Some people think that cloning experiments should be up to scientists to manage, whereas others say that it is purely a government concern.
I think that cloning must be under government’s control. First of all, it is difficult to predict the consequences of such experiments. If it gets out of control it might cause bad things like horrible diseases, sufferings of cloned animals or people and so on. Second, we should figure out the moral side of this process first. For example, are people that would come from these experiments real humans?
At the same time there are people who say that scientists have to get more freedom. They have a right to decide what is moral and what is not. If they were not controlled by government, they would make serious progress in this field.
Actually, I do not agree with this oppinion. If scientists were in charge they would make much more troubles, since nobody knows where all their experiments could lead. In fact, there are a lot of aspects of these experiments that are beyond scientists’ competence.
In conclusion, I would like to say that cloning has to be elaborately discussed before any decision is taken. It is one of the questions that does not have an obvious answer and contains many important and debatable aspects of people’s life that need to be thoroughly investigated, since a wrong decision can lead to serious consequences. Thus, that is the reason why I strongly believe government should be incharge.
In conclusion, I would like to say that there are opposing views on this issue. At first sight scientists should be in charge in questions of cloning but in actual fact mistakes can lead to serious consequences. Thus, that is the reason why I strongly believe that government should control these experiments.
Photo by: Perov Stanislav
Yes, because of the potential physical dangers and the profound ethical
dilemmas it poses, the cloning of human beings should be prohibited.
No, the cloning of human beings should not be prohibited because the
potential for medical accidents or malfeasance is grossly overstated, and
the ethical questions raised by detractors are not unique to
cloning—indeed, ethical questions attend every scientific
Since the birth of Dolly, the cloned sheep, in 1997, several reproductive
scientists, including Severino Antinori, Brigitte Boisselier, and
Panayiotis Michael Zavos, have announced that they were ready to clone
human beings. However, cloning mammals is still a highly experimental
technique. Scientists involved in cloning various mammals have reported
many technical problems. A large majority of the clones die during
gestation or soon after birth. Placental malfunction seems to be a major
cause of death. Many of the surviving clones are plagued with serious
physiological and genetic problems. During embryological development,
cloned sheep, cows, pigs, and mice tend to become unusually large. Clones
are often born with a condition called «large offspring
syndrome,» as well as severe respiratory and circulatory defects,
malformations of the brain or kidneys, or immune dysfunction. It is not
yet known whether clones will develop and age normally, or whether subtle
failures in genomic reprogramming or genetic imprinting might lead to
various defects. Theoretically, tissues generated from cells cloned from a
patient’s own adult nucleus should not trigger an immune response,
but it is possible that subtle differences caused by the foreign cytoplasm
in the donor egg might cause a rejection response. Although scientists at
Duke University suggested that human clones might not experience the
problems encountered in cloned animals, the risks remains very high and
quite unpredictable. Eventually animal research may indicate that human
cloning can be accomplished with no greater risk than in vitro
fertilization posed when Louise Brown, the first «test-tube
baby» was born in 1978. However, scientists generally agree that
human reproductive cloning should not be permitted before the scientific
and technical issues have been clarified.
Many scientists believe that, at least in the near future, experiments in
human cloning would involve many failures, miscarriages, stillbirths, and
the birth of deformed babies. Some observers think that the reckless
claims made by some scientists stimulated the passage of premature
Congressional legislation that would ban all human cloning, both
reproductive and therapeutic (non-reproductive). Similar reactions have
occurred in other nations. For example, the French and German governments
jointly asked the United Nations to call for a worldwide ban on human
After a heated debate about human cloning, on July 31, 2001, the U. S.
House of Representatives voted 265-162 to institute a total federal ban on
human cloning. The bill included penalties of up to 10 years in prison and
a $1 million fine. The House rejected competing measures that would have
banned cloning for reproductive purposes while allowing nonreproductive or
therapeutic cloning for scientific research. The emotional nature of the
debate, and the lack of understanding of the scientific aspects of the
subject, is epitomized by House Majority Whip Tom Delay (R-Texas) who
declared: «Human beings should not be cloned to stock a medical
junkyard of spare parts.» On the other hand, Rep. Jim Greenwood
(R-Pennsylvania) lamented that the House had missed an opportunity to
balance potential biomedical breakthroughs with ethical concerns.
The Human Cloning Prohibition Act outlaws the process known as somatic
cell nuclear transfer (SCNT) using human cells. Although this process can
be used for reproductive cloning, as in the case of Dolly the sheep, the
technique can also be used for non-reproductive or therapeutic cloning, a
process that could be used to create cells and tissues that would be
immunologically compatible with the donor of the nuclear material. The
potential uses of therapeutic cloning include cures and treatments for
many diseases. Cloned cells could be used to create replacement tissue for
diseased hearts, pancreatic cells for diabetics, treatments for
neurodegenerative diseases, such as Parkinson’s and
Alzheimer’s, nerve cells for victims of spinal cord injuries, and
skin cells for burn victims. Researchers, as well as leaders of
biotechnology and pharmaceutical companies, believe that therapeutic
cloning will result in major medical breakthroughs. Therapeutic cloning
could provide valuable new means of testing drugs for safety and efficacy,
thus streamlining and improving the drug development process.
Another modification of the nuclear replacement technique known as oocyte
nucleus transfer could help women with defective mitochondrial DNA.
Defects in mitochondrial DNA are known to cause more than 50 inherited
metabolic diseases. Theoretically, a child produced by this process would
inherit its nuclear DNA from its mother and father and healthy
mitochondrial DNA from a donor egg. This procedure would not constitute
reproductive cloning because the child’s genetic makeup would be as
unique as that of a child produced by conventional sexual means.
Nonreproductive cloning is legal in the United Kingdom. Since the early
1990s British scientists have been allowed to create human embryos for
research purposes and perform experiments in therapeutic cloning. The
Human Fertilization and Embryology Act of 1990 established a system for
regulating the creation and use of embryos. Research leading to
reproductive cloning is banned, but therapeutic cloning in order to
generate healthy replacements for diseased tissues and organs is
permitted. Some ethicists and religious leaders object to all experiments
on embryos, while others argue that even therapeutic cloning should be
banned because it would eventually lead to reproductive cloning. While
human cloning and human stem cell research are actually technically
distinct, these issues have become virtually inseparable because both
involve the use of human embryos.
President George W. Bush, who opposes cloning humans for research and
reproductive purposes, immediately announced support for the anti-cloning
bill passed by the House. President Bush has taken the position that:
«like a snowflake, each of these embryos is unique with the unique
genetic potential of an individual human being.» Further confusion
and controversy was, therefore, sparked by Bush’s decision to allow
limited federal financing for stem cell research on 60 cell lines that had
already been established. Despite recognition of the potential value of
the research, the president ruled out any future flexibility in his stem
cell policy. Thus, Bush’s decision angered groups on both sides of
the argument: those who hoped that stem cell research would help people
with serious diseases and disabilities and those who believe that the
fertilized egg should be accorded full human status.
