It's a nightmare scenario. A maniacal dictator harnesses the ability to clone a "superman" soldier, creating an indomitable army. Perhaps a wealthy genius clones himself to expand his empire. Is it possible we might one day live in a "Brave New World," where castes of citizens are cloned to fulfill specific functions?
Before 1997 such scenarios were limited to science fiction. But when Scottish scientists at the Roslin Institute revealed they had successfully cloned an adult sheep, the world took note. While the researchers said they had no aim to ever clone human material, human cloning was now theoretically possible, the Washington Post reported. Rather, the scientists said, the ability to clone adult animals held out the promise of agricultural and medical advances.
Nevertheless, the scientific watershed--astounding scientists worldwide who had repeatedly attempted to clone other adult animals--has led to an ethical maelstrom. Should human cloning be outlawed? Is it ethical to grow human embryos to use in potentially life-saving treatments? Is cloning the next logical step (after in vitro fertilization) for infertile couples who desire children?
To grapple with the moral dilemma, an understanding of cloning is helpful. The recent breakthroughs--first Dolly and now the hotly debated use of stem cells--have only been possible due to more than 40 years of genetic research. Scientists have been cloning cells for years by copying genes and other parts of chromosomes to create enough identical material for further study.
Two other types of cloning produce genetically identical animals. Twinning involves splitting a developing embryo soon after fertilization to give rise to two or more embryos. The resulting organisms are identical twins (clones) containing DNA from both the mother and the father.
Dolly is the result of a third type of cloning. Scientists used a technique called nuclear transfer to create an animal that carries the DNA of only one parent. They transferred the nucleus of an adult sheep's udder cell to an egg whose nucleus had been removed. This newly created cell was then planted in the uterus of a sheep. Thus, Dolly is a genetic twin of her mother, having genetic material from only one parent. See this diagram for more information about the creation of Dolly.
After Dolly's birth more questions fueled the evolving controversy. How safe was it to even consider cloning a human when so many variables and unknowns existed? Dolly was one success out of more than 200 attempts. How could some scientists, like Chicago's Richard Seed, consider human cloning a safe, moral option when so many things could go wrong?
Stemming the Debate
More recently, the cloning debate has intensified around the topic of therapeutic cloning. Instead of creating an identical organism that grows to maturation--as in the case of Dolly--embryonic cells are cloned for the purpose of harvesting stem cells. These non-specialized cells have the ability to form into specific types of tissue, making it possible to repair imperfect organs and other body parts.
In a recent decision, President Bush approved limited stem cell research funding. His decision allows scientists to perform research on a designated number of cell lines already taken from embryos, but does not allow the harvesting of thousands of currently frozen embryos located at numerous fertility labs around the United States. However, his decision has come under much criticism due to questions of the approved cell line's availability.
Both politically and ethically, the questions and concerns regarding the cloning of human cells remain. To further examine the issues surrounding this debate, visit the following sources: