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Good Enough - The Tolerance for Mediocrity in Nature and SocietyDaniel S. Milo |
The prevalence of insignificance makes postdocs perish like fruit flies
Significance arises only where a relationship is not due to chance. In these cases, the null hypothesis is refuted and an alternative hypothesis vindicated. Impotantly, the null hypothesis does not need to be proved; it is only refuted trough expriments demonstrating significant results. […] The fact that the overwhelming majority of results are insignificant proves the wisdom of the presumption of chance. The prevalence of insignificance also explains why postdocs end up perishing like fruit flies rather than publishing.
Scientists are supposed to presume the null hypothesis
The trouble is that biologists consider function rather than neutrality as the default state. They presume significance - selection - rather than chance, which in this case is mostly drift. This stance is unscientific. Scientists are supposed to presume the null hypothesis, which roughly postulates that every relationship is the result of chance unless proved otherwise. The burden of proving significance weighs on the scientist except in evolutionary biology, where significance is the starting point. In this field, the burden of proof lies with whoever argues that chances determines the emergence, morphology, and size of a particular trait.
Generality is the signal and uniqueness the noise
Fundamentally, neutraity helps us keep our attention on the case that matters most, which is the general case. Aristotle described the proper focus of science when he aserted that “the universal is more important than the perception of particular cases.” Yet biologists obsess over uniqueness, hence Romanes’s unheeded admonition that specific characters - traits that distinguish a species from its nearest relatives - are precious to taxonomists but may well be useless for the organisms themselves. The traits on which species boundaries are based need not be useful; the need only be nonlethal. Indeed, as I detail in Chapter 7, the most useful traits tend to be those shared by many species, those that have proven their value to survival and reproduction across geological time and thus have persisted through bottlenecks. Generality is the signal - the selected - and uniqueness the noise. For evidence, we might look to our own eyes and genomes and fingerprints. Every human iris has its special patterns of colors, every genome its unique contents, and every fingerprint its singular topography of ridges and valleys. These signatures are useful to criminal investigators and designers of biometric passwords; they are biological indicators of the individual and no one else. All useful traits resemble each other; each neutral trait is special in its own way.
Nineteen tails in a row may still be due to chance?
The textbook example of the null hypothesis is the flip of a coin. Each coin flipped has a fifty-fifty chance of landing on heads or tails. According to the lat of large numbers, one has to repeat the flip many times in order to achieve the expected 1:1 ratio of heads to tails. How many times? The consensual number, twenty, was theorized by the statistician an geneticist Ronald Fisher. According to Fisher’s significance level, nineteen tails in a row may still be due to chance, but twent signifies a loaded coin. In experimental science, results obtained twenty times are said to be signfiicant, refuting the null hypothesis.
Aversion to neutrality is also embedded in language
Aversion to neutrality is also embedded in language. In Enlish, neutrality is expressed through the cancellation of other states. One may be nonaligned, disinterested, detached, unbiased, asexual, indifferent, or impartial. In this way, neutrality is coded as exceptional rather than normal. The normal state is one of preference or tendency, and neutrality is its negation. Linguists would describe neutrality as marked, which is to say uncommon, while the absence of neutrality is unmarked.
A universal theory is dubiously derived from an extreme case
If archipelagos are not nature simplified but rather nature in exceptional form, then the Galápagos is the exception to beat all others. Although situated in an equatorial region, the Galápagos archipelago has an exceptionally harsh climate. It is a kind of tropical desert - nothing like lush mainland Ecuador. Darwin notes in his Journal of Researches, “This archipelago, instead of possessing ahumid climate and rank vegetation, cannot be considered oherwise than exremely arid.” In average years, only the highest altitudes of the larger islands receive enough rainfall to support tropical life. The littoral and inland areas of the islands are classified as “arid” and “very arid” and are covered by brown and gray vegetation. Rainfall also varies considerably with altitude, between islands, and over time. Such conditions foster competition, the backbone of natural selection. One millimeter of beak length might be a question of life and death on the Galápagos’s lava, but two meters of neck length are negligible in the African savanna. A universal theory is dubiously derived from such an extreme case.
The Galápagos archipelago is unique
The finch, it turns out, is a good model for the study of natural selection, but this does not mean that the evolution of its beak followed a typical, much less unbiquitous pathway.
No lone road to the promised land
Alongside the numerous Galápagos species that did not stimulate Darwin’s genius, even the finches demonstrate D’Arcy Thompson’s dictum, announced in this book’s epigraph, that there are many paths to survival. Some were traced by darwin and his acolytes, some by Romanes, some by other theorists. Perhaps some have not yet been imagined or discovered. Nature may follow one or another of these paths more frequently, but none is the lone road to the promised land.
