By April Sanders, eHow Contributor
In genetics, to clone an organism is to make an exact copy of its DNA. Cloning is commonly done on small organisms, mostly plants, and on animals, such as the famous sheep called Dolly. The most controversial aspect of cloning is whether or not it should be done on humans. This includes the cloning of any and all human tissue, including organs.
In January of 2008, scientists Wood and Andrew French claimed to have successfully created five healthy human embryos from DNA taken from adult cells. The embryos were destroyed, however, because reproductive cloning is currently illegal in the United States. The advantages and disadvantages of cloning humans have been discussed in great detail, and the arguments are ongoing. Other People Are Reading
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* British biologist J.B.S. Haldane is given credit for having coined the word "clone" during a speech in 1963. In 1966, scientists Marshall Niremberg, Heinrich Mathaei, and Severo Ochoa broke the genetic code, allowing for studies on genetic engineering. The first gene was isolated in 1969 and the first recombinant DNA molecules, a combination of the DNA from two different organisms, were created in 1972. In 1977, a German biologist created mice with a single parent. By 1979, Karl Illmensee claimed to have successfully cloned three mice. The method of nuclear transfer was created in 1983, and in 1984, Danish scientist Steen Willadsen cloned a sheep from embryo cells, which is considered the first true cloning of a mammal using nuclear transfer. In 1986, it was discovered that cloning could be done by using the nucleus of an adult cell, not just embryo cells. This eventually led to Ian Wilmut's cloning of the infamous sheep "Dolly" in 1996. Dolly was the...