Simplicity, simplicity, simplicity!" Example: Thoreau ends his essay with a metaphor: "Time is but the stream I go a-fishing in." This is an easy rule to remember: if you use a complete sentence to introduce a quotation, you need a colon after the sentence.
/ / Genetic Engineering Essay
GENETIC ENGINEERING - The benefits and problemsGenetic engineering is a powerful and potentially very dangerous tool. To alter the sequence of nucleotides of the DNA that code for the structure of a complex living organism, can have extremely ill effects although the potential benefits can be huge.Before advances in genetic applications, gene therapy was unheard of and genetic defects were always inherited, plaguing generations. Today genetic testing is widely available, such as prenatal karyotyping of chromosomes to check for genetic abnormalities. Genetic testing is also useful for families in which autosomal recessive disorders are known to exist, when these are planning to have children. In addition, genetic testing is available for people who might have inherited a genetic disorder which only becomes apparent later in life (for example Huntington's Disease). Individual choice decides whether a person would rather know if they are particularly vulnerable to certain diseases or more likely to die young. Knowing that your life may be short could inspire you to make the most of it while it could equally well cause severe depression.Today`s advances in gene therapy make it possible to even remove a faulty gene and replace it with a functioning gene in cells lacking this function. Though these techniques are available, they are still in the experimental stages. Somatic cell therapy, for example, uses faulty genes to target the affected areas for genetic treatment. This technique is beneficial in the treatment of cancers and lung, blood and liver disorders. Since the treatment is localised, any unwanted effects of this are not passed on to the next generation.A more controversial technique is the genetic alteration of gametes which causes a permanent change for the organism as well as for subsequent generations. Of course if the gene is corrected without further negative effects, the genetic disorder has beensuccessfully eliminated; but if a problem arises it could pass on. These advances in genetic engineering make the possibility of "designer babies" a reality. When the choice to change every aspect of every characteristic of a child is available, who would refuse? Why have an average child, when it is possible to have one with perfect health, good looking, intelligent and matching every other desirable characteristic which parents could want? The benefits seem endless: the potential for a perfect society without physical imperfections, low intelligence nor undesirable personality traits. How far this could go, is unpredictable; theoretically humans could for example be made more efficient - requiring less food but able to work harder. However, one of the problems with changing the structure of human DNA, is the subsequent loss of natural variation. As well as the unattractive possibility of very little variation in personalities and looks, the loss of natural variation would stop the formation of new genes, thereby severely decreasing the available gene pool. On the larger scale of life, natural variation is vital for subtle adaptions that help species accommodate to changing environments. If genetic alterations become widespread, genes required for particular circumstances or different environments that may be encountered by the organism, could conceivably be bred out. If then the organism encounters a change without the gene which would have made adaptation possible, it could suffer or even perish.Another large problem with all types of genetic engineering is the interdependence of genes: while on the one hand one gene may code for several features, on the other hand many genes are frequently required to code for one characteristic. While chromosome mapping is useful, without test crossing with every possible variable characteristic of an organism, it cannot be known what the functions of each gene are. Hence when a gene is removed, what is known about the function of that gene may not be all it codes for. The removed gene may also have a part to play in other functions. Similarly, the inserted gene may have other functions that are not known about. Some of the effects of these unknown gene functions may be noticed immediately and possibly be rectifiable, while others without immediate effect may cause significant long term changes. Little is known about the long term effects and potential dangers which may be inherited before they are noticed. Such problems may be cumulative and become harder to stop through time as the spread of new genetic problems continues through generations.This problem of inadequate knowledge regarding a gene's complete function applies also to the use of genetic engineering in food production. Be it livestock or crops, the alteration of genes, for example to boost growth, could have side effects such as weakening resistance to a particular disease. The inserted gene could even code for something harmful to humans. These problems may not even be immediately noticed and are hard to stop once cattle have been bred, crops sown or distributed. On the other hand, the benefits to humans are obvious where gene replacement has been successful in improving aspects of food production. For example, production costs can be lowered and health, taste and look of a product maximised. Equally, a