Read The Flamingo’s Smile Online
Authors: Stephen Jay Gould
Maupertuis was among the first European scientists to trace the pedigrees of unusual traits through family lines. He recognized that these results, apparently so unrelated to embryology, might solve the great debate in favor of epigenesis. He compiled a pedigree for polydactyly (extra fingers) through three generations of a German family and proved one cardinal fact, long touted in anecdote and folklore but never conclusively established: inheritance passes through
both
male and female lines; that is, extra fingers could be inherited from either fathers or mothers. Maupertuis then recognized that this feature of heredity rather than any direct aspect of embryology, might resolve the problem of development; for how could preformationism be supported if
both
parents can contribute to the form of their offspring. If homunculi are curled up in eggs or sperm, the noncontributing parent should not play an equal role in the form of its offspring. And what about hybrids who bear characteristic features of two parents belonging to different species? Maupertuis concluded:
It seems to me that one of these systems [either the ovist or spermaticist version of preformationism] is completely destroyed by the resemblance of the child, sometimes to the father, and sometimes to the mother, and by the intermediate animals born from parents of two different species…. Since the child resembles both, I believe we must conclude that both parents play an equal role in its development.
Maupertuis could not compute the pedigree of the albino child of black parents on exhibit in Paris. But he learned that albinism had been traced through family lines among blacks in Senegal, and he argued that albinism would, like polydactyly, drive another nail into the preformationist coffin. In any case, the “white Negro” inspired him to organize his thoughts on development and to write one of the classics of eighteenth-century science.
Preformationists had a standard response to the phenomenon of biparental inheritance. They argued that one parent carried the homunculus, while the seminal fluid of the second parent modified it. Maupertuis ridiculed this argument, especially as applied to the development of mules from a horse and a donkey parent:
If the fetus were in the [spermatic] worm that swims in the seminal fluid of its father, why should it sometimes resemble its mother? If it were only in the egg of its mother, what form would it have in common with its father? If the little horse were already formed in the mare’s egg, would it develop a donkey’s ears because [the seminal fluid of] an ass puts parts of the egg into motion?
Despite Maupertuis’s rhetoric, the preformationist response was not absurd when applied to ordinary, continuously varying traits. The short homunculus of one parent might be lengthened by spermatic fluid from a taller parent; even the ears of a horse might be elongated after contact with the vigorous motions of an ass’s semen. But Maupertuis had a very strong argument for odd and discrete traits—polydactyly and albinism, for example. These features looked exactly the same in offspring, whether they were inherited from fathers or mothers. Could one really believe that inheritance would work precisely the same way for traits rigidly preformed in a homunculus and those merely caused by motions in the seminal fluid of the noncontributing parent?
Maupertuis also used the white Negro to formulate two other arguments against preformationism. First, he considered albinism as a kind of deformity and therefore analogized it with monstrous births (from Siamese twinning to polydactyly). Such fetal abnormalities posed a great problem for preformationists. If they accepted the monstrosity as fully preformed, they faced the theological dilemma of a bumbling or malevolent deity who would plan such unhappiness and program it into Eve’s ovaries. If they argued (as they usually did) that extra parts indicated the accidental amalgamation of two homunculi, then did it not stretch the imagination to claim that a polydactylous child received nearly all of itself from one germ and merely an extra finger from another? Such an explanation wouldn’t serve for albinism in any case. One had to believe that a few white homunculi had been scattered into the progenitor of black people. Possible but unlikely.
Second, Maupertuis argued that preformationism could not easily explain the origin of different human skin colors from a single progenitor:
The first mother must have contained eggs of different colors, which themselves carried an innumerable suite of eggs for the same color…but which would only hatch in the time that Providence had marked for the origin of the people contained in them. It would not be impossible that, one day, the suite of white eggs for peopling our region would run out, and all European nations would change color; as it would not be impossible also that the source of black eggs might become exhausted, and that Ethiopia would only have white inhabitants.
Maupertuis effectively used the white Negro to marshal his arguments against preformationism, but what could he offer to explain his own peculiar brand of epigenesis? Since he refused to admit any vitalistic, external directing forces, he had to discover a source of order within the seminal fluids themselves. How did all the disaggregated parts come together and why did the right ones usually join—thus making it so difficult for an extra part to insinuate itself and accounting for the rarity of such abnormalities as polydactyly? Here Maupertuis reached an impasse, though he labored mightily to break through.
His best suggestion harked back to the Newtonian perspective so important to his general scientific view. If gravity regulated the attraction of physical objects, then a kind of gravity must bring the right parts together to form a fetus. Eye parts would have a natural affinity for nose parts, nose for teeth, and so forth, until a whole animal might be constructed, just as the dry bones came to life on Ezekiel’s desert. Moreover, maternal and paternal eye parts would have an equal chance to join the fetus and a completed embryo would therefore be an amalgam of traits from both parents.
