For humans, inbreeding is a behavior that cannot be recognized under the dual aspects of physiological requirements and ethics. Most countries will also restrict it by law, which shows that its harm is great.
It is not uncommon to see inbreeding of dogs. Some people even use dogs of the same blood to breed their offspring. Why? Is there no problem with inbreeding dogs?
In fact, the inbreeding purpose of dogs is well understood
For example, if you want to have a dog to accompany you, you will give priority to a cute-looking and pure-blooded one. A purebred or a hybrid with a different appearance and impure blood? It is estimated that most people will choose the former without hesitation. Since there is a demand, there will be a market. How to breed purebred dogs with the least effort? Inbreeding is undoubtedly the best way.
From a scientific point of view, the inbreeding of dogs mainly involves two major theories of genetics: heterosis and pure breeding.
Heterosis
Heterosis refers to the fact that the hybrid generation produced by two non-same vein individuals is likely to be better than the parent in terms of body size, growth rate, fecundity, and behavioral characteristics. In layman's terms, it is a hybrid. It is easy to mutate. The advantage is that it can only inherit a single gene from one parent, but it can also inherit a high-quality gene shared by both parties. There is a lot of randomness. To put it bluntly, it is dominant gene and recessive gene The problem.
purebred advantage
purebred advantage is relatively simple to understand. By breeding two individuals with roughly the same bloodline gene,The resulting purebred generation will likely have the same traits as the parent, so as to continue the pedigree and traits of the original line of the breed. The advantage lies in the relative stability that is greater than randomness.
Usually inbreeding of dogs is achieved by backcrossing. What is backcrossing?
Backcrossing refers to the re-mating of parents and reproductive offspring. Simply put, it means parents and daughters, mothers and sons. If this is placed in us humans, it would be shamelessly "incest", but for To get offspring that are closer to their parents’ traits, dogs will continue to cross each other many times. As long as the next generation’s appearance is better, it is possible to continue to any generation.
Regardless of the breed of dog, its pedigree will fade away from the parental generation. Usually, the identification of purebred dogs has an authority based on the dog’s skeleton, hair, facial features, etc. The judging criteria are specified, and the special gene bank can also be used to judge whether the dog's pedigree is pure.
Although the inbreeding of dogs is mainly due to the demand for purebred dogs, part of the reason is to reduce the difficulty of breeding.
Many dogs have a large degree of personality change after entering the estrus period, and they will be hostile and resistant to unfamiliar species. In inbreeding through mutual intercourse, the breeding partners are likely to be the same species who have lived together for a long time. The breath of time is very familiar, and the whole breeding process will be much simpler.
Why is human inbreeding strictly prohibited?
Why human inbreeding is strictly prohibited, and it has become a consensus that almost everyone resists, because the genetic similarity between close relatives.
Although good genes have a high chance of being inherited and becoming better,But at the same time, bad genes will be inherited and become worse and worse. Such bad genes are called recessive genes.
Many genetic diseases are inherited through recessive , which will be suppressed by dominant genes and will not show up. Inbreeding will greatly increase the probability of recessive genes. The offspring suffering from congenital malformations or genetic diseases are not only weak in physical fitness, but also have a higher mortality rate than non-inbreeding. Therefore, human inbreeding is extremely harmful and is absolutely prohibited.
Since human inbreeding is harmful, does the inbreeding of dogs have no effect? Of course not. Just like humans, inbreeding dogs may pass the recessive genes of their parents to their offspring. In general, purebred dogs are more likely to suffer from genetic diseases than hybrid dogs. For example, purebred short-legged Corgi often has spondylosis, purebred Teddy’s hip dysplasia, and purebred husky’s gastrointestinal fragility problem criticized by others.
Then why is there someone specializing in inbreeding dogs? Is it purely to pursue the same line of blood and traits?
In fact, to put it plainly, it is the social activities that humans impose on dogs, just to satisfy their own preferences. After all, natural selection is the law that can be passed down to the present in each species. If humans want to interfere with natural selection, it is equivalent to breaking this law. , The consequences may be long-term.
Although there is no ethics and morality in the pet and animal kingdoms such as dogs, as long as they are in heat, they will follow their nature to mate.But we shouldn’t be too strong for the purity of the pedigree to interfere too much. After all, animals coexist with us in the world, and dogs are our human’s best friends. Let them not be imposed and restrained and make them more diverse. It is the best practice, and it is also a major consideration for their life safety.
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