With their huge eyes and spindly limbs, the two cloned macaque monkeys, whose births in China were announced last week, made irresistible front page fodder. Created by scientists at the Institute of Neuroscience in Shanghai, the animals, Hua Hua and Zhong Zhong, certainly looked cute. Cuddled together, they displayed an almost human vulnerability, a connection that was not lost on headline writers: “One Step Closer to Human Clones,” claimed one front page.
It is only 21 years since the Observer revealed to the world that scientists in Scotland had created the world’s first mammalian clone, Dolly the sheep. Now this triumph has been followed up with a pair of cloned macaques, creatures that are much closer to Homo sapiens in genetic terms than sheep. The suggestion that a similar trick would soon be carried out on humans was therefore too tempting to ignore.
We should be cautious before reaching such a dramatic conclusion, however. For a start, there was a crucial difference in the procedures adopted to create Dolly and those involved in bringing Hua Hua and Zhong Zhong into the world. The latter were cloned from a cell taken not from an adult macaque but from a macaque foetus. In contrast, Dolly was cloned from the cell of an adult ewe. The Chinese team did try to emulate this process and did indeed create – with considerable difficulty – two baby macaques from embryos cloned from adult cells. However, both died: one from impaired body development, the other from respiratory failure. Thus the Shanghai scientists still fell short of the achievement of Dolly’s creators who took an adult cell and from this created a viable foetus.
For good measure, it should also be pointed out how inefficient were the procedures used in creating Hua Hua and Zhong Zhong. They involved implanting a total of 79 embryos into 21 surrogate mothers, and from these a mere six pregnancies were established. Hua Hua and Zhong Zhong were the only live births that survived these pregnancies. As several geneticists have since observed, the creation of the two genetically identical macaques actually shows that the cloning of primates remains a highly inefficient and unsafe business and that the idea of humans becoming the focus of such work is still a far-off prospect.
To be fair to the team responsible for creating Hua Hua and Zhong Zhong, it was not their intention to develop techniques that could make it possible to clone human beings. “We cloned macaques to produce animal models useful for medicine, for human health. There’s no intention for us to apply this method to humans,” one project scientist told journalists last week. Instead, their work is directed at gaining new awareness of diseases such as Alzheimer’s, they argued. If they could set up a pool of genetically identical primates it should then be possible to study their DNA in order to understand how neuro-degenerative ailments progress.
This kind of research is undoubtedly worthy. Nevertheless, by involving primates, the scientists – unavoidably – reopened the debate about human reproductive cloning. Work on such a goal is already banned in many countries, including the UK, and, as we have seen, it remains a remote prospect. Yet the idea that one day it may be possible to create an exact copy of a person – a deceased loved one, for example – continues to obsess writers and columnists. It is a delusion. Even if it did become possible to create a clone of an individual, that person would still be a very different entity. Changes in gene expression that occur in the womb, a process known as epigenetics, as well as nutritional variations and other random events, would produce a person who might look achingly familiar but who would behave quite differently to that lost loved one.
Far from providing succour, a clone is far more likely to cause unhappiness and distress. In short, human cloning is neither practical at present or desirable in the long term. We should cherish the variety that is inherent in our species instead.