Reproductive Cloning

  1. Reproductive Cloning
  2. Science & Policy History
  3. Ethics
  4. The Arts
  5. Media Monitoring
  7. References & Links
Human reproductive cloning is the creation of an individual who has identical nuclear genetic material (DNA) to an existing human being, and who is allowed to develop to term and beyond.  Human reproductive cloning is widely regarded as unethical and inappropriate and is specifically prohibited in many jurisdictions.  An initiative at the United Nations General Assembly led to the United Nations Declaration on Human Cloning, that calls on all states to prohibit all forms of human cloning.


Science & Policy History

Basic scientific concepts 

A gene is a hereditary unit consisting of a sequence of DNA that occupies a specific location on a chromosome. Chromosomes consist of long coiled chains of genes and are found within all nucleated cells in the human body.  Human beings normally have 23 pairs of chromosomes; one of each pair is  inherited from the genetic mother and one from the genetic father.   

In sexual reproduction, a child receives half of their genes from the mother (contained in the egg) and half from the father (contained in the sperm).  The combination of maternal and paternal genes which occurs at fertilisation forms the basis of human genetic variety and diversity.  A small amount of genetic material is contained within mitochondria within the egg and this mitochondrial DNA is passed on to the child entirely from the mother. 

In embryo splitting, an early human embryo divides into two genetically identical embryos which are then capable of developing independently.   This process may happen spontaneously and is the mechanism whereby genetically identical twins (technically described as monozygotic twins) are formed.  Embryo splitting can also be induced artificially.   

In reproductive cloning the entire genetic code (except for the mitochondrial DNA) is reproduced from a single body cell of an adult individual.  The most common cloning technique is somatic cell nuclear transfer (SCNT). The procedure is as follows1: 

  • The nucleus is removed from an egg leaving the cytoplasm and mitochondria (cellular components derived from the mother)
  • A body (or somatic) cell is taken from an adult individual who is to be cloned.  The DNA is extracted from the nucleus and inserted into the prepared egg.
  • The new cell is then induced to divide using either chemical or electrical stimulation, thereby commencing the development of an embryo.
  • After several days the dividing embryo is then placed into the womb of the recipient and allowed to develop to term. The result is a clone – an individual that is the genetic duplicate of the individual from whom the original body cell was taken. To date this process has not been proven to occur in a human being.  If it did so, it is important to note that the resulting child would neither be the individual’s son or daughter, nor their twin brother or sister. The child would truly be a new category of human being – a clone.

Hans Spemann, an eminent Germany scientist, conducted the first nuclear transfer experiment in 1928, in which he transferred the nucleus of a salamander embryo cell to a cell without a nucleus. This was followed up in 1952 with experiments carried out by Robert Briggs and Thomas J. King, using embryonic donor cell nuclei from amphibia2.  Earlier attempts by the two had failed, but by the completion of the project they had been successful in cloning thirty-five complete embryos and twenty-seven tadpoles from one-hundred and four successful nuclear transfers3. At the time they were unaware of the work of Hans Spemann4. The work of Briggs and King helped initiate decades of substantial research into cloning research.

John Gurdon of Oxford University, discovered in 1962 that differentiated cell nuclei could also result in cloned offspring, the result of which proved that as differentiation occurred, there was no loss of genetic material. Whilst this attracted the attention of many, some scientists doubted the validity of Gurdon’s work, uncovering flaws in his work5.

Research and development continued into nuclear transfer work in the use of mammals in the 1970s all the way through to the 1990s, resulting in the conception of the first mammal cloned from an adult nucleus taking place in 1996, by Ian Wilmut and Keith Campbell of the Roslin Institute, Scotland. The birth of the clone, “Dolly” the sheep, was first announced in the journal, Nature, in 1997 and initiated worldwide discussion about the possibility of cloning humans6 

Since the birth of Dolly the sheep, there have been many more mammals that have been cloned from differentiated cells. These include: 

  • Horses – On May 28th 2003, “Prometea” a Haflinger foal, was the first cloned horse and the first to be born from and carried by its cloning mother. Prometea was born after a natural delivery and a full-term pregnancy in Laboratory of Reproductive Technology, Cremona, Italy.
  • Mice – In 1998, Ryuzo Yanagimachi and Teruhiko Wakayama of the University of Hawaii announced that they had cloned fifty mice from adult cells since October of 1997.
  • Lambs – In July 1997, Ian Wilmut and Keith Campbell built upon the success of “Dolly” the sheep and successfully cloned “Polly”, a Poll Dorset lamb cloned from skin cells grown in a lab and genetically altered to contain a human gene7.
  • Cats – “Little Nicky” was born on 17th October 2004 and was the first commercially produced cat clone.