Alternative pathway of evolutionary biology
So Mendel got lucky, too. Had he continued with mice, he would not have been able to understand the genetic basis of the experimental outcome. But genetics would have been the same because Mendel’s laws, being universal, would have been discovered by others. In fact, they were - thirty-five years after he first presented his findings. The same is probably not true of evolutionary biology. If Darwin had not stumbled onto the finches, evolutionary biology would likely have taken another course: one less selectionist and less prone to the fallacies of the domestication analogy and to capitalism.
Nature's wide ranges are counterproductive
Nowhere is this antinomy more flagrant than in physiological ranges. On the farm, ranges keep narrowing; in the wild, as I discuss in Chapter 6, they keep widening. Wide ranges are counterproductive because they drive specimens away from the optimal point. That is why optimizers of all stripes declare war on quantitative variability. Consider what has become of the domesticated cow. The size of its ancestors must have been as variable as the behavior of wild foxes and the look and flavor of uncultivated apples. But geneticists, zoologists, bankers, marketeers, engineers, and consumers took it upon themselves to fabricate, sell, and buy the most cost-efficient cow. Their success is evident in a remarkable degree of standardization. Less than a hundred pounds separate the heaviest and lightest breeds, from Herefords at 1,419 pounds to Gelbvieh at 1,323 pounds. Nature’s cattle don’t have to meet the efficiency targets of business; only artificial selection grudges pennies like that.
...an organism's sole purpose was to cover its expenses
Optimization is the heart of breeding. Before breeders bent nature to human whim, an organism’s sole purpose was to cover its expenses. In the context of breeding, the organism’s purpose is to provide humans as much as it can, at least the expense. Even the earliest breeders of the Fertile Crescent couldn’t settle for whatever supplied their own subsistence, since the had to feed growing numbers of nonproductive people such as chiefs, soldiers, and priests. Margins were bordn. Nowadays, with a vastly larger human population, optimization is imperative. Thanks to the domestication analogy, humanity is convinced that this sort of optimization is necessary in nature too.
Humanity stops at nothing
Wheras nature knows enough, humanity stops at nothing. The cult of excellence venerates just one winner - or, in some cases, one especially important loser. In nature, there are many good enoughs. The survivors and reproducers are multiple and varied.
Chance governs life, waste is everywhere, novelty is the exception
Optimization is the sort of thing neoclassical economists dream about. It combats chance, waste, and stagnation, but these are the consitutive properties of nature: chance governs life; waste is everywhere; novelty is the exception and stasis the rule. And because there are never two identical individuals, at least one in any pair is not optimized. Whereas the art of breeding consists in creating the next improved model, more functional and standardized than the last, nature prefers none of that. Domestication, the foundation on which Darwin’s understanding of nature is built, has one enemy: nature itself.
Natural selection and eugenics
By inferring natural from artificial selection and thereby favoring selection over elimination and toleration, Darwin not only fostered an enduring intellectual error but also set the table for the horrors of eugenics. His defenders have separated him from this legacy of death and oppression by distinguishing his evolutionary ideas from those of Spencer and Galton and by pointing to his own avowed preferences. Rather than espousing improving the human stock by terminating the unfit, Darwin argued for uplifting the disadvantaged through welfare policies, which he saw as expression of “the instinct of sympathy, which was originally caquired as port of the social instincts, but subsequently rendered…more tender and more widely diffused.” But we should not absolve him so easily. The discoverer of natural selection was certainly humane, but he also warned against the suicidal aspect of his disposition: “No one who has attended to the breeding of domestic animals will doubt that this must be highly injurious to the race of man… Excepting in the case of man himself, hardly anyone is so ignorant as to allow his worst animals to breed.” Again – for the point cannot be made often enough – natural selection describes the way that humans act, not the ways of nature; it ascribes human modes of action to nature. Thus did nature become an authoritative supporter of social competition and hierarchy.
No one has ever equated evolution with stagnation
Change is the exception in nature and conservatism the rule. “Stasis is data, stasis is data, stasis is data,” was Gould’s mantra. “Say it ten times before breakfast every day for a week, and the argument will surely seep in by osmosis.” He meant that evolution cannot reasonably be a theory of change alone, for stasis is everywhere, and this observation counts, too. Dawkins agrees: “Although evolution may seem, in some vague sense, a ‘good thing,’ especially since we are all the product of it, nothing actually ‘wants’ to evolve. Evolution is something that happens, willy-nilly, in spite of all the efforts of the replicatios (and nowadays of the genes) to prevent it happening.” In nature, stagnation is good and change is bad unless proved otherwise. We shouldn’t glean too much from Gould’s and Dawkins’s enunciation of this principle, though. They are arguably the two best-known evolutionary writers of their generation, but in practice, the discipline and its public communication are viscerally change-oriented, always emphasizing variation and not adaptation. Not for nothing is the word evolution often used synonymously with progress and development. No one has ever equated evolution with stagnation.
