GENETIC SCREENING

Abstract

Human, as a species, is very variable, and his variability is at the basis of his social organization. This variability is maintained, in part, by the chance effects of gene assortment and the variation in these genes is the result of mutations in the past. If our remote ancestors had not mutated we would not he here; further, since no species is likely to he able to reduce its mutation rate substantially by the sort of selection to which it is exposed, we may regard mutations of recent origin as part of the price of having evolved. We are here: all of us have some imperfections we would wish not to have, and many of us are seriously incommoded by poor sight, hearing or thinking. Others among us suffer from some malformation due to faulty development. A few are formed lacking some essential substance necessary to metabolize a normal diet, to clot the blood, or to darken the back of the eye. We will all die and our deaths will normally be related to some variation in our immu­nological defences, in our ability to maintain our arteries free from occlusion, or in some other physiological aptitude. This massive variation, which is the consequence both of chance in the distribution of alleles and variety in the alleles themselves, imposes severe disabilities and handicaps on a substantial proportion of our population. The prospects of reducing this burden by artificial selection from counsel­ling or selective feticide will be considered and some numerical estimates made of its efficiency and efficacy.