January 5, 2014

Evolution in reverse

There is nothing encouraging or uplifting in the case I am about to make. I think it reflects reality, but I take no pleasure in it.

Throughout most of human history the great majority of people lived and died pretty much as any other animals lived and died. Prior to the industrial age civilization produced only the thinnest surplus of food and goods, and the population ebbed and swelled as that surplus (primarily the food surplus) ebbed and swelled. While humans lived a bit more comfortably than most other animals, the factors that determined both the survival and reproductive success of other animals were nearly as decisive for human beings. We died of the combined effects of hunger and disease. We were prolific in proportion to our health and our capacity to provide sustenance for our offspring. The merciless engine of natural selection culled the weakest and least adaptable members from the human population, just as it might thin a herd of African wildebeests in a bad year. This, to the best of my ability to determine such things, is a plain, historical fact.

The state of medical care in pre-industrial times was a primitive one. To have access to a doctor of some sort improved one’s odds of surviving a serious disease only modestly. Many ancient treatments were as dangerous as the diseases they purported to cure. Thus, as in the case of hunger, people survived or succumbed to disease largely in proportion to the combination of their own genetic robustness and their particular nutritional circumstances. The blind hand of evolution acted on human beings more-or-less as it acted on all the other species in the animal economy. Perhaps we were special to one another, but we were not then – and are not now – given any special dispensation by the processes of nature.

In this broad biological context at least, Nietzsche was quite right – that which does not kill us makes us strong. Left in conditions of relative scarcity, natural selection breeds true the healthiest and most adaptable individuals in any population.

In pre-industrial times, some of the least fit human beings (those least exposed to normal evolutionary processes) were the people at the pinnacle of society – the royalty, and, to a lesser extent, the nobility. While I’m not aware of any systematic study of the health of royal families relative to the rest of the populations of their respective countries, there are plenty of examples of European rulers from the Roman era through the early 20th century who were subject to all sorts of genetic liabilities. The spastic emperor Claudius, a host of frail or feebleminded kings and emperors, Kaiser Wilhelm with his withered arm, and the hemophiliac heir to the Russian throne are but a few examples. Inbreeding can account for some of these problems, but it cannot be ignored that these were all people who were well fed on the best available food, lived in the most comfortable accommodations, and were the least prone to suffer lethal consequences from their infirmities. The idiotic, half-blind son of a peasant might be deprived of adequate sustenance during a particularly desperate year, but the son of a King was a royal heir no matter how miserable and unfit he happened to be. His highest risk of death was probably from court intrigue of one kind or another – but that could as easily strike down the fittest as the least fit. Royalty were bred to fill political niches, and were protected, as much as was humanly possible, from the ordinary evolutionary pressures to which their subjects were exposed.

In industrial times, and especially in the 20th century, the eternal rules of the game have been gradually overturned. Consider the common problem of poor vision. Wearing eyeglasses isn’t even something we consider an infirmity now – yet in the middle ages being unable to see without an artificial aid would have been a major handicap. It probably wouldn’t have been fatal – typically, society would have found some work for the myopic – but, unless they were of royal blood, poor vision would have greatly reduced their marriage prospects. In traditional societies, the right to legitimately produce children was closely tied to the ability to take care of them. An infirmity like poor vision would have made a person a marginal worker, and therefore unattractive as a marriage partner. To the extent to which poor vision is a heritable condition, a kind of sexual selection would have repressed it. Families with myopic genes would have tended to produce fewer offspring. The cheap availability of eyeglasses from the 19th century on has, in practice, made poor vision common by making it not an immediate problem.

Readers with a knowledge of modern history will see where I am going here. In the late 19th and early 20th centuries, the eugenics movement made precisely the sort of argument that I have made above. The human impulse to be as charitable as possible toward individuals that a heartless natural world would weed out produces, after some number of generations, a real and predictable physical weakening of the species. As awful as this assertion sounds, I don’t see any way for an intellectually honest person with a general understanding of evolution by natural selection to refute it. One would need to have a magical belief, religious or otherwise, that the rules that govern the characteristics of all other species somehow don’t apply to us. To be clear, I am not advocating a renaissance of the old eugenics movement, with all of its biases and its appalling devolution into noxious race theories. I am asserting, rather, that the core thesis of the eugenics movement – that the weakening of evolutionary pressures weakens the human species in the same way that it would weaken any other species – is not only still valid but practically irrefutable.

Imagine a farmer who managed the care and breeding of his pigs in a way analogous to the way most industrialized societies prioritize the care and breeding of people. The farmer would adopt a sort of no-piglet-left-behind mentality with regard to veterinary healthcare. Piglets born with serious health problems would be given a maximum of care, and put into the reproductive pool to pass on their defective genes. Generation by generation, veterinary costs would increase as more and more unhealthy pigs were born and more and more interventions became necessary. Eventually, almost all the pigs in the herd would be dependent on artificial medical support to live at least tolerable piggy lives.

