Textbook Assignment: Chapter 28, Pages 787 - 800. The notes also contain links to online copies of several articles that have been published in The Scientist within the last year about topics covered in this lecture. There are also a few other links related to eugenics. You are encouraged to look at these articles and web pages, but they are not considered to be mandatory reading assignments.
Major concepts
Introduction: Rapidly expanding knowledge of genetics and related areas of molecular biology and recombinant DNA technology has opened almost limitless possibilities for modification of all types of living organisms, including humans. We are thus caught in the middle of a period of trying to determining what modifications should be made, as opposed to what modifications could be made. This has given rise a whole new discipline of bioethics, whose goal is to try to develop reasonable guidelines and where necessary appropriately restrictive laws. There is also a lot of apprehension among the general public, which in some cases is being manipulated by individuals with private agendas on one side or the other. Chapter 28 of our textbook discusses some of the major issues that currently must be dealt with. The chapter begins with a discussion of the dubious history of attempts to produce genetically superior humans through eugenics. This is followed by sections on genetic testing, patenting of genetic information, recombinant DNA safety, and problems associated with educating the general public about the rapid advances that are occurring in genetics. We will discuss eugenics in detail and sample the other topics briefly.
Eugenics: The term eugenics was coined by a quantitative geneticist, Francis Galton, in 1883, well before the rediscovery of Mendel, and at a time when "blending" theories of heredity were still quite popular. The basic concept was based on Darwinian evolutionary theory and the assumption that the human species could be improved by encouraging higher levels of reproduction among the gifted and talented (positive eugenics) and restricting reproduction of individuals displaying less favorable characteristics (negative eugenics). In some ways, this can be viewed as an extension to humans of some of the principles that have been used since antiquity to improve domestic animals and crop plants. It can also be viewed as an attempt to apply the principles of population genetics to a human population, although the eugenics movement was started well before the principles of population genetics had been formalized mathematically.
Negative aspects of the eugenics movement" Early in this century, there was a strong and mostly very negative eugenics movement in the United States. Starting in 1907, numerous state laws began to require sterilization of "genetically inferior" individuals. The traits they sought to irradicate by genetic means included imbecility, feeblemindedness, criminal behavior, lack of intelligence, antisocial behavior, insanity, idiocy, epilepsy, and chronic alcoholism, as well as various other "undesirable" traits. In practice, the focus was on impoverished and poorly educated ethnic minorities and immigrant groups, who were quite generally portrayed as genetically inferior. The belief that this was the correct thing to do became so ingrained in our society that in 1927, the United States Supreme Court voted 8 to 1 to uphold a state sterilization law, comparing the benefits to those of vaccination (textbook page 788). In 1924, immigration from a number of countries in Eastern Europe and Asia was severely restricted because of the belief that immigrants from those countries were mentally inferior. The fallacy of those early perceptions is now clearly evident. In fact, Asian-Americans are currently doing so well academically, particularly in science and technology, that today's alarmists are concerned about them being overrepresented in those fields.
Aryan supremacy: The most extreme abuses that were done in the name of eugenics occurred in Germany during the 1930's and early 1940's when the Nazis sought to erradicate certain ethnic groups they considered to be inferior. However, other forces besides ethnic purity were obviously involved. Hitler himself did not conform to the supposed Aryan ideal, and the Germans appeared to have no problem accepting the Japanese as allies in World War II.
Disillusionment with eugenics: Even before those extremes turned many people away from the basic concept of eugenics, numerous leading geneticists had begun to challenge the premises it was organized around. Boxed example 28.1 describes an early publication that clearly stated how little the elimination of individuals afflicted with homozygous recessive diseases would do to rid the population of the disease alleles, which are carried primarily in disease-free heterozygous individuals. Research on the basic principles of genetics was progressing rapidly during the time period when the eugenics movement fluorished. As the the complexity of inheritance and the interplay between heredity and environment became better understood, it became clear that many of the practices of eugenics were both unfair and incapable of achieving their goals. Also, there was a growing awareness that variability in a population plays an important role in long-term survival and that a high level of homozygosity is extremely dangerous, as we discussed in the lectures on population genetics.