Color blindness was certainly not elected
But while color blindness was certainly not elected, it is not so bad that the afflicted have to be eliminated. Had Darwin gone with natural elimination and exploret its implications, the persistence of these mutations would cause no theoretical difficulty. He would have inoculated the theory of evolution against most of its lingering contradictions, the misunderstandings it provokes, and the resistance it encounters. Where natural selection follows clear rules of breeding at odds with the products of evolution around us, natural elimination allows the idiosyncrasies observed in nature. At the risk of importing the subject even here, one might say – metaphorically – that natural elimination sometimes closes one eye and naps, allowing lousy variations to endure. And sometimes it closes both eyes and takes its shot, killing off the good and the bad alike. Natural elimination has no direction, goal or bias; it is as volatile as it is indifferent.
The principle of breeding
Darwin had celebrated the capacity of ruthless selection to obtain comparativelty minor results: “Lord Rivers, when asked how he succeeded in always having first-rate greyhounds, answered, ‘I breed many, and hang many.’”
A conceptual metaphor does for arguments what scaffolding does for buildings.
There is, in theory, nothing wrong with using an analogy in the course of arguing for natural selection. A conceptual metaphor does for an argument what scaffolding does for buildings. […]
The creators of new thought styles must have one-track minds
Darwin’s defensiveness may also have been a product of blind love. As the founder of a scientific paradigm, he was especially devoted to its vindication. Ludwig Fleck, an inspiration behind Thomas Kuhn’s development of the concept of paradigm shift, noted that creators of new thought styles must have one-track minds. Others are entitled to partake of several approaches, but the revolutionary is left to secure his or her own. For Darwin, this meant a degree of obstinacy in the face of criticism. There was no other way to make such a huge difference in the history of truth.
Never discard a genius's idea...
Never discard a genius’s idea. I uphold that although the domestication analogy is wrong, it can render great service to knowledge if, and only if, it is turned on its head. Instead of inferring natural selection from artificial selection, we should infer from emestication what nature is not. In what follows, I explore what breeders do in order to isolate how their values and activities produce results different from what occurs in nature. We will see here the true source of the eugenic and capitalistic ethics ascribed to evolution: not natural law but human hybris.
'Natural elimination' instead of 'natural selection'
Had Darwin not been under the spell of fanciers, he may have called his discovery “natural elimination” and reserved “selection” for the rare cases of fixation and stabilization of advantageous varieties. What is eliminated? The lethal and the luckless. In this alternate universe, the history of biology, and its contemporary predilections,would be vastly different. Instead of fitness, we would speak of chance. The recipe for escaping natural elimination? Take normalcy and add luck. Luck is the necessary ingredient for the good enough; often it is the sufficient one, too.
The organic law of the balancing between the volumes of organs
“…One cannot meet a body more cramped from front to back.” But he also thought to explain, in universal terms, the giraffe’s thriving in spite of such disproportionality. He credited the “organic law” of “the balancing between the volumes of organs,” whereby “asystem of organs acquires a dimension out of proportion only when other organs are restricted and reduced by an equivalent amount.” This notion of physiological trade-offs was axiomatic among scientific minds of the era and is maintained even in today’s evolutionary language. As Goethe wrote and Darwin quoted in the Origin, “The budget of Nature is fixed, but she is free to dispose of particular sums by any appropriation that may please her. In order to spend on one side, she is forced to economize on the other side.” Saint-Hillaire thought the giraffe’s disproportions a “memorable” example of this law at work.
The domestication analogy run amok
One cannot blame the giraffe for leading evolutionists astray. It did not choose its strangeness and celebrity, the qualities that made it such an inviting target for theorists’ assumptions of adaptation. Chapter 2 takes up this assumption directly. Why were Darwin and his interlocutors so certain that traits were adaptive in the first place? In some cases, such as that of the finches discussed in Chapter 3, there was good evidence. But in many other cases, all that theorists had to go on was a mistaken analogy between nature and domestication. They thought the jungle was like a farm, where a breeder called natural selection wrought ever-finer creatures from one generation to the next. This analogy ran amok, we will see, is foundational to the selectionst dogma that continues to afflict thinking about evolution and its ethical consequences.
Such a consequential weapon could never be the claim of one country alone...
