PHIL 2120: Introduction to Ethics
Dr. Robert Lane
Lecture Notes: Wednesday October 13, 2010 [partial]

 

 

[5.5.] Reproductive Cloning.

 

Reproductive cloning is nearly a form of asexual reproduction:

 

asexual reproduction (df.): reproduction requiring only one donor of genetic material rather than two.

 

Rather than having half of all of its chromosomes donated by one parent and the other half by another, all 46 of a human clone’s chromosomes would come from the single donor of the DNA. It’s nearly, but not exactly, a form of asexual reproduction, because a small amount of the egg donor’s genetic material (mitochondrial DNA) is left behind on the mitochondria of the egg.

 

A human created through SCNT would be nearly a genetic twin of the DNA donor—if not for mitochondrial DNA, he or she would be an exact genetic twin.

 

 

[5.5.1.] Recent History of Reproductive Cloning Research.

 

Human reproductive cloning research has not yet resulted in a live birth: no children have yet been created by way of SCNT.

 

But recent advances in cloning other species of mammals indicates that it may be technically possible to create a human being by cloning an adult:

·         On February 24, 1997, it was reported in newspapers around the world that Ian Wilmut, a scientist at the Roslin Institute in Edinburgh , Scotland, working for PPL Therapeutics, had cloned a lamb (sheep): Dolly. (Dolly was born in July 1996, but Wilmut and PPL waited months to announce her birth so that the patent on their cloning technique would be secure).

·         Since then, the following animals have all been cloned successfully: cows, mice, goats, pigs, mouflons (the first clone of an endangered species )[1], cats (2002)[2], mules (2003)[3], horses, (2003)[4], rats (2003)[5], white-tail deer (2003),[6] dogs (2005), and an endangered species of wolf (2007).[7]

·         It was reported in Science in April 2003 that scientists have run into difficulty cloning monkeys -- to date, no primates have been successfully created by SCNT.[8] They speculated that perhaps there was something about primate (including human) reproduction that would make it impossible to clone primates.

·         In December 2004, the same American team that had problems cloning monkeys announced that, they were able to grow cloned monkey embryos to about 200 cells--large enough to harvest stem cells, and far beyond the point they had achieved previously.[9]

 

 

[5.5.2.] Popular Misconceptions About Human Cloning.

 

Pence discusses the following misconceptions, and others, in his book Who’s Afraid of Human Cloning.

 

(1)   A human originated by SCNT will be incubated in an artificial womb until he or she matures. There is no such thing as an artificial womb, and probably won’t be for a long time. Humans can’t be grown in vats! Each pregnancy takes a real living breathing woman, who has a right to decide when and how she will become pregnant, and whether to continue the pregnancy to term. There won’t be “people factories” where clones are “grown.”[10]

 

(2)   A human originated by SCNT will grow from zygote to adult very quickly, even instantaneously. As in the movie Multiplicity.

 

But a clone would take just as long as a non-clone to grow to adulthood. A clone is a delayed twin, and there is no more reason to believe that he or she would mature at an accelerated pace than there is to believe that identical twins do.

 

(3)   A human originated by SCNT will be treated as a slave or as less than human. Pence says that it would be immoral, as well as illegal, to enslave a clone:

 

Morally: In the real world, there would be no difference between a clone and his “father,” or her “mother,” that would justify treating the clone differently. Just as race, sex, ethnicity, religion and sexual orientation are not morally relevant differences, method of origination isn’t a morally relevant difference: it would be immoral to treat two people differently simply because they were originated differently. This is the Principle of Non-Discrimination by Origins. Although this principle has not always been accepted (e.g., children born out of wedlock have frequently been denied the rights accorded to others), it is now accepted as true.

 

Legally: Humans originated by cloning would be protected by the 13th Amendment to the Constitution (ratified in 1865): “Section 1. Neither slavery nor involuntary servitude, except as a punishment for crime whereof the party shall have been duly convicted, shall exist within the United States, or any place subject to their jurisdiction. Section 2. Congress shall have power to enforce this article by appropriate legislation.”

 

(4)   A human originated by SCNT will be an exact copy of another person (i.e., it is possible for a person to “reproduce himself.”)

·         A being created via SCNT is almost a genetic duplicate of the donor of the DNA.  But he won’t be an exact genetic duplicate, because the mitochondrial DNA that remains in the egg after its nucleus has been removed will become part of the clone’s genetic make-up. (In mammals, mitochondria are inherited from the mother and carry “a few dozen genes,” according to Pence.) This is why a person created by SCNT would only be a virtual identical twin of the DNA donor—he will share all 46 chromosomes, but will not (necessarily) share mitochondrial DNA.

·         Apart from the genetic difference, he won’t otherwise be an exact physical duplicate, because hormones, proteins, and other substances in the uterus, as well as the mother’s dietary habits and other behavior while pregnant, will have significant effects on the physical development of the embryo.

