Cloning is the process of creating organisms that are genetically identical. These organisms are identical twins and are to some extent copies of each other.
Many organisms can clone themselves, including most plants and some animals. Reproducing this way avoids the need to find a sexual partner and allows a new generation to be produced rapidly.
However, when most people think of cloning they think of clones being produced artificially by scientists.
Artificial cloning has often been shown in a negative, sinister light. This arguably began with Aldous Huxley’s dystopian novel Brave New World and can be seen in more recent stories like The Boys From Brazil, Jurassic Park and Never Let Me Go. However, while the technology certainly has potential for abuse, it also offers many benefits if used wisely.
Early experiments in cloning were performed in the late 1800s and throughout the 20th century, but the most dramatic breakthrough came in 1996 with the birth of Dolly the sheep. Dolly was the first mammal to be cloned from an adult body cell, which had been re-engineered into an embryonic cell. This led to an explosion of interest in cloning and inquiries into the ethical pitfalls.
Medical applications are emerging: for example, cloning can be used to replace damaged or dead cells in our bodies. A particularly significant development came in 2018, when the first monkeys were cloned. Because these animals are closely related to us, the clones could be used to create new treatments for diseases like Alzheimer’s and cancer.
Some scientists hope to use cloning to help critically endangered species by boosting their populations with clones. There are even plans to clone and resurrect extinct animals, such as mammoths, using preserved tissue, but even if this is possible there is no consensus on whether it is the right thing to do.
However, cloning specialists continue to wrestle with technical problems. For instance, there is evidence that cloned animals die unusually young. Dolly only lived six and a half years, yet many sheep reach the age of 12. However, more recent clones have lived longer and without unusual health problems.
The field has also seen scandal. In 2005, Korean researcher Woo Suk Hwang was one of the world’s leading cloners, having produced the world’s first cloned dog. However, before the year was out he had resigned after it emerged that junior researchers had donated their own eggs for studies of human cells. It then became clear that some of Hwang’s results, including his claim to have cloned human cells, were faked. Hwang was later convicted of offences including violating bioethics law, but he has nevertheless continued his research. His faked results were eventually achieved legitimately by other scientists.
Beyond such blatant cases, cloning still faces ethical issues. For example, some people have had their pets cloned to order, so when the original dies it can be replaced by its clone. However, the new animal will have different life experiences and will therefore not be truly identical.
Finally, there is the vexed issue of human cloning. Despite repeated rumours in the early 2000s that cloned babies had been born, at present it seems no human clones have been made, and doing it presents massive difficulties. Many countries have banned human cloning, and companies that have claimed to do it have been investigated by law enforcement.