Why, if this force [gravity in the sense of attraction] exists in nature, should it not regulate the formation of animal bodies? If the seminal fluid of each parent contains parts destined to form the heart, the head, the gut, the arms, the legs, and if each of these parts has a greater affinity for union with neighboring parts of the completed animal than with any other part, then the fetus will build itself.
Maupertuis felt that monsters with extra parts offered special support for his gravitational theory because supernumerary organs always formed in the right place. An extra finger never protrudes from the belly or the back of the head, but always joins the other five, thus proving that finger parts have a natural affinity for each other and for neighboring sections of the hand.
Since I love to participate in intellectual battles, if only vicariously, I was most excited, in reading the
Vénus physique
, by the opportunity to watch a brilliant man struggling to explain the greatest mystery of biology and knowing full well, despite all the effort strung out over two hundred pages, that he had not succeeded. Maupertuis sensed that his gravitational theory was weak, based on no direct evidence, and rooted more in analogy than in any concrete observation. Yet, he had to propose something and could think of nothing better. For Maupertuis was firmly committed both to his general mechanistic perspective and to the specific theory of epigenesis—and these intellectual positions forced him to argue that material particles to form the fetus must exist in the seminal fluids of both parents, for vitalistic forces could not direct the differentiation of complex structures from nothing. He opted for disaggregated parts, mixed together in the seminal fluid but able somehow to find each other and form the embryo. And he correctly sensed the unsatisfactory and improbable nature of his theory.
We would say today that Maupertuis’s basic insight was correct: complexity cannot arise from formless potential; something must exist in the egg and sperm. But we now hold a radically different concept of this “something.” Where Maupertuis could not think beyond actual parts, we have discovered programmed instructions. Eggs and sperm do not carry parts themselves, but only coded instructions, written in DNA, to direct the building of a proper embryo.
But how could Maupertuis have reached this elegant solution, for his century lacked analogs in thought and technology to imagine a process of abstraction from actual parts to programmed rules for their construction. Programmed instructions were not part of the intellectual equipment of eighteenth-century thinkers. Music boxes pointed in the right direction, but the first revolutionary invention based on programmed instructions, the Jacquard loom, was not introduced until the early 1800s. This automatic weaving device, with instructions on punched cards, directly inspired Hollerith’s later invention of data cards for census machines (later transmogrified to the famous IBM computer card—do not fold, spindle, or mutilate). How could Maupertuis imagine the correct solution to his dilemma—programmed instructions—in a century that had no player pianos, not to mention computer programs?
We often think, naïvely, that missing data are the primary impediments to intellectual progress—just find the right facts and all problems will dissipate. But barriers are often deeper and more abstract in thought. We must have access to the right metaphor, not only to the requisite information. Revolutionary thinkers are not, primarily, gatherers of facts, but weavers of new intellectual structures. Ultimately, Maupertuis failed because his age had not yet developed a dominant metaphor of our own time—coded instructions as the precursor to material complexity.
“
HE IS HURLING
the insult of the century against our mothers, wives, daughters and sisters, under the pretext of making a great contribution to scientific research.” Thus did Louis B. Heller, congressman from New York, label the Kinsey report on
Sexual Behavior in the Human Female
(1953) in a letter to the postmaster general, urging that the book be banned from the mails. Dr. Henry Van Dusen, president of the Union Theological Seminary, doubted Kinsey’s facts but proclaimed that if true nonetheless, “they reveal a prevailing degradation in American morality approximating the worst decadence of the Roman empire.” “The most disturbing thing,” Van Dusen continued in castigating Kinsey’s report, “is the absence of a spontaneous, ethical revulsion from the premises of the study.”
Yet the premises seemed uncomplicated enough. Kinsey had sought, through extensive interviews with more than 5,000 women, to compile a statistical record of what people do do, rather than what law and custom say they should do. He passed no judgment and merely reported his findings; he did, however, discover a frequency of premarital and extramarital sexual relations that, to say the least, disturbed the chivalric code of many naïve, hypocritical, or smugly satisfied people—particularly older men in power.
