Cloning has been going on in the natural world for thousands of years.

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                                                                                                                                       Stotler

Cloning

Cloning has been going on in the natural world for thousands of years.  A clone is simply one living thing made from another, leading to two organisms with the same set of genes.  In this sense, identical twins are clones because they have identical DNA.  Sometimes, plants are self-pollinated, producing seeds and eventually more plants with the same genetic code.  When earthworms are cut in half, they regenerate the missing parts of their bodies, leading to two worms with the same set of genes. Any organism that reproduces asexually produces a clone.  However, the ability to intentionally create a clone in the animal kingdom by working on the cellular level is a very recent development.  From sheep to monkeys, scientists have made great strides in the past few years in cloning mammals.  The birth of these transgender animals provides a major stepping-stone for the cloning of humans (Rantala 26).  Now groups say they are ready to clone a human being.  Controversy over their plans run high, but scientists believe the technology for human cloning, at least a limited type of cloning for now, is available.  A revolution in reproductive biology is now taking place which provides the technical means for cloning humans.  Many scientists who work with cloned animals say that the procedure is difficult and dangerous and unethical to try on humans.

Dolly, born at the Roslin Institute in Scotland in 1996, was the first mammal to be cloned from an adult mammal.  When Ian Wilmut, Keith H. S. Campbell and their colleagues announced in February 1996 that they had cloned and adult sheep to create a lamb with no father, they stunned the world unprepared to understand virgin births.  They also startled a generation of researchers who had grown to believe, through many failed experiments, that cells from adult animals cannot be reprogrammed to make a whole new body.  Using a technique called nuclear transfer the Roslin Institute scientists created Dolly (Wilmut 13).

The Roslin scientist took a cell from the udder of an adult sheep and cultured it for several weeks.  Then they harvested an unfertilized egg from a second sheep and removed the part that contains the genetic material after starving them for several days.  By starving the donor cells for five days before extracting their nuclei, Wilmut and Campbell made the nuclear DNA susceptible to being reprogrammed once placed in the egg.  Electricity was used to combine the two cells.  The egg then began dividing as a “naturally” fertilized egg would, become an embryo.  That embryo was implanted into a third sheep, a surrogate mother that gave birth to Dolly.  Dolly was, therefore, identical to the sheep that donated the udder cell.  This procedure was said to be impossible (14).  Many animal development experts now suspect that genetically duplicating humans is possible, especially as Donald Wolf of the Oregon Regional Primate Research Center has already cloned rhesus monkeys from embryonic cells.

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Researchers at the Oregon Regional Primate Research Center, using a different procedure from the one that made Dolly, cloned Tetra, a rhesus monkey born in 1999.  Researchers used embryo splitting, a technique that makes Tetra a clone of her sisters, rather than a clone of an adult mammal.  Researchers fertilized an egg from a female monkey with the sperm of a male monkey to make and embryo.  When the embryo divided into eight, researchers split it into four identical two-celled embryos.  Each two-celled embryo was implanted into a surrogate mother.  Only one embryo survived, and Tetra was born.  Tetra is ...

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