A recent study revealed that sheep created from the same biological matter used to make Dolly, the first cloned mammal, were aging normally and living healthfully – crumbling an apparently widely held impression that cloning created unhealthy animals.
The study comes 20 years after Dolly blurred the lines between science fiction and reality, sparking worldwide debate that spanned the fields of science, ethics and religion over the appropriateness of cloning and whether someday humans would be grown and experimented upon.
And while the recent findings, published in the journal Nature Communications, reinforced scientific conclusions that clones aren't sicker than other animals, they also reflected how in the decades since cloning became a reality, it hasn't really lived up to the promises or the fears that surrounded it.
"People were worried that cloning would be used as a means to harvest organs or to replace people that had died," says Lawrence Brody, director for the Division of Genomics and Society at the National Institutes of Health.
Those opposed to human cloning even today fear narcissists would employ the procedure in misguided attempts to live forever, that parents would try to replace children that had died, and that clones would not be given human rights. Fears accelerated as Dolly became sick within six years, and examinations of her cells suggested she was aging prematurely. In creating a clone, some said, science was creating a monster.
Several countries quickly passed laws to ban human cloning. The U.S., however, does not have such a law. Though bills were introduced in Congress in the 2000s, politicians could not agree at what stage of development cloning should be banned. Lawmakers who believed life begins at conception were opposed to embryonic cells being created and destroyed, but some scientists countered that cloning and growing these cells could lead to replacing damaged tissue or organ cells.
Many lawmakers agreed that the next stage of cloning should be banned, as it would involve implanting a cloned embryo into the womb of a surrogate so she would give birth to another human, but some were opposed to bills that prohibited cloning during early stages. As stem cell research later took off, the interest in human cloning appeared largely to dissipate.
Dolly's ailments were eventually attributed to bad luck, and the sheep was euthanized in 2003. But most people remain staunchly opposed to creating human clones.
"Are there people out there hoping to clone humans? I hope not," says Steven Stice, director of the Regenerative Bioscience Center at the University of Georgia. "I don't see any great value or reason for cloning humans. I'm against it from an ethical side. I don't know of anyone doing it."
So why did it never catch on?
One reason is that researchers have a hard time arguing that there's a dire social need for cloning a whole person: Much that can be learned from studying two people with the same genes can be seen in nature, by simply studying identical twins.
Another reason cloning never became widespread is that it is fraught with ethical dilemmas because it's still hard to get right – even in animals. It requires an egg donor as well as a surrogate, meaning animals are subjected to hormones and invasive surgery. Even if the most difficult step is achieved, in which an embryo is transferred to a surrogate and results in a pregnancy, the fetus may die during gestation, or soon after birth. It took 277 tries to bring Dolly to the world.
"It's an extremely inefficient process," says Brody from the NIH. "Lots of embryos died."
The egg donation step is another reason human cloning is seen as ethically objectionable.
"It's risky, and the risks have never been properly studied," says Marcy Darnovsky, executive director of the Center for Genetics and Society, a public interest organization based in Berkeley, California. "It's invasive and it's no walk in the park for women to donate eggs. We need to think about if we want to put real young women at risk for this speculative kind of research."
States have passed their own laws banning human cloning, but Congress never reached a consensus. In 2001, former President George W. Bush banned the use of government funds for most embryonic stem cell research, which was considered to apply to cloning as well.
President Barack Obama later lifted the ban on embryonic stem cell research but said he would ensure the government would not open the door to the use of cloning for the creation of another person.
"It is dangerous, profoundly wrong and has no place in our society, or any society," he said.
Since the U.S. ban was lifted, two different teams of scientists have reported successful cloning of human cells here.
Jeremy Berg, editor-in-chief of the journal Science, run by the American Association for the Advancement of Science, says the consensus is that human cloning is not ethically appropriate.
"I think even if it is not banned the ethical framework is so universally accepted that I can't imagine any organization that had resources would do it because the backlash would be incredible," he says.
Even without federal law, Food and Drug Administration officials have some authority to put a stop to human cloning if it occurs. They can investigate allegations of the procedure because researchers aren't allowed to experiment on people with a new drug or device without the FDA's approval.
That doesn't mean some people haven't tried. A U.S. biotech company once known as Advanced Cell Technology tried to clone humans during the 2000s but was not successful, and several scientists over the years have claimed to clone humans but have not proved it. In 2002, a religious sect in the U.S. claimed to have cloned a girl named Eve and 12 other humans but never offered any evidence.
Scientist Hwang Woo-suk claimed when he was at Seoul National University in South Korea in 2004 that he had cloned a human embryo in a test tube. He wrote about his finding in two papers, published in the journal Science, that were later retracted after an independent committee investigated the claims and found no proof of the clone.
Hwang lost his university position and was convicted of embezzling research funds but years later went on to found the Sooam Biotech Research Foundation, which now charges owners $100,000 apiece to have their dogs cloned.
Sooam is also working on a project to bring the wooly mammoth back from extinction and is partnering with the world's biggest cloning factory, Boyalife Group in China, to create primate clones. Boyalife's chief executive, Xu Xiaochun, said in December that the company's technology had advanced enough to clone humans but that it would not do so because of likely public backlash.
Cloning of animals also occurs in the U.S., and some have built commercial businesses from it. Animal clones are even in American food.
About a week before the findings about Dolly's relatives were published, a company called ViaGen Pets had quietly created the first dog clone in the U.S. The company's parent group, Intrexon Corp., had been cloning thousands of livestock for more than 15 years and had recently delved into the pet-cloning business. In October, it delivered two litters of cloned kittens.
In some cases, cloning can be the best reproductive option. A prodigious police dog may be cloned for its bomb-sniffing skills, or a horse may be cloned for its jumping abilities. Sometimes a valuable work animal cannot reproduce sexually or becomes injured.
"I know the technology very well," says Stice from the University of Georgia, who has been involved in hundreds of clonings. "It works for people that need an identical animal."
Stice says the lack of publicity around cloning is no accident, that generally the public and the food industry are afraid of cloning and don't want to be associated with it. Still, it's in some food because in 2008 the FDA declared that milk or meat created from cloned animals was just as safe as those from animals that hadn't been cloned. The European Parliament, however, voted to ban cloning of farm animals in 2015, citing animal welfare. Prominent animal rights groups have also voiced opposition.
While scientists have made progress in refining the procedure, and while failure rates aren't as high as they used to be, a majority of cloning efforts still fail, experts say. Stice says given the different moving pieces it's hard to say how successful cloning is, but that it's possible the procedure may work up to 30 percent of the time. In comparison, artificial insemination of animals works 50 to 75 percent of the time.
Stice's position is that cloning should happen in limited scope, as merely another reproductive option, rather than in any massive capacity.
"I think cloning is safe," he says. "It's one of many reproductive tools that can be used by people trying to get better quality and safer meat and milk for more people." He adds that the ethical treatment of the animals involved has improved dramatically.
Stem cell research has largely taken the place of cloning. In the field of genetics, ethical conversations of late tend to be centered on gene manipulation and the creation of so-called "designer babies." Some hope to rid infants of devastating genetic diseases, while others are concerned about targeting physical or personality traits that are merely not prefered, like a certain hair color or gender.
Despite the shift, experts say the focus on the ethics of human cloning during the 2000s was important and is still valuable today.
"It brought up large societal discussions, and having these discussions before you do something is a very good way to move forward," Brody says.
Image via Geograph
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