Alfred C. Kinsey suffered the misfortune of publishing his report in 1953 at the height of McCarthyite hysteria in America (his earlier 1948 report on
Sexual Behavior in the Human Male
had caused a stir but had not inspired such calumny, perhaps because society has always accepted a wider range of behavior among males and because the early political climate of post-war years had been much more liberal). Many labeled Kinsey’s report on female sexuality as an exercise in communism or, if not directly subversive, sufficiently weakening of American moral fiber to allow easy communist access to our troubled shores. A special House Committee, established to investigate the use of funds by tax-exempt foundations and led by noted cold warrior B. Carroll Reece, dragged the Rockefeller Foundation onto its carpet. The foundation capitulated to these and other pressures, and Kinsey’s main source of support ended abruptly in 1954. The Reece Committee issued its majority report in December 1954, accusing some foundations of using tax-exempt monies for studies “directly supporting subversion.” The Kinsey reports were explicitly cited as unworthy of the aid they had received. Kinsey never did find an alternate source of support; he died two years later, overworked, angry, and distressed that so many years of further data might never see publication (renewed funding arrived later, but not in time for Kinsey’s personal vindication).
Kinsey was no lifelong crusader for sexual enlightenment. He drifted into sex research almost by accident (though not without prior interest). He had been trained as an entomologist and was, at the time of his shift in careers, one of America’s foremost taxonomists of wasps (six-legged, not two-legged). Soon after his switch, he began a Phi Beta Kappa lecture at Indiana University with these words:
With individual variation as a biologic phenomenon I have been concerned during some twenty years of field exploration and laboratory research. In the intensive and extensive measurement of tens of thousands of small insects which you have probably never seen, and about which you certainly cannot care, I have made some attempt to secure the specific data and the quantity of data on which scientific scholarship must be based. During the past two years, as a result of a convergence of circumstances, I have found myself confronted with material on variation in certain types of human behavior.
Most people, when they learn about Kinsey’s earlier career, tend to regard the discovery with quaint amusement. How odd that a man who later shook America should have spent most of his professional career on the taxonomy of tiny insects. Surely there can be no relationship between two such disparate careers. As one wag wrote in a graffito on the title page to Harvard’s only copy of Kinsey’s greatest monograph on wasps: “Why don’t you write about something more interesting, Al?”
I wish to argue, however, that Kinsey’s wasps and WASPs were intimately related by his common intellectual approach to both. And since wasps preceded WASPs, Kinsey’s career as a taxonomist had a direct and profound impact upon his sex research. In fact, Kinsey pursued his sex research by following a particular “taxonomic way of thought,” a valid style of science that does not match most stereotypes of the enterprise. The special character of Kinsey’s work—the aspects that brought him such fame and trouble—flowed directly from the taxonomic approach he had learned and perfected as an entomologist.
Aside from the specific conclusions that so shocked America—basically the high frequency of things that nice people supposedly didn’t do, from homosexuality to premarital and extramarital sex among women to the high frequency of sexual contact with animals among men who had grown up on farms—Kinsey stirred the world with his different procedural approach to sex research. He worked with three basic premises, all flowing directly from his taxonomic perspective. First, he would base his conclusions upon samples far larger than any previous researcher had gathered. No more extrapolations to all of humanity from a small and homogeneous population of college students. Second, his sample would be heterogeneous—old and young, farm and city, poor and rich, illiterate and college educated. As wasps varied from tree to tree, classes, sexes, and generations might differ widely in their sexual behavior. Third, he would pass no judgments but merely describe what people did.
Kinsey received his Ph.D. in entomology from Harvard and then accepted a post as assistant professor of zoology at the University of Indiana, where he remained all his life. He spent the first twenty years of his career in a study, conducted with unprecedented detail, of the taxonomy, evolution, and biogeography of gall-forming wasps in the genus
Cynips
. These small wasps lay their eggs within the tissues of plants (usually the leaves or stems of oaks). When the larvae hatch, they induce the plant to form a gall about them, thus securing both protection and a source of food. The larvae mature within their galls, eventually emerging as winged insects to begin the process anew. Kinsey presented his work on
Cynips
in a number of shorter papers and two large monographs,
The Gall Wasp Genus
Cynips:
A Study in the Origin of Species
(1930) and
The Origin of Higher Categories in
Cynips (1936)—see bibliography.
In 1938, in response to student petition, the university established a noncredit course on marriage (a euphemism, I suppose, for some sex education). Kinsey, who had planned to spend the rest of his life studying wasps, was asked to serve as chairman of the committee to regulate this course and to give three lectures on the biology of sex. Kinsey was conscientious and empirically oriented to a fault. He went to the library to find the required information about human sexual response—and he couldn’t. So he decided that he would have to compile it himself. He began by interviewing students but soon realized that he was not getting representative information about American heterogeneity. He began to travel on weekends, gathering information in nearby towns at his own expense. He developed an extensive format for interviews and wrote the responses in code to assure anonymity (Kinsey’s intuitive skill as an interviewer became legendary). He recorded enormous variation in sexual behavior among people of different economic status, extending his researches to Gary, Chicago, Saint Louis, and to Indiana prisons. As his work became more public, criticism mounted, but the university remained firm in its support of Kinsey’s right to know.
