Cloning of plants has been a common practice of human being for hundreds and perhaps thousands of years.

Cloning of small animals also has a long history at around 1960's.

However, human cloning had not been thought possible until the successful cloning of the first mammal, Dolly the sheep, in 1997.

Dolly result from cloning is a major scientific and technological breakthrough. But, it also raised ethical issues and concerns since cloning of human will become possible.

Following the cloning of Dolly, many other animals, including cows and mice, have been successfully cloned.