to download the file - Ramsey School District


Published on

  • Be the first to comment

  • Be the first to like this

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

to download the file - Ramsey School District

  1. 1. Name: __________________________________ As You Read • Take notes on the main ideas. Start by highlighting the main ideas and circling key words. • Review the terms in the Understanding the Discussion section of the Overview. Cloning: An Overview In 1997 Scottish scientists created the first cloned mammal, a sheep named Dolly. The cloning of a mammal stimulated debate because technology used to clone a sheep might also be used to clone a human. For the first time, the question of whether human beings should be cloned was seriously discussed. There are three types of cloning: DNA cloning, therapeutic cloning, and reproductive cloning. DNA cloning is largely accepted, although some activists oppose it. DNA cloning is the process of copying a single gene or short segment of DNA in order to transfer it into another organism. Agricultural scientists make alterations to crop species in this way. Therapeutic cloning does not produce a living clone, since its purpose is to make stem cells. Stem cells are undifferentiated cells that are capable of becoming whatever type of cell is needed. When introduced into a damaged heart, they become healthy heart cells. Stem cells in the brain can become neurons that heal damage from Alzheimer's disease. Stem cells have great potential to treat disease, but the best source for them is human embryos. Some pro-life activists believe that such embryos represent human life, and do not approve of their use in the cloning process. Reproductive cloning is the most controversial form of cloning because it produces a living animal from only one parent. Proponents of reproductive cloning include conservation biologists, people who want to clone valuable domestic animals and those that see cloning as a new way to have children. Some critics are opposed to reproductive cloning on religious grounds, while others are concerned about the viability of clones produced in this manner. Currently, cloning has a very low success rate, and failed attempts produce stillborn, malformed or sickly offspring. Reproductive cloning is banned in some U.S. states but is legal in many other countries. Understanding the Discussion Alzheimer's disease: A degenerative neurological disease often suffered by the elderly. Alzheimer's patients suffer from memory loss progressing to dementia. Symptoms are caused by the death of nerve cells in the brain. DNA: A molecule in the nucleus of a cell. Genetic information that can be passed to offspring. Ethics: Morals, pertaining to right and wrong. Embryo: An organism before birth or hatching that is in a very early stage of development. A five- day-old human embryo is a microscopic ball of undifferentiated cells. (Also known as a Blastocyst) Uterus: Female reproductive organ where the baby develops. Stem Cells/Undifferentiated Cells: Cells that have not become a specific cell type. They have the potential to become any type of cell, and thus have applications in the treatment of disease. After You Read • In a single sentence, state what you currently think is the controversy surrounding cloning. __________________________________________________________________________________ __________________________________________________________________________________
  2. 2. As You Read • Take notes on the main ideas. Start by highlighting the main ideas and circling key words. • Review the terms. Point: The Medical and Moral Advantages of Cloning Thesis: The possibly lifesaving benefits of therapeutic cloning outweigh moral arguments against the cloning process. Summary: Therapeutic cloning fulfills a critical medical and moral obligation to potentially alleviate human suffering. Cloning can generate treatments or even cures for a wide range of diseases and conditions including diabetes, Alzheimer's disease, cancer and Parkinson's disease. Although promising research is underway to find alternative methods of obtaining embryonic stem cells, the only method currently available to scientists requires the destruction of an embryo. However, the potentially lifesaving benefits of therapeutic cloning outweigh moral doubts about the cloning process. Therapeutic Cloning Since 1998, controversy has swirled around the ethics of using human embryonic stem cells in a laboratory setting. However, human reproductive cloning (the creation, by nuclear transfer, of embryos for the purpose of creating human beings) has already been outlawed in many nations around the world in response to its near universal disapproval by scientists, doctors, medical ethicists, and popular opinion. Common themes repeat in the news media; practicing Catholics criticize cloning for the same reasons they uphold the church's stance against abortion; lawmakers and political leaders face tough choices between maintaining popularity and supporting controversial practices. In the United States, several states have passed legislation specifically forbidding human cloning but permitting therapeutic cloning (the cloning of human embryos to produce stem cells). Therapeutic cloning involves transferring a nucleus from a donor cell, such as a skin cell, into an unfertilized egg. The injected egg is chemically made to divide. When it reaches the blastocyst stage, by which time it consists of a few hundred cells forming a ball roughly one-tenth the size of a pinhead, it can give way to embryonic stem cells that are genetically identical to the original donor. As no sperm is involved, no