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017 - Conclusion · Percheron horse

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  Speaker 1: Section sixteen of the Genetic Effects of Radiation. This is
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  Speaker 1: a LibriVox recording. All LibriVox recordings are in the public domain.
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  Speaker 1: For more information or to volunteer, please visit LibriVox dot org.
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  Speaker 1: Read by T. R. Love of Pleasant Hill, California. The
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  Speaker 1: Genetic Effects of Radiation by Isaac Asimov and theodocious Dobzanski.
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  Speaker 1: Section sixteen conclusion, It is unrealistic to suppose that all
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  Speaker 1: sources of mad made radiation should be abolished. The good
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  Speaker 1: they do now, the greater good they will do in
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  Speaker 1: the future cannot be abandoned. It is, however, reasonable to
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  Speaker 1: expect that the present Nuclear Test Band Treaty will continue,
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  Speaker 1: and that nations such as France and China, which have
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  Speaker 1: nuclear capabilities but are not signatories of the treaty, will
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  Speaker 1: eventually sign It is also reasonable to expect that X
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  Speaker 1: ray diagnosis and therapy will be carried on with the
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  Speaker 1: greatest circumspection, and that the use of radiation in industry
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  Speaker 1: and research will be carried on with great care and
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  Speaker 1: with the use of ample shielding. As long as man
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  Speaker 1: made radiation exists, there will be some absorption of it
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  Speaker 1: by human beings. The advantages of its use in our
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  Speaker 1: modern society are such that we must be prepared to
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  Speaker 1: pay some price. It is not a matter of callousness.
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  Speaker 1: We have come to depend a great deal for comfort
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  Speaker 1: and even for extended life upon the achievements of our technology,
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  Speaker 1: and any serious crippling of that technology will cost us lives.
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  Speaker 1: An attempt must be made to balance the values of
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  Speaker 1: radiation against its dangers. We must balance lives against lives.
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  Speaker 1: This involves hard judgment. Those working under the conditions of
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  Speaker 1: greatest radiation risk in atomic research in industrial plants using
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  Speaker 1: isotopes and so on, can be allowed to set relatively
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  Speaker 1: high limits for total radiation dosages and dose rates that
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  Speaker 1: they may absorb with time with reasonable safety. But such
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  Speaker 1: rates will never do for the population. Generally. A relative
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  Speaker 1: few can voluntarily endure risks both somatic and genetic, that
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  Speaker 1: we cannot sanely expect of mankind as a whole. From
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  Speaker 1: fruit fly experiments, it would seem that a total exposure
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  Speaker 1: of thirty to one hundred rads of radiation will double
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  Speaker 1: the spontaneous mutation rate. So much radiation and such a
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  Speaker 1: doubling of the rate would be considered intolerable for humanity.
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  Speaker 1: Some geneticists have recommended that the average total exposure of
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  Speaker 1: heat human beings in the first thirty years of life
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  Speaker 1: be set at ten rads. Note that this figure is
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  Speaker 1: set as a maximum. Every reasonable method, it is expected,
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  Speaker 1: will be used to allow mankind to fall as far
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  Speaker 1: short of this figure as possible. Note also that the
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  Speaker 1: ten rad figure is an average maximum. The exposure of
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  Speaker 1: some individuals to a greater total dose would be viewed
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  Speaker 1: as tolerable for society if it were balanced by the
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  Speaker 1: exposure of other individuals to a lesser total dose. A
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  Speaker 1: total exposure of ten rads might increase the overall mutation rate.
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  Speaker 1: It is roughly estimated by ten percent. This is serious enough,
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  Speaker 1: but is bearable if we can convince ourselves that the
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  Speaker 1: alternative of abandoning radiation technology altogether will cause still greater suffering.
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  Speaker 1: A ten percent increase in mutation rate, whatever it might
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  Speaker 1: mean in personal suffering and public expense, is not likely
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  Speaker 1: to threaten the human race with extinction or even with
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  Speaker 1: serious degeneration. The human race as a whole may be
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  Speaker 1: thought of as somewhat analogous to a population of dividing
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  Speaker 1: cells in a growing tissue. Those affected by genetic damage
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  Speaker 1: drop out, and the slack is taken up by those
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  Speaker 1: not affected. If the number of those affected is increased,
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  Speaker 1: there would come a crucial point or threshold, where the
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  Speaker 1: slack would no longer be taken up. The genetic load
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  Speaker 1: might increase to a point where the species as a
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  Speaker 1: whole would degenerate and fade toward extinction, a sort of
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  Speaker 1: racial radiation sickness. We are not near this threshold now, however,
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  Speaker 1: and can therefore as a species absorb a moderate increase
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  Speaker 1: in mutation rate without danger of extinction. On the other hand,
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  Speaker 1: it is not correct to argue, as some do, that
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  Speaker 1: an increase in mutation rate might be actually beneficial. The
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  Speaker 1: argument runs that a higher mutation rate might broaden the
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  Speaker 1: gene pool and make it more flexible, thus speeding up
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  Speaker 1: the course of evolution and hastening the advent of superman brainier, stronger,
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  Speaker 1: healthier than we ourselves are. The truth seems to be
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  Speaker 1: that the gene pool as it exists now supplies us
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  Speaker 1: with all the variability we need for the effective working
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  Speaker 1: of the evolutionary mechanism. That mechanism is functioning with such
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  Speaker 1: efficiency that broadening the gene pool cannot very well add
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  Speaker 1: to it, and if the hope of increased evolutionary efficiency
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  Speaker 1: were the only reason to tolerate man made radiation, it
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  Speaker 1: would be insufficient. The situation is rather analogous to that
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  Speaker 1: of a man who owns a good house that is
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  Speaker 1: heavily mortgaged. If he were offered a second house with
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  Speaker 1: a similar mortgage, he would have to refuse. To be sure,
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  Speaker 1: he would have twice the number of houses, but he
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  Speaker 1: would not need a second house, since he has all
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  Speaker 1: the comfort he can reasonably use in his first house,
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  Speaker 1: and he would not be able to afford a second mortgage.
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  Speaker 1: What humanity must do, if additional radiation damages absolutely necessary,
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  Speaker 1: is to take on as little of that added damage
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  Speaker 1: as possible, and not pretend that any direct benefits will
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  Speaker 1: be involved. Any pretense of that sort may well lure
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  Speaker 1: us into assuming still greater damage, damage we may not
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  Speaker 1: be able to afford, under any circumstances and for any reason. Actually,
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  Speaker 1: as the situation appears right now, it is not likely
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  Speaker 1: that the use of radiation in modern medicine, research and
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  Speaker 1: industry will overstep the maximum bounds set by scientists who
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  Speaker 1: have weighed the problem carefully. Only nuclear warfare is likely
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  Speaker 1: to do so, and apparently those governments with large capacities
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  Speaker 1: in this direction are thoroughly aware of the danger, and
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  Speaker 1: so far at least have guided their foreign policies accordingly.
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  Speaker 1: End of section sixteen. End of The Genetic Effects of
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  Speaker 1: Radiation by Isaac Asimov and Theodosius Dobzansky.