Meet Zhong Zhong and Hua Hua, two cloned macaque monkeys.
Chinese scientists first unveiled these monkeys several weeks ago, marking the first time primates have been successfully cloned with the same method that created Dolly the sheep in 1996. Just as it did then, the science research community instantly raised ethical questions and concerns about human cloning.
Theoretically, human cloning could be achieved in two ways. Reproductive human cloning would entail creating a living human, identical to another person previously or currently alive. Therapeutic cloning would employ stem cells from a human embryo to treat diseases.
Prof. Thomas Fox, molecular biology and genetics, underscores that these results could be “very useful” in understanding genetic diseases in people. He does, however, agree with Prof. Marcos Simoes-Costa, molecular biology and genetics, that there are ethical concerns about human cloning which need to be thoroughly debated.
“Personally, I feel it’s too bad that it may be possible to clone humans from existing adults. Evolutionary history demonstrates the enormous advantages of sexual reproduction for populations of complex organisms,” Fox said. “Cloning on a large scale would be a perilous step backwards.”
Fox added that the scientists were only able to clone cells from a monkey fetus and not a living monkey, but that “the methods will probably be improved so that they eventually will be able to clone existing adults, as is possible with several other mammals.”
Zhen Liu and his colleagues at the Chinese Academy of Sciences in Shanghai used a method called Somatic Cell Nuclear Transfer Animation to clone the monkeys. Using this process, scientists take out the nucleus from a healthy egg and replace it with a nucleus from another animal. The egg is then inserted into a surrogate mother, where the embryo develops and a clone is born.
“You can produce cloned monkeys with the same genetic background except the gene you manipulated. This will generate real models not just for genetically based brain diseases, but also cancer, immune or metabolic disorders and allow us to test the efficacy of the drugs for these conditions before clinical use,” Qiang Sun, a senior author of the study from the Chinese Academy of Sciences, said.
Reproductive cloning aside, the arguments for and against therapeutic cloning recall the case for and against abortion. While both involve destroying an embryo, therapeutic cloning would entail creating an embryo marked at the outset for destruction. Critics of human therapeutic cloning believe that would undermine human dignity and respect for human life.
According to the Center for Genetics and Society, about 46 countries have banned human cloning, including more than a dozen members of the European Union. In 2005, the United Nations General Assembly passed a non-binding resolution calling for “[the] ban of all forms of human cloning, including cloning for medical treatment, as incompatible with human dignity and the protection of human life.”
Although the United States has no such restrictions, the federal government does not fund research that involves using embryonic stem cells from human clones.
Scientists like Simoes-Costa believe that it is imperative to start preparing for the possibility of human cloning.
“While reproductive cloning of humans could be technically feasible in the short term, it does not mean that this experiment should be performed,” Simoes-Costa said.
He explained that it is not possible to guarantee “developmental abnormalities” will not occur in the process of cloning nor the welfare of potentially cloned children.
“It is important to foster discussion on the ethical implications of the procedure, so that the appropriate policies are in place when the time comes,” Simoes-Costao said.
Despite the breakthrough in genetics, Fox argues that reproductive cloning will not become common-place anytime soon.
“It’s hard to imagine human cloning becoming more than a hobby for a few wealthy narcissists,” he said.