The Life Sciences Recent Progress and Application to Human Affairs The World of Biological Research Requirements for the Future (1970) / Chapter Skim
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The Opportunities
The Opportunities
Pages 452-470
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From page 452... ...
Even medically advanced countries still experience different life expectancies and infant mortalities, and it is likely that at least a major share of the differences is the result of social differentials. It is regrettable that infant mortality in the United States still exceeds that in more than a dozen other advanced nations.
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From page 453... ...
Research directed at rational prevention of this process by simple means should markedly reduce or delay the incidence of coronary artery disease, aneurysms of the great vessels, and stroke. Death will still come to all, but the quality of adult life should be markedly enhanced as the onset of debilitating disease is delayed into the latter years of a prolonged life.
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From page 454... ...
Increased understanding of the genetic machinery and exploration of drugs that interfere with its operation or create a temporary diversion are our greatest hope of finding a rational basis for antiviral therapy, although there is, as yet, nothing to assure success. The most promising avenues of approach to the problem of cancer derive from the fact that a variety of neoplastic lesions in experimental animals are definitely associated with the presence of specific viruses in affected tissues.
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From page 455... ...
Artificial blood vessels made of synthetic tubing can serve as substitutes for defective natural vessels, and external artificial hearts can, at least for some hours, take over the pumping function of the inborn organ. And there is every reason to believe that each of these devices can be improved markedly in the future.
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From page 456... ...
For coronary artery disease, prevention and early therapy of atherosclerosis must surely be the more fruitful long-term approach. Moreover, a useful mechanical heart, responsive to body needs, offers more promise as a replacement for a seriously defective heart than does homotransplantation for the medium term, while avoiding the serious ethical problems occasioned by the latter procedure.
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From page 457... ...
Moreover, similar considerations must also apply to the dedication of resources to the care of nonproductive individuals as compared with that of potentially productive persons. Viral diseases of childhood, congenital malformations, hereditary disease, leukemias of childhood, endocrine dyscrasias, demyelinating diseases that strike young mothers, trauma, accidents, etc., all appear more worthy of attention than do the afflictions of advanced age.
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From page 458... ...
The example that we considered earlier, phenylketonuria, is a rare but serious inherited condition in which a specific enzyme, formed in the liver of normal persons, is not synthesized in the livers of affected individuals. A single gene, present in normals and absent or present in a defective mutant form in phenylketonurics, is responsible for the difference.
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From page 459... ...
Or, in a congenital malformation such as cleft lip and palate, plastic surgery can not only save the life of severely affected infants but also produce an esthetically acceptable appearance. Clearly, a euphonic solution has to be discovered separately for each untoward genetic effect.
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From page 460... ...
Early experiences, however, do more than condition behavioral patterns; they also profoundly and lastingly affect many biological characteristics of the adult. Events during the prenatal and early postnatal period condition the initial growth rate, maximum adult size, efficiency in utilization of food, resistance to malnutrition, to infection, and to other forms of stress.
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From page 461... ...
Most importantly, when environmental phenomena act adversely on the human organism in early life, their anatomical, physiological, and psychological effects are to a large extent irreversible; the fact that the various tissues and organs develop at different rates accounts for the existence of several critical periods in giving complete or partial irreversibility to responses that the developing organism makes to environmental forces. In the human species, the critical periods for the development of various mental capacities probably occur before 6 to 8 years of age and most critically during the first year, a phenomenon of great relevance to the determination of "intelligence" in different socioeconomic and ethnic groups.
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From page 462... ...
To yield the greatest scientific rewards, these models should use laboratory animals of known genetic and experiential history, observed throughout their life-spans and, preferably, for several successive generations. Such longitudinal studies will require appropriate animal quarters, extensive facilities for recording and retrieving information, and, possibly, a new type of scientific organization.
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From page 463... ...
on the characteristics of populations. These questions arise because there is generally an inverse relation between fertility and socioeconomic status, measured in terms of occupational status, education, or income, and because there are differences in the fertility of the major races of man.
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From page 464... ...
3. In the developed world, as birth rates have declined since the midnineteenth century, the inverse relation between socioeconomic status and fertility first became stronger and then weakened.
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From page 465... ...
Nevertheless, deliberate breeding practice has shown that a great amount of concealed genetic variation was present beneath the apparent unifo~ityvariation that enabled man to select for traits that appeared desirable. Such selection led to the establishment of cattle specialized for milk or for meat production, the astonishing manifoldness of races in dogs, and chickens high bred for egg-laying or for meat yield.
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From page 466... ...
Notwithstanding the complexity of genetic population dynamics, gross interference with natural conditions is clearly possible. It would not take many generations to breed Caucasians whose average adult body size is four feet or average Japanese of six feet.
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From page 467... ...
Careful selection of the mothers by an appropriate agency and subsequent inbreeding might, however, accomplish the goal of a "superior" breed of man exhibiting the criteria chosen, but this was not essential to Muller's suggestion since the loss of free choice diminishes the social acceptability of the scheme. A much more efficient and a most revolutionary way of selecting for specific human genotypes has been suggested on the basis of experiments with frogs and other amphibians experiments whose original purpose had nothing to do with plans for genetic selection.
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From page 468... ...
At the present moment of extremely dangerous population growth, social pressures are best directed to lower reproduction, in general, without qualitative considerations. But one day, when populations are stable, world peace is the norm, and man's social and political institutions are sufficiently mature to assure that biological understanding will not be utilized to perpetuate injustice or strengthen dictatorship but, rather, to expand human potential, man will be free to guide his own evolutionary destiny.
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From page 469... ...
Although the hypothetical production of multiple identical copies, discussed above, may become technically feasible, there can be no certainty that a given genotype, successful under one set of conditions, would be equally successful under different circumstances. The future of man is more likely to be rich and exciting, to progress to greater possibilities, by exploring the variety of the gene pool than by standardizing on some uniform Homo sapiens.
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