[Paleopsych] Plausible Futures: Conservative Eugenics and Human Evolution

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Conservative Eugenics and Human Evolution
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4.9.14
[Thanks to Ole Peter for finding this.]

    Crow's essay (1966) on "The Quality of People: Human Evolutionary
    Changes" posed a number of important problems concerning the
    evolutionary future of the human species. Particularly important are
    the problems resulting from the slow increase in frequency of mutant
    genes in human populations which must inexorably follow in the most
    obvious democratic and humane termination of the population explosion.

    Leonard Ornstein
    Mount Sinai Graduate School of Biological Sciences
    Editor's Note: This article appeared in a somewhat different form in
    the Bulletin of Atomic Scientists, (Ornstein, 1967). The editors of
    BioScience asked Dr. Ornstein to allow its publication in this journal
    as well because they felt it deserved the attention of a larger
    audience of biologists.
    Among knowledgeable biologists, much confidence is placed in our
    current understanding of the broad outlines of the evolutionary
    process in populations of sexual organisms. Evolution is seen to
    result from the interplay of the genetic endowment of the members of
    an interbreeding population with that population's environment.The
    genetic endowment is continuously subject to recombination as a result
    of processes associated with sexual reproduction. Occasional random
    physical rearrangements, duplications, etc, provide opportunities for
    linking together of especially adaptive recombinations. Rare random
    point mutations of the coded genetic message provide the seeds for
    adaptive inovation. Those mutations and rearrangements that provide
    their carriers with some adaptive advantage will, on the average,
    gradually replace the parental stock. Those mutations which, on the
    average, confer a selective disadvantage to their carriers are
    generally eliminated--or held at a low incidence--in competition with
    the parental stock. Thus, evolution results from balanced interaction
    of random mutation and selection (Dobzhansky, 1951).
    In the absence of mutation, a non-human species would ultimately be
    expected to become extinct if its fixed genetic resources were
    inadequate to permit it to adapt to the kinds and magnitudes of
    environmental changes to which it might be exposed to over periods of
    millions of years. In contrast, man, with his unique ability to revamp
    his environment, now depends upon cultural and technological mutations
    to provide even greater plasticity for coping with natural
    environmental change than that provided by the adaptive innovations
    which are sparked by random genetic mutation. Therefore, the absence
    or elimination of mutation in humans need not constitue a biological
    threat.
    In the absence of selection, however, any species (including Homo
    sapiens ) would be expected to degenerate gradually through a process
    closely related to genetic drift (Dobzhansky, 1951). The resulting
    increasing accumulation of mutations would produce wider and wider
    departures of the individual phenotypes from one another and from the
    parental type. The mechanism is quite simple. The overwhelming
    majority of mutations which occur in a selective environment are
    deleterious and are therefore eliminated, tending to keep the
    population relatively monotypic. Selection plugs the multiple leaks
    that are forever occuring in the genetic dyke and channels the flow of
    life thermodynamically uphill along adaptive paths. In the absence of
    selection, the dike would slowly crumble and the flow would dissipate
    down a multitude of exentropic gulleys, producing a vastly refashioned
    species. The only directions or styles that would be apparent in this
    kind of evolutionary process would be those which reflect changes in
    those genetic code words which for whatever reasons, mutate at the
    highest rates--and these mutations will almost always represent
    phenotypic departures from the parental type. And later generations of
    mutations would represent still further departures from this more
    heterotypic base.
    Now what can reasonably be meant by "in the absence of selection"? If
    death were eliminated and fertility maintained indefinitely, there
    would be, at least initially, no selection--however, in an extremely
    short period of time, a species would exhaust any "real" environmental
    resources--and this hypothetical kind of "elimination of selection"
    thus would be too short-term to be relevant to our present discussion.
    But there are two other ways to eliminate selection: (a) a mechanism
    which maintains a stable population size, in the presence of random
    fluctuations of fertility, by random elimination of offspring,
    independent of the genetic endowments of the individuals; and (b) a
    mechanism which maintains a stable population size by uniformly and
    randomly limiting fertility of individuals, independent of their
    genetic endowment.
    If the elimination of offspring occurs before birth (e.g., abortion
    and some forms of birth control), it is essentially equivalent to a
    limitation on fertility, or what is commonly called birth control.
    With this frame of reference, we will now consider two facts of life
    which, although in and of themselves are quite encouraging from a
    humanistic point of view, nonetheless conspire to generate the next
    great threat to humanity.