Less than a month after President Bush announced his decision on embryonic
stem cell research observers noted that the substance of public debate had
shifted from whether such research was ethical to a debate about whether
essential biomedical research could be conducted in the United States.
Despite confusion about scientific and technical issues, there is
widespread public awareness of predictions that human cloning and stem
cell research could provide treatments and cures for many diseases, if
scientists are allowed the freedom to pursue all promising pathways. If
patients and their advocacy groups think that cures are being withheld
because of political and religious forces, there is little doubt that the
nature of the public debate will become increasingly hostile.
The debate about the scientific and technical uncertainties of human
cloning will presumably be settled in the not-too-distant future through
experimentation in countries that allow this type of research to proceed.
The situation is likely to be quite different where ethical issues are
concerned. Those at one extreme believe that the use of embryos for
research purposes is morally unacceptable on the grounds that an embryo
should be accorded full human status from the moment of its creation. In
contrast, some people believe that early embryos should not be considered
human begins with special moral rights. Others consider the embryo a
potential human being, but argue that the rights of the early embryo
should be weighed against the potential benefits arising from research.
The British Human Fertilisation and Embryology Act attempted to maintain
an ethical «middle ground.» Indeed, British authorities
suggested that cloning embryos by the cell nuclear replacement technique
that produced Dolly might be considered a form of transitional methodology
that could eventually provide insights into genetic mechanisms for
reprogramming adult cells.
Although many Americans believe that stem cell research and therapeutic
cloning are morally justifiable because they offer the promise of curing
disease and alleviating human suffering, others are unequivocally opposed
to all forms of experimentation involving human embryos. Despite the
potential benefits of cloning and stem cell research, most scientists
acknowledge that there are still many technical and scientific problems.
However, even if the scientific issues are resolved, ethical, emotional,
and political issues will probably continue to dominate debates about
—LOIS N. MAGNER
Viewpoint: Yes, because of the potential physical dangers and the
profound ethical dilemmas it poses, the cloning of human beings should
On July 31, 2001, the U.S. House of Representatives passed legislation
to prohibit the cloning of human beings (Human Cloning Prohibition Act
of 2001, H.R. 2505). As defined in the bill, «human cloning means
human asexual reproduction, accomplished by introducing nuclear material
from one or more human somatic cells into a fertilized or unfertilized
oocyte whose nuclear material has been removed or inactivated so as to
produce a living organism (at any stage of development) that is
genetically virtually identical to an existing or previously existing
human organism.» The bill makes it a federal crime with stiff
penalties, including a fine of up to $1 million and imprisonment up to
10 years to attempt to or participate in an attempt to perform human
cloning as defined by the act.
With this step the United States is now poised to join the international
community. Many nations have already adopted the prohibition against
human cloning. International scientific bodies with oversight for
medicine, research, and health as well as biotechnology industry
interest groups mostly support the prohibition. But the matter is not
yet settled. Before the measure can take effect, it faces a vote in the
U.S. Senate and it needs the president’s signature.
What reasons or fears prompted U.S. law-makers to take such strong
measures? The sanctions in the act are more commonly associated with
major felonies. Are there sufficient dangers to the nation and to its
citizens to call for prohibition of a scientific technique whose
applicability to humans seems as yet theoretical?
Since 1997, when Dolly the sheep, the first mammal ever derived from a
cell (from the udder) of an adult mammal (sheep), was announced to the
world, the possibility of human cloning has entered a new stage. After
276 unsuccessful attempts, the «cloned» embryo implanted
in a ewe went through the normal gestation period and was born alive,
surviving and healthy to the present. This was indeed a first and a
major breakthrough. Since that event, the feat has been replicated in
several types of livestock on different occasions. In 1998 mice were
successfully cloned from adult cells. Humans bear certain genetic
similarities to mice, and so often mice are the experimental model for
what will be studied subsequently in humans. The technique of cloning by
somatic cell nuclear transfer (SCNT) is steadily improving, suggesting a
The animal successes have inspired some groups and scientists to
announce publicly their aim of embarking on the cloning of human beings
through the same technique that gave us Dolly and the several other
groups of mammals that followed.
The technique itself raises fundamental questions. SCNT, as noted in the
definition of the Human Cloning Prohibition Act, involves taking a
cell—many types of cells seem to work—from a full-grown
animal and removing the nucleus, which contains the complete genetic
makeup, or DNA, of the animal. The nuclear DNA is then inserted into a
separate unfertilized but enucleated ovum harvested from an adult
mammal, even a mammal of a different species. After special preparation
in a nutrient medium to allow the cell to reprogram itself and a small
trigger of electric current to start mitosis, the «cloned»
blastocyst, now with the nuclear DNA of an adult somatic cell in each of
the multiplying cells, is implanted in the womb of a
«gestational» mother, previously treated and made ready to
accept the pregnancy. If the process is successful, the resultant birth
yields a new individual animal, genetically identical to the animal that
donated the nucleus yet at the same time different from any other
animal: the DNA in the nucleus of its cells does not come from the
mating of two animals, in which each parent’s DNA combines to
create a new individual. Rather the DNA is from one animal only.
Sexual reproduction with its commingling of the genetic endowment of two
individuals has demonstrated its existential value. Over hundreds of
millions of years, nature has used the
process to great advantage to perpetuate and vary species, to bring new
beings and new species into existence throughout the plant and animal
kingdoms, to ensure the continued and enhanced adaptation of living
things to changing environments, and to preserve life itself. It is also
the process that in our experience gives the «stamp of
individuality,» producing new members of a species with a novel
genetic endowment and, not rarely, new individuals with traits that are
remarkable and prized as well as unique.
The Status of a Clone
Perhaps a superior or functionally perfect breed of animal might offer
special advantages—although a world of racing in which thousands
of Secretariats challenged each other over and over might give
oddsmakers and bettors nightmares. Then again, some rare or endangered
species might be preserved. When we turn to humans, however, the
technique raises many questions and challenges regarding our most
important values and basic notions.
Intuitively, then, we ask, «What kind of human being would the
individual be who has the nuclear DNA of another preexisting
individual?» Would the «clone» be another
individual human being or somehow not «truly» human? Is
the «latest edition» of the cloned individual an
individual in his or her own right? If he or she has the nuclear DNA
from only one preexisting individual, if he or she was not the product
of separate sperm and ovum, would such an individual fit the term
«human,» the way the rest of us do? What of the
relationship to the individual supplying the DNA? How would we describe
their relationship? Would the term «parent» fit the
relationship? Could this clone of an individual ever be accepted by
society? Or, much more profoundly, could the clone come to accept
himself or herself as each one of us do: a unique and special person,
with a nature and a future that is no one else’s?
