Cloning involves creating a population of genetically identical cells by asexual reproduction. A second definition involves creating an exact replica of a gene, or gene cloning.

Cloning is a natural process. Natural cloning occurs in unique ways. For example, identical twins start as a single fertilized cell, which then divides into two complete entities. Since ancient times pants have been known to propagate by asexual means. These genetically identical plants are clones. Cuttings of the leaves, stems, or roots clone some varieties.

Identical cell cloning is done by nuclear transfer. This idea is not new. In 1952 scientists cloned frogs with identical genetic materials. In the 1980s, researchers removed the nucleus from a body cell of a mouse embryo and put it into the fertilized egg of another mouse. Also, in the 1980s, animal research organizations began looking for ways to produce live calves by...