These results all point to the possibility of somatic nuclear transfer eventually being successful in all mammals, including humans. Yet it is still the most commonly held opinion that reproductive cloning of humans should be opposed.  

Despite this widespread opposition to reproductive cloning, some scientists have nonetheless pursued this goal, and several claim to have successfully cloned humans, and even to have brought some to term.

  • The first human clone, a healthy 7-pound girl named Eve, was born on the 26th of December 2002, according to Clonaid, a private company linked to the Raelian religious sect.  (The Raelian’s believe that human life was created in an alien laboratory, and that human cloning provides the opportunity for human immortality.)  The claim was never verified.
  • In 2003 Panayiotis M Zavos, Professor Emeritus of Reproductive Physiology and Andrology at the University of Kentucky, claims to have cloned a human embryo but to have cryopreserved it at an early stage of development.
  • In November 2002, Dr Severino Antinori announced that he had successfully used cloning to induce pregnancy in three women, with birth of the first child expected in January 2003.  There is widespread skepticism about the truth of these claims.

In 1984 the Report of the Warnock Committee recommended that human cloning should not be permitted.  However current legislation in the UK concerning human cloning are somewhat ambiguous. Whilst the law in its current form does not allow any form of reproductive cloning to be licensed, there is no explicit ban on cloning.  In 1999, in answer to a question in the House of Lords the official UK Government position was that “human reproductive cloning is ethically unacceptable and cannot take place in this country”8    

The nuclear replacement of an egg (such as in the process which led to the creation of Dolly the sheep) and embryo splitting are currently allowed in human embryos under the jurisdiction of the Human Fertilisation and Embryology Authority (HFEA) but only for short experimental use.  Embryo splitting purely for treatment purposes is not approved by the HFEA, and the UK Government stated clearly in 1999 that “it will not licence cloning by embryo splitting for treatment purposes”9. As laid out in the Human Fertilisation and Embryology Act 1990, the HFEA also regulates the current legislation which allows embryos up to 14 days old to be destroyed, frozen or researched on for specific purposes.   

In order to consider and explore the ethical issues and possible applications of human cloning, in 1998 the UK Government asked the HFEA and the Human Genetics Advisory Commission (now called the Human Genetics Commission) to undertake research into these issues and present a report on their findings. The conclusions of this project were published in the report Cloning Issues in Reproduction, Science and Medicine. The report included a recommendation stating that no human reproductive cloning should be allowed but that therapeutic cloning should be allowed10 

In August 2000, an independent advisory group commissioned by the government and chaired by the Chief Medical Officer Dr Liam Donaldson, presented its recommendations on the future development and benefits of research or therapeutic cloning and reproductive cloning. Aside from its recommendations concerning research cloning, it recommended that reproductive cloning remain illegal in the UK11 

The government fully accepted the recommendations of the report which consequently led to the introduction of The Human Reproductive Cloning Act (passed on December 4, 2001) which outlaws any attempts at reproductive cloning. For more information concerning UK policy on research or therapeutic cloning click here.


Arguments against the creation of human clones12

The majority of arguments against reproductive cloning have highlighted the possible adverse consequences on individuals, family relationships and society as a whole.  However principled objections to human cloning in itself have also been raised.  

a) Principled objections to reproductive cloning 

  • Instrumentalisation of human beings.  Cloning represents the creation of a human individual as an instrument of another human’s will and purposes.  It reflects a view of humans as objects that can be tailor-designed and manufactured to meet certain characteristics and specifications13.
  • The child as a reflection of the love between a man and a woman.  In orthodox Christian thinking, human procreation is seen as indissolubly linked to the committed love of a man and a woman.  In other words “making love” and “making babies” belong together and every child should be a reflection of a love relationship.  Reproductive cloning as an asexual form of reproduction destroys the link between a human relationship and the being of a child.  
  • Uniqueness diminished.  Reproductive cloning threatens widely and deeply held convictions about the individuality of human beings, which is closely linked to notions of human freedom.

 b) Adverse consequences of reproductive cloning 

  • Safety Fears Concerning Human Cloning. Current scientific experience indicates that between 95 – 98% of mammalian cloning experiments have resulted in miscarriages, still births and life threatening abnormalities14.  There is increasing evidence that mammalian clones are likely to have subtle abnormalities of complex and poorly understood genetic control mechanisms.   In 2001, at a National Academy of Sciences conference in Washington, DC scientists who opposed reproductive human cloning presented the results of s research, which indicated that approximately a third of cloned mammals have developed abnormalities15. Such abnormalities include the large offspring syndrome (LOS), where the offspring is born oversized with disproportionately large internal organs and suffers from respiratory, circulatory and other problems.  Many argue that with current understanding of cloning techniques similar abnormalities would probably occur in human somatic cell nuclear transfer.

