Controversies Associated With Cloning and Stem Cells
Because cloning for stem cells requires the destruction of human embryos, the procedure has all the same ethical drawbacks of conventional embryonic stem cells. Some bioethicists believe that killing an embryo is a form of murder. In addition, therapeutic cloning itself opens a number of new ethical problems.
In somatic cell nuclear transfer, an embryo is created for the sole purpose of destroying it. Conventional embryonic stem cell research often uses stem cells taken from embryos that were created via in vitro fertilization for reproduction. Some bioethicists believe that the embryo does not have the full rights of a person, but that it nevertheless deserves respect. They believe that using "leftover" embryos is ethically acceptable, but creating embryos just for experimentation is not.
The development of cloning technology for therapeutic purposes may also make reproductive cloning possible. Many ethicists are concerned with reproductive cloning, arguing that it would violate the human rights of the clone. They are concerned that therapeutic cloning will inevitably lead to reproductive cloning.
In 2001, the United States government outlawed all forms of human cloning, including both reproductive and therapeutic cloning. In 2004, researchers in South Korea announced they had successfully obtained stem cells from a cloned human embryo, but their claims were later shown to be based on fabricated data. To date, no cases of successful human cloning are known.