The ready response to questions like these is to recognize that the
questions relate to imponderables. Of course, we wonder about them, but
there is no evidence on which we can base an answer and no way of
predicting the reactions of the clone or of society to the clone. We can
only surmise that, just as now, if there were a world where clones
existed, there would be tolerance and prejudice. Some individuals would
display resilience and others would experience psychological challenges
that test them sorely. People and the laws of society would adjust in
time, just as we have for artificial insemination and in vitro
fertilization. If anything, the imponderables
Matilda, a sheep cloned in Australia.
Reproduced by permission
ought to give us pause, to prompt us to think before taking any fateful
steps to clone a human being. Yet are the imponderables grounds enough
to restrict the freedom of inquiry our society endorses? What does
prohibiting experiments in human cloning—in fact, making it a
crime—do for our right to pursue knowledge? Ironically, is it not
the imponderables that intrigue us? They exert a pull on our minds to
seek answers to precisely those questions we are on the verge of
forbidding. Is this bringing us back to the message of the story of the
garden of Eden of the Book of Genesis in the Bible: is there knowledge
we are forbidden to seek?
A Threat to Free Inquiry?
Is this a dilemma? A «catch-22»? Will prohibiting cloning
of human beings cut us off from learning the answers to significant
scientific information? Many argue that the research into the techniques
of human cloning and the use of cloning technology are critical to
advances that may lead to cures for many diseases. For example, the use
of cloning may allow us to develop ways to culture replacement tissues
and bodily fluids that can be used to treat individuals without the
usual difficulties of HLA matching and tissue rejection. A somatic cell
taken from a burn victim may be inserted into an oocyte and the process
of cell division initiated to grow skin in tissue culture without the
intent ever to create another human being. So too for bone marrow, so
vital for treating forms of cancer and immune deficiency diseases. Nerve
tissue can be developed in the same manner to be used to treat paralysis
in accident or stroke victims without the problems of rejection of
tissue and the complications of using immunosuppressive drugs.
It is not yet certain that such potential advances will actually occur.
But it is questionable how feasible they will be in practical
application. Obviously, at some early stage of life, even just after
birth, somatic cells might be harvested and banked to be used if there
was ever a therapeutic application for the individual whose cells would
be preserved and reengineered in this way. But the system for
accomplishing this is impractical. No matter where the somatic cells,
however transformed and primed for therapeutic application, are stored,
there are problems of availability at the point of need. Even more
problematic is the management of a storage and centralized system of
reference to manage the process. However, might the technology be used
in an ad hoc way, case by case, to meet an individual patient’s
The prospect of cures like these is on the horizon. But they do not
require human cloning by SCNT to accomplish. If the projections of
scientists are correct, the techniques of embryonic and adult stem cell
harvesting and transformation will yield a supply that can be
universally available. It will not be necessary to clone an
individual’s own tissue via SCNT. SCNT is a more complicated
process with many more foreseeable logistical and technical problems.
The technology of stem cell development appears to present fewer
problems and the prospect of more widespread uses and greater
Potential Compassionate Applications
Perhaps these are reasons enough to deemphasize human cloning through
SCNT. Even to abandon it. But the Human Cloning Prohibition Act of 2001
places an absolute ban on the procedure. Consequently, even humanitarian
uses, out of compassion, are prohibited.
Advocates of human cloning through SCNT use the example of a couple
whose child might be replaced through the use of SCNT. For example, a
young child is so severely injured that recovery is impossible, and the
child lingers a brief time before dying in a comatose state. A cell
taken from the child could be inserted into the specially prepared
ooctyte of the mother and implanted in her. In this way, the child could
be replicated as a replacement. The parents would have regained their
lost child. A moving scenario, no doubt, even melodramatic, although we
are very far from knowing how this situation would turn out. For one
thing, it seems much more natural to have another child. The replacement
may serve only to generate ambivalent
feelings, and the child will bear a heavy burden, perhaps not loved for
the distinct and separate individual he or she is.
Secondly, the harvesting of the oocytes is not straightforward. It takes
time because there is not likely to be a supply of these on hand from
the same mother. Thirdly, as we have learned from animal cloning, the
technique has a minimal success rate. Disappointment and failure are
likely, and at best it is a prolonged process. In making the decision to
attempt cloning the lost child, the parents are acting under the strain
of profound grief. Their loss is keenly felt and their judgment affected
by the tragic circumstances. The doctor or research team required to
carry out the procedure would need to divert their attention and
resources to this set of tasks. Unless the parents had enormous wealth
so they could assemble their own team, the scenario is more in the realm
of fiction than a realistic exercise. Nor should we expect scientific
research to channel itself to meet the rare occurrences of replacing
children lost through tragedy.
However, cutting off research on human cloning through the technique of
SCNT can cost us valuable knowledge of important benefit in another
area: the treatment of infertility. Thousands of couples in the United
States are unable to bear children because their reproductive systems
function poorly or not at all. Assisted reproductive technology (ART)
has been developed to remedy the condition. Artificial insemination, in
vitro fertilization, drugs to stimulate ovulation, techniques of micro
sperm extraction and direct injection into an ovum, and other techniques
have been introduced successfully to treat human infertility.
Human cloning by means of SCNT offers a new method, giving hope to the
thousands whose fundamental reproductive rights are thwarted by defects
that cannot be treated by these accepted methods. For example, when the
male is unable to produce sperm and the couple does not wish to use
artificial insemination by a donor, cloning by SCNT would be an
alternative. The insertion of the male spouse’s nuclear DNA into
the enucleated ovum of his wife allows the couple to have a child in a
way that closely approximates a natural process of reproduction: the
nuclear DNA, the ovum with the mitochondrial DNA of the woman, the
implantation and natural process of pregnancy. Prohibition of human
cloning cuts off this avenue for individuals to exercise their
fundamental reproductive rights. A variant of this technique, in which
the ovum of another woman is substituted for the ovum of the mother with
a mitochondrial DNA defect and the nuclear DNA extracted from the
fertilized embryo of the couple is inserted into the donated ovum, has
been used with some success. Therefore, doesn’t this prohibition
interfere not just with the pursuit of knowledge for its own sake, but
also run counter to the fundamental reproductive rights of individuals?
The Ethics of Human Experimentation
The argument that prohibiting human cloning through SCNT interferes with
freedom of inquiry or impedes gaining knowledge essential to treating
conditions that interfere with fundamental human reproductive rights
overlooks an important consideration. The quest for knowledge for its
own sake or to benefit others is not unrestricted. Ethical rules and
codes govern the kinds of experimentation allowed on humans. Harms are
to be avoided; risks must be minimized. Worthy goals and hopes do not
justify harmful procedures or those unlikely to produce reliable
results. Good intentions or claims of widespread benefits do not
automatically redeem procedures of uncertain outcome. In a phrase, the
end does not justify the means. The rules and codes for experimentation
on humans are precise. Those who propose to perform the experiments must
provide evidence that the experiment can work; that any harms it may
cause can be avoided or limited; that the expected outcomes are based on
earlier work that allows an extrapolation to the proposed experiment,
and that the experimental design is methodologically sound and well
It is not sufficient to cite lofty goals or pressing needs when
experiments may entail costs of personal loss, distress, and harm to
individuals—or even significant risks for these harms. Aircraft,
vehicles, bridges, buildings, equipment are all designed with extra
margins of safety and outfitted with safeguards as a fail safe to
prevent harms. Experiments that involve humans must also meet rigorous
standards, including review by experts and by nonscientists, to meet the
so-called sniff test. No one contends that we know enough about SCNT as
a technique in other mammalian species to try it out in humans.