fertilization occurs. Because the blastocyst is never implanted in a woman's uterus, no viable pregnancy ever results. Few leading medical researchers argue the extraordinary potential of stem cells to reshape the way the medical field addresses disease. Stem cells created using therapeutic cloning could potentially be transplanted into the original donor and would be recognized by the body as genetically identical, thereby avoiding the problems of rejection and immunosuppression (weakening of the immune system) which may occur with transplants from unrelated donors. Such breakthroughs are hypothetically possible because all of the body's tissues trace their origins to stem cells, which, under the right conditions, can be persuaded into performing specific physiological functions. Not only are stem cells capable of being programmed to develop into specialized tissues and organs but, unlike ordinary cells, they also possess the ability to divide and thus provide more stem cells. Stem cells have the promise of providing scientists with a renewable source of replacement cells that could potentially treat or even cure a multitude of neurological, cardiovascular, and hematological (blood) diseases. There is hope that therapies for Parkinson's disease, a problem caused by changes in only a very few cells, could easily be improved through stem cell therapy. Stem cell research brings hope for enhancement of tissue repair or cancerous solid organ transplant treatment heretofore resistant to treatment with chemotherapy alone. Many scientists also believe that stem cells play an essential role in the development of many types of cancer, and that a better understanding of
  3. 3. this role could lead to new cancer prevention and treatment strategies. Scientists' ability to differentiate stems cells by body organ brings hope for enhancing research even further, perhaps some future day finding a cure for HIV infection or cystic fibrosis. Although scientists have been carrying out therapeutic cloning for less than a decade, stem cell-based therapies, delivered in the form of bone marrow and cord blood transplants, have already saved many lives. However, the administration of President George W. Bush opposes therapeutic cloning on moral grounds. This opposition has resulted in the restriction of federal funding to stem cell research, which has significantly slowed the pace of progress. In 2001, President Bush announced that the U.S. government would provide funding for research on only those stem cell lines which were already in existence. He has twice vetoed measures which would have lifted the funding restrictions. The tides may be changing, however, as a January 2009 U.S. News and World Report made the noteworthy announcement that the U.S. Food and Drug Administration had approved stem cell testing to treat human spinal cord injuries. This approval brings hope of a increasing acceptance in the current White House administration to support stem cell research. In March 2009, President Obama lifted the ban on federal funding for embryonic stem cell research. Carried out under proper ethical guidelines, therapeutic cloning serves a reasonable medical purpose. It is morally acceptable and very important to use the potential of stem cell technology to lessen the suffering of millions of people whose lives have been devastated by cancer, Parkinson's disease, or any of the many other diseases and conditions for which therapeutic cloning may provide effective therapies. Scientific research has already begun to show favorable results when applying therapeutically-produced stem cell techniques in Parkinsonian symptoms in laboratory mice. The Greater Good Driving the controversy is the reality that, for now, the only method scientists have to obtain embryonic stem cells requires the destruction of a blastocyst-stage embryo. More research is required and should be supported to allow scientists to develop alternative origin techniques. Some consider a blastocyst-stage embryo the moral equivalent of a fully-developed human being. In 1995, Pope John Paul II argued that blastocysts, which, if fertilized, could potentially lead to the existence of a new human being, should not be used as research material. The question of exactly when personhood begins is not settled in the minds of many Americans. Polls consistently indicate that, in the view of a majority of Americans, the health-restoring and even lifesaving potential of stem cell research justifies the destruction of a few hundred human cells smaller than a pinhead. The moral good of potentially lessening the suffering of human beings through stem cell therapy outweighs the ideal of preserving human life in its earliest phase of development. Families or troubled individuals suffering under the tragedy of Parkinson's disease, or diabetics facing long-term consequences of this common chronic disease must be offered the hope of safe options to treat loved ones if they exist. New Technologies on the Horizon Recent developments in the field of bioengineering may eventually stop the debate over the ethics of therapeutic cloning. In 2007, a group of researchers succeeded in generating new lines of stem cells using single cells extracted from three embryos. After removing the cells, they placed the embryos, unharmed, into frozen storage. The same year, a second group of researchers reported that they had succeeded in reprogramming mouse cells to revert back to an embryonic state. If scientists are able to apply the same procedure to human cells, it could quickly produce a large supply of cells nearly impossible to tell apart from embryonic stem cells, without using eggs or embryos.