Human intelligence: One of the goals of the eugenics movement was to reduce the number of "genetically feeble-minded" individuals in the population. As discussed on page 621 of our current textbook, the process of measurement of human intelligence and the role of heredity in determining the outcome of that measurement are both highly controversial topics. This topic was also discussed in last year's textbook (Klug and Cummings, Concepts of Genetics, 5th Edition, pages 676-677, available at Norlin reserve). The current concensus is that IQ has a heritability of about 0.6. This observation continues to be used by some individuals to suggest that low performance by students from disadvantaged backgrounds is largely genetic and that attempted social or educational intervention is doomed to failure.
Inappropriate conclusions: The boxed article in Klug and Cummings summarizes several fallacies in such conclusions that are partially echoed on page 621 of our current textbook. . First, heritability applies to differences within a population, and does not say anything about individuals. Second, heritability cannot be used to compare populations (and thus to conclude that one of them is inferior). Third, heritability applies only to the population under the conditions when it was studied, and does not say anything about whether the mean level of achievement can be increased for the entire population by environmental changes. Thus, Klug and Cummings conclude that heritability must never be used as a biological justification for discriminatory social policies. (For an opposing viewpoint, see the Future Generations web site, described below).
Eugenics web sites: Plugging the term "eugenics" into any web search engine generates a lot of hits. One can find web sites reflecting a wide spectrum of views, including some who consider eugenics an absolute necessity for survival of the human race as we know it. You may find the following sites to be of interest.
Visions of Perfection: Despite its name, this site presents a fairly even-handed historical view of eugenics, including documentation of the harsh steps that were taken in the United States in the early 1900's and the artocities that occurred in Germany under Hitler. After the home page comes up, click on "an ideal society". You may also find the section entitled "exploited genes" of interest. It deals with whole animal cloning and genetic manipulation.
Future Generations: This is a site dedicated to the belief that we need eugenics. It makes an attempt to use scientific concepts to support that belief. However, its bias is fairly evident. Interestingly, I found this page from the web page for a History of Science course at the University of Connecticut, whose students were assigned to read parts of the site and comment on it. .
Non-eugenic interventions: With a modern understanding of genetics and medicine, today's emphasis is far more on reducing the phenotypic manifestations of disease alleles than on total elimination of the alleles. In many cases, this is done through ameliorative procedures such as administration of insulin to diabetics. In addition, through the use of prenatal diagnosis and early termination of pregnancies, it has become possible in many cases to selectively prevent the birth of infants with uncurable genetic diseases or severe birth defects, without eliminating the possibility for the parents to have unafflicted children. .
Genetic testing: Quite apart from its sometimes controversial role in the decision to terminate a pregnancy, genetic testing is now widely practiced in many other contexts. One cited in the textbook is early detection of phenylketonuria (PKU). Without prompt medical intervention, PKU leads to severe mental retardation. However, with careful dietary control to avoid excess phenylalanine starting immediately after birth, afflicted individuals can lead relatively normal lives and become productive citizens.
Occupational genetic testing: One area of major controversy is whether of not genetic screening can be made a condition for employment. The textbook cites glucose-6-dehydrogenase deficiency, which renders afflicted individuals more susceptible to the effects of oxidizing agents. Because this is an X-linked trait that also has a higher frequency in certain ethnic groups, the testing has become entangled in issues of gender and ethnic discrimination. Questions have also been raised as to whether such testing may exclude individuals from jobs that they are fully capable of performing without undue risk.
