Cloning History and Background of Term Paper
- Length: 13 pages
- Sources: 15
- Subject: Genetics
- Type: Term Paper
- Paper: #59839357
Excerpt from Term Paper :
For example, the most common instrument used in cloning today is known as a "micromanipulator," described by Baird as being an expensive machine that requires the use of a skilled technician to capture an egg cell under the microscope, insert a very fine needle to suck out its nucleus, and then use another needle to transfer a nucleus from the animal to be cloned. "This process is tricky and time consuming, and results are somewhere in the 25% range. In the new technique, egg cells are split in half under a microscope using a very thin blade. The halves are allowed to heal and then a dye is introduced to identify the halves containing the nucleus" (Baird, 2002, p. 20). The two halves of embryo that contain the original nucleus are then discarded, a processs that leaves the empty cytoplasts alone (these are the cells that do not contain the nucleus); in order to create the cloned embryo, a cell from an adult animal is fused first with one cytoplast, then another, by quickly introducing an electric current (Baird, 2002). According to this analyst, "This new method of cloning is much cheaper and can be performed without the need of a skilled technician. Another advantage is that this method will be relatively easy to automate, with the end result being mass produced cloned embryos. A major concern of this evolving cloning technique is that its cheapness (the electrofusion machine can be purchased for around $3,500) will allow increased attempts at human cloning" (Baird, 2002, p. 20).
Furthermore, cloning technology has been extended into some areas that appear to represent very real opportunities for improvement in the human condition. For instance, therapeutic cloning is used to clone embryos that are not used for reproductive purposes but as sources of cells, tissue and possibly organs for research, therapy and transplantation. "So-called therapeutic cloning," Harris notes, "involves the cloning of an embryo to make the cells, tissue or organs of that embryo compatible with a proposed recipient" (2004, p. 113). According to this author, stem cells represent the most likely application of therapeutic cloning in the foreseeable future; not surprisingly and notwithstanding federal government opposition, a massive research effort is underway to encourage the untold potential of this type of cloning research (Harris, 2004).
According to Baird, scientists have reported that the cloning of animals, particularly those that have been modified genetically, has a wide range of medical, agricultural, and industrial applications; for instance, if human genes were introduced into animals such as pigs, cows, and sheep, such transgenic animals would possess the capability to produce a wide variety of proteins and enzymes (Baird, 2002). "Large numbers of transgenic animals could produce vast quantities of drugs and other substances more efficiently and at a lower cost than is currently possible with today's bioengineering technology," Baird adds (2002, p. 20). Future innovations in cloning will ultimately result in other practical applications as well, including the potential genetically modified animals that could provide organs for human transplants, the mass production of healthier, more productive, disease resistant farm animals, more nutritious produce, and the development of crops that are disease, insect, and drought resistant (Baird, 2002).
Furthermore, future research and innovations in cloning may also contribute to disease treatments for humans by allowing scientists to reprogram cells. Through this research, for example, skin cells could be reprogrammed into the insulin producing cells in the pancreas; such skin cells would then be introduced into the pancreas of diabetic patients, a treatment that holds the promise of enabling them to produce their own insulin (Baird, 2002). Yet another example of the potential benefits to be derived from future therapeutic cloning involves Parkinson's disease, a degenerative disease affecting neurons. "Because neurons do not regenerate, cloning research could allow the reprogramming of cells into neurons to replace those damaged by the disease" (Baird, 2002, p. 20).
By using cloning techniques, human organ transplantation has the potential to become more successful, a feature that is especially important due to the ongoing chronic shortage of organs; today, just a small percentage of patients that stand to benefit from such transplants actually receive them, and there remain important issues of rejection mean the recipient is forced into a regime of drug taking to combat foreign body tissue rejection (Baird, 2002). In response, researchers are attempting to develop genetically modified pigs as an alternative source of organs; transplanting organs from one species to another is called xenotransplantation, and through nuclear transfer, transgenic animals could be produced that create human proteins on their cell surfaces, thereby reducing the risk of rejection during xenotransplantation (Baird, 2002).
Beyond the foregoing known and potential benefits, there are also a number of practical applications that could be realized through the cloning of actual human beings. According to Baird, "Infertile couples not wishing to adopt could use cloning to have children who are biologically related to them. Cloning could also be used to produce offspring free of certain diseases; a fertilized ovum could be cloned and the duplicate tested for disease and/or genetic defects. If the clone were free from defects, then the other would be as well and could be implanted in the womb" (2002, p. 20). Today, using in-vitro fertilization, many women have implants of a number of fertilized ova into their uterus in a "shotgun" effort to produce a pregnancy; however, some women are only able to supply one egg during this process. By using cloning technologies, Baird notes that one egg could be transformed into eight, a feature that significantly contributes to the potential positive outcome for a viable pregnancy; however, many researchers believe that in the future, cell cloning therapies can provide cures or more effective treatments for a number of diseases that afflict humanity, and even organ regeneration could be accomplished by reprogramming a patient's own cells, thereby obviating the requirement to create and destroy human embryos (Baird, 2002). In sum, this author maintains that, "As the field of biotechnology expands, so do the possibilities and ethical responsibilities" (Baird, 2002, p. 20), which leads to the several possible negative consequences of cloning technology gone astray.
Possible Negative Consequences and Their Consequences. The ethical issues involved in ongoing human stem cell research introduce a number of controversial and important issues concerning their possible negative consequences. A number of these issues involve the different sources used to harvest stem cells. According to Harris (2004), "In principle stem cells can be obtained from adults, from umbilical cord blood, from fetal tissue and from embryonic tissue. Clearly there are widely differing views as to the ethics of sourcing stem cells in these four different ways" (p. 115). While researchers continue to identify superior potential sources such as amniotic fluid, there remains a general consensus among researchers that human embryos remain the best source of stem cells for therapeutic purposes (Harris, 2004).
According to Baird (2002), "Around the world a debate is raging over the subject of human cloning. At the core of this controversial issue are ethical, religious, societal, scientific, and medical concerns" (p. 19). The potential for misuse of cloning technology is very real, of course, but so is the possibility of a radioactive dirty bomb being used against the United States and its interests abroad in the future. The potential impact of the negative consequences currently being attributed to cloning technology fail to take into considerations the possibility that the present generation could attain the scientific knowledge and technical ability needed to eliminate genetic defects that contribute to common diseases and directly intervene in shaping human evolution (Baird, 2002). These concerns demand that a technologically literate society be developed, enabling well-informed decisions to be made within the controversial realm of the biotechnologies dealing with human genetics (Baird, 2002).
There is also the controversial issue of whether or not embryos or fetuses may be deliberately produced in order to be sources of stem cells, whether or not they are also intended to survive stem cell harvesting and grow into healthy adults (Harris, 2004). Likewise, as Mcgee (2000) points out, if current trends continue, there is the potential for human beings to be created without the need for the sexual union between men and women, something that carries with it some profound implications for the traditional family unit: "It goes without saying that human cloning does not involve, or need to involve, sexual intercourse," Mcgee advises. "As one probes the seeming asexuality of cloning, one is initially drawn to the metaphors that feed and follow the asexual nature of the technology" (p. 266). Likewise, Lyon (2002) reports that, "Cloning, however, introduces an entirely new creation story, one which challenges our 'continuous history' through human reproduction (p. 7). Clearly, such approaches to human reproduction negate the intimacy that has historically been part and parcel of the husband…