·         He won’t be a psychological duplicate, because anyone cloned from a currently living human being would be raised in a very different social setting, with different parents and siblings, education, access to different social and cultural resources, and any number of other environmental differences that will have some impact on his personality.

 

 

[5.5.3.] The Argument from Genetic Benefit (for Reproductive Human Cloning).

 

Pence takes this to be the strongest argument in favor of human SCNT: “The possibility of reducing risk of genetic disease for a child by selective choice of ancestor-genes is the strongest direct argument in favor of originating a child by SCNT. It directly counters a major objection that such origination may harm the child.” (Who’s Afraid of Human Cloning, pp.104-5)

 

1.      Many devastating, fatal diseases are genetic (caused by genes inherited from one’s parents).

2.      Human SCNT would allow parents to have children without the risk that certain genetic disorders will be passed on to them.

3.      This would result in an increase in overall well-being for everyone concerned.

4.      Therefore, human SCNT is morally permissible.

 

One of the fatal genetically-transmitted diseases Pence has in mind is Huntington’s Disease:

 

Huntington’s Disease (HD) is a devastating, degenerative brain disorder for which there is, at present, no effective treatment or cure. HD slowly diminishes the affected individual’s ability to walk, think, talk and reason. Eventually, the person with HD becomes totally dependent upon others for his or her care.

 

Early symptoms of Huntington’s Disease may affect cognitive ability or mobility and include depression, mood swings, forgetfulness, clumsiness, involuntary twitching and lack of coordination. As the disease progresses, concentration and short-term memory diminish and involuntary movements of the head, trunk and limbs increase. Walking, speaking and swallowing abilities deteriorate. Eventually the person is unable to care for him or herself. Death follows from complications such as choking, infection or heart failure.[11]

 

·         HD is an autosomal dominant trait

·         autosomal (df.): describes a trait that is carried by one of the first 22 chromosomes, the non-sex chromosomes; in humans, the 23rd chromosome carries the gene that determines one’s sex; so an autosomal trait is not sex-linked and can be inherited from either parent by a male or a female child.

·         dominant (df.): describes a trait that a person will develop even if he or she inherits the gene for the trait from only one parent; if you inherit such a trait, then on average, you will transmit the gene to half of your own children; dominant traits are not recessive (if a trait is recessive, you have to inherit its gene from both parents in order to develop the trait).

·         The HD gene is located on human chromosome 4.[12]

·         The gene that causes Huntington’s was discovered in 1993.[13]

 

Imagine a couple who want to have a child. They discover that the female partner has the gene for Huntington’s—so any child they have together will have a 50% risk of inheriting the gene. They want to avoid this risk, but also want to have a child with whom they both have a genetic connection. They can use the male’s DNA and the female’s enucleated egg to create a child. Since the male does not have the Huntington’s gene, the child will not have it either. And since the child will inherit mitochondrial DNA from the female, he will have a genetic connection to both parents.

 

Is the Argument from Genetic Benefit valid?

 

To be valid, it must depend on an implicit premise. If this premise is part of the argument, then the argument is valid (without this premise, the argument is invalid):

 

“If x results in an increase in overall well-being for everyone concerned, then x is morally permissible.”

 

So Pence’s Argument from Genetic Benefit is ultimately a utilitarian defense of human SCNT.

 

 



[1] http://news.nationalgeographic.com/news/2001/10/1025_TVsheepclone.html (no longer available)

[2] A recent update, on how cloned cats aren't physical duplicates: http://abcnews.go.com/wire/US/ap20030121_1780.html (no longer available)

[3] http://www.foxnews.com/story/0,2933,88088,00.html

[4] http://www.cnn.com/2003/TECH/science/08/07/cloned.horse.racing/index.html

[5] http://news.bbc.co.uk/2/hi/science/nature/3136776.stm

[6] http://www.msnbc.msn.com/id/3785448/

[7] http://www.the-scientist.com/news/home/53172/

[8] http://www.philly.com/mld/inquirer/5606663.htm

 

[9] http://wired.com/news/medtech/0,1286,65926,00.html

 

[10] In Feb. 2002, it was reported that researchers at Cornell U. are in fact developing artificial wombs and hope to have a fully functioning artificial womb, in which a baby can be grown, in a few years. They've gotten an embryo (left over from IVF) to implant and begin growing (they had to stop it after a few days, due to (US?) restrictions on how long an IVF embryo can be allowed to grow in an experiment. The point of this research is to allow women with damaged wombs to have children. Other researchers, in Japan, are working on artificial wombs into which premature infants can be placed.   http://www.observer.co.uk/international/story/0,6903,648024,00.html

[11] Huntington's Disease Society of America: http://www.hdsa.org, 3/31/2000.

[12] Kalat, Biological Psychology, 3rd ed., 1988

[13] http://www.hdsa.org, 11/12/2000.

 




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