W. French Anderson, the pioneer of human somatic gene therapy in the early 1990s, has remarked that due to the unknown harmful effects of manipulating the germline, there needs to be long-term research carried out with somatic gene therapy in hundreds of patients, with data generated over the course of at least ten years. Furthermore, reliable, reproducible, and safe procedures must be shown in primates first before proceeding any further with human reproductive cloning.  Anderson also argued that before germline intervention is initiated in human beings, a full understanding of the risks and costs associated with germline interventions, as well as social awareness and societal approval, must also be gained16.   

  • Social and psychological consequences of cloning. It has been argued that a child clone would inevitably suffer adversely from the existence of their nuclear donor and from the knowledge that they had been created for a specific purpose.  Thus a “replacement” child would suffer from continuous comparisons and memories of somebody else, and would not have the normal celebration of a new person, a new life: their life. Simply creating a clone to replace a beloved child tends to dehumanise both the child and its replacement clone.  Similarly a child that was created to be a genetically identical donor for an existing human may feel coerced or abused by the process.  Reproductive clones may also encounter various forms of social discrimination and stigmatisation. 

  • The slippery slope argument.  Once reproductive human cloning was permitted, it may become more difficult to prohibit and restrict other more dangerous applications of genetic and reproductive technology.  The technology can easily be utilised outside governmental scrutiny and is ultimately impossible to control.

Arguments in favour of creating Human clones17

  • The existence of identical twins. It is argued that identical twins represent a natural form of cloning.  However, whilst the identical twins share the same genetic make-up, they are not deliberately planned copies of their parents created by asexual reproduction.  In addition identical twins are the same age as one another, and recognise each other as brothers and sisters, whereas a cloned child would be genetically the same as a parent or another human of a different age.
  • A novel form of human reproduction. For those who are unable to have children through other fertility treatments (i.e. those who produce neither eggs nor sperm), human cloning may provide a viable alternative to having a genetically related child.  However, individuals who are in this position are relatively rare.
  • Children for lesbian couples or single women. Human cloning would provide lesbian couples or single women with an opportunity to have a child without using donor sperm.
  • My Child: Mark II.  Protagonists of human cloning such as Dr. Richard Seed, argue that parents of a child who died prematurely or even through a tragic accident would, through reproductive cloning, be able to compensate for their loss through having a ‘second version’ of their child [18]. On the other hand, seeking to create a “replacement child” may not bring all that the parents aspire to replace.  Indeed, the clone will be exposed to different environmental influences and will develop in a different way from the original child. 
  • Creation of a genetically identical donor.  Cloning will enable the creation of a genetically identical child who may provide desperately needed tissue or organs for the cloned adult which cannot be obtained in any other way.  A clone could provide bone marrow, tissue (such as skin or muscle) or even solid organs such as a kidney.  

  • Safety concerns can be overcome.  Proponents of cloning argue that most medical technology brings with it an element of risk, and that normal human reproduction is not risk free.  There were initial safety concerns about in vitro fertilisation but this is now widely accepted and practiced.  It is also argued that incidents of LOS are probably due to poor embryonic culture conditions. The techniques of embryo manipulation are rapidly improving and the problem may be eradicated  [19].Once the process of reproductive cloning has been improved and perfected in mammals, it is believed that human trials can be commenced with a reasonable degree of safety.  

  • The slippery slope can be prevented. It is argued that robust legislation, democratic accountability and effective governance of professional practices will prevent the abuse of reproductive technology. Gradual extension of practices are not inevitable and as a society we have the mechanisms to prevent unacceptable developments from occurring. 
  • A reproductive right? Some believe that human cloning is a reproductive right.  Hence from a libertarian perspective it should be allowed without restriction, provided that the safety concerns have been overcome and cloning is demonstrated to be no less safe than natural reproduction. Yet rights are socially negotiated and imply duties and responsibilities on others.