lot of food shortage problems in the Third World could be solved by adapting crops to grow in such harsh conditions.An extreme idea of the future of meat production (Man Made Life- Jeremy Cherfas) involves the engineering of entirely new forms of meat: "a vast organ culture of immortal muscle cells supplied with a steady stream of crude nutrients (perhaps from other engineered cells) and harvested by hacking off a slab". Personally the idea of this is extremely unappealing but it is clear that the efficiency of meat production would rocket as the result of such an advance. In addition, the resources saved in such forms of meat production could be used elsewhere for human benefit.An example of another controversial but popentially beneficial form of genetic engineering is the alteration of pig DNA to suit human immunology. Recently the problem of organ donor shortage has become apparent due to increases in road safety and life saving technology. A simple solution is to use pig organs which function in similar ways and have a similar size to human organs. The immunology of pigs is also similar to that of humans but there is still the problem of organ rejection. Human antibodies would recognize the pig tissue as foreign and either destroy it or cause harm to the recipient.The solution is to change the antigenic properties of the pig tissue by genetically introducing human DNA that won't be rejected by the human immune system. Hence a breed of pigs containing human elements in their DNA was created. The obvious benefits would be a ready supply of organs not dependant on the death of ahealthy person as well as advance preparation time for the transplant to minimise the risk of rejection. The main problem consists of the possible introduction of new diseases to humans. A particular retrovirus has been discovered which, harmless to pigs, has the potential to cause severe ill effects in humans. All the previously mentioned applications of genetic engineering have had clear benefits to the human species in spite of equally apparent risks. However, one of the perhaps most dangerous risks of the new advances is their undeniable potential for biological warfare. This potential for engineering deadlier and more resistant infections or diseases scares all nations. Weapons could now be directed at the water supply or even crops grown by the enemy. Strains of pathogens could be tailored to the enemies strain of livestock or crops, starving a nation into surrender. By changing other common diseases, an antidote could be found to vaccinate allied populations while only the enemy would suffer. The benefit to the inflicting power is removal of enemy population without destroying buildings and resources (as an atomic weapon would). Since all sides are likely to have some form of biological weapon, however, none would go unaffected, thereby causing large scale suffering. This problem would be worsened if fast spreading diseases were used - without treatment whole populations could disappear in very little time.I feel that although some of the applications of actual genetic 'engineering' could be of immense use to humans (as the applications of gentic testing already are), too little is known about genetic structure to inflict the risks involved on the population. Despite this, genetically altered food has already started to fill the supermarkets, only labelled as such if genetically altered substance is present (and not when genetic engineering has taken place in the production process)."It has been estimated that the entire human genome will be mapped and all important genes sequenced before the end of the century" (British Medical Journal Vol.299). Surely with advances at this rate, these visions of the future of genetic engineering are not as far off as I would like to think. The potential risks involved to humanity rank alongside developments such as nuclear power in that the extent to which the whole population of this planet could be affected, is immense. Equally, the wide range of applications of genetic engineering make it possibly of the greatest use since the discovery of electricity. It is worth remembering, when the risks of the use of nuclear power became apparent to the scientists and ethical considerations started amongst the scientific community, the decision was taken out of the scientists' hands by political powers- which resulted in the disaster of Hiroshima. It is possible that the technological advances with genetic engineering could lead to equally or even more disastrous effects. It seems to me, that decisions regarding these technological tools are of a highly moral nature and need to be regarded as the responsibility of all of humanity. It is debatable and unclear, which form this 'taking of responsibility' should take, - but it seems to me that a wide international public debate is required about the issues involved. SOURCES- Tomorrow`s World: 'Genetics Special' BBC 1 Wed. 28th May 97- 'World Book' Encyclopedia- Encarta encyclopedia (CD ROM)- Jeremy Cerfas (1982). 'Man Made Life'. Blackwell Oxford - Helen Kingston (1989) DNA Analysis in Genetic Disorders. British Medical Journal Vol.299 - Anne Fullick (1994) Biology. Heineman Oxford - J. Simpkins & J.I. Williams (1990) Advanced Biology. Unwin Hyman London
The National Endowment for the Humanities, Remembering people essay As an example, in the totals per customer report we looked at earlier, you might want to only show customers whose total order value exceeds a certain amount, that amount to be supplied by the user when viewing the report.