Nearly 16 years ago, the world marveled at the birth of the first cloned mammal: Dolly the sheep. While experiments with cloning technologies had been ongoing since the 1950′s, this was the first time a mammal had been successfully cloned using adult somatic cells. Previous cloning attempts made use of embryonic cells, which are not yet differentiated into different types like nerve cells or skin cells. Essentially, these researchers were simply creating twins, not clones. Dolly, on the other hand, was created from a cell derived from an adult sheep’s mammary gland and the DNA from a different sheep. This is how Dolly got her name; after the world’s most famous mammary glands.
This was extremely exciting to scientists – for the first time in history it became possible to take the DNA from an adult human and clone them. Theoretically, we could create multiple Einsteins or Steven Hawkings, or for the most dire of circumstances an army of Batmen. But it’s been nearly 20 years and there is still only one of me. What happened, or rather, didn’t happen?
It turns out that, as usual, the media jumped the gun and ran wild with a sensationalist story. Cloning technology has been a hotly debated topic since the idea was first conceived nearly a century ago, with ethical and moral questions at the forefront of most debates. And the process used to create Dolly the sheep is itself fraught with problems. Dolly herself only survived for 6 years, about half the life expectancy for a normal sheep. It’s still unclear whether or not her origin had anything to do with her shortened life-span; on the one hand the illness that led to her death is very common among sheep kept indoors as she was, but on the other hand a postmortem examination showed some signs of premature aging in her genes.
Whether or not Dolly herself was a victim of the circumstances of her birth, animals created using this form of cloning, known as “somatic cell nuclear transfer,” are fraught with developmental challenges and deformities. Only 0.1 to 3 percent of these cloning attempts actually work. Even if the clone survives until birth, it is likely to be born much larger than than their naturally occurring counterparts. Scientists have christened this deformity “Large Offspring Syndrome,” or “LOS.” The organs of these unfortunate individuals are oversized, leading to problems with breathing, blood flow, and other bodily processes. Even clones born without LOS often suffer from deformations of the kidneys, brain, and immune system which can lead to premature death or at least make life more difficult.
It’s should be fairly clear now why experiments into human cloning haven’t progressed any further than they have. Even if a researcher were to somehow conjure the funding and backing to undertake such a project, their chances of success are quite small. If they managed to bring a cloned human successfully to term, more likely than not that individual would suffer from one or more developmental disorders. The ethics and morals of human cloning are a moot question at this point – no one would even try with such a high chance of failure.
As it turns out, this process isn’t even really “cloning” in the purest sense of the word. Each cell contains two sets of DNA: nuclear DNA and mitochondrial DNA. Somatic cell nuclear transfer – the process used to create Dolly – only copies the nuclear DNA of the donor organism. The mitochondrial DNA comes from the organism that donated the host cell, and so the resulting clone is actually a hybrid of these two animals (although not in the same way that natural animals are hybrids of their parents).
With the media focused mainly on the headline-grabbing cloning projects like Dolly the sheep, important research into similar, but less sensationalist technologies is being over-looked. Recombinant DNA technology has been around since the 70′s, and work in this field is yielding amazing results that will help us engineer food with higher nutritional value, better taste, and shorter growing seasons. Therapeutic cloning, the cloning of human embryos for research, is currently our best bet for eventually beating diseases like Alzheimers, cancer, and heart disease.
While its fascinating and incredible that our technology has reached the point where we can clone mammals like Dolly the sheep, we must be careful with how these technologies are utilized. Without careful control of how the research is conducted, we run the risk of creating Frankenstein’s Monster and turning the public off to the potential benefits.