    There is a growing agreement that some form of birth control will
    provide the only reasonable solution to the population explosion and
    the limited resources of our planet. All efforts to increase food
    production to relieve, at least temporarily, population pressures
    should be encouraged. But no one supposes that exponential population
    growth can be matched by food technology. Therefore, in the long run,
    enthusiasm for such efforts is not likely to be permitted to reduce
    attempts at population control. Those who divert attention from the
    real and pressing problem by appeal to science fiction--expecting "to
    reap the resources of the universe"--will hopefully soon begin to
    appreciate the sobering cost estimates of even a trip to a nearby star
    (von Hoerner, 1962).
    The ranks of those who at least pay lip service to the principles of
    equalitarianism and classless or open-class societies are swelling
    rapidly both within bona fide democracies and in major totaitarian
    states. It seems not only undesirable from a humanistic point of view
    that this trend should be reversed, but reversal is also unlikely.
    The expected solution, if any, to the population explosion therefore
    will probably involve the almost universal application of birth
    control and voluntary (although socially and/or economically rewarded
    or coerced) individual commitment to the maintenance of a reproductive
    rate of two offspring per pair of adults, independent of the genetic
    (or other) endowment of the parents. If such a program is successful
    in maintaining a stable population and avoiding racial, class and
    individual biases in the rates of reproduction (and therefore in the
    composition of future generations), the human species may eliminate
    selection and thus be on the road to ultimate biological degradation
    and probable extinction!
    Is there a democratic way out? Lederberg (1966) has stated that "It
    would be a tour de force to demonstrate any change (increase) in the
    frequency of a specific harmful gene in a human population that could
    be unambiguously traced to relaxation of natural selection against it.
    In comparison to the pace of medical progress, these exigencies are
    trivial." Crow also has pointed out that "An increase incidence [of
    homozygotes for a rare recessive harmful gene] of 2% per generation
    would mean about 40 generations for the incidence to double. This is
    more than a thousand years. The genetic consequences of the successful
    treatment of diseases caused by rare recessive genes are slight." The
    tone of such remarks is calculated to lull the reader into a state of
    evolutionary complacency. Yet, on the following page, Crow's tone
    turns. "However, I must introduce two cautions in this perhaps
    over-optimistic discussion of simple examples. One is that the
    increase is geometric, not arithmetic, and over a long period will
    become important" (itallic supplied).
    Effective tools for recognizing the human cariers of recessive genes
    (the great majority of new mutations are recessive and harmful) have
    only been discovered within the past few years. Changes in the
    frequency of such genes due to mutation in large breeding populations
    (the human population now is effectively a very large breeding
    population) occur very slowly. Therefore an extremely large random
    sample of each of two successive generations would probably be
    required to demonstrate a change unambiguously. Lederberg's first
    statement is therefore correct.
    His second statement, however, requires more careful examination.
    "Trivial" by what standards? Examine the case of a disease such as
    diabetes. Assume that diabetes is due to a recessive gene in the
    homozygous state. Prior to the discovery of insulin, a large fraction
    of diabetics died before reaching sexual maturity (or soon enough
    thereafter to lower the probability of the survival of their
    offspring). The human efforts, in terms of research and medical care,
    and the economic and other social costs of the production of drugs
    which control diabetes clearly are trivial when compared to the
    suffering of millions of diabetics and their families that was endured
    before the development of such drugs. Medicine has, in this case,
    effectively begun to neutralize the harmfulness of diabetes genes.
    Their frequencies and the frequency of afflicted carriers will
    therefore automatically increase among future generations due to
    unapposed mutation pressure (Dobzhansky, 1961). In a similar way, eye
    glasses, artficial kidneys, and all the devices, transplants, and
    drugs of the coming euphenic revolution will reduce or eliminate the
    harmfulness of many genes. But the genetic base from which harmful
    mutations arise has until now been kept relatively homogenoeous by
    selection. Therefore, the numbers and kinds of mutations that at
    present can occur are constrained by the homogeneity of that base. As
    this special variant of genetic drift slowly takes over, the base will
    become more and more heterogeneous, and euphenic correction of each
    new mutation will become more and more a problem of the custom
    engineering of individual medical or biochemical crutches or
    prostheses. Insulin solves the problem of a very large number of
    diabetic individuals and the social cost per individual is very
    small.*
    *The production of insulin has been coupled with, rather than
    competitive with, food production. It is, however, perhaps instructive
    to note that until very recently, the maintenance of an average
    diabetic over a 30-year period required the production and destruction
    of about 1000 head of cattle.
