Biological Ethics

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Chapter 21. Eugenics

A. del Amo (died 10 July 1985)

a) Man's biological uniqueness and his responsibility towards the living world

One of the features that distinguishes man from all other species is his ability to freely interfere in natural processes, among others, in the evolution of other species and, if he so wishes, in his own biological endowment. Man does not appear to us, unlike the rest of the species, as result of an evolutionary process, but as a being capable of actively protagonising his own and others' evolution; what is more, he is endowed with the surprising capacity to proceed against what modern biology recognises as the "purpose", the most radical "purpose" of all living beings, namely: the production of more life. Such uniqueness is sample of the presence, in man, of the spirit. Thanks to him, human existence is not a totally closed existence, imprisoned by the rigorous determinism of the laws of nature, but an open and free existence.

And that is why man can truly feel manager responsible for the biological fate of the other species, as well as his own.

b) Eugenics and its forms

We are aware of generational continuity. We feel linked to the past, but also to the future. We can, and should, ask ourselves whether or not our inherited heritage is degrading. And even in the case of a negative answer, we might consider the possibility of future improvement. In terms of allele frequency, two kinds of Eugenics have been distinguished. One, which has been called positive: what could we do to make favourable genes more frequent in the human population; the other, negative: how could we reduce the frequency of deleterious genes in the human population?

So-called positive eugenics

The following historical fact highlights the main technical difficulty of any positive eugenics project . Muller, award Nobel for his programs of study of X-ray induced mutability, proposed an improvement of the hereditary heritage of mankind by application of methods that had been successful in livestock breeding; by the establishment of sperm banks of "selected" individuals, and artificial insemination of women. He presented a list of "select" individuals whose sperm would have merited collection in such banks. They were famous figures of culture, politics, etc. Among them he included Stalin. But Muller worked in the USSR from 1933 to 1936, and witnessed the brutal persecution of Vavilov - who would eventually die in the Siberian concentration camp - and the other Russian geneticists of the time, and was disappointed. On his next list, Stalin's name had disappeared.

The anecdote highlights the main technical difficulty of the method: the impossibility of deciding, a priori, the optimal hereditary heritage for future humanity. For, although we spoke earlier of favourable genes and deleterious genes, in reality, with the exception of a few disadvantageous genes in any of the environmental conditions in which life develops, genes are not good or bad. Their value is always relative, i.e., relative to specific environments. Thus, since the environmental conditions in which humans will live in the future are unpredictable, we do not know what the "optimal" genotypes of this future, which is also changeable, will be. The choice of selected genotypes for the future is therefore arbitrary and even capricious. Biologically it makes no sense, it is utopian.

So-called negative eugenics

Is there an urgent need for some negative eugenic measures internship ? Is it true that hygienic, medical or surgical advances constitute a selection in favour of deleterious genes, thus relaxing the beneficial effect of natural selection? Is the gene pool of mankind deteriorating?

As Motulksky states, "some biologists have raised the problem of the deterioration of the human gene pool. It is argued that hygiene and modern medicine keep alive many individuals who would have died under more rigorous selective conditions, and that therefore genes that contribute to disease will accumulate and contaminate the human gene pool. He goes on to say: "some go so far as to assume that the Degree of gene deterioration will be such that in the future, in fact, all people will have to be involved in some way in the health care of others".

These gloomy predictions ignore or silence the fact that, if the frequency of these genes has increased thanks to medical and hygienic care, it is because the viability and fertility - and therefore the reproductivity of the individuals carrying these genes - has improved, or, in other words, because, under such conditions, the genes are no longer unfavourable, at least in that respect, even if this has been done with some economic, expense , staff or collective.

Natural selection still works with extraordinary efficiency. It is estimated that, out of every 1000 pregnancies, 160 - one sixth - do not reach full term, and that, of the remaining 840, only 5 are born with chromosomal abnormalities. The proportion of chromosomal abnormalities in individuals born alive at term is therefore 5/840, or about 6/1000. 50-60% of miscarriages are due to chromosomal abnormalities. Natural selection therefore hardly allows individuals with chromosomal alterations to complete their embryonic development . In addition, the vast majority of these are individuals that do not reproduce, even if, thanks to special care, they manage to survive and reach adulthood. It is clear, therefore, that the medical care of this subject group of patients does not represent a significant deterioration of humanity's hereditary heritage.