Livestock with specially prized traits, laboratory animals with unique
characteristics, the endangered species whose existence is
imperiled—if our cloning experiments fail or turn out to have
unacceptable consequences, corrections are possible and unwanted
outcomes can be disposed of. Society does not permit such liberties with
human life. A breed of sheep or cattle that has unexpected flaws along
with or instead of the sought after traits may still have other uses or
can be euthanized and autopsied to understand the reasons for lack of
success. These options do not exist with the cloning of human beings,
and therefore the prohibition from even beginning the process is
necessary until the highest standards of safety and effectiveness can be
The Risks of Cloning
Some advance the argument that human cloning may be premature at this
time, but scientific progress might reach the point of removing or
offsetting the risk. However, prohibiting human cloning closes off the
opportunity to ever reach the point of eliminating the possibility of
failure or reducing it to acceptable levels. Humanity would never have
succeeded in reaching outer space or landing on the moon if the terms
were elimination of all risk. More to the point, there would be none of
the cures, the vaccines, or the interventions of modern medicine if the
advances needed to be free of risk. Life is full of risks. The
achievements of humans could never have been made if the terms were
This argument has force. But like many apparently persuasive arguments
in favor of proceeding with human cloning, it obscures a feature of all
the human achievements on which progress has been built. Of course there
were risks. Those who accepted the challenge knew the risks and
voluntarily accepted them. Experimental human cloning is different. The
subjects in the cloning experiments are not only the healthy volunteers,
for whom, after all, the risk is over once a cell is removed, once the
oocytes are harvested and the pregnancy complete. The subjects in
cloning experiments are not high-minded adventurers, heroic explorers,
dedicated scientists, not even the desperate terminally ill or
grievously afflicted or those showing their altruism by joining
researchers in the quest to relieve suffering through biomedical
experimentation. We recognize and appreciate the contributions and
sacrifices that individuals make when they choose with a mind and voice
of their own. The risks of human cloning experimentation fall
disproportionately on the clones. And we who make the decisions on their
behalf must think from what would be their point of view. When flaws and
failures turn up later, we cannot point to the most fundamental precept
for human experimentation: the well-informed and voluntary agreement of
the individual to accept the risks, even those not currently
foreseeable, and the freedom to quit the experiment when, in the
individual’s sole judgment, the risks no longer seem acceptable.
This is the universal standard for human experimentation in the world
Human clones would of course have no opportunity to weigh the risks in
advance. Moreover, the flaws or risks are now incorporated into their
very existence. The inexorable outcome of the uncertainties or failures
of the experiment determine their destiny. Hence there is no voluntary
agreement to accept the risks as a price of coming into existence and no
opting out in the event the burdens seem no longer acceptable.
It is true that no human gets to choose to be born or to whom or under
what circumstances. We have no choice but to accept and make the most of
the natural lottery of existence. This is part of what defines being
human. For most individuals it is normal to honor and appreciate the
choice our parents made for us in deciding to conceive and bring us into
the world. The same rules and codes of human experimentation noted
earlier recognize the special and pivotal role of parents whenever
medical research calls for children to be the experimental subjects.
Procedures are in place that reflect the universal assumption of law,
policy, and common sense, that parents are best situated to make
decisions in the best interests of their children. There are even
provisions to have checks and balances, should the situation suggest the
parent(s) may not be guided by normal parental instincts. In addition,
by giving permission for experimentation on their children, parents are
agreeing to accept the outcomes, even in the event that they are less
than what was hoped for. Experiments always have a degree of
uncertainty. Parents are free to withdraw their children from the
research and children themselves may request that the experiment be
terminated when they find they do not wish to continue.
Are There Reliable Safeguards?
Inherent in the human cloning process is the unavoidable shifting of the
burden of choice unequally to the clone, who is to be involuntarily
recruited into the experiment with no chance to withdraw or to be
withdrawn. Once begun, the experiment has passed the point of no return.
Ideally, perhaps, an improved, even a fully perfected human cloning
process ought to incorporate safeguards to detect potential flaws. Some
of these safeguards already exist. Preimplantation genetic diagnosis
(PGD) is a technique already available to screen embryos in vitro for a
number of genetic diseases. With the rapid growth of genetic technology,
it is possible that one day most, if not all, genetic defects could be
screened for and so no anomalies would occur in the clone. Many other
intrauterine techniques can detect developmental flaws during pregnancy.
Serious congenital defects and damage as well as inherited metabolic
deficiencies can be detected at birth or shortly thereafter. These
problems can be managed in accordance with accepted standards of medical
But so little is known at this time about the way the genome—each
individual’s genetic endowment—works developmentally and
functionally before and after birth that many deficiencies or disorders
will only emerge after many years. Evidence indicates that cells may
have inherent in them a defined limit of passages: some reports claim
Dolly the sheep is revealing indications of a more rapid cellular aging.
rates in animal cloning through SCNT are poor: most clones never reach
or complete the gestation process, or they display major abnormalities
during gestation or at birth. The DNA of each individual has a
complement of cellular mechanisms or switches that act to replicate
cells at mitosis and to repair the damages to microscopic and molecular
structures and processes essential to health, development, and survival.
Some evidence of genetic instability has been identified in mice clones
and in cellular processes with cognate human processes. More subtle
differences in development or gene expression might only emerge from
latency after years or in reaction to environmental influences, too late
to detect or intercept.
Some scientists have offered the view that many of the more subtle
effects in genetic structures may owe themselves to the sort of
«imprinting» that takes place in the normal fertilization
process. At that point, meiosis II, initiated by the single sperm that
triggers a succession of biochemical events, reaches completion. Shortly
thereafter, the events of embryonic development occur with the formation
of the zygote and the beginning of cell division into daughter cells,
each having the complement of DNA representing a component of each
parent and with one set of the pair of parental genes becoming
deactivated. It is possible that subcellular events at this stage,
currently not well described or identified, may play a decisive role in
Recent reports have emerged surrounding a process of SCNT in a variant
of the model we have been discussing so far. Scientists and clinicians
have succeeded in overcoming defects in the mitochondrial DNA of women
by the process of substituting a healthy oocyte from a donor for the
oocyte with the deficiency. The donated oocyte has the nucleus removed
or deactivated. Then the nucleus of an embryo, created in vitro with the
sperm of the father and the mother’s ovum, is inserted in the
donor’s enucleated ovum. The reconstituted embryo is implanted in
the uterus of the wife for normal gestation. However, a number of the
embryos thus created revealed signs of chromosomal defects, related to
sex differentiation and mental retardation (Turner’s syndrome).