  4. 4. The mouse cells manufactured in this way, however, have demonstrated a weakness to viruses causing cancer and mutations. Unless scientists can figure out how to solve this problem, any human cell that might eventually be created using a similar process would be too dangerous to transplant into human patients. This breakthrough would be a first step in improving ethical and religious concerns that exist surrounding the current methods. Yet much more study and refinement is obviously needed. Conclusion Scientists are gradually getting closer to finding stem cell production methods that do not require the destruction of a human embryo. However, waiting until researchers have perfected these methods would morally fail the millions of sick and injured human beings who currently stand to benefit from therapeutic cloning. Until a viable alternative is found to replace the current technology, the potential disease-fighting breakthroughs of therapeutic cloning justify its continued, carefully monitored use. After You Read • Organize your ideas. Use one of the graphic organizer templates provided to break the essay down into its main points. Judge Fact and Opinion FACTS  Facts are statements that can be proved true or false.  Facts tell what actually happened and/or what is happening now.  Facts state something that can be easily observed or verified. OPINIONS  Opinions are statements that can’t be proven true or false because they express a person's thoughts, beliefs, feelings or estimates.  Opinions tell what should or should not be thought or done. They express worth or value.  Opinions are based on what seems true or probable. Example 1: (Note the difference between the following facts and opinions) Fact: It took the Roslin Institute 277 attempts to clone Dolly the sheep. Opinion: In drafting cloning legislation, our representatives must consider the 276 failures as well as the single success. • In this example, the opinion tells what "must" be done.
  5. 5. Counterpoint: Human Life is not a Commodity Thesis: Mammalian cloning is an unethical practice with potentially dangerous implications that violates the deepest principles of humanity and nature. Summary: While human and animal cloning is risky, therapeutic cloning may be medically warranted and ethical, depending on the technique. Less than 10 percent of Americans support human cloning. Some conservative religious groups view all types of cloning as immoral and an attack on human dignity. Others view reproductive and therapeutic cloning as a gross invasion on nature and animal rights, ignorant of religious views. Mammalian cloning is ethically problematic, and is not a valuable undertaking of the scientific business. Reproductive cloning is the most irresponsible and sacrilegious type of cloning, and the majority of people and scientists throughout the world are opposed to this practice. Animal cloning, which is used for the biopharmaceutical industry (biopharming), food consumption, and xenotransplantation (a surgical procedure in which tissue or whole organs are transferred from one species to another species), has generated opposition from animal rights activists and other groups. Three Types of Cloning There are three types of cloning technologies: reproductive (adult DNA) cloning, therapeutic (biomedical) cloning, and recombinant DNA (deoxyribonucleic acid) technology. Less than 10 percent of Americans support all three types of cloning. Many Roman Catholics and Protestants are undecided towards recombinant DNA technology, but view reproductive and therapeutic cloning as immoral. Other groups view one or more types of cloning as a gross invasion on nature and animal rights, ignorant of religious issues. Recombinant DNA technology was introduced in the 1970s and has since been used by basic science researchers to shed light on the molecular origins of disease. Recombinant DNA technology continues to be an important scientific tool and is generally not considered a controversial practice. However, the use of recombinant DNA technology to genetically modify fruits, vegetables, cotton, and other plants has come under fire in recent years. Public opinion polls show that the majority of Americans are doubtful about the safety of genetically modified (GM) plants, which they believe are still in the experimental phase and pose unknown risks to human and animal health and the environment, as well as documented risks to non-GM crops. The increase in GM food production in the United States is not the result of wide public support, but rather a reflection of misrepresentation and secrecy by the food industry. The lack of food labeling legislation in the United States has also contributed to the continued distribution and eating of unmarked GM foods. Many organizations are pushing for labels so that consumers can make informed choices about the foods they purchase. Therapeutic cloning (also called biomedical cloning) utilizes stem cells obtained from human embryos to replicate human organs and tissue that may one day be used for transplants, or to generate treatments for