What about genetic conditions? Here status is somewhat different. Allele frequencies will increase over successive generations, as a consequence of the "relaxation" of natural selection, but these increases will be very small, so that change will be very slow, particularly if the initial allele frequencies are very low. For example, if we assume that all current phenylketonuria patients (allele frequency = 0.01), thanks to a special phenylalanine-free per diem expenses , can grow to adulthood and reproduce, which is a lot to assume, and that the rate of reverse mutation, i.e. the change from mutated to normal allele, is ten times less frequent than direct mutation, the frequency of the mutated allele will increase very slowly, to an equilibrium frequency of about 0.90; but this would take about 3,000 generations (3,000 years).3,000 generations (75,000 years) would have to elapse.

The maximum relaxation of selection would occur if all diseases of genetic origin were to move from lethality to normal reproductivity, which would mean the suppression of natural selection. Even in that case, the World Health Organisation has estimated that, taking dominant, recessive, X-linked and multifactorial pathological traits together, it would take 6-7 generations, or about 150 years, for the frequency of these traits to double in the human population.

But as Motulksky states, "our technology Genetics has changed, so markedly, in just one generation, that it would be foolish to be alarmed for now"1.

Eugenic sterilisation

In the 1920s, in the United States, under the pretext of negative eugenics, some states adopted provisions requiring the sterilisation of those carrying dominant genes responsible for certain diseases. In Nazi Germany, too, in the late 1930s, eugenic sterilisation programmes and even the extermination of the mentally handicapped, the malformed, etc., were implemented, thus gaining experience for the genocide, which followed, of Jews and Poles.

If sterilisation were to reach all those exhibiting the pathological trait, and the recurrent mutation were not counted, elimination would be complete in a single generation, in the case of a dominant trait. If the trait were recessive, the change in allele frequency would depend on the original frequency. If it were 1%, the reduction to a quarter would require ten generations with sterilisation of all affected individuals. And if it were 4 per 10,000 - a fairly normal frequency in recessive hereditary diseases - it would take 1,200 to 1,600 years to reduce that 4 per 10,000 to 1 per 10,000. Clearly, even under these hypothetical conditions, the method would be inefficient, except in the case of dominant inheritance.

But if the detection of diseased individuals were not total, and sterilisation could only reach 50% of them, the elimination of the gene would still be much slower. And if instead of one gene there were two, it would be even slower. And even more so if polygenic inheritance is involved. If we also consider the possibility of recurrent mutation, then the effectiveness of this barbaric method of compulsory sterilisation is very low indeed.

Eugenic abortion

In our time, another possibility of negative eugenics has been considered - and many countries have legalised it - that of aborting those individuals who, by means of amniocentesis techniques, are known or presumed to have hereditary defects. The centrifugation of amniotic fluid allows the culture of embryonic cells, and the biochemical and cytogenetic study makes it possible to recognise, with greater or lesser certainty, certain metabolic errors and major chromosomal alterations.

Even using rigorous techniques this method can lead - especially in the case of chromosomal alterations - to unfavourable misclassifications. And, of course, the error in these grades can be even greater if dubious criteria are arbitrarily applied. Let us recall, in this respect, what happened at a public discussion in which some French scientists and intellectuals who were in favour of abortion took part. Someone asked: "Would you allow the induced abortion of an exhausted tubercular woman, abused by a brutal and deeply alcoholic husband, with a foetus irremediably destined to serious emotional disturbances and insurmountable congenital defects"? He was answered: "It would be a clear case of an affirmative answer". The questioner immediately asked for a minute's silence "because Professor Monod has just murdered Beethoven".

