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4 The Fifth Revolution
- Indiana University Press
- Chapter
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52 Wondergenes The Fifth Revolution 4 When the human genome is completely unraveled, we will discover the genes not just for diseases or anti-social behaviors, but those that interact with the environment to produce all heritable physical and mental characteristics. Once the proteins associated with these characteristics are identified, we will be able to create drugs that mimic or suppress the actions of these genes, making it possible to produce short-term physical or mental changes. Genetic tests for non-disease traits will enable parents using assisted reproduction techniques like in vitro fertilization (IVF) to select embryos with the best combination of these genes. The same genetic engineering techniques used to prevent genetic disorders ultimately could be employed to install desirable non-disease characteristics in these embryos. These techniques are the armamentarium of the fifth and final revolution in human genetics: the revolution in genetic enhancement . Some are still half-way, but some are whole, and all of them produce significantly more rapid and effective impacts than traditional patterns of human evolution. 53 The Fifth Revolution The tools of genetic enhancement—drugs, genetic tests, genetic manipulation—will grow out of the tools of genetic medicine. In fact, enhancement techniques can be thought of merely as genetic medicine provided to “healthy” populations. The drugs that normal individuals may use to increase their brainpower, for example, will most likely be the same drugs physicians use to combat Alzheimer’s and other cognitive impairments. This presents major challenges for those trying to regulate these enhancements, for manufacturers, health insurers, physicians, and for individuals deciding whether or not to use them. In the first place, when is an intervention “enhancement” rather than “therapy”? This is important for a number of reasons. For example, health insurers may reimburse for genetic treatments to fight disease, but may consider enhancement to be like cosmetic procedures, which they do not cover. Bioethicists and philosophers who have struggled with this question have proposed that an intervention be considered an enhancement when it produces an effect beyond that which is normal. But what is “normal”? For the most part, “normal” refers to some frequency of a characteristic in a population. We measure everyone’s height, and call the average height “normal.” But then is everyone who is shorter or taller than average “abnormal”? To avoid upsetting a lot of children and parents, child development specialists have adopted a statistical convention: people are abnormally tall or short if their height is more than two standard deviations from the population mean. This translates to about 5 percent of the population. Thus, a drug or genetic manipulation that resulted in a height greater than two standard deviations from the population mean would be considered an enhancement, while an intervention that moved a short person to within two standard deviations would be considered therapeutic. Similar conventions obtain for weight, IQ, and many personality traits. But these conventions are entirely arbitrary. Why should the line for abnormal height be drawn at two standard deviations from the mean, rather than one (in which case approximately 30 percent of the population would be abnormal) or three (virtually zero percent abnormal)? How is the relevant population defined? The normal height for a professional basketball player is much taller than the normal height for [3.229.122.112] Project MUSE (2024-03-19 12:46 GMT) 54 Wondergenes other persons. If the law prohibited employers from refusing to hire people because they were short, would a basketball team have to hire someone who was more than two standard deviations below the normal height for a basketball player to avoid being guilty of illegal discrimination? Conventions also can change as people alter their conceptions of what it means to be normal, and as the characteristics of the population change over time. If a lot of people used genetic enhancements to increase their height, the overall height of the population, as well as the mean, would rise. Families that were once considered to be of normal height might then find themselves abnormal. In response to these conceptual problems, some philosophers have proposed that an intervention be considered an enhancement only when it produces a result, either in kind or degree, that goes beyond the bounds of the species.1 A drug that allowed someone to grow a third arm would be an enhancement, as would a drug that increased a person’s height to ten feet, but not a drug that only increased height, say, to seven...