Natural human cloning occurs every day in the world in the form of identical twins who are conceived during the process of reproduction. It is a magical thing to behold: two living beings that are seemingly identical in every physical way. Such an occurrence has given rise to the possibility of artificial human cloning or using an existing or growing tissue from a human being to clone a genetically identical copy of that individual.

Human cloning can be classified into reproductive cloning and therapeutic cloning. In reproductive cloning, the cloned embryo is implanted in a woman’s uterus and this results into the development of a normal baby that is genetically identical to the DNA donor. Therapeutic cloning aims to provide replacement organs or tissue for people. It is essential that cloned organs are compatible with the patient’s immune system. For this reason, the cloned embryo contains DNA taken from the transplant patient.

Great strides have been made in the area of human cloning and stem cell research in recent years. To many, the biggest and clearly the most visible accomplishments in this arena of science were the successful cloning of two mammals: Dolly the Sheep in 1996 and Snuppy the dog in 2005. Dolly has since died (in 2003) after six years from non-cloning related conditions. Meanwhile, Snuppy was voted as Time magazine’s “Invention of the Year” in 2005 and his Korean creators are optimistic that he will live past the six-year benchmark set by Dolly.

Clearly, the potential of human cloning to save lives is enormous. Just imagine the possibilities. We could clone deteriorating organs like the heart, lungs and tissues affected by degenerative disorders such as Parkinson’s disease and Alzheimer’s disease. We could clone defective organs in the reproductive system to give childless couples a chance to have kids. We could replace damaged cells in the spinal column and eye area to help the crippled walk and the blind see. We could put an end to cancer. Human cloning has the potential to make virtually all diseases a thing of the past and could greatly alleviate sickness and suffering.

But, as the saying goes, we have to walk before we can run. And at this point in the development of human cloning science, mankind has taken mostly baby steps. Some scientists believe that it will take a hundred years before we can successfully clone the first human being. In this regard, the track record of today’s scientists is not very good. In fact, most claims of success in the field of cloning (some dating back to 1978) have been exposed as a hoax or as a study with questionable credibility over the years.

The most recent of these controversial studies involved Korean scientist Hwang Woo-Suk, who gained worldwide acclaim in 2004 for claiming to have grown 30 cloned human embryos and successfully harvested stem cells from them. In 2005, Hwang made the news again when he announced that he had created 11 lines of human stem cells, which are vital in the cloning process. However, later that year, an investigation revealed that Hwang was guilty of lies and fraud and his studies lost their credibility.

Yet, despite these setbacks, the early progress in the field of human cloning is encouraging, particularly in the area of cloning other mammals. Since the birth of Dolly the Sheep, the world’s first cloned mammal in 1996, scientists have successfully cloned horses, bulls and dogs. In 2006, scientists were able to successfully clone damaged spinal tissues in crippled rats which eventually helped them walk again. All these are significant steps in the right direction.