Genetic testing and health insurance: The extent to which health insurance companies may use genetic information to exclude certain individuals from coverage remains controversial. Guidelines designed to avoid such problems have been recommended by study groups, and in some cases have resulted in passage of state laws. However, such protection is not uniformly available. With rapid progress of the human genome project and the development of simple tests for a wide range of genetic diseases, including susceptibility to various types of cancer, the economic concerns of the insurance companies have become quite large. This remains a poorly resolved issue that must be dealt with in the near future.
Forensic use of DNA testing: DNA fingerprinting, especially when combined with PCR amplification of very small samples, has become a major investigative technique that often provides convincing evidence of the guilt (or innocence)of a suspect. However, the technique is so sensitive that it is extremely easy to reach wrong conclusions due to the presence of minute amounts of contaminating DNA. A major effort has been mounted to define strict standards, including appropriate controls against contamination. However, defense attorneys continue to find clever ways to cast "reasonable doubt" on the conclusions.
Confidentiality of genetic testing: Unauthorized release of the results of genetic testing can be harmful in a variety of ways. For the individual, these include denial of employment, denial of health insurance, and denial of life insurance, as well as potential impacts on personal relationships. There can also be major implications for relatives of a person who is diagnosed with a particular inherited condition, or even just shown to be a carrier of that condition (see boxed example 28.2 for a discussion of what constitutes "informed consent" in such cases).
Genetic patenting: The textbook provides a history of the gradually evolving trend toward more and more patenting of genetically modified organisms and cloned genes. The controversy over such practices has accelerated sharply as several large companies have entered the genomic sequencing business and are beginning to undertake massive patenting of sequences. Such patents tend to slow progress, because results cannot be released to the public until patent applications have been filed. In addition, when patents are granted, the patent holder can demand royalties for all uses of the gene sequence in question.
Disease genes: The patenting of genetic sequences has become particularly troubling with regard to disease genes and diagnostic tests based on mutations to those genes. An article in the October 11, 1999 issue of The Scientist summarizes many of the problems that are being encountered as a result of patenting of disease genes. Another article in the July 19, 1999 issue describes Celera Genomics, which has become one of the major players in the genome sequencing for profit business. An article in the December 6, 1999 issue focuses on the race between Celera and the Human Genome Project, which have each now sequenced about one billion base pairs of human DNA. That article mentions that Celera claims to have already plucked "most of the low hanging fruit" by filing provisional patent applications on some 6,500 putative huiman disease genes. Celera has made a huge investment in this work, and it is obvious that they expect to earn a good return on that investment. Depending on point of view, this is either good business policy or placing corporate greed ahead of rapid progress in medicine.
Recombinant DNA safety: Although there is still a rather widespread distrust of genetically engineered crops, generalized fear of recombinant DNA technology seems to be decreasing. For several years after gene cloning and recombinant DNA technology first became possible, there was enough concern about the risks involved so that strict guidelines were put in place for safety precautions that must be followed. As the research has matured, those guidelines have gradually been relaxed. Thus, for example, a number of genetically engineered crops are now grown quite routinely, although not without some lingering concerns. The extent of this concern and the continuing controversies are summarized in the October 11, 1999 issue of The Scientist, which contains two articles and a statement of opinion about genetically modified food crops and the controversy surrounding them, particularly in Europe.
Possible ecological damage: In most cases, it can be argued that genetic engineering has simply achieved more quickly and efficiently the same types of changes that can be achieved by selective breeding. One of the more legitimate concerns, however, involves the introduction of genes that are entirely foreign to the host species. Such changes may seriously alter its ability to dominate an ecosystem or to damage native species. An example in the news recently is the possible effect on Monarch butterflies of pollen from corn that has been genetically altered to be resistant to insect pests.
Genetics education: The final area that our textbook addresses is the failure of the educational system to keep up with the current pace of discovery in genetics. This is reflected at all levels from the education of the general public to the education of physicians. In addition to providing an educational background in these areas, it is necessary to find a way to provide frequent updates to keep physicians and other professionals in touch with recent progress.