Thumbing one’s nose at evolution has consequences – as is amply shown by real examples of selective breeding. Animals bred for show – with exaggerated characteristics the breeders find appealing – are notoriously prone to health problems. Mutts are usually healthy dogs; Shar Pei require surgery even to open their eyes.1

I can think of no good way to get out of this dilemma – this conflict between compassion and the processes of nature. Negative eugenics, as practiced in the United States, Great Britain, and parts of Europe in the early 20th century is not a very endearing public policy. Under such a scheme, people’s genetic merits were assessed by order of the state, and those human specimens found most lacking were summarily sterilized. While I personally don’t get dewy-eyed about every low-functioning person’s right to make equally low-functioning copies of himself or herself, I do get quite nervous about the state impinging that deeply on anybody’s freedom. People who claim the right to decide whose genes are worthy and whose are not are prone to all sorts of abuses. The eugenics movement itself went rapidly from the goal of weeding out the worst physical specimens to the goal breeding ideal ones. Human beings are neither wise enough nor impartial enough to conduct such an enterprise benignly. If a society is willing to sterilize a person involuntarily it is hard to imagine any other individual rights such a society would long feel bound to respect. The Nazis, of course, engaged in the ironically named positive eugenics of killing first the mentally and physically handicapped and ultimately the deviant, the politically undesirable, the Gypsies, and the Jews. The counterforce of human compassion produced the inevitable backlash. After the horrors of the holocaust, the world, for the most part, turned uncomfortably away from eugenics for moral and emotional reasons. The broad argument of the eugenics movement has never been refuted scientifically – it has simply been made undiscussable by the specter of the gas chamber and the crematorium.

Recently, methods of correcting genetic problems at a cellular level have begun to become feasible. Currently, this would not correct a genetic defect in the individual who already has it, but would modify a gamete cell to prevent the disorder from occurring in an offspring. Perhaps this will solve the problem of genetic decline brought on by a more forgiving life, but there are reasons to be skeptical. First, practically all reproductive interventions are expensive. While such genetic manipulations would probably be cost effective in the long run, complex and expensive procedures would have to be paid for now by a healthcare system that is already overwhelmed with basic care. Such treatments, in the foreseeable future, will probably be restricted to those that can afford them. Were they made cheap, widely available, or even mandatory, there is always the concern that manipulations would not stop at eliminating disease per se. Were it possible, isn’t it likely some well-meaning planner would eventually ask the obvious – “Why not splice in the genes for certain desirable physical or mental traits as well? Or suppress certain undesirable ones?” What eugenicists of all stripes could only imagine accomplishing in many generations might soon be accomplished in only a few. A brave new world of perfectly engineered, monotonously similar semi-persons. Nazism – without the death camps. It is a near enough possibility to merit our concern.

In uncovering the facts of nature science is a powerful and useful tool. We shouldn’t delude ourselves, though, that it illuminates nothing but the sunny path to a better and better world. As often as not, the practical application of our knowledge alleviates one form of suffering only to produce another.


1 An argument, incidentally, against misguided notions of racial purity.

3 comments:

  1. “The human impulse to be as charitable as possible … produces, after some number of generations, a real and predictable physical weakening of the species.”

    How do you measure weakness? By the ability of a human to survive naked in a jungle?

    Natural selection operates based on the suitability of individuals to their environment. When a family of beavers builds a dam, do you demand to know how well they would do without the dam?

    Poor eyesight is not much of a weakness now, because of the widely available corrective lenses you mention. Eyeglasses have made us less weak, even if your belief that a larger proportion of people have poor vision today than in the past is true.

    The distinctive characteristic that has made us so successful as a species is our big brains and resulting ability to invent. To count the fruits of this adaptation against us is tantamount to measuring our strength by wrestling alligators.

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    1. Consider a congenital heart defect that, if not corrected, will probably prove fatal before adulthood. It isn't hard to see that, given the presence of modern medicine, such a characteristic would not be selected against. So long a affordable modern healthcare exists, this is not a problem. However, it does make whatever portion of the public that carries those genes dependent on a certain standard of living. To the extent to which such conditions cannot be guaranteed, the defect is a real liability. No alligator wrestling required.

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  2. "A brave new world of perfectly engineered, monotonously similar semi-persons."

    It doesn't sound like you find this image very appealing. Why do you think everybody else would want to have monotonous, homogenous kids? Once blue eyes are the majority, won't brown be sexier?

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