The Price of Altruism (11 page)

Meanwhile he was wowing the world with his talents, emerging as a top-flight biochemist (identifying cytochrome oxidase in different taxa), geneticist (finding more instances of linkage), physiologist (inventing a method to relieve divers of the bends), enzymologist (deriving the Briggs-Haldane equation), popular science writer (writing
Daedalus
and
Callinicus
), and intrepid self-experimenter (drinking ammonium chloride—more than had killed a dog—to prove that breathing is controlled by carbon dioxide). Even by Oxbridge standards he was a character extraordinaire. Alongside these achievements, as the following note to his secretary shows, he’d begun searching for his ideological home:

Wanted:

Fascism was ascendant in Europe, economic depression everywhere. With Britain failing miserably either to show political resolve or to stage a recovery, disaffected liberals had fallen into lethargy and ennui. The barren, self-pitying “spiritual muddle” drove Haldane, and an entire “social relations of science movement,” to rage. It was morally bankrupt and even worse, scientifically illiterate. After all, “the progress of society depends…on the progressive application of science,” but England still cuddled “essay-writers” instead of scientists.
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Not so in Russia. There, only the ballerina could compete with the scientist for cachet. Haldane, like many other left-leaning Western scientists, was completely enamored. In 1928 he and Charlotte had visited Russia on the invitation of the famously handsome and fearless plant geneticist Nikolai Vavilov. Lavished with a gala dinner and carted around to busy institutes, JBS took little notice of the shabby apartments and empty canteens. Even as they stood in the long line waiting for their exit visas he pontificated to Charlotte about how impressed he was by the Soviets. Russia was where the future lay because in Russia science had been endowed with the authority of religion. “Our present rulers and those who support them,” he pronounced upon return, “will be well advised explicitly to imitate the extremely capable Bolshevik leaders, and adopt an experimental method.”
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Marxism could combat fascism where liberal democracy had failed. It divined the winning attitude for using science and technology to save civilization. It honored the everyman and gave respect to the underdog. But Marxism provided something even more fundamental: the tools to grasp reality, to see the world the way it is rather than how people want it to be. Before his conversion Haldane joked that his favorite Marx was Groucho, but he was quickly coming into the fold. Whether this was lip service or the real thing, he’d been using the method of dialectical materialism to get a grip on evolution. Or so at least he claimed.
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The Causes of Evolution
, published in 1932, was the popular exposition of nine pathbreaking technical papers (with a tenth still on its way) detailing “A Mathematical Theory of Natural and Artificial Selection.”
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Haldane’s equations were not pretty, he was a “plodding algebraist,” not, like Fisher, a “mathematician’s mathematician.”
³⁷
And yet, just like Fisher, he spoke to Mendelians and biometricians both, showing convincingly how natural selection, operating on genes in a population slowly and gradually could account for dramatic evolutionary change. More like a greasy-hands repairman/engineer than a pristine apostle of Nietszche, he felt no need to posit a fundamental theorem. To Haldane evolution was a process, not an edict.

Partly this was related to dialectics. Fisher worshiped the purifying hand of natural selection, but Haldane thought it had to be “negated” somehow by the chanciness of genetic mutation.
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This didn’t mean that natural selection wasn’t a force to be reckoned with: Thirty years before the Oxford geneticist E. B. Ford sent his student Bernard Kettlewell to the forests outside Birmingham to prove it, JBS predicted that the dark peppered moth, the melanic
Biston betularia
, could hold up to a 50 percent selective advantage over its white counterpart. In the span of only a few generations, its ratio in the population compared with the white morph had jumped from 2 percent to over 90, the Industrial Revolution having provided blackened birch trunks to hide from preying birds, and left the rest to natural selection.
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But if natural selection was driving populations to higher fitness, it was also being frustrated by mutation. Fisher argued that fitness depended on variation, but this led to a paradox: After all, the more natural selection weeded, the less variation was left. This meant that the mutation rate had to be higher than he allowed for. But since most mutations were harmful, if their rate was too high the fitness of the population would drop. On the other hand, if natural selection scrutinized too harshly, the population could be wiped out entirely. There had to be a dialectic, to JBS this was clear. From the mouth of Marx via Hegel,
⁴⁰
whatever the fundamental theorem promised, there was a cost to natural selection.
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Evolution had accomplished amazing feats but was no panacea. Where Fisher had turned to a divine Nature and the upper classes, Haldane chose radical politics. He’d been back from the Spanish civil war for some years now, and had recently been elected to the executive board of the Communist Party of Great Britain. Sure, he had heard of the rise in the Soviet Union of the Ukrainian farmer Trofim Lysenko, who marshaled Marxist doctrine to lambast “Western, bourgeois, exploitative” genetics, calling its practitioners “fly lovers and people haters.” He had heard that the “barefoot professor” was promising a “genuine,” “proletarian” agricultural revolution based on false Lamarckian claims, and whispering into Stalin’s ear that “determinist” and “racist” genetics needed to be shut down. He had heard the rumors of colleagues losing their jobs, of the disappearance of his gracious host Vavilov, even of executions and purges. But he waved them all aside. There was no hard evidence. Besides, even if Lysenko’s claims were “seriously exaggerated” there might be a grain of truth to them.
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Haldane was a hereditarian. Back in 1932 he had remarked: “The test of the Union of Soviet Socialist Republics to science, will, I think, come when the accumulation of the results of human genetics, demonstrating what I believe to be the fact of human inequality, becomes important.” He enjoyed quoting Engels’s assertion that “the real content of the proletarian demand for equality is the demand for the abolition of classes” any demand that goes beyond that, he said, “of necessity passes into absurdity.” Though not a rabid eugenicist like Fisher, he judged the logic behind its tenets sound. He was convinced that the mean IQ was falling due to the abstinence of the educated classes. Genetically speaking, capitalism was frustrating the survival of the fittest. By abolishing classes and getting rid of the differential birth rate, socialism would be the perfect corrective.
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This was hardly the reactionary Fisher’s plan, but it was not exactly Lysenko’s either. Pointing his finger at the Nazi perversion of genetics, the “madman” from the Ukraine had convinced Stalin that Mendelism was a noxious sham. It was by changing the environment, not manipulating imagined genes, that man’s destiny would be forged and provided. A French colleague said of Haldane: “Ce n’est pas un homme, c’est une force de la nature!” By all accounts he was a Goliath, a bastion of reason and logic. And yet somehow it didn’t seem to bother him—one of the few modern prophets of evolution—to be apologizing for a man who denied the existence of the gene and called survival of the fittest a bourgeois plot. What mattered was the cause. As long as capitalism had yet to show that it could keep people from want and communism that it could not, Haldane was going to side with the Party.
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Sewall Wright was no kind of Marxist. Nor, in truth, was God usually on his mind. A Harvard trained theoretical population geneticist, he looked a bit like a very handsome mouse. And as colorful as Haldane and Fisher were, Wright was the son of a small college professor from the Midwest whose “idea of a fun night out was a discussion with his university chums at the local faculty club.”
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Still, just like his English counterparts, he’d applied equations to evolution, and even though he was sedate and mousy, the fundamental theorem of natural selection just blew him away.
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Emboldened by its generality, he offered a theory of evolution of his own, grander than Haldane’s engineerlike approach, more visual than Fisher’s obscure but soaring mathematics.
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Life, he explained, was like a landscape of valleys and mountains. Organisms could be imagined in the process of climbing in an upward direction, improving their fitness as they scaled a crest. As the fundamental theorem showed, once an ascent had begun there was no turning back, for natural selection could push in only one direction. This was well and fine. But what if the summit was in fact a foothill, not all that towering: Would organisms find themselves stranded with nowhere else to climb?

