East Island bison inbreeding for 350 years, small island wolves back-cross many times

There is a special island in Xisha Islands, which is a paradise for cattle, where hundreds of wild cattle live.

Acording to the history books, this is the end of the Ming Dynasty, the coastal people ran to the island to escape from the war and settled there, and then returned home, leaving the cattle on the island.

Since the island is surrounded by sea on all sides, these cattle basically lost contact with the outside world and they became wild cattle, mating with each other and reproducing for at least 350 years.

However there is a problem, people bring up a limited number of cattle, and after breeding for a few generations, everyone is related, and inbreeding inevitably occurs here.

Why did the cattle herd here not die out due to inbreeding?

Heartless backcrossing

Backcrossing is one of the most disgusting types of inbreeding, and people may think of inbreeding as something like the cousins of Jia Baoyu and Lin Daiyu.

However, backcrossing, when defined in terms of human relationships, is incest!

Let's take an example to see how heartless backcrossing is, Queen Elizabeth II's favorite dog is called the Corgi.

The Corgi's short limbs, placed in the world of dogs, is equivalent to the dog in the Wu Da Lang.

Let's assume that Wu Dalang's shortness is a recessive gene, and he and Pan Jinlian had a daughter who inherited Pan Jinlian's tall stature, but carried Wu Dalang's short gene.

If this daughter marries an average person, then it is basically impossible for the offspring to be short.

If the daughter is married to Wu Dalang, she will have children who will be short, or tall but carry the short gene.

Then let Wu Dalang and his short granddaughter get married and have children, then the probability of having short people in the offspring will increase dramatically.

Then Wu Dalang married his great-granddaughter and his genetic granddaughter until none of the offspring were tall, indicating that the short gene had formed a stable trait.

Finally, when these stable individuals mated with each other, the offspring were all short.

This is the origin of the Corgi, the same reason, the golden hair is also the same, analogy to the human is the Golden Lion King Xie Xie and their blonde offspring married and had children.

Erha's blue eyes, Dachshund's long belly, and Bulldog's short nose all come from this, so the pet industry is behind the cuteness of this heartbreaking incest.

It is just a pity that animals have no ethics only instincts, and in front of the reproductive estrus period, there are no relatives, only male and female.

Backcrossing is not only used in animals, the use of more in plants, because plants are even less ethical, we live in plants, there is the breeding process more or less used backcrossing technology.

This also makes the human attitude towards backcrossing more ambivalent, we enjoy the benefits of backcrossing technology on the one hand, on the other hand, backcrossing makes it difficult for us to accept emotionally.

Moreover, there are many negative effects of backcrossing.

Just look at the shoehorned faces of the Habsburgs and the hemophilia of European royalty to see how harmful inbreeding can be.

The harm of backcrossing is a step up from inbreeding in the traditional sense, because it is reproduction between direct blood relatives.

Humans engage in backcrossing techniques simply to try to obtain the trait they need, a trait that is most likely itself a disease of plants and animals.

If two close relatives carrying a recessive gene have offspring, the probability of the offspring having the disease is 25%, but if it is a backcross, the probability is 50%.

The progressively outrageous chin of the Habsburgs

The purpose of backcrossing is the appearance of individuals with recessive genes, then naturally it is running to the maximum probability, generally speaking, in the third generation of backcrossing, the desired trait can appear, but in order to be more stable, generally backcrossing four to five generations or more.

Humans have now explicitly banned inbreeding between humans, but not between animals and plants.

In fact, in nature, plants and animals also try to avoid inbreeding whenever possible.

Herd animals drive away adult individuals from their populations, especially males, to other areas, and plants use animals for their own pollination.

Although animals have no ethics, they will follow the laws of nature and develop in the healthiest direction for their group.

But even so, the phenomenon of backcrossing still occurs in nature.

The Eastern Island bison mentioned earlier started out as a few domesticated cattle, and backcrossing must have occurred during their reproduction.

After analyzing the DNA of the East Island bison, researchers obtained their genetic profile and found that inbreeding among them was very serious.

After 350 years of breeding, more than 400 bison on the island are all related and very close to each other, and if they continue to be allowed to breed freely, the East Island bison herd will be weakened.

In order to improve the genetics of the bison, our country decided to introduce cattle from other regions to mate with the East Island bison so that they would be diluted from generation to generation and reduce the kinship between individuals.

The same thing happened on the small island of Lake Superior in the United States, where a wolf pack lives in isolation.

Zoologists speculate that these wolves most likely took advantage of the lake drought to ascend the island, only to later rise and get trapped on the island.

After genetic testing, these wolves came from the same wolf couple.

Wolves are a blood-based family society, where only the head wolf couple has reproductive rights and the other members are either the children of the head wolf couple or absorbed exotic members.

However, the alpha couple is subject to death, and when one dies, the other will find another mate.

However, on the isolated island, there are no foreign members to join, and the wolves inside the pack are almost all the children of the head wolf, which, stimulated by hormones, finally looks for its own offspring to breed.

After that, every generation of wolves did the same, and this resulted in the isolated island wolf pack today.

However, such a way did not bring prosperity to the wolves on the island; instead, they weakened year by year, changing from the initial nine observed to three afterwards.

Of course, the decline is also due to the lack of resources on the isolated island, which makes the wolves unsuitable for survival here.

From the East Island bison to the isolated island wolf pack, we find that one commonality among them all is that these animals were left in an isolated environment and their inbreeding was forced.

But the Australian wild dog, also abandoned, has lived a new world and they have prospered in Australia, eventually reaching the top of the local food chain.

Why were the Australian Wild Dogs not defeated by inbreeding?

Firstly, the original population of Australian Wild Dogs was larger than the East Island Bison and the Lone Wolf Pack, which set up a gene pool from the start.

Secondly, inbreeding has occurred in the Australian Wild Dog, but diseased and unsuitable offspring were eliminated.

Australian wild dogs have been breeding in Australia longer than these isolated island creatures, which have been breeding for at least 5,000 years.

It is not that inbreeding does not produce normal offspring, but that the probability of offspring disease far exceeds other cases.

The reason it is so serious in human societies is that humans produce a relatively small number of offspring, and it is easy for them all to get hit. For canines, on the other hand, they are inherently fertile and can give birth to many at a time, which have genetic diseases, and most of them do not survive and are eliminated naturally.

After screening, the Australian Wild Dogs are now basically individuals with dominant health genes that are stably inherited.

The last thing is that Australia is not an island, it is a continent, far larger than the East Island and the small islands of Lake Superior in the United States.

Here, food is more plentiful, plus Australia itself has a shortage of animals of the true animal subclass, making the Australian wild dog's survival less stressful.

This gives them enough resources to breed more offspring, which in turn are naturally screened for stronger offspring.

The ancients were so fond of inbreeding because, in addition to the benefits associated with it, inbreeding sometimes resulted in the birth of fine offspring.

The ancient inbred marriage is to open the blind box

Only, it is a kind of open blind box, good luck to open the SSR, bad luck is easy to lose all the troops.

For example, Darwin's grandparents were first cousins, which did not affect Darwin's IQ.

Darwin himself followed this example and married his own cousin, resulting in the birth of 10 children who died 3 inside, and several other children with mental illness.

It is because of this uncertainty that future generations will suffer unjustifiably and we cannot gamble with human lives that many countries have banned consanguineous marriages.