Firs, Mivart argued that if having a long neck was so advantageous, “we ought to have seen at least several forms, similar to the giraffe, developed from different Ungulata… Being needful, there should be many animals with it.” In other words, if the long neck is adaptively beneficial, why is it not seen among related animals? Darwin retorted that there are events, in the hiotory of humanity, that occurred in one country but not in others. This seems an ungraceful pirouette. The long neck, as Darwin saw it, was not any odd event in the giraffe’s evolution but its survival edge. Such a consequential weapon could never be the exclusive claim of one country, as the nuclear arms race reminds us.
Answers tend to die young, but a good question lives forever.
The giraffe’s carreer as a scientific challenge seemed to be over. Posterity’s verdict was unanimous - Darwin was right, Lamarck was ridiculous, affair closed. After Darwinism solved the mystery of the neck, biologists lost interest in the giraffe for nearly a century. But the case was reopened when field researchers studied giraffes in Africa.The accumulating facts reveal many holes in the canonical understanding.
Evolutionary biologists invert the scientific principle
In science, methodological neutrality is expreses by the null hyptothesis, namely that every relationship between phenomena is, by default, the fruit of chance. The burden of refutation weighs on the researcher. You don’t have to prove innocence of justify chance.
The essence of mathematics, physics, and biology
Again, I question the roles of novelty and merit in the selection process. But though I come to this subject from my same philosophical perspective, I might add that there aee serious and even trailblazing biologists on my side. True, none of them has offered a comprehensive complementary theory to explain what Darwin and his followers leave out. Even so, I take heart from the words of Sydney Brenner, who won the Nobel Prize for his efforts in discovering messenger RNA (mRNA). “Wheras,” Brenner explains, “mathematics is the art of the perfect and physics the art of the optimal, biology, because of evolution, is only the art of the satisfactory.” Species need not be perfect or optimal, only satifactory. Fancois Jacob opposes in his autobiography Jacques Monod’s Cartesian idea of nature to his: “I saw nature as a rather good girl. Generous, but a little dirty. A little messy. Working in a piecemeal way. Doing what she could with what she found.”
The absurdity of intelligent design
Partisans of intelligent design argue in bad faith, so they might still claim my views on behalf of their mistaken ideas. In fact, my arguments vitiate theirs; there is a strong corellation between the uqiquity of neutrality and the falseness of intelligent design. That is because intelligent design is parasitic on selectionism. Intelligent design begins from the premise, supplied by selectionism, that species are optimized. ntelligent design takes Darwin’s analogy to domestication as more than figurative, asking how the perfection of nature - or, in Wallace’s case, the human specifically - could possibly be achieved without the intervention and direction of an intelligent force, a great cosmic breeder or sculptor. In contrast to both selectionism and intelligent design, the theory of the good enough turns our attention to nature’s many imperfections. Because nature is not optimzed, intelligent design advocates are actually assigning waste and mediocrity to the handiwork of an omnipotent being of supernatural intelligence. Why venerate such a lazy and inept God? When we temper our selectionist expectations, the absurdity of intelligent design emerges in even sharper belief.
Why should we struggle and strain when we are all good enough?
In chapter 10, I conclude with an exploration of what humanity’s safety net means for ethics, resolving that competition within society is a fool’s game. We need far less excellence than we cultivate. We do it anyway because the best of our neurons, those that rescued us from extinction, are underemployed and overqualified - not because doing so is necessary or even, in many cases, useful. More often, it is crushing. Being excellence-driven myself, I am well placed to know to futility and the masochism of this pursuit. Though our capitalist institutions tell us that we mst constantly strive, that nature ordains competition to be the best and reap the rewards, nature in fact offers no rewards beyond survival and reproduction. Both are assured by a safety net that allows us to be just fine even though we are so much less than optimal. Why should be struggle and strain when we are all good enough?
Much that distinguishes organisms from one another is not adaptive
And I explain more thoroughly the idea of the two evolutions. The first, concering qualitative variation, is in the province of Darwinism and adaptation. The second, concerning quantitative variation, is in the province of the good enough and neutrality. Again, natural selection is real; adaptation is real. But much that distinguishes organisms from one another, particularly differences in size, is not adaptive. These variations are not selected; they are tolerated.
Posterity heuristics
Posterity tends to make its choices with the help of two heuristics. One in incumbency bias: the earlier one enters the pantheon, the harder he or she is to expell, no matter the quality of the work celebrated. The other is laziness bias: posterity tends to select those who were already recognized by their own contemporaries; a lifetime of success is an important, if not strictly necessary, condition for posthumois lionization. Rare exceptions such as Gregory Mendel will console only inveterate optimists.