But we will not dwell on these technical limitations of the eugenic efficacy of this method, because the ethical evaluation of a eugenic abortion is, for the biologist, identical to that of any other abortion, since it results from the knowledge that every embryo is already an individual: an individual in one of the stages of the development of its individual life. Indeed, Ontogeny tells us that an individual passes through different stages: embryonic, infantile, juvenile, adult and senile. The passage from one stage to another does not imply either the loss or the acquisition of the condition of an individual, constituted as such from the training of the zygote. Obviously, an old man did not cease to be an individual when he lost his genetic capacity. Nor does an embryo acquire this status when it leaves the protection of the uterus at birth. At three weeks after conception, the heart, already constituted, beats; at one month the arms, legs and head are outlined; at two months it has hands, feet, head, organs, brain, and the folds of the hand can be seen, so that it could be cast in good fortune, and with a microscope it could even be identified by its fingerprints. But a newly formed zygote is no less an individual of our species than a two-month-old embryo. This does not lose biological validity if the individual is diseased or malformed, because malformation or disease does not deprive it of the status of an individual of our species. The modern molecular Genetics has informed us that the zygote already contains in its DNA all the information by meeting of the 3.3 x 10 to the 9th pair of instructions of the DNA of each gamete; that immediately after this programme is constituted, its execution begins; and that, from the biological point of view, the life of an individual is the execution of this programme. So it is false to point to the beginning of the human condition at birth, at 28 or 20 weeks, or at any other time than conception.

The biologist has an important duty to spread these scientific truths among other members of society, because many slogans exploit the biological ignorance of the general public, and even of the ruling classes, in order to overcome the innate repugnance towards abortion: "a woman's right over her body", "women's liberation", "the risks of clandestine abortion", "status of the raped woman", "social inequality", etc. If one looks at these slogans one by one, one notices that they include the denial or falsification of these scientific truths, and they lose all their argumentative force when they are known.

c) grade ethics of the eugenic measures described above

It is clear that the eugenic measures referred to so far are unlawful, not because of the aim they pursue - to improve human offspring - but because of the implicit errors they impose on internship and the unlawfulness of the means they employ. As far as artificial fertilisation with "selected sperm" is concerned, it dissociates reproduction from the bodily union between the parents. As for the prohibition of marriage, it is contrary to the dignity of the person, to his or her freedom, and to the natural right to marry and have children; sterilisation, whether compulsory or voluntary, is unlawful, since man is not the absolute master of his own body or that of others. And abortion, which constitutes the most violent form of oppression by denying the freedom of a human life, is clearly unlawful.

Ethically lawful eugenic measures

Among these measures is information about risks to possible future offspring. First of all, the information that can be given to a couple wishing to marry. The premarital medical visit Genetics should be aimed at informing and making those wishing to marry aware of their responsibility. But no one can assume the function of deciding for the persons concerned, since marriage is a right of the individual, and it is the duty of the individual to weigh up the possible eugenic risks. Secondly, it is also legitimate to inform parents of the risk of having a morbid offspring. To inform, that is to say, to give them the elements of judgement, in case they decide to prevent the possibility of future pregnancies, either by total continence or by periodic continence during the agenic periods (Ogino or Billings method). This information has been said with regard to future pregnancies, because with regard to an ongoing pregnancy, the only information that the geneticist can give is that the existing embryo is a human individual whose life must be respected.

It should be noted that the information Genetics matrimonial and premarital is usually not scientifically correct. The genetic committee comprises three aspects: diagnosis of the existing disease in relatives, prognosis of the occurrence of the disease in the subject or in possible descendants - if possible expressed numerically - and the communication of the answer to the questioner. Logically, the determining factor is the precise prognosis of the risk, and today we do not know all that is necessary to give this prognosis with full guarantee.

Getting to eliminate or actually decrease the frequency of deleterious genes in the human gene pool is a major challenge for scientists.

Given the current state of the art in DNA recombination and gene transfer techniques, it is to be hoped that in about 30 years it will be possible to introduce, thanks to a suitable vector, a normal gene to replace the deleterious gene and thus correct hereditary defects of mono-factorial control, and that this will be possible in a way that respects the dignity of the person and the reproductive act.

In addition, the ongoing programs of study work on centromere regulation will make it possible to avoid nondisjunction phenomena, which are the cause of many genetic alterations.

