 256 ancestors in 8 generations of a dog's pedigree. Dogs only carry 78 chromosomes, so unless there was heavy inbreeding in those past generations, and a minute segment of a chromosome has been passed on, it is unlikely that these dogs contributed any genetic influence let alone even are related to the first generation dog of the pedigree. Dogs in the first 3 generations are the ones that have the most genetic influence, the parents each passing 50% of those genes. A pedigree is a good reference, but one of the many misconceptions breeders make is that they put too much emphasis on a pedigree. The term used for that is "Kitchen Table Breeding". Breeders look at the names of dogs in the pedigree, when they should be looking at the phenotype and genotype of the individual dogs that they are planning on mating.
It is important though to use the pedigree as a perspective and remember that the top titled dog has the same pedigree as its litter mates that may have not been trained or titled. The individual dog itself is always more important than the pedigree when predicting the dog's breeding value for passing on desired traits. The same goes for just breeding dogs based on the titles they and their ancestors have. This is referred to as how much "Red Ink" there is in a pedigree. As discussed about placing emphasis on a pedigree, it doesn't matter how many titled dogs are in the pedigree. A highly trained and titled dog could very well be an inferior producer and it's non titled litter-mate could be the superior producer. The progeny are the "report cards" of whether the dogs being used in a breeding are good producers regardless of how many titles the breeding dogs have acquired. On occasions, a mediocre dog can come from a great pedigree and a great dog can come from a mediocre pedigree. A great dog from a mediocre pedigree is like getting dealt a lucky hand in cards. This may be due to a random lucky combination of genes being passed on. Since the dog would only pass on 50% of its genes, it very well might be a disappointing producer.
To sum things up, a pedigree is a general guide and that the information on the individual dog is more critical than information on its ancestors. Most importantly the outcome of the offspring will give us the best clues to the breed value of a specific dog and the quality of how good of a producer it is.
Inferior offspring = inferior producer, Superior offspring = Superior producer.
Some other misconceptions most breeders have......
1. Galton's Law
Inheritance of genes; 50% from Parents, 25% from Grandparents, 12.5% from Great grandparents and so on, cut by 1/2 with each generation.
Geneticists have learned that the only definite % of inheritance come from the parents, 50% from sire and dam. Distribution during crossover, what is inherited from grandparents, is random and tends to be unequal. There is no guarantee that each grandparent will pass on 25% of its genes.
2.Tail male/ Tail female theory.
This theory was originally developed by Bruce Lowe, an Australian that worked with racehorses. The principles of this theory is that the main players in a pedigree were the sire's sire line and the dam's dam line (top and bottom lines) of the pedigree. There is no scientific proof that the tail male/female lines are any more important then any other line in the pedigree.
The closest relatives in a pedigree are the most influential with regards to genetic inheritance.
3. Pedigree Ancestors
It is believed by some breeders that a dog inherits genes from ALL its ancestors.
It's possible, however, for a dog to have certain ancestors in its pedigree from which it has received no genetic inheritance and to which it is not biologically related.
To be related to a particular ancestor a dog must carry one or more of its genes.
M.B.Willis
The German Shepherd Dog: A Genetic History
Practical Genetics for Dog Breeders
Genetics of the Dog
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