The Arts


Alien Resurrection
Scientists on a space colony have cloned both an alien and Ripley (Sigourney Weaver), who died in Alien 3; the scientists, however, have accidentally mixed alien DNA with Ripley's human chromosomes.

American Ninja 2
A drug dealer is kidnapping Marines on an unknown tropical island in order to genetically engineer "super ninjas," and the American Ninja is dispatched to control the situation.



Johnny 2.0
The protagonist wakes up in a hospital only to learn that he is a clone and he only has one week to live due to a flaw in the cloning technique. He must find his original because his original has developed a software program that corrects the flaw.

Jurassic Park/The Lost World
Two films that introduce the reality of cloning and illustrate the chaos theory in typical Hollywood fashion. Yet they raise the question of how to "control" what has been created.

Star Wars Episode II: Attack of the Clones
Ten years after Episode I, Padm1 Amidala, now a senator, resists the creation of a Republic Army to combat an evil separatist movement.

The Boys from Brazil
Violence and greed rule the minds that tap into the scientific world of cloning. An attempt to bring to life a clone of Hitler is diabolically played out.

The Clonus Horror
A man tries to break out of a high security government research facility. He has learned that the government is freezing people so that their body parts can be used to make clones of them.

The Fifth Element
This film posits the question: What if an opposite form of life existed in another dimension - one that is an embodiment of all that is evil? Scientists recreate the whole body of an alien from just the remains of a hand


Acts of God: Book Three of The Christ Clone Trilogy by James BeauSeigneur
In the conclusion to the Christ Clone Trilogy, miracles are happening and and the world as we know it is completely changing.

(Warner Books, 2004)

Birth of an Age: Book Two of the Christ Clone Trilogy by James BeauSeigneur
The coming of a new era, promised by Christopher Goodman (a man cloned from DNA on the burial shroud of Jesus Christ), seems highly unlikely as humankind experiences unparalleled pain and suffering in this second of three books taking place in the end times.

(Warner Books, 2004)

Cloning Christ: A Challenge of Science and Faith by Peter Senese and Robert Geis
A genetic scientist discovers what is believed to be the cross that Jesus was crucified upon and confronts the effect that cloning Jesus will have upon modern-day religion.

(Orion Publishing & Media, 2003)

Glory Season by David Brin
Set in a world where almost everyone reproduces through cloning, this book traces the life of a "variant" born through sexual reproduction

(Bantam Books: New York, 1993)

In His Image: Book One of the Christ Clone Trilogy by James BeauSeigneur
A mix of fact and fiction, this book tells the story of Christopher, a baby cloned from cells stuck to the Shroud of Turin.

(Warner Books, 2003)

The Bones of Time by Kathleen Ann Goonan
This ambitious 1996 novel takes place in 2034 and focuses on the attempt to re-create genius for the benefit of humanity.

The Boys From Brazil by Ira Levin
This novel is about a scheme to clone Hitler.

(Dell, 1977)

The Jesus Thief by J.R. Lankford
This book chronicles an attempt to clone Jesus using DNA stolen from the Shroud of Turin (believed by many to be the burial shroud of Jesus Christ).

(Great Read Books, 2003)

The Klone and I by Daniel Steele
The heroine in this romance novel is a divorced woman who falls for a clone.

(Random House, 1998)

The Sacred Helix: Do We Dare Do the Unthinkable? by Mark Garon
This book tells the story of a top-secret governmental cloning project that extracts DNA from the Shroud of Turin and clones Jesus Christ.

(Writers Club Press, 2000)

Visual Arts

Multiplicity: 24 artists look at cloning by Various
There is an online display, adapted from the exhibition Multiplicity: 24 artists look at cloning that features the work of 24 artists at Central Saint Martin·s College of Art, London, who collectively call themselves frIendly fIre. It is available at

Radioactive Biohazard by Hunter O'Reilly
Geneticist and artist Hunter O·Reilly paints biological themes. She created an exhibit entitled Radioactive Biohazard, which reinterprets science as art by examining biotechnology from a positive perspective. In this specific exhibit, O'Reilly confronts issues related to human cloning, stem cell research and the human genome project, among others. This and other O·Reilly work is available at

Media Monitoring

Chinese scientists produce alternative to embryonic stem cells
Scientists in China use cells from adult mice to breed new mice. The breakthrough results are hailed as an advance toward eliminating the need for fetal stem cells in a variety of applications.