Above all, it will be possible to prevent further increases in the mutation rate. Mutations can be genetic - changes in the molecular structure of DNA - or chromosomal. Normally, individuals who have undergone them, those heterozygous for translocations, etc., have reduced fertility despite being phenotypically normal. The causes of spontaneous mutation are known: a small part of the natural mutation is caused by natural radiation, due in turn to cosmic radiation, radiation from soil elements and natural radioisotopes; the rest of the mutation is caused by added radiation, as shown in the following table sample :

The rem is equivalent to the action of a Roentgen.

The radiation added to the natural radiation is a fraction of approximately half. Of the added radiation, expressed as a percentage of the natural radiation, 45% is due to X-ray diagnosis; 8% is due to the atomic bomb; 2% is due to scientific research ; 1% is due to nuclear power plants; and 0.5% is due to X-ray therapy. In other words, the added radiation is mainly due to X-ray diagnosis, which accounts for 3/4 of this radiation.

What effects does radiation have on the production of mutations? The cumulative radiation per generation is thought to be approximately 5.4 rem, and may increase by 1 or 2 rem. But, also, great care is being taken not to increase it; it could reach a radiation per generation of about 7 rem. Individuals working in atomic power plants can reach a cumulative radiation of up to 200 rem.

The consequences of an increase of one rem per generation could be calculated in the case of translocations and aneuploidies. Of the 43,558 live-born individuals examined, result found that the frequency of de novo structural alterations was 23. The mutation rate would be 23/(2 x 43,558); this gives the proportion of gametes in which a de novo mutation has occurred.

From experience with mice it is known that the chronic radiation dose which would be capable of doubling the mutation dose is 93 rem, received chronically, not acutely, i.e. throughout the generation, because if it is given abruptly, instantaneously, only 30 rem are required. The effect of one rem will be: 1/93 x 23/2 x 3,558 =2.8 x 10 at -6.

As a result of 1 rem radiation, 2.8 mutated gametes would be produced for every million gametes. In other words, out of every million individuals, 5.6 would show this alteration as a consequence of having increased the added radiation dose by 1 rem.

Currently, there are about 500 structural alterations per million. Therefore, the increase in radiation would only affect an additional 5% of individuals. Since mice are more sensitive to mutation, this percentage would be somewhat lower in humans. Therefore, although there is no cause for alarm, some vigilance and appropriate measures for radiation-induced mutability risks, such as protection staff, surveillance in facilities, and monitoring of mutation frequencies in the population, are necessary. To prevent reproductive cell disruption, radiation for diagnostic purposes should also be avoided in both males and females from eight weeks before conception, as well as in the first weeks of pregnancy. As for chemical mutagens, the fifth month of pregnancy is critical, as the embryo is most sensitive to them.

It is also of interest not to delay the onset of childbearing, since the older the mother, the greater the risk of nondisjunction, and the older the father, the greater the risk of gene mutations.

d) Cultural enhancement versus enhancement Genetics

By eugenics we mean the environmental control of the manifestation of the hereditary heritage that advances in the development of Phenogenetics will make increasingly effective. Culture is part of the human environment. This is why we can contrast with Beadle the improvement Genetics with cultural improvement. We are the only species that complements biological inheritance with cultural inheritance, 90% of which has accumulated in less than 1% of our species' time on earth. When one realises that it is theoretically possible for our species to revert, in a single generation, to the barbaric state of hundreds of thousands of years ago, and, in a second generation, to revert the whole process again, assuming a suitable mechanism, one immediately concludes that it is much easier and safer, and enormously faster, to raise the cultural level of our species than to change its composition Genetics. That is why I advocate," says Beadle, "that our efforts should be concentrated on improving our cultural heritage, at least for the foreseeable future.

Notes

(1) The overdose of responsibility - the universal responsibility - so characteristic of today's scientific world is evident in these concerns. Our responsibility as scientists is concrete and determined. We are not answerable for all the consequences of every act and every omission. There is no universal responsibility for the future of the human species over and above attention to the specific individual, today, with the knowledge available to cure him or her. N. López Moratalla.