More subtler forms of deficiencies could only be ruled out by the
process of trial and error, an unacceptable method for human
experimentation. Thus the possibility of human cloning cannot be
demonstrated without a huge and, in large part, unacceptable cost, both
personal and financial, to the individuals involved—be they
parents, the offspring, or the rest of society. To advocate investment
of public research funds or expect any public endorsement for the dim
and distant prospect of, at best, a highly limited success with slight
benefit and significant risks is not justifiable.
The Public Interest
Even so, the recent bill approved by the U.S. House of Representatives
is not limited to use of public funds. It proscribes all efforts at
human cloning by SCNT. This must surely intrude on an area of scientific
inquiry and reproductive rights. Private funding and initiatives are
banned. How can this be justified? The reason is clear: this is an area
that lawmakers have seen as a matter of public policy and profound
public interest. Over a decade ago, a federal law was passed, with no
real controversy, prohibiting the sale and trafficking of human solid
organs. It was determined that it was against public policy and not in
the public interest to have individuals sell their organs, even if they
as donor and the recipient would stand to benefit from what is a
lifesaving procedure. The prospect of a commercialization of human
organs was ruled to be against the public good. Although cloning of
human beings under private auspices is very different, still the
authority of the Congress and federal government to prohibit what is
detrimental to the public interest is clear. Cloning of human beings is
antithetical to the fundamental notions of what constitutes human
conception. The rationale for prohibiting human cloning is that it
entails outright commodification of human embryos derived from
laboratory manipulations and puts society at risk for the untoward
results of flawed and unethical experimentation on humans. It is not in
the public interest to allow human cloning to go forward.
Proponents of human cloning rebut this view by arguing that it is based
on the irrational fears of the so-called slippery slope argument. This
argument uses the logic that without an absolute prohibition of some
possible course of action, society will by degrees move down so far that
precedent after precedent we will incrementally reach a point no one
ever wanted or foresaw, and it will then be impossible to turn back,
just as if one step on the icy slope makes the fall inevitable. The
argument for prohibiting human cloning is not at all an instance of
arguing based on slippery slope logic, however. It is not that the
possibility of misuses of human cloning or abuses to create
«novel human beings» or to replicate outstanding or
favored types of human beings is what induces the prohibition. It is not
just to rule out looming science fiction scenarios.
The prohibition of human cloning through the process of SCNT is based on
a thorough understanding and appreciation of the methodology of
scientific experimentation. The experimental method proceeds by a
process of trial and error. A hypotheses is formed. Data are gathered
that either support or fail to support the hypothesis. Based on better
data and clearer objectives garnered through the first experiment, new
hypotheses are developed and the steps repeated.
The result is greater accuracy and precision in the hypothesis or
improved data collection. Or it leads to abandonment of the hypothesis
as fundamentally flawed and not worth pursuing. The prohibition of human
cloning is a declaration that efforts to engineer human embryos or
beings in this way is off-limits to the method of trial and error. In
effect, it is the rejection of a fundamentally flawed hypothesis.
In experimentation on human beings, the basic principles of human
society apply. There must be a reasonable likelihood of an unequivocal
outcome, not some 1% to 3% limited success rate with failures and
successes allowing incremental advances at intolerable cost. We can only
proceed based on thorough preliminary research and sound scientific
design, and at this point the evidence seems to be leading in a
direction away from the attempt at human cloning. Harms are to be
avoided and risks minimized. But it is not possible to foresee the harms
or risks, and it is impossible to reverse them should we discover them
later. There is no turning back if we are unsuccessful. There is no
opportunity to quit the experiment if the subject so decides.
The test is not whether we should allow human cloning on the premise
that useful information or some possible benefit may emerge. The test is
to adhere to the standards for human experimentation that have been
developed and refined over the past 50 years and codified in a
succession of declarations, pronouncements, and laws by governmental and
international bodies throughout the world. The burden of proof for
meeting these standards falls on those who propose to clone human beings
Viewpoint: No, the cloning of human beings should not be prohibited
because the potential for medical accidents or malfeasance is grossly
overstated, and the ethical questions raised by detractors are not
unique to cloning—indeed, ethical questions attend every
Every generation confronts moral, ethical, legal, and political problems
regarding the appropriate use of new technology and the limits of
scientific research. Which is to say, every generation confronts the
problems that attend to the new knowledge and understanding about our
world that such technology and research affords. At the same time,
however, societies continue to promote the advancement of the science
and research that makes possible such new technologies and the societal
advances they facilitate.
This essay attempts to demystify the cloning process and demonstrate how
cloning, both in its reproductive and therapeutic capacities, provides
much needed and sought after answers to otherwise intractable medical
problems and conditions. As it turns out, the fears and ethical concerns
regarding the cloning of humans (or even human embryos) that have moved
many, including the U.S. Congress, to favor an absolute prohibition on
human simply are unfounded. Indeed, many of the fears regarding cloning
are not novel to human cloning; they are the same fears of the unknown
that generally are raised more out of naive, knee-jerk reactions to new
scientific procedures than well-thought-out, empirically supported
assessments. On all fronts, the fears regarding human cloning can be
In light of the many benefits human cloning can provide, it would be
foolish to prohibit by law the cloning of human beings or human embryos.
This is not to say we should ignore the many ethical and legal issues,
as well as other potential problems, that cloning humans may create, but
rather, it simply is to recognize that human cloning per se is not the
moral monstrosity that many are making it out to be.
There is, however, an overlap between the issues of human cloning and
abortion, discussed in more detail later. Consequently, those who are
morally opposed to abortion may also be morally opposed to human
cloning, at least its therapeutic aspect. Many will continue to believe
that human cloning is inherently morally unjustified, if not evil, for
the same reasons they believe abortion is inherently immoral: both
abortion and cloning of human embryos for medical research involves the
destruction of (at least) potential life. Of course, whether human
embryos are deserving of the same respect as a viable human fetus
depends on personal definitions of what constitutes life and the scope
of certain protections and this invariably is the point where moral
Rather than attempting the futile enterprise of rearranging the moral
intuitions of others, this essay explains first that cloning essentially
is just another method of reproduction. Second, related to this first
point, it demonstrates a common reoccurrence in the history of science
and technology, namely, the presence of what could be called the
«offensive factor,» which tends to accompany new
scientific and technological breakthroughs. Although initially the
majority of people may view these breakthroughs with disdain, in time,
that same majority comes to accept them.