Read More

Cloning a human embryo
A controversial fertility doctor has claimed to have cloned 14 human embryos and transferred 11 of them into the wombs of four women who had been prepared to give birth to cloned babies.

Read More

Disgraced cloning scientists convicted
A South Korean scientist who created the world’s first cloned dog but was disgraced for falsifying dramatic discoveries in stem-cell research, was convicted yesterday of embezzlement and harvesting human eggs from female subordinates.

Read More

Medicine, not food, may have more to gain from cloning
The cloning of animals may have come from agriculture, but its real promise may be in the lucrative field of medicine rather than as food.

Read More

Peter Singer Under Fire: The Moral Iconoclast Faces His Critics
Peter Singer is renowned within the field of ethics both for his philosophical rigour and his controversy. Some conclusions of his utilitarian ethic have been condemned as irresponsible and inhumane, with his views on infanticide provoking much public disgust. His academic career has seen taunts from audiences during speeches, conferences cancelled for fear of uproar and death threats from pro-life campaigners. Yet, amid the stir, Singer has remained uncompromisingly consistent in his moral outlook. Above all else, he seeks to be a pure philosopher. He rides the paths of logic and reaches what he considers sound conclusions.

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The complexity of identity

From eugenics to twin studies, there are many ways to pin down the complexities of identity as a London exhibition shows. I have a clone, something not only genetically identical to me but that has shared most of my experiences, up to the end of our time together at medical school. Having a clone can be a blessing and a curse.

Read More

The World's First Commercial Clone

Read More


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References & Links

  1. Center for Genetics & Society (2003), Reproductive Cloning: Basic Science, [accessed 23rd January 2007]. 
  2. Bryne, J.A. and Gurdon, J.B., Commentary on human cloning, (Blackwell, 2002), [accessed 23rd January 2007]. 
  3. Fatahalian, K., Schneider, B., Reavis, B., 1952: Briggs & King clone tadpoles, Conceiving a Clone website (1998), [accessed 23rd January 2007]. 
  4. Ibid.  
  5. Fatahalian, K., Schneider, B., Reavis, B., 1962: Did Gurdon clone frogs?, Conceiving a Clone website (1998), [accessed 23rd January 2007]. 
  6. Bryne, J.A. and Gurdon, J.B., Commentary on human cloning, (Blackwell, 2002), [accessed 23rd January 2007]. 
  7. Fatahalian, K., Schneider, B., Reavis, B., ), 1998: Generations of Clones, Conceiving a Clone website (1998), [accessed 23rd January 2007] 
  8. Fatahalian, K., Schneider, B., Reavis, B., ), 1997: Polly is born, Conceiving a Clone website (1998), [accessed 23rd January 2007]. 
  9. Reply to House of Lords Written Parliamentary Question tabled by Baroness Gould of Potternewton and answered by The Parliamentary Under-Secretary of State, Department of Trade and Industry (Lord Sainsbury of Turville), 24 June 1999, col 106, [accessed 23rd January 2007]. 
  10. Baronness Hayman, House of Lords debate on Human Embryos and Cloning, 28th April  1999, col 350, [accessed 23rd January 2007] 
  11. HFEA and Human Genetics Advisory Committee report, Cloning Issues In Reproduction, Science And Medicine (Issued December 1998), paras 9.2 and 9.3 [accessed 23rd January 2007] 
  12. Department of Health, Stem cell research: Medical progress with responsibility, 15th April 2005, [accessed 23rd January 2007] 
  13. Center for Genetics & Society (2003), Reproductive Cloning Arguments, [accessed 23rd January 2007].
  14. The President’s Council on Bioethics, The Ethics of "Reproductive" Cloning: Child, Family, and Society, (Staff Working Paper, February 2002), [accessed 23rd January 2007] 
  15. Center for Genetics & Society (2003), Reproductive Cloning Arguments, [accessed 23rd January 2007].
  16. Bryne, J.A. and Gurdon, J.B., Commentary on human cloning, (Blackwell, 2002), [accessed 23rd January 2007].  
  17. Institute on Biotechnology and the Human Future, Impact of the Germline Intervention on Individuals and Society, [accessed 23rd January 2007]. 
  18. Center for Genetics & Society (2003), Reproductive Cloning Arguments [accessed 23rd January 2007]. 
  19. Human Cloning Foundation, People: Richard G. Seed PhD, [accessed 23rd January 2007]. 
  20. Bryne, J.A. and Gurdon, J.B., Commentary on human cloning, (Blackwell, 2002), [accessed 23rd January 2007].