Moral people would not weigh fixing of superficial traits as an equal benefit to offset the expression of a horrible disease. But again and again we observe in the world of purebred dogs people who take the risk for purely cosmetic reasons and their dogs who suffer heavily for it.
Breeding of purebred dogs focuses on the selection of individuals displaying the desired physical and behavioral phenotypes given by the breed standards. That's how breeds are formed in the first place, otherwise, we would have mongrels of no specific type or function. The assumption that all line breeding necessarily leads to disease, is a false assumption. It does not necessarily mean that, as unfit animals are culled from the gene pool. Many young breeds, and by that I mean from the end of the 19th Century, established from a few founder animals less than 100 years ago which experienced a bottleneck during the Second World War. The only way to restore a breed to its former size and function was to breed from the limited number of individuals that remained after the War. People were focused no rebuilding normal lives after the great war as opposed to animal husbandry. However, our ability to increase milk supply in domestic cattle, increase wool production in sheep, and create some of the world's most beautiful and fastest horses could not have come otherwise but by selective breeding. Wright was thinking that since we know inbreeding has two consequences that matter to a breeder, one positive (uniformity and prepotency) and one negative (loss of vigor and fertility), it would be useful to be able to calculate the degree of inbreeding of an animal because it would make these effects more predictable. This was important because these two effects were at odds with each other; breeders could increase predictability and uniformity by inbreeding, but not without also having detrimental effects on an animal’s health and fertility. Breeders couldn’t just keep inbreeding and inbreeding to get better and better cattle or dogs or horses; with each incremental improvement in uniformity and homozygosity, there would be a price to pay in health, vitality, and reproductive performance, traits that are collectively referred to as “fitness”. The short-term gain in consistency from inbreeding was paid for by a longer-term penalty in viability. For those in the business of agriculture, it was critically important that the balance between the positive and negative be controlled. Producing great dogs today would be counterproductive if the ability to produce new stock in the future was diminished. Wright wanted was a way to predict the degree of homozygosity that would result from inbreeding, in which an allele originating from a single ancestor could be passed down on both sides of the pedigree and result in a descendant that is homozygous for that allele. Knowing that there are two possible alleles for each gene, and that which of the two is inherited was random, Wright could assume that for each generation the probability of inheriting one allele or the other was 50%. The sum of the probabilities for each generation would provide an estimate of homozygosity in a descend. Done not intelligently, you're right, it produces terrible results. But done intelligently, it has tremendous benefits.t would have been impossible otherwise. The art and science of animal breeding and biology have very little to do with a religious point of view. There is a practical matter to be achieved: to create a breed for a specific purpose and function in the service of mankind. Thus, we have farm horses suitable to pulling a plow, such as a Clydesdales as opposed to fast racing horses like Arabians. By selective breeding, we have harvested the animal world to our view of form and function.
You are a great teacher Sir, I have learned a lot from your videos during the last weeks. Thanks for sharing 🧬🔝
Thank you very much for your kind words.
Great video and learned lot of valuable things.
Glad it was helpful!
Great information Alex. Thank you for sharing this knowledge.
Moral people would not weigh fixing of superficial traits as an equal benefit to offset the expression of a horrible disease. But again and again we observe in the world of purebred dogs people who take the risk for purely cosmetic reasons and their dogs who suffer heavily for it.
Breeding of purebred dogs focuses on the selection of individuals displaying the desired physical and behavioral phenotypes given by the breed standards. That's how breeds are formed in the first place, otherwise, we would have mongrels of no specific type or function. The assumption that all line breeding necessarily leads to disease, is a false assumption. It does not necessarily mean that, as unfit animals are culled from the gene pool. Many young breeds, and by that I mean from the end of the 19th Century, established from a few founder animals less than 100 years ago which experienced a bottleneck during the Second World War. The only way to restore a breed to its former size and function was to breed from the limited number of individuals that remained after the War. People were focused no rebuilding normal lives after the great war as opposed to animal husbandry. However, our ability to increase milk supply in domestic cattle, increase wool production in sheep, and create some of the world's most beautiful and fastest horses could not have come otherwise but by selective breeding.
Wright was thinking that since we know inbreeding has two consequences that matter to a breeder, one positive (uniformity and prepotency) and one negative (loss of vigor and fertility), it would be useful to be able to calculate the degree of inbreeding of an animal because it would make these effects more predictable. This was important because these two effects were at odds with each other; breeders could increase predictability and uniformity by inbreeding, but not without also having detrimental effects on an animal’s health and fertility. Breeders couldn’t just keep inbreeding and inbreeding to get better and better cattle or dogs or horses; with each incremental improvement in uniformity and homozygosity, there would be a price to pay in health, vitality, and reproductive performance, traits that are collectively referred to as “fitness”. The short-term gain in consistency from inbreeding was paid for by a longer-term penalty in viability. For those in the business of agriculture, it was critically important that the balance between the positive and negative be controlled. Producing great dogs today would be counterproductive if the ability to produce new stock in the future was diminished.
Wright wanted was a way to predict the degree of homozygosity that would result from inbreeding, in which an allele originating from a single ancestor could be passed down on both sides of the pedigree and result in a descendant that is homozygous for that allele. Knowing that there are two possible alleles for each gene, and that which of the two is inherited was random, Wright could assume that for each generation the probability of inheriting one allele or the other was 50%. The sum of the probabilities for each generation would provide an estimate of homozygosity in a descend. Done not intelligently, you're right, it produces terrible results. But done intelligently, it has tremendous benefits.t would have been impossible otherwise. The art and science of animal breeding and biology have very little to do with a religious point of view. There is a practical matter to be achieved: to create a breed for a specific purpose and function in the service of mankind. Thus, we have farm horses suitable to pulling a plow, such as a Clydesdales as opposed to fast racing horses like Arabians. By selective breeding, we have harvested the animal world to our view of form and function.
Some people will never understand
Give me a working line over a pet quality any day
I fully agree with you.