Humans forbid inbreeding, but let the dog to "backcross"? And even demand that the purer the breed, the better?

Humans allow most animals to interbreed, not even a species can, such as lions and tigers, cetaceans.

However, in the face of the matter of pet dogs, people have an obsession with purebred again, the more pure the dog, the more expensive.

However, the birth of a purebred dog is a very cruel and dangerous thing.

It requires backcrossing the dog to get the shape that people want, such as non-shedding hair, golden hair, curly hair, etc.

So backcrossing is what it is, and purebred dogs really are better.

Dogs are not differentiated from wolves in terms of genetic sequence, so biologically, they are simply treated as a subspecies of the gray wolf, biologically named the domestic dog.

Then why the difference between dogs and wolves is so great, it has to be said that humans have improved their genes.

There are some genetic mutated individuals in domesticated wolves, which have novel traits, but their offspring may not be visible.

So people will let this mutant mate with their offspring of each generation until a stable trait is born, and this process is backcrossing.

As an example, the teacup dog, which is very hot on the Internet, is small enough to fit into a cup, but many people respond that the teacup dog they bought did not last long before they died.

If you know the breeding process of teacup dogs, you will know why they always fail to live.

Teacups are smaller than small dogs, and if small dogs are short wolves, teacups are dwarf wolves.

It is the first to select the smallest small dogs, let them mate, and after the birth of the offspring, select the smallest individual inside to mate with the first generation of parents.

This is not a simple marriage, it is a violation of ethics.

However, the breeding of teacup dogs is not finished, the offspring and the parent backcross not necessarily will get the desired traits, so it must continue to backcross with the second generation, with three generations.

This is similar to the human world where after having offspring with children, one has to have offspring with one's own grandchildren and then continue to have offspring with great-grandchildren.

As long as the desired trait is not obtained, backcrossing will continue.

When the desired traits finally appear in a certain generation, then the puppies of the same litter will be allowed to mate with each other, that is, the union between siblings, or inbreeding.

It can be said that every breed of dog is basically born in this way, which is full of all kinds of inbreeding.

And how harmful inbreeding is, I think humans are all too familiar with the Habsburgs point a stomp.

Inbred marriage

For a long time in human history, it was in a variety of inbreeding. Although humans learned early the bad effects of consanguineous marriage, they were very vague about the division of close relatives.

For example, in the West, because many noblemen do not have their own surname, they can not distinguish their own generation, so as long as they are not biological siblings can get married, and even some heartless family pro-life are not spared.

In the East, because it is patrilineal, so only the same name is not allowed to marry each other, but there is no restriction on the matrilineal side, so a variety of cousins married cousins.

For example, inside "Dream of the Red Chamber", Jia Baoyu's future wife will be either Lin Daiyu or Xue Baochai, both of whom are his cousins, so consanguineous marriages still exist.

So history gave birth to the odd shoe plucked face Habsburg family, royal hemophilia, some of our dynasties, the last emperors often had problems with fertility, all kinds of children could not be born.

This is because the closer the relatives are, the more disease-causing genes they carry will be the same, and having offspring is a combination of genes you half and I half.

If it so happens that each half has a disease-causing gene, then the offspring is the one who will have the disease symptoms.

Since these strange phenomena have occurred, why did the ancients insist on inbreeding?

First of all is the question of interest, fat water does not flow outside the field, in order to let their interests will always exist, then look for the same interests with their own, looking for their own family.

Second, inbred marriage is not necessarily a problem with the offspring, just the probability of problems will be higher.

The ancient times are born many children, the tolerance rate is greater, anyway, a problem there are a group of other children.

Of course, there are also those who are unlucky enough to have all their children hit, such as Darwin.

Finally, consanguineous marriage increases the probability of meeting disease-causing genes, but also increases the probability of meeting dominant genes, giving the offspring a chance of having a gifted person.

For the ancients, consanguineous marriage was a bit like opening a blind box, not knowing whether it was a diseased body or a genius.

But the ancients were born with more children, like Louis XVI's mother-in-law, who gave birth to 16 children in one breath, betting big enough.

The pain of return intercourse

Perhaps many people do not know that their dogs are suffering great pain.

Because the pet dog breeds on the market now are basically born through backcrossing, so no matter what kind of dog it is, there are more or less problems.

Labradors, for example, are jokingly referred to as eating more than they poop. In fact, this is because the Labrador has lost the gene for sensing fullness, making it unaware that it is full, and so it eats when it sees food.

Together with the owner's indulgence to give a lot of food, resulting in many Labrador was fed into the pig, and accompanied by obesity, fatty liver, high blood fat and other diseases.

Another example is the King Charles Spaniel, known as Disney's dog at large, has an extremely high probability of suffering from spinal cord cavity.

This is because during the breeding process, the brain capacity of the Cavalier King Charles Spaniel became smaller, but its head would keep growing, which led to the final cranial cavity not being able to accommodate its brain.

In addition, the Chihuahua's tendency to bark is also related to the fact that their brains have become smaller.

Not only pet dogs, but also pet cats have these problems because they are also backcross bred breeds.

Folded cats, for example, almost always get arthritis and it starts at 6 months of age and they can't escape this spell for the rest of their lives.

If backcrossed animals are so painful, why do humans go to such lengths to pursue pure breeds?

The lure of purebred

In fact, there are many crossbreeds of pet dogs, called "string dogs", but these dogs are despised in pet circles.

Pet dogs were first played by a group of European aristocrats.

They themselves are supporters of purebred pedigree theory, even themselves in various inbreeding marriages in pursuit of purity of blood, blue-blooded nobility, etc., so of course the dog is also the pursuit of purebred.

Furthermore, because of the recent changes in Europe, the bourgeoisie replaced the original aristocratic class, the old aristocrats were forced to marry with these new bourgeoisie aristocrats, somehow rescued the Europe that was shrouded by inbreeding marriages.

However, the pursuit of purebred that was ingrained in the DNA of the old aristocracy could not be lost, so they tossed pet dogs to their death.

The pet dog bred with the traits that humans like, the purer the trait the more obvious it is, then the more expensive it will be.

Pet dogs are also a commodity, expensive goods will meet the vanity of some people, so the pursuit of purebred dogs did not disappear because of the decline of the aristocracy, but spread among ordinary people.

Once a dog is crossbred, it is likely to lose its valuable traits, thus discounting the price and certainly not being popular.

And some crossbred dogs are unfortunate enough to inherit the shortcomings of their parents at once, and there is a lot of uncertainty.

In fact, in order to be able to reduce the pain caused by backcrossing, many countries have recommended adoption instead of purchase, so that dog dealers have no money to earn and weaken the commercial nature of pet dogs.

This way there will be fewer kennels and at least a little less backcross breeding will be done.

But there are those who believe that there is no excuse for such breeding because a dog is not a human being and has no ethics, morals or laws.

Its life itself is given by humans, so what is wrong with humans modifying its genes?

What's more, the dog's lifespan has been extended compared to that of its ancestor, the gray wolf, plus the existence of veterinary hospitals that euthanize the animal if it is too painful.

There are currently more than 1,400 species of dogs around the world, with a wide variety of sizes and looks, and they all belong to the gray wolf subspecies in the biological classification.

The vast majority of pet dogs have been bred for nearly 300 years, which shows the heartlessness of backcrossing technology.