New Technology and New Ideas: Overcoming the Offensive Factor
As with virtually any new scientific advancement, there are a range of
opinions on the issue of human cloning, from those that are morally
opposed to it on religious grounds (e.g., the Catholic church), to,
somewhat ironically, those that are in favor of it also on religious
grounds (e.g., the Raelians, a religious order begun in the early 1970s
in France that claims 55,000 members throughout the world; in 1997 the
Raelians founded Clonaid, a company that conducts human cloning
The majority view, however, appears to be strongly opposed to the idea
of cloning humans. That is not surprising. Indeed, throughout history,
we can find many examples where a society initially condemned, or even
was repulsed, by a new scientific practice or idea, although it would
later come to accept and even embrace it. The performance of autopsies,
organ donation, and the use of robots in manufacturing are but a few
examples. Indeed, in the early 1970s, when in vitro fertilization (IVF)
began on human beings, many in society—including medical
professionals—opposed it vehemently on moral and ethical grounds.
A doctor involved in one of the first IVF procedures was so appalled by
the procedure that he deliberately destroyed the fertilized embryo
because he thought the process was against nature. Now, of course, IVF
clinics are so commonplace that the birth of so-called test-tube babies
no longer are newsworthy events, and few, if any, contemporary medical
professionals claim that IVF procedures are immoral, unethical, or
should be prohibited.
For a more current example, witness the Internet. Although the Internet
has greatly improved the exchange of information and ideas, it also has
facilitated cybercrime and other economic crimes, and it has made it
easier for individuals to engage in such illicit activities, which pose
extreme threats to the security of nations and the stability of global
markets. Does the fact that even a single individual could cause
widespread damage mean we should dismantle the entire Internet? Few
would agree, and the billions that benefit from and rely on its
existence would undoubtedly fight such efforts. Indeed, in
today’s interconnected world, dismantling the Internet probably
would be impossible.
Thus when new technology and new ideas spring forth, it often is
difficult, if not impossible, to prevent their propagation. The
«new» generally has both aspects of the
«good» as well as the «bad.» But the bad
should not necessarily deny us the benefits of the good. Therefore,
rather than futilely attempting to prevent human cloning because of the
evils that might spring from it, we should, as we have done with other
new technologies and ideas, embrace it for the benefits and new
knowledge that will emanate from it, all the while doing the best we can
to minimize abuses. Otherwise, we risk driving the cloning of humans
underground, and that could be a far worse evil.
To be sure, many moral, ethical, and legal issues must be addressed with
respect to cloning humans, not the least of which concerns the
possibility that cloning humans will open a market for «designer
babies,» which could lead to eugenics. Again, the potential for
abuse always accompanies the advent of new technology. Although human
cloning now may be perceived as something bizarre and foreign to us,
within a generation—perhaps even earlier—cloning humans
will be as noncontroversial as IVF, surrogate motherhood, and organ
transplantation. So while we grow accustomed to the new technology and
knowledge that human cloning may bring, there simply is no good reason
why human cloning should be prohibited, but there are many
reasons—discussed later—why research in the area should
continue. And while research continues, we can work toward addressing
the ethical issues regarding human cloning by developing professional
codes of conduct and governmental regulation where necessary in order to
minimize potential abuse, just as we did regarding organ transplantation
and initial fears that organ transplantation would create black markets
in organs. The problem, then, is not the technology per se, but how we
use that technology.
What Is Human Cloning?
Perhaps the most significant impediment to new technology and ideas is
that few people understand exactly what they are at first, and these
misunderstandings breed fear and contempt. First and foremost, human
cloning is not anything like photocopying oneself. For example,
let’s say Jackie A, a 30-year-old female, decides to clone
herself. If she wants to «replicate» herself so there will
be another 30-year-old female—we call this replicant Jackie
B—that looks identical to her, Jackie A will be disappointed.
Literally replicating oneself physically is impossible, and it is
what is meant by human cloning.
But Jackie A could do exactly what scientists in Scotland did with Dolly
the sheep. Known as somatic cell nuclear transfer (SCNT), a doctor would
first remove a mature but unfertilized egg from Jackie A or utilize one
from a donor. The doctor then would remove the egg’s nucleus,
which only would have 23 chromosomes, half the necessary amount for
human reproduction, and replace it with the nucleus of another
cell—a somatic cell, which would have a full complement of 46
chromosomes. As we have assumed, if Jackie A wished to clone herself,
the somatic cell simply would come from
Jackie A. The egg with the new nucleus then would be chemically treated
so it would behave as if it had been fertilized. Once the egg begins to
divide, it then would be transferred into Jackie A’s uterus,
Essentially, except for the nuclear transfer, the procedure is identical
to now common IVF procedures. If all goes well, within approximately
nine months, Jackie A will give birth to a daughter—an infant
daughter, to be sure—who is genetically identical to Jackie A.
Thus Jackie A has «cloned» herself. Jackie A’s
daughter, whom we have named Jackie B, is not a
«replicant,» but a completely separate
individual—she will not share any of Jackie B’s memories
or consciousness, just as a child does not share any such traits of its
parents. Jackie B, however, will grow up to look nearly identical to
Jackie A inasmuch as she shares all of Jackie A’s genetic
identity. The «odd» part is that not only is Jackie B the
daughter of Jackie A, but Jackie B also is Jackie A’s genetic
Some people may find this result a bit unsettling inasmuch as it appears
to be quite unusual or «unnatural»—how can someone
be both a daughter and a sister to her mother? First, whether we refer
to someone as a sister, mother, brother, or father often turns not on
genetic or biological relationships but on other social conditions and
relationships. Adopted children, for example, do not share any of the
genetic features of their adoptive parents, yet they still are
recognized as the children and heirs of their parents. We speak of
birth parents as opposed to their (adoptive) parents to make such a
Similarly, in light of the phenomenon of surrogate motherhood, merely
because someone is born from a particular woman does not necessarily
mean that same woman is even the individual’s biological mother:
a surrogate mother could simply be a woman who has agreed to carry the
fertilized egg of another woman. As a result, in such situations the
child born to the surrogate mother shares none of the surrogate
mother’s genetic material. Thus familial relations no longer are
simply a matter of biology and genetics, but more a matter of social
Second, sometimes even in nature we can witness so-called unnatural
results. If your mother, for example, is an identical twin, then her
twin, of course, is your aunt. But, interestingly enough, she also is
mother in the sense that genetically speaking, she is identical to your
mother. In such a situation, your aunt—genetically
speaking—both is your aunt and your mother. Of course, we do not
really consider your aunt to also be your mother merely because she is
genetically identical to your mother. That would be silly. Your mother
is your mother by virtue of the fact that she bore and reared you
(although, as we discussed earlier, giving birth to someone does not
necessarily mean the child and mother are genetically related).
Likewise, it would be absurd to seriously consider Jackie A’s
daughter to also be her sister merely because she is genetically
identical to Jackie A.