Alzheimer's disease, diabetes, cancer, and other diseases. The debate over stem cell research refers to therapeutic cloning. For those who believe that life begins at conception and that all human life is sacred, embryonic stem cell research is considered profoundly wrong. However, therapeutic cloning has gained favor among some moderate Christians, Jews, Muslims, and other religious groups who justify the use of some embryos to save human lives and to make new medical breakthroughs. As a result, several states have passed legislation that will help fund stem cell research that uses discarded embryos obtained from reproductive clinics. In 2007, Congress voted to support such a bill, but the legislation was ultimately vetoed by President George W. Bush. However, in 2009 President Barack Obama reversed the Bush ban on embryonic stem cell research in the U.S., promising to assign federal funds for scientific research into new embryonic stem cell lines.
  6. 6. The issue of using embryos, regardless of their origin, may not be an issue in the near future. Scientists have discovered that stem cells can be obtained from sources other than embryos, including skin and other parts of the adult body. Stem cells obtained from embryos (known as embryonic stem cells) are more versatile because they can form any type of cell in the body, while adult stem cells are less controversial but can only differentiate into the type of tissue from which they were obtained. Although the uses of adult stem cells are more limited, this technology has gathered more public support. The problem with therapeutic cloning, however, is that it represents a slippery slope that brings scientists one step closer to human reproductive cloning. Ultimately, therapeutic cloning may be used to justify all animal cloning as well. Reproductive cloning produces new life through the replication of DNA obtained from another individual. However, reproductive cloning is extremely problematic on legal, ethical and moral levels. Reproductive Cloning is Unethical Most nations object to human cloning. In 2005, the United Nations called on all countries of the world to ban human reproductive cloning, and at least 46 countries, including Canada, Australia, Mexico, Japan, and Germany, responded by instituting bans. The American Association for the Advancement of Science, the American Medical Association, and thousands of scientists throughout the world have also voluntarily imposed a freeze on human cloning. Approximately 90 percent of Americans oppose human cloning, regardless of the reason. The goal of reproductive cloning is to create new life by replicating an individual's DNA. The process that has been used successfully on animals is somatic cell nuclear transfer (SCNT). The name sounds complicated, but the process is simple: Scientists remove the genetic material from an unfertilized female egg and then fill the egg with genetic material taken from an animal they want to clone. The embryo is implanted into a female and carried to term, just as with a normal pregnancy. Trustworthy scientists state that human cloning has yet to be achieved and isn't being attempted despite previous claims of success from CLONAID, a company founded by members who believe that life on Earth was created by extraterrestrials. In 2008, a California-based biotechnology firm announced that they had successfully cloned embryos from adult human DNA. The claim has yet to be confirmed, but such reports are expected to increase in the future. Why would anyone want to clone a human being? The answers range from those that produce the most sentimental response to those that provoke outrage: to reproduce a child lost early in life, to bring back a father or mother who died in Iraq, to clone geniuses and star athletes, to produce a winning team or an army. However, contrary to what many people believe, a clone will not necessarily display the same characteristics as the DNA donor. As scientists have determined in animal experiments, the skin color, temperament, or immune system of a cloned animal can be completely different. Although this is not at the heart of the ethical dilemma, it raises many questions. What would happen to the clone if the expectations of the cloner were not met? Scientists are learning more about mammalian genetics every day, but there are still many unknowns regarding the functions and capabilities of DNA. Furthermore, scientists are still learning more about the genetic and environmental origins of behavioral, cognitive, and emotional qualities that make each human an individual. As if the philosophical questions and scientific uncertainties aren't enough to question the safety of cloning, this practice belongs to the multi-billion dollar biotech industry that stands to profit enormously from reproductive cloning. To date, biotech companies have applied for more than 4,000 patent requests on DNA sequences and genes from animals and humans. The United States government has yet to implement protective regulations. What are the potential consequences of big businesses owning such information?
