“The bill would ban human cloning and any attempt at human cloning, whether for reproductive purposes or medical research. The import of cloned embryos or derived products is also prohibited"; these are the opinions of a representative of the United States, Ken Calvert. Humans have been cloning plants and small animals such as invertebrates for centuries, but the idea of ​​human cloning is controversial and up for debate. Human cloning refers to the asexual production of a human being from an ancestor to which he or she would be genetically identical. Scientists began their research on animal cloning in the 18th century. August Weismann, in 1880, proposed that a cell's genetic information would decrease with each cell division. Hans Spemann disputed his idea and in his book entitled “Embryonic Development and Induction” talked about a fantastic cloning experiment that later became the basis for animal cloning. He called it a “nuclear transfer experiment” and suggested that cloning could be done by transferring the nucleus from a cell to an enucleated egg, which is a cell whose nucleus has been removed. John Gurdon, of Oxford University, put forward his idea and cloned South African frogs from an intact nucleus of a Xenopus tadpole. After Gurdon, an English embryologist, Dr. Ian Wilmut began research on mammalian cloning and cloned a sheep called "Dolly", which became a major scientific and technological breakthrough. With the birth of Dolly, the world realized that animal cloning was no longer a dream or an element of a science fiction movie, and the debate over human cloning captured a lot of attention. Theoretical human cloning has been divided into two main types: therapeutic cloning and reproductive cloning. Cloning. Therapeutic cloning...... middle of paper......m>."Population clock." Population clock. U.S. Census Bureau, nd Web. 09 May 2014. .Rowan, Carl. “The cloning of people is coming, with astonishing results.” Kentucky New Era March 1, 1997: 13. PrintShelby, Richard. "USATODAY.com - Cloning Devalues ​​Humanity." USATODAY.com - Cloning devalues ​​humanity. USAToday.com, November 27, 2001. Web. May 11, 2014. "Statistics." Donate to Vita America. Donate to Life America and Web. May 11, 2014. .The Koran. Trans. by Tarif Khalidi. New York: Viking, 2008. Print.Woodward, John. The ethics of human cloning. Thomson Corporation, 2005. Print."WHAT YOU NEED TO KNOW ABOUT ADOPTION." Pakistani adoption. PakistanAdoption.com and Web. May 11 2014. .