Why Should We Clone at All?
As of this writing, it is unknown whether human cloning actually could
be performed today. It also is unclear whether it already has occurred.
What is evident, however, is that if human cloning is not
technologically feasible now, it certainly is theoretically possible,
and, once the procedures are refined, likely will occur soon. Indeed, in
addition to the Raelians, Severino Antinori—a controversial
fertility doctor from Italy—has announced publicly that he will
be going forward with implanting cloned human embryos in volunteers
shortly. Whether these experiments will be successful remains to be
seen, but if they are, the first cloned human may be born in the summer
In light of this (temporary) uncertainty with respect to the feasibility
of successfully cloning a human, many opponents of human cloning argue
in favor of a moratorium on human cloning. Such opponents point out that
the process by which to clone mammals, let alone humans, is not yet
perfected and could result in severely malformed and stillborn children.
Certainly these are valid worries that cannot be ignored. Unfortunately,
such worries cannot be resolved via a moratorium, for how can the
necessary science advance if no research is being performed?
Experimentation can be performed without impregnating human females of
course. But just as there had to be a first heart transplant patient,
there will have to be a first cloned embryo implanted into a woman if
human cloning ever is to be achieved. There are always risks. The point
of research is to minimize them, and a moratorium simply misses that
In any event, what follows with regard to human cloning assumes that the
science will, if not now, eventually be perfected so these worries about
malformations and stillbirths (both of which occur naturally anyway,
lest we forget) can be greatly reduced. Assuming that human cloning will
not present such dangers to either the child or the mother, there still
remains the question of why we would want to clone humans at all.
As already mentioned, human cloning essentially is a method for asexual
reproduction. As such, it can allow infertile couples or even single
persons to reproduce offspring that are biologically related to them. A
husband who no longer is able to produce sperm nevertheless still could
have a biological heir by implanting his DNA into the egg of his wife
(or, if the couple so choose, a surrogate). Likewise, via human cloning,
a single woman, a single man, or even same-sex couples would be able to
reproduce biologically related heirs. Adoption always is an option for
such persons, but for some, the desire for biologically related children
is a more attractive option. Essentially, then, human cloning makes
available the possibility of reproduction to those who otherwise would
be unable to reproduce.
The imagination can run wild with the possibilities that cloning humans
for reproductive purposes provides. For instance, a couple’s
child dies in a horrific accident and they no longer are able to
conceive a child. They are devastated. Would it be unethical of them to
clone the child? Certainly, if they believe the cloned child will be
just like their deceased child. They should be disabused of their
misconception. The cloned child will be a completely new person even
though it will look just like the deceased child. The parents cannot
bring their deceased child back to life. Even if they understand that,
is there still a problem with them wanting another child to replace the
one they have lost?
Similarly, assume the same couple has a child dying of a terminal
disease in need of a bone marrow transplant. No donors can be found.
Some couples have, in fact, conceived children for the purpose of
actually creating a possible donor for their dying child (which creates
ethical issues of its own). Unfortunately, the new child may not
necessarily be a good match for the dying child. Thus would it be
for the couple instead to clone their dying child in order to use the
marrow from the clone—who necessarily will be a perfect
match—to save their dying child? In effect, in order to save the
child’s life, the couple simply would be reproducing their
Finally, cloning raises the specter of eugenics, which many associate
with Nazi Germany and those who promote beliefs in racial supremacy.
With cloning, we could «breed» superior humans who are
smarter. Certainly, so-called designer babies would be possible with
cloning. If that bothers us, however, we could impose specific
restrictions on the cloning of humans and create a regulatory and
enforcement body to oversee such procedures, just like we have done with
organ donation. And just as importantly, we can inform those who are
interested in cloning themselves, or a relative, or a friend, about what
cloning actually is and clear up any misconceptions they might have
about the procedure. In short, it is possible to define appropriate and
inappropriate uses for cloning just as we have for a variety of other
new medical procedures. Merely because some might abuse cloning should
not preclude others from otherwise benefiting from the cloning
Unlike reproductive cloning, therapeutic cloning does not involve
reproduction, but the initial process is the same. A human embryo is
cloned not to produce a child, but in order to retrieve its stem cells.
Stem cells are unique in that they can be «grown» into
virtually any type of cell in the body. According to some researchers,
stem cell research may provide breakthroughs in the treatment of spinal
cord injury and repair and a way to overcome the debilitating effects of
many neurological disorders.
Because stem cells can be cultivated into the tissue of any organs, they
also suggest a way for doctors to avoid the problems of organ
transplantation. Often the patient’s body receiving the organ
rejects it. As a result, the patient must be given high doses of
anti-rejection drugs. The same problems hold true for artificial organs.
But anti-rejection drugs often have severe side effects. In addition to
these problems, far more patients are in need of organs than are
available. These patients often must wait for long periods of time,
sometimes years, for an available organ and then hope the organ is not
rejected by the body. Very often, such patients die just waiting for the
Using stem cells to cultivate new organs would alleviate both these
problems. First, because the organ simply would be cloned from the
patient’s DNA, the patient’s body likely would not reject
the organ for it essentially is the same organ from the perspective of
the body. Second, there would be no waiting list for the patient.
Whenever a new organ is needed, the patient’s doctor would clone
the needed organ from the patient.
So what possibly could be the problem with therapeutic cloning in light
of these potential benefits? The retrieval of stem cells requires
destroying the embryo. Note that stem cells can also be retrieved from
adult cells, rather than embryos. However, whether such adult stem cells
are as effective as embryonic stem cells still is an open question.
Because of this, some religious groups are morally opposed to
therapeutic cloning for the same reason they are morally opposed to
abortion: they consider the embryo to be a human being (or, at least,
with the potential for life), and therefore the destruction of the
embryo is unjustified even if it will save the life of another.
Whether Americans consider an embryo to be a human being certainly is a
matter of debate. According to an August 14, 2001, Gallup poll, only 36%
of Americans believe that embryos deserve the same protection as human
life. The same poll revealed that more than 70% of Americans think
research on stem cells is necessary including, surprisingly, 31% who
think that stem cell research is morally wrong. In light of this, it
certainly appears that such moral objections do not dissuade most
Americans from the importance of stem cell research. In contrast, a June
27, 2001, Gallup poll revealed that 89% of Americans are opposed to
reproductive cloning. Evidently, therapeutic cloning is not as offensive
as reproductive cloning.
Human cloning essentially is human reproduction—nothing more,
nothing less. How it is performed and the results that may follow,
however, are new. This is where the offensive factor mentioned earlier
comes in. As with other new technologies and new ideas that have been
fostered by scientific research, we need to (and hopefully will), get
beyond the repugnance we feel about human cloning. Recently, the U.S.