    This is likely to gradually become less and less the case for the
    correction of newly arising mutations. It may not be possible to
    predict, with any accuracy, the relative rates of progress of medical
    and euphenic research as compared to the rates of increase of problems
    with which medicine will have to deal as a result of the elimination
    of selection. In the short run, the benefits from the development of
    crutches will clearly outweigh the costs, but in the long run (and how
    long is problematical) the costs are likely to become prohibitive. It
    takes little effort to conjure up glimpses of the bizarre brave new
    world--a world of enormous individual variability, each individual
    (human?) uniquely wired up and supported by his own special set of
    transplants and external biochemical plant. A glimpse into a
    relatively modern hospital will convince one of the rapidity with
    which this vision is being realized at present, although admittedly
    for a relatively tiny fraction of the world population. But later, a
    major portion of technology and virtually all of society's resources
    would be consumed by that technology. An individual that would be
    recognizable as a member of Homo sapiens would be rare indeed. Are
    such exigenicies "trivial"?
    The cultural relativist might argue that provided such a culture does
    not exhaust its resources in trying to keep itself alive, its values
    and way of life may be just as good for its members as ours are for
    us. I would counter that if we can now, by judicious planning, provide
    greater adaptive flexibility and fewer biological and economic burdens
    for our descendants, as judged by our standards of value, then we
    cannot entertain the relativist's rationalization with a clear
    conscience.
    What alternatives exist? Lederberg (1966) states "Eugenics is
    relatively inefficacious since its reasonable aims are a necessarily
    slow shift in the population frequencies of favorable genes" (italics
    supplied). He and others (e.g., see Dobzhansky, 1962) have rightly
    emphasized the problems of defining "favorable" genes in our present
    state of genetic ignorance. The problems of defining "unfavorable"
    genes may often be equally difficult. If the genes for schizophrenia
    were responsible, in the heterozygous state, for attributes of the
    kind of intelligence which we believe we value, eugenic attempts to
    reduce the frequency of schizophrenics from their present levels of 1%
    to 2% might reduce average intelligence of the population as a whole.
    This might produce an undesired and unexpected by-product which would
    outweigh the desired reduction in human misery and in the social
    burden that elimination of schizophrenia should represent. Would
    schizophrenia genes average out as favorable or unfavorable? And would
    we want to increase or decrease their frequency? Because of the
    difficulty in defining "favorable" genes as well as "unfavorable"
    genes, I question Lederberg's implication of the absence of other
    reasonable (short-term, i.e., within the next 10,000 years?) aims of
    eugenics.
    In discussing the evolutionary process, Crow reminds us "...that for
    many, and probably most traits there is little selection toward
    systematic change in a fixed direction. Most natural selection is not
    changing things. Rather it is acting to remove deviants in both
    directions from the mean, or adjusting to fluctuations in the
    environment, eliminating recurrent harmful mutations, or maintaining
    polymorphisms. Considerable selection is needed to maintain the
    genetic status quo, even without any progressive evolutionary changes"
    And later on he asks, "...must we soon begin genetic steps if the
    human phenotype is not to deteriorate? And should we be content merely
    to keep ourselves from getting worse?"
    I believe we must begin by being "content merely to keep ourselves
    from getting worse," and that perhaps the only reasonable short-term
    and conservative aims of eugenics, taking into account the impending
    reduction in natural selection and our present state of ignorance of
    human genetics, are: (1) the approximate maintenance of the present
    distribution of gene frequencies and frequencies of "linked"
    combinations of genes, and (2) the reduction of the frequency of those
    rare mutations which clearly confer severe phenotypic disabilities
    that are not easily compensated by present medical technology. Such
    conservative aims should be vigorously pursued, provided that the
    individual and social costs are not excessive.
    If we had methods for decoding and reading the complete set of genetic
    messages of each and every individual and for recording this data in a
    central computer file, it would be possible, in principle, to examine
    the message sets of any two prospective mates to compute
    recommendations as to the number of offspring they should have in
    order to help to contribute to the maintenance of the genetic status
    quo. For most couples, the recommended number of children would be
    two; for many, one or three; and in rare cases, none or more than
    three. As Crow (1958) previously demonstrated, variances in
    reproductive rate of this sort can provide very "considerable
    selection". The computer would be programmed to take past frequencies
    of both intentional and accidental departures from the recomended
    values (continuously updated from birth records) into account in
    formulating recommendations. Some such program of conservative
    eugenics is probably the only kind of eugenic program that would have
    a chance to start to function successfully in democratic societies.
    Some reasonable eugenic measures have begun to be put into effect to
    hold down the frequencies of rare genes that produce severe
    disabilities. Those with the highest natural mutation rates pose the
    greatest threat, and it is just those which tend to be among the first
    to be singled out for attention. This is the kind of genetic
    counselling program to which informed and humane physicians are often
    privately committed.