  7. 7. Animals Have Rights, Too Human cloning is still in the exploratory stage, but animal cloning has almost become routine. Since Dolly, the cloned sheep, debuted scientists have successfully cloned other livestock, including cattle, pigs, and goats. Mice, cows, pigs, rabbits, deer, goats, cats, and dogs have each undergone cloning. The latest successes for the industry include racehorses and mules. The newborn clone is an exact genetic copy of its parent, allowing ranchers to spread high-quality animals and ensure that the offspring will be first-rate. The United States Food and Drug Administration (FDA) approved the sale of meat and milk from cloned livestock in late 2006. But because the process is so expensive - upwards of $20,000 per clone - it's unlikely that cloned animals will end up in the meat market anytime soon. Instead, they will be used to breed and produce milk. The majority of Americans (60 percent) believe cloning animals is morally wrong. As with genetically modified foods, labeling is the least that can be done to ensure that Americans can make intelligent choices. Many people may choose not to buy these products because of the unknown risks of consuming cloned meat, or because of the ethical problems surrounding animal cloning. The pharmaceutical (biopharming) industry, which has been researching new ways to deliver medicine using cloned animals, raises additional ethical, environmental, and scientific concerns despite the good intentions behind such research. Cloning is dangerous and harmful to animals. Deformities, lung tumors, heart defects, and disease are routine in cloned animals. They also experience higher percentages of premature births, miscarriages, and premature deaths. The Center for Food Safety claims that over 90 percent of cloning attempts fail. Wayne Pacelle, senior vice president of the Humane Society of the United States, has cited an experiment performed by Texas A&M University on cloned pigs in which only 28 pigs survived from over 500 attempts, and one was born without an anus or a tail. Dolly the sheep, the first cloned mammal, took over 250 attempts, and in the end, she lived only half as long as normal sheep. Animals are not just lumps of clay waiting to be molded or exploited for human use. Rather, these creatures are intelligent, capable of emotion, and feel pain. Researchers are continually learning more about the special qualities inherent in the animal kingdom. Owners of dogs, cats, and other pets often confirm the uniqueness of their animals, and most believe that pet cloning is offensive on basic principle. Human-Animal Hybrids Chimeras, or part animal and part human "creatures," may still be the stuff of science fiction but may eventually represent the ultimate attack on the dignity of humans and the animal kingdom. Scientists have cloned sheep, rabbits, pigs, and mice using some human cells with the hope that organs obtained from the chimeras can be used to provide better test subjects for drug testing experiments. Scientists are open to other possibilities as well, and are curious to see what happens when the cells are mixed. The major concern about animal cloning is that scientists are interfering with the natural evolution of life and stimulating potential major risks. Human-animal hybrids demonstrate how science has truly gone off course. After You Read • Organize your ideas. Use one of the graphic organizer templates provided to break the essay down into its main points.
  8. 8. YOU DECIDE Based on the readings, consider the Point and Counterpoint essays in light of your own set of personal values. • Reflect on which arguments about cloning you accept: Point, Counterpoint, or a completely different argument. For you, what is the single most compelling argument regarding cloning, and why? Write a response to the above question that contains a thesis statement and 2 supporting arguments. • Use facts from the resources provided; the Overview, Point, and Counterpoint essays. Refer back to the "Judge Fact vs. Opinion" section to help determine the value of the information you find. • Suggest ways in which the controversy surrounding cloning affects us and our society. Thesis Statement (Your view/opinion): ___________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ 1st Supporting Argument/Reason Why: ___________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ 2nd Supporting Argument/Reason Why: __________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ How does cloning affect you and/or our society? ___________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________