House of Representatives passed the Human Cloning Prohibition Act of
2001 (H.R. 2505), and this legislation currently is being considered by
the Senate. The act will make the cloning of human embryos a crime
punishable by up to 10 years in prison and a civil penalty of at least
Whether such legislation will become law is uncertain as of this
writing, but undeniably the genie is out of the bottle—the
technology already exists. Such legislation, most likely enacted out of
political expediency in the face of the offensive factor, likely will do
little to prevent determined researchers and advocates of human cloning
from going forward with experimentation abroad.
Given that religious views often govern and guide our feelings toward
such new technologies and new ideas, we return to the events surrounding
what arguably was the first instance of cloning: God’s creation
of Eve from a rib of Adam. After their creation, both Adam and Eve were
instructed by God not to eat the fruit of the Tree of Knowledge on pain
of death. Tempted by a serpent, however, Eve disobeyed God by eating the
fruit and offered it to Adam. By eating the fruit, both Adam and Eve
suddenly became aware of their surroundings; they had acquired new
knowledge. Afraid they would soon eat the fruit of the Tree of Life and
thereby become immortal, God quickly banished them from the Garden of
Eden «lest they become like one of Us.»
Traditionally, the tale of Adam and Eve is thought to represent the
first instance of sin, the «original sin,» and the
consequences that flowed from that sin. But there is another way to
interpret their story. The serpent, after all, tempted Eve by informing
her that should she eat of the Tree of Knowledge her eyes would be
opened, and she would come to know right from wrong. In essence, it was
this fact—a craving for new knowledge—that moved Eve to
disobey God’s command and risk death.
Although many take the moral of the story to concern the ramifications
of disobeying the command of God, we also can see that it represents the
ramifications of new knowledge. Eve, who essentially was the first
scientist, sought out new knowledge, and like some of the millions of
scientists who have followed her, also suffered some severe
consequences. Thus new knowledge always comes at a price, but what is
the alternative? Human cloning should not be prohibited because of the
new knowledge it affords—its abuse, of course, should be.
—MARK H. ALLENBAUGH
The Clone Age: Adventures in the New World of Reproductive Technology.
New York: Henry Holt, 2000.
Annas, George, and Michael Godein, eds.
The Nazi Doctors and the Nuremberg Code: Human Rights in Human
New York: Oxford University Press, 1992.
Human Cloning Prohibition Act of 2001.
107th Cong., 1st sess., H.R. 2505.
Jaenisch, Rudolf, and Ian Wilmut. «Don’t Clone
291 (March 2001): 2552.
Kass, Leon. «Preventing a Brave New World,»
The New Republic
, May 21, 2001, p. 36.
——, and James Q. Wilson.
The Ethics of Human Cloning.
Washington, D.C.: American Enterprise Institute, 1998.
Clone: The Road to Dolly, and the Path Ahead.
New York: William Morrow, 1997.
National Bioethics Advisory Commission,
Cloning Human Beings: Report and Recommendations.
Rockville, Md.: June 1997. Also available at
Remaking Eden: Cloning and Beyond in a Brave New World.
New York: Avon, 1997.
Remaking Eden: How Genetic Engineering and Cloning Will Transform the
New York: Avon, 1998. U.S. House.
Report on Human Cloning Prohibition Act of 2001, H.R. Rep. No.
Developing preimplantation embryo, consisting of a sphere of cells made
up of outer support cells, a fluid-filled cavity, and an inner cell
Composed chiefly of DNA, the carrier of hereditary information, these
structures are contained in the nucleus of the cell. Normal human
chromosomes contain 46 chromosomes, one half from each parent.
Deoxyribonucleic acid; found primarily in the nucleus of the cell. It
carries all the instructions for making the structures and materials
necessary for bodily functions.
Ovum from which the nucleus has been removed.
Process by which sperm enters the ovum and initiates the process that
ends with the formation of the zygote.
Working subunit of DNA that carries the instructions for making a
specific product essential to bodily functioning.
Process that determines which one of a pair of genes (mother’s
and father’s) will be active in an individual.
Complete genetic makeup of a cell or organism.
IN VITRO FERTILIZATION:
Assisted reproduction technique in which fertilization occurs outside
Special type of cell division occurring in the germ cells by which each
germ cell contains half the chromosomes of the parent cell. In humans
this is 23 chromosomes.
Cellular organelle that provides enrgy to the cell and contains maternal
Process of ordinary cell division, resulting in the formation of two
cells identical genetically and identical to the parent cell.
Cell structure that contains the chromosomes.
Mature female germ cell or egg.
Mature male reproductive cells.
The single-celled fertilized egg.
IMPRINTING AND THE DISCOVERY OF IGF2R
On August 7, 2001, the United States National Academy of Sciences
convened a panel of international experts in the scientific, medical,
legal, and ethical aspects of human cloning. The debate centered on the
potential hazards and current limitations of the cloning process in
animals. Scientific and medical opinion weighed in heavily against the
prospect of human cloning. Not enough was understood about the cloning
process in animals to employ the current technology to clone humans.
Scientists cited the inherent difficulties of inducing safe and
successful gestation in animals as evidence of the high odds against
achieving success in humans. The effects of culture media on embryos
cloned by somatic cell nuclear transfer (SCNT) had not yet been examined
enough to permit detection of possible flaws traceable to contamination
by the nutrients in which the clones are maintained or to rule out
cross-species pathogens. Other data pointed to possible interactions of
the culture medium with the cloned embryo, which might trigger anomalies
in the critical processes of gene expression, resulting in developmental
failures or abnormalities.
More concrete parallels with problems encountered in animal cloning
suggested that a technical barrier might exist as well. If so, the
fundamental feasibility of human cloning was in question. Sexual
reproduction involves a step called «imprinting.» In this
step one set of the pair of complementary genes from each parent becomes
deactivated. The corresponding genes from the other parent ensure that
the development and functions determined by the gene remain active.
Because SCNT is asexual reproduction, the «imprinting»
process does not occur. In the transferred genome critical parts of the
genome are permanently deactivated. Consequently, genes critical to
successful gestation and embryonic development do not function. If this
proves to be the case, then we are up against an insurmountable barrier
to human cloning.
On August 15, 2001, scientists startled the world with a new finding:
humans and other primates receive two functioning copies of genes. In an
article published in
Human Molecular Genetics,
scientists J. Keith Killian and Randy Jirtle and their collaborators
identified a key gene called insulin-like growth factor II receptor
(IGF2R) which they had traced in mammalian evolution. Sometime about 70
million years ago, the ancestors of primates evolved to possess two
functional copies of this gene. The IGF2R gene is critical to normal
fetal development. The absence of a working copy in the livestock and
murine models used in cloning accounts for the failures, according to
the scientists who published the article. Dr. Killian stated,
«This is the first concrete genetic data showing that the cloning
process could be less complicated in humans than in sheep.» It is
too soon to know whether other factors in the human genome also
contribute to, or hinder, the technical possibility of cloning humans.
But this key finding settles one question about the phenomenon of
—Charles R. MacKay