Thursday, January 01, 2009

Antagonistic Pleiotropy

I’ve been thinking about this rather forbidding term ever since I ran across it in a book called Buddha’s Way Through Darwin’s World, by Charles Fisher (2007).  Now, in light of the Israeli attack on Gaza for the usual reasons of “security,” the term comes to mean even more.
            Antagonistic pleiotropy, or negative pleiotropy, refers to the phenomenon that occurs when a gene which confers an evolutionary advantage in one situation turns out to have negative effects in another. Fisher uses sickle cell anemia as his type case. In Africa, the gene that codes for sickle-shaped blood cells survives because it confers resistance to malaria, which is endemic. In the United States, however, where malaria no longer threatens survival, the gene’s negative quality emerges: it leads to sickle cell anemia among African Americans. Thus we have antagonistc pleiotropy, where a condition that promotes human survival in one circumstance becomes a malignancy in another.
            Fisher points to an even more vivid example of this phenomenon in the human taste for sugar. In the hunter-gatherer world where humans evolved, sugars were scarce, so our genetic attraction to them did not constitute a problem, but rather led us to needed carbohydrates and higher rates of survival. This situation pertained throughout most of human history. But when refined sugar became widely available, the human taste for sugar became problematic and even life-threatening. With no natural limit to our desire for sugar, suddenly the massive addition of sugars to all kinds of corporate-produced foods and beverages has in our time contributed to an epidemic of sugar diabetes, overweight children and all the ills attendant upon such conditions. Again, the genetic craving for sugar aids survival, but when it becomes an addiction to soft drinks and artificially enhanced “carbs,” it can turn deadly.
            Now we come to the human desire for “security.” We all have it, so one might say it is more or less innate or genetic. We all want to be secure from want, from attack, from untimely or painful or humiliating death, and that desire helps us survive. To be sure, this craving for security surely differs, not just between humans, but among human societies themselves. Some people seem to be natural risk-takers, willing to risk even death to live at a high pitch. Others seem more determined to construct their lives in a way that minimizes risk, minimizes any situation that could prove dangerous. Experience surely has something to do with it, especially where whole cultures are concerned, as does the era in which one lives. As someone who lived through both World War II and the Cold War, it seems to me that today’s Americans—with their exaggerated fear of aging and penchant for life insurance and a “nest egg”—worry more about personal security than ever. 
            What really sets the concern for security into high gear, however, are external events. Living through the Depression was one such event that never left those who went through its worst days. Saving every item that might one day be useful, and never wasting anything of value, are some of the results. In our time, the attacks of 9/11 have had a similar effect on today’s Americans. The retaliatory attacks on Afghanistan and Iraq (however mistaken), the huge industry that arose with the creation of the Department of Homeland Security, the willingness of many Americans to forfeit their constitutional rights to allow the government to spy on them and others, can all be attributed to this transformative event.
            In the same vein, the experience of the holocaust in Nazi Germany can be seen to have had a similar effect for most Jews. To the extent that they are able, most vowed that “never again” would they be reduced to such depths of vulnerability and humiliation and near-extermination. The flight to the newly-founded state of Israel was one manifestation of that “never again” thinking. The determination to make that state safe from all threats, whether real or imagined, became concretized in a state apparatus that built itself upon a military capability so fearsome that it could never be challenged. 
            It takes little thought to see that here is where the natural human urge to be secure can take a negative turn, can manifest in antagonistic pleiotropy. That is, circumstances have changed, the human population has changed, human technology has drastically changed. This means that where once the urge to be secure could mean “saving for the rainy day,” today it means being determined to earn so much money that one must be prepared to wipe out all competition, ethics be damned. Where once one simply saw the need to cooperate with one’s neighbors to be secure, today it can easily morph into rejecting all associations with the herd and colluding only with like-minded fellows hiding behind armed guards and gated communities. It also means that where once one prepared to fight off an attacker by arming oneself with a club or a sword or even a gun, today that urge very quickly escalates to devastating weapons and plans for their use that involve not merely defense but mass destruction and even annihilation.
            Both Israel and the United States of America have done precisely this. Not content with having the most advanced conventional weapons and the most bellicose policies aimed at their presumptive adversaries, both have amassed nuclear arsenals that can be unleashed, and that are meant to be unleashed on any enemy foolish enough to even consider a confrontation. During the Cold War, this meant that on more than one occasion, the nuclear warheads mounted on intercontinental ballistic missiles in both the United States and its perceived adversary, the Soviet Union, were placed on high alert. Thousands of such missiles could have been launched in minutes if given the proper signal. During the Cuban Missile Crisis, when Russian ICBMs were placed on the island of Cuba, that signal very nearly arrived, and the world came closer to an all-out nuclear conflagration than ever before. And the root of the crisis was the same human desire or demand for security raised to the level of mutually assured destruction.
            Perhaps the clearest modern instance of this condition pertains in today’s Middle East. Israel has, with American aid, made itself the 5th most powerful military in the world—this for a nation of about 5 million people. It has threatened war with virtually every Arab nation and fought and won wars with most of its neighbors, maintaining its occupation over the Palestinians it displaced with ever more brutal methods. It has refused to sign the Nuclear Non-Proliferation Treaty (NPT), instead using its scientific prowess to amass a nuclear arsenal that insiders have estimated to exceed 200 weapons, mounted on missiles capable of reaching anywhere in its part of the world. It has attacked the installations of neighboring nations such as Iraq and Syria, when it thought they were nearing the ability to build their own nuclear weapons. And most recently, it has several times threatened to attack Iran (a signatory to the NPT), not for having nuclear weapons, but for possibly nearing the point where it might be able to build one. Most ominously of all, its leaders have more than once publicly reiterated their determination to unleash those nuclear weapons if they felt sufficiently threatened.
            In short, we are now, all of us, in the realm of antagonistic pleiotropy where security is concerned. What begins as a biological condition that enhances survival—the inborn desire to be secure from want, from danger—has, in the nuclear age, transformed into a mania that threatens not only other persons or nations that appear dangerous to us, but huge swaths of the earth, and perhaps life itself. That is because though no one knows what would happen if thousands of thermonuclear explosions were to go off in a short period of time, the terms “chain reaction” and “nuclear winter” express the grim possibilities.
            In the end, whether humans can get control of this fundamental urge depends on belief. If you believe that humans can control their sugar craving, perhaps you will feel confident that the urge to be secure can also be brought within reasonable bounds. If you see nothing but disaster in the proliferation of not just sugars but many other technologies like plastic surgery and genetic enhancement and carbon-based energy, any or all of which threaten to swamp the human ability to control them, then you may not be so sanguine.
            In either case, it is time for us all to realize the larger truth, i.e. that the biological equipment nature has given us does not always and forever contribute to our survival. Indeed, what antagonistic pleiotropy tells us is something fundamental: the demand for perfect security is a chimera, an ultimately self-defeating illusion. That is because life is NOT perfection but incessant change; thus, perfection would mean stopping the process of change, and that would mean stopping life itself. Though we may yearn for perfection, for perfect security, even coming close to it would be a monstrosity—as the examples we have, Auschwitz, Hiroshima, Dresden, and now Gaza, should agonizingly demonstrate.
Lawrence DiStasi

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