The hottest "star" of 1997 was not Leonardo in Hollywood, but a British lamb, Dolly. Its birth marked a great advance in human biotechnology, as Dolly was a cloned sheep, an advanced and controversial technique at the time.
Big star Dolly's grazing routine
However, Dolly's birth did not make cloning technology mainstream in the world, on the contrary, more than 20 years have passed, and cloning technology has been mentioned less and less. So what happened to Dolly the Clone Sheep?
To understand Dolly, we must know how Dolly was born. What happened to Dolly? What happened in the post-Dolly era? How should we use clones?
Why is there so little mention of "cloning" nowadays? Dolly's life is the answer, it's so pathetic!
Dolly of the Scottish Museum
How was Dolly born?
Dolly's birth involved 3 ewes, which we call 1, 2, and 3. Ewe No. 1 provided one of her own cells, and the scientists removed its nucleus and kept it for later. Ewe No. 2 also provided a cell, which the scientists only retained, leaving the rest of it.
The nucleus of No. 2 was placed into the cytoplasm of No. 1, and then transplanted into the reproductive organs of ewe No. 3, where it was conceived, and finally Dolly was born on July 5, 1996, and officially launched on February 27, 1997. Miraculously, the No. 3 ewe is not Biologically Dolly's mother, it can only be counted as a "birth mother", and the real blood relationship with Dolly is the No. 2 ewe, and Dolly's genes are one hundred percent the same. As for Ewe No. 1, it doesn't seem to have anything to do with Dolly, which scientists call "mitochondrial mother."
Dolly's family chart
The newborn Dolly was like a superstar, and all the media around the world came to take pictures of her and make headlines. It can be said that every step of Dolly's growth is carried out under the witness of the world. Dolly grew up and matured, mating with other rams and giving birth to six lambs. This suggests that Dolly, though a clone, is fertile. Just when everyone thought that cloning technology could be popularized, Dolly had an accident!
The big star Dolly attracted the attention of many reporters
What happened to Dolly?
Sheep generally live 10 to 15 years, but in 2001, dolly, who was only 5 years old, developed arthritis. The 5-year-old sheep are in their prime, but Dolly has a disease that only old sheep have. The next year, 6-year-old Dolly developed lung cancer, and after several treatments, Dolly's body did not get better, but became more and more painful, and finally people could only euthanize Dolly.
Dolly was only 6 years old when she died, but her body was like an old sheep, and many people believed that cloning would cause organisms to age rapidly and shorten their lives. As the scientists dissected Dolly, they were surprised to find that Dolly's real age was not 6 years old, but should be 12 years old!
Dolly, 6, looks old
Dolly uses the DNA of ewe #2, and Dolly inherits everything from ewe No. 2, including age. The No. 2 ewe was 6 years old when she provided dolly with a nucleus, and the telomeres on her chromosomes had been shortened after several divisions, so dolly cloned by it was already shorter than sheep of the same age on the telomeres. Dolly's cell age has reached 6 years old since birth. This is the reason why Dolly, who looks young, is suffering from senile disease.
After her death, Dolly was made into specimens and put into museums in the United Kingdom, and was admired by the world, starting from Dolly, cloning technology began to develop in an all-round way, and more and more species were cloned.
Even though Dolly went to heaven, she was still a big star
What happened in the post-Dolly era?
At that time, people called the period of rapid development of cloning technology "post-Dolly" in recognition of Dolly's contribution to cloning technology. After the cloning of sheep, cloned cows, cloned pigs and other creatures have been introduced, but these cloned organisms, either directly premature, or have a particularly short lifespan, are about to catch up with ephemerals.
It was found that a problem that cloning technology could never overcome emerged, and that was longevity. Clones are generally not as long as natural bodies, dolly, who can live more than half the life of ordinary sheep is rare, and most clones have a lifespan of only one or two years. This is not what scientists are worried about, the most worrying thing is that many people have expressed support for the proposal of human cloning, and even some people say that they want to sign up for the study of human cloning and voluntarily become experimental subjects.
Clones in movies
A storm called Madness is gathering over the world. Subsequently, countries issued bans on the use of human cells for cloning. First of all, the cloned person and the person who provide the nucleus are genetically identical, and in essence, the clone is not a separate individual, it is a replica of the provider. That is, clones have no genetic diversity, they are simply repeating someone else's DNA.
If the number of clones reaches a certain number, the genetic diversity of the entire human race will be seriously damaged. Throughout the history of biological evolution, whenever the genetic diversity of organisms begins to decline, it means extinction. By virtue of this alone, human beings cannot use cloning as a normal means of reproduction.
Beautiful genetic world
It is also true that clones have a short lifespan and will inherit 100% of the provider's genes, including those genetic diseases. Each clone will be like Dolly in the past, suffering a lot in her short life. Imagine a clone who suffers from a disease that only an elderly person can have not long after birth, and who has Alzheimer's disease at a young age.
Genetics is also sometimes a painful thing
Human cloning is Pandora's box for humans, and once opened, the negative energy released will destroy the entire human world.
So this means that cloning technology has no benefits at all and should not be developed? Of course not.
How should cloning be used in the future?
In the movie "Jurassic Park", scientists extracted the DNA of dinosaurs from ancient amber mosquitoes, so with the help of cloning technology, crocodile eggs were used as a carrier to resurrect dinosaurs, thus starting this series of stories. Theoretically, there's nothing wrong with the method mentioned in the movie, and scientists hope to use cloning to revive extinct species.
Can humans resurrect dinosaurs with cloning?
However, scientists also mentioned that such a way can only clone individuals, can not clone the entire population, therefore, the fate of extinction can not be changed, just a sense of return to the light. But just a glimpse is enough, at least to let future generations see the true appearance of this animal again.
In 2017, China successfully cloned the world's first pair of cloned monkeys, marking the breakthrough of the cloning difficulties of primates. Chinese monkey cloning is not to lay the foundation for human cloning, but the world's demand for experimental monkeys.
We all know that before new drugs can be applied, a lot of experiments need to be carried out. Since humans cannot be used for live experiments, primates are needed instead of this step.
However, most monkeys are protected animals, and such a big demand cannot be solved by catching one or two monkeys. If every country needs to do this experiment to catch it, it will not be long before the monkeys will become extinct.
If humans can clone primates such as monkeys, then in animal experiments, the problem of insufficient number of experimental subjects can be solved, which is also a huge help for human drug research and development.
The wave of cloning that was all the rage of the past has gradually receded, and the meaning of cloning is not as good as everyone imagined in advance. First of all, it can't overcome the disease, but it will be affected by the disease, and the clone is not genetically novel, that is, the new bottle of old wine.
Clone of a pet dog
Second, clones have little economic value. For example, people hope to clone a large number of cows to solve the world's milk shortage, but the cloned cows can not survive for too long, before they start to produce milk, they die, the cost of cloning a cow is not low, and the final return is almost nothing, which is a loss-
Finally, cloning technology is too dangerous, and many countries are afraid of being used on people, so they have set up many rules and regulations, and cloning technology is increasingly restricted. With Dolly's death, the controversy over cloning technology grew, and some even opposed it.
Should cloning technology evolve?
The clone vividly shows the world what is called "technology is a double-edged sword", good or bad, depending on which side the person wielding the sword swings the blade to.