Wright’s answer was that in addition to natural selection another force sometimes operated, called “random drift.” Imagine a crowd of a million angry demonstrators walking down Main Street in the direction of Town Hall and one falling accidentally into a pothole. However tragic to the particular individual, the torrent, and the demonstration, will not have been affected. But if only three friends are walking down an alleyway toward a demonstration and one falls randomly into a pothole, it’s almost certain they’ll never make it to the rally; their direction and cause will have changed dramatically. As with demonstrators, so with genes in a population: Chance events will influence small groups much more than large ones. And just as the pothole may have swallowed the friend least interested in the demonstration, genetic drift will be divorced from the “goals” of evolution. Unlike its deliberate older brother, drift would not always push organisms to higher genetic peaks: If natural selection was the taskmaster of fitness, drift was the shifting sands underfoot, changing the course of weak and strong alike.

Still, there was a bright side. If populations were not large and homogeneous, if they didn’t all walk together through Main Street but rather advanced in parallel alleys in small, partially isolated groups, drift could do what natural selection could never accomplish: alter the genetic structure enough to allow a dramatic change in direction. In Wright’s model this was tantamount to blowing a group from a peak into a valley. Working against the fundamental theorem, in the short run it meant a decrease in fitness. But just as a grieving letter to the mayor from one of the two remaining friends might do more for the cause, in the end, than the mass rally, it could ultimately provide a surprising opportunity. For a blow off a foothill might lead to the foot of a new and higher mountain. What looked like a dive would actually mean liberation—the start of a glorious, transcendent new ascent.
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He called it the “shifting-balance” theory, since the population shifted between the poles of directed selection and random drift, respectively. Wright thought of it as an enrichment of the fundamental theorem, chance blowing new tunes into the sometimes limited winds of progress. But the “adaptive landscape” left Fisher cold. Mutations were both necessary and random, but it was the guiding hand of selection that ultimately shaped life. Without it there could be no purpose or end. Wright’s “landscape” was “picturesque” but biologically nonsensical.
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Small isolated groups where random events could leave their mark were either on the way to extinction or becoming new species. The sweeping majority of creatures in a population were continually connected genetically, since each had a fair chance of mating with the other. They were all marching steadily together down Main Street. Drift might shift a handful of genes in a vast, never-ending sea; from the point of view of the population it was negligible.

Nature was uniform, not a landscape of troughs and peaks. And the great ocean of life was constantly rising.

Fisher, Haldane, and Wright would become known as the architects of the evolutionary synthesis, each in his own way wedding Darwin to Mendel.
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However different their models, all three celebrated the power of natural selection to bring about evolution. For that reason, too, just like Darwin before them, they were puzzled by the conundrum of the ants: How could traits that reduced fitness be selected, going against the interest of those who bear them? Traits, that is, like altruism.

Fisher’s reply came via butterflies and caterpillars. Naturalists were familiar with butterflies (and other insects) that are terribly distasteful to the birds that try to eat them. This would be a wonderful defense if only the birds knew it before taking a bite. Since such understanding usually came too late for the butterfly, Fisher wondered how “distastefulness” could have evolved.
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