Natural selection is spectacular, chance is not
And yet spectacular as natural selection is in these cases, most birds are primarily generalists, most crickets are simple-minded, most antilopes are guileless, and springboks also pronk in the absence of predators. Species and organisms often survice not because they are are special but because they don’t have to be. On this view, however, they possess no magnetism, no elegance. They tell no story and project no significance into the world. To say that most of what survives was not selected but is just not bad enough to be eliminated is to demote natural selection from its exalted place in the order of life. Natural selection is biology’s greatest intellectual contribution; of course it is prized. Natural law leaves us quaking in wonder, while chance interests only gamblers.
Natural selection is not a natural law; it is a relative frequency.
Lynn Margulis, the pioneer of the theory of symbiosis in evolution, defined herself as an adherent of descent with modification and an adversary of selection as its principal agent. She rejected the “capitalistic, competitive, cost-benefit” interpretation of Darwin.
The absurdity of intelligent design
Partisans of intelligent design argue in bad faith, so they might still claim my views on behalf of their mistaken ideas. In fact, my arguments vitiate theirs; there is a strong corellation between the uqiquity of neutrality and the falseness of intelligent design. That is because intelligent design is parasitic on selectionism. Intelligent design begins from the premise, supplied by selectionism, that species are optimized. ntelligent design takes Darwin’s analogy to domestication as more than figurative, asking how the perfection of nature - or, in Wallace’s case, the human specifically - could possibly be achieved without the intervention and direction of an intelligent force, a great cosmic breeder or sculptor. In contrast to both selectionism and intelligent design, the theory of the good enough turns our attention to nature’s many imperfections. Because nature is not optimzed, intelligent design advocates are actually assigning waste and mediocrity to the handiwork of an omnipotent being of supernatural intelligence. Why venerate such a lazy and inept God? When we temper our selectionist expectations, the absurdity of intelligent design emerges in even sharper belief.
Natural selection as nature's safety net
Chapter 7 draws on the theory of facilitated variation, developed by Marc Kirschner and John Gehrhart, to explain the mechanisms underlying this tolerance. This theory holds that for three billion years, a process of natural selection furnished the biological foundations of all extant creatures. Secured by this sturdy infrastructure, which I call nature’s safety net, organisms havespent the last four hundred million years getting away with much waste and inefficiency. They can afford their waste thanks to highly optimized selected traits, but the waste itself is not selected.
Our excess bubbles and blooms
I argue that the future powers a division of labor so thorough that it obliterates all challenges to humanity’s survival, leaving us with a world of free lunches, ease, and boredom. We face no species-level threats except perhaps those ecological ones that are products of unavaoidable excess. This excesss is unavoidable because we have little to do from a survival standpoint. Humans have the ultimate luxury of wasting time and resources in order to divert ourselves. The skills our ancestors cultivated for the purpose of survival no longer serve that purposem yet the skills remain. We have the means to achieve ends we no longer need to worry about, so the means become ends themselves. Our excess bubbles and blooms not because it is selected through a process if struggle but because there is no struggle.
Evolutionary biologists invert the scientific principle
In science, methodological neutrality is expresed by the null hyptothesis, namely that every relationship between phenomena is, by default, the fruit of chance. The burden of refutation weighs on the researcher. You don’t have to prove innocence of justify chance.
Darwinian bias toward natural selection is baked into popular understanding
Because the Darwinian bias toward natural selection is now baked into popular understanding of evolution, it is not enough to tell the truth, nothing but the truth, but also to tell the whole truth. Rather than presume and seek out a selectionist explanation for what most likely are neutral traits, biologists might presume the ubiquity of the latter even as they marvel at the exceptions. And they might talk about it in public. Doing so would make an immense difference. Differential algebra, organic chemistry, and optical physics have no impact on our worldview; the theory of evolution does. When specialists in these other fields realize that they have been operating on the basis of unsound presuppositions, the corrections tend to stay “in house.” Their fields are torn down and rebuilt, but the rest of us are unperturbed. By contrast, Darwinian and neo-Darwinian ideas such as survival of the fittest, optimization, adaptation, and Malthusian competition reverberate in the way we experience reality, society, and ourselves. It follows that when these ideas misrepresent nature, they weigh heavily on our self-representation.
Darwin would not be published in Nature today
“Scientists apply themselves to what they believe to be the most important of the problems that seem tractable,” the Nobel Prize-winning biologist Francois Jacob wrote; “those that rightly or wrongly they think they will be able to solve.” Peter Medawar, another biology Nobelist, calls science “the art of the soluble.”