    It is clear that the evolutionary process itself has selected, in some
    cases, for reduction of effective mutation rate to compensate for
    increase in generation time and decrease in number of offspring per
    mating. We are now beginning to understand something of the workings
    of some mutation-rate control mechanisms such as excision of
    nucleotide codons which constitute coding errors and replacement with
    correct codons (using an unmutated complementary strand as a model?).
    Increased redundancy in the genetic code (e.g., polyteny and
    polyploidy and gene duplications) may have provided natural means for
    reduction of effective mutation rates through the action of such
    genetic reading and editing mechanisms. And in so far as we can
    discover artificial means to reduce natural mutation rates, the rate
    of genetic drift can be slowed.
    New high-resolution electrophoretic techniques for the separation of
    proteins (which are the direct translation of genetic messages) and
    techniques for fingerprinting of the peptide digests of pure proteins
    begin to permit us to collect significant amounts of data on gene
    frequencies. These techniques more often than not permit the
    identification of heterozygous carriers of otherwise pheotypically
    recessive genes. Routine cataloguing of the accessable proteins of
    blood cells and serum and other body fluids of each individual (to be
    followed up later by routine analyses of the proteins of samples of
    tissue biopsies or cultures from such biopsies) will begin to lay a
    foundation for the kind of genetic analyses of human populations that
    is required to guide conservative eugenics.
    Although the pace of genetic drift in large populations is initially
    very slow, the development of the kind of biomedical
    information-retrieval system and genetic decoding techniques required
    to stem the tide of drift may also be very slow, and attempts to
    discover practical means for reducing mutation rates may be even
    slower in reaching fruition. Therefore, the sooner a very much more
    substantial social commitment is made to the pursuit of such ends,
    including making adequate genetic education a required part of all
    high school curricula, the more secure will be the future of humanity.
    Removing the spectre of suicide by nuclear, chemical, or biological
    warfare and putting a damper on the population explosion (which
    includes world-wide democratic application of birth control and the
    elimination of poverty) come first and second on my personal list of
    social priorities. Attending to our evolutionary future comes a very
    close third. Learning to live with leisure and computers follows. A
    1000 BEV Alternating Gradient Synchnotron, trips to the moon and
    planets, listening for messages from outer space (Project OZMA), etc.,
    all seem trivial by comparison. As for large-scale application of
    "algeny" and positive eugenics to the improvement of mankind, I
    believe, with Lederberg (1966), Dobzhansky (1962), and Hotchkiss
    (1965) that these must wait at least until we are both technicallyt
    more proficient and genetically vastly more knbowledgeable.
    References Crow, J.F. 1958. "Some possibilities for measuring
    selection intensities in man" Human Biology, 30: 1.
    Crow, J.F. 1966. "The quality of people: human evolutionary changes".
    BioScience, 16: 863-867.
    Dobzhansky, T. 1951. Genectics and the Origin of Species. Columbia
    University Press, New York.
    Dobzhansky, T. 1962. Mankind Evolving. Yale University Press, New
    Haven, Conn.
    Hotchkiss, R.D. 1965. "Portents for a genetic engineering". J.
    Heredity, 56: 197.
    Lederberg, J. 1966. "Eperimental genetics and human evolution". Bull.
    Atom. Sci., 22: (10) 4.
    Ornstein, L. 1965. "Subnuclear particles: a question of social
    priorities". Science, 149: 584.
    Ornstein, L. 1967. "The population explosion, conservative eugenics
    and human evolution". Bull. Atom. Sci., 23: (6) 57.
    von Hoerner, S. 1962. "The general limits of space travel". Science,
    137: 18.
    ------------------------------------------------------
    1997 Postscript:
    Thirty years later, the above arguments about the priority that
    Conservative Eugenics deserves still hold.
    In the interim, the gel electrophoresis methods which I co-invented
    have been successfully extended (by others) to the resolution of
    nucliec acid fragments that differ by single nucleotides, and serve as
    the main analytical tools for reading the genetic code. The
    multi-year, 3-billion dollar Human Genome Project is well on the way
    to sequencing the "complete set of human genetic messages" and the
    first generation of the required kinds of computers and computer
    programs to do the job already exist. To make execution of my
    recomendations practical will require methods that reduce the
    3-billion dollar cost by about five more orders of magnitude, and the
    years to at least days, that appears feasible to me within the
    life-time of the next few generations. It hasn't been my priorities
    that have driven this revolution, but curiosity and the wide-spread
    belief in the power of the new technologies for euphenic (mainly
    medical and agricultural) applications and the possibilities for "gene
    repair" (algeny). But for the long run, conservative eugenics still
    warrant the higher priority.