The truth seems to be that the gene pool, as it exists now, supplies us with all the variability we need for the effective working of the evolutionary mechanism. That mechanism is functioning with such efficiency that broadening the gene pool cannot very well add to it, and if the hope of increased evolutionary efficiency were the only reason to tolerate man-made radiation, it would be insufficient.
The situation is rather analogous to that of a man who owns a good house that is heavily mortgaged. If he were offered a second house with a similar mortgage, he would have to refuse. To be sure, he would have twice the number of houses, but he would not need a second house since he has all the comfort he can reasonably use in his first house—and he would not be able to afford a second mortgage.
What humanity must do, if additional radiation damage is absolutely necessary, is to take on as little of that added damage as possible, and not pretend that any direct benefits will be involved. Any pretense of that sort may well lure us into assuming still greater damage—damage we may not be able to afford under any circumstances and for any reason.
Actually, as the situation appears right now, it is not likely that the use of radiation in modern medicine, research, and industry will overstep the maximum bounds set by scientists who have weighed the problem carefully. Only nuclear warfare is likely to do so, and apparently those governments with large capacities in this direction are thoroughly aware of the danger and (so far, at least) have guided their foreign policies accordingly.
SUGGESTED REFERENCES
Books
Radiation, Genes, and Man, Bruce Wallace and Theodosius Dobzhansky, Holt, Rinehart and Winston, Inc., New York 10017, 1963, 205 pp., $5.00 (hardback); $1.28 (paperback).
Genetics in the Atomic Age (second edition), Charlotte Auerbach, Oxford University Press, Inc., Fair Lawn, New Jersey 07410, 1965, 111 pp., $2.50.
Atomic Radiation and Life (revised edition), Peter Alexander, Penguin Books, Inc., Baltimore, Maryland 21211, 1966, 288 pp., $1.65.
The Genetic Code, Isaac Asimov, Grossman Publishers, Inc., The Orion Press, New York 10003, 1963, 187 pp., $3.95 (hardback); $0.60 (paperback) from the New American Library of World Literature, Inc., New York 10022.