Eventually, with the university’s backing, he established the Institute for Sex Research and secured Rockefeller Foundation money for his burgeoning interviews and their publication. His work culminated in two great volumes,
Sexual Behavior in the Human Male
and
Sexual Behavior in the Human Female
, each based on more than 5,000 interviews with white Americans of diversified backgrounds. (True to his convictions about the fundamental character of variability, Kinsey knew that he did not have enough data to reach conclusions about black Americans or to extrapolate to other nations and cultures.) Long before these volumes appeared, Kinsey had, with great reluctance and sadness but with creeping inevitability, abandoned the wasp studies that had brought him so much pleasure and had set his standards of scientific work.
Although Kinsey confined his major works on wasps to a single family, the Cynipidae, his aims were as broad as natural history itself. He thought deeply about the practice and meaning of classification and hoped to reformulate the principles of taxonomy. He wrote in 1927:
From our work on Cynipidae, in connection with a study of the published work in other fields of taxonomy, I propose to attempt a formulation of the philosophy of taxonomy, its usefulness as a means of portraying and explaining species as they exist in nature, and its importance in the coordination and elucidation of biologic data.
Kinsey felt that he could achieve these larger goals by performing a specific study with such unprecedented factual detail that larger principles would emerge from the volume of information itself. Kinsey was a workaholic before the word was invented. On a traveling fellowship in 1919–1920, he logged 18,000 miles (2,500 on foot) in southern and western regions of the United States and collected some 300,000 specimens of gall wasps. His two trips to rural Mexico and Central America in the 1930s were monuments to his insatiable industry. Still, he was never satisfied. In his 1936 monograph, he lamented that for each of his 165 species, he had collected, on average, “only” 214 insects and 755 galls. For 51 of these species (variable groups in regions of uniform topography), he stated that he would not be satisfied until he had gathered a grand total of 1,530,000 insects and 3 to 4 million galls!
More than mere collection mania underlay Kinsey’s expressed desires and actual efforts. A modern statistician might well argue that Kinsey had an inadequate appreciation of sampling theory; you really don’t need to get every one. Still, Kinsey pursued his copious collecting because he operated and centered his biological beliefs upon one cardinal principle: the primacy and irreducibility of variation.
Ironically, much of taxonomic practice had not fully assimilated this fundamental change brought to biology by evolutionary theory. Many taxonomists still viewed the world as a series of pigeonholes, each housing a species. Species, in this view, should be defined by their “essences”—fundamental features separating them from all others. Variation was regarded as a nuisance at best—a kind of accidental splaying out around the essential form, and serving only to create confusion in the correct assignment of pigeonholes. Most classical taxonomists treated variation as a necessary evil and often established species after studying only a few specimens.
Taxonomists like Kinsey, who understood the full implications of evolutionary theory, developed a radically different attitude to variation. Islands of form exist, to be sure: cats do not flow together in a sea of continuity, but rather come to us as lions, tigers, lynxes, tabbies, and so forth. Still, although species may be discrete, they have no immutable essence. Variation is the raw material of evolutionary change. It represents the fundamental reality of nature, not an accident about a created norm. Variation is primary; essences are illusory. Species must be defined as ranges of irreducible variation.
This antiessentialist way of thinking has profound consequences for our basic view of reality. Ever since Plato cast shadows on the cave wall, essentialism has dominated Western thought, encouraging us to neglect continua and to divide reality into a set of correct and unchanging categories. Essentialism establishes criteria for judgment and worth: individual objects that lie close to their essence are good; those that depart are bad, if not unreal.
Antiessentialist thinking forces us to view the world differently. We must accept shadings and continua as fundamental. We lose criteria for judgment by comparison to some ideal: short people, retarded people, people of other beliefs, colors, and religions are people of full status. The taxonomic essentialist scoops up a handful of fossil snails in a single species, tries to abstract an essence, and rates his snails by their match to this average. The antiessentialist sees something entirely different in his hand—a range of irreducible variation defining the species, some variants more frequent than others, but all perfectly good snails. Ernst Mayr, our leading taxonomic theorist, has written elegantly and at length on the difference between essentialism and variation as an ultimate reality (“population thinking” in his terminology—see his recent book,
The Growth of Biological Thought
).
Kinsey, who understood the implications of evolutionary theory so well, was a radical antiessentialist in taxonomy. His belief in the primacy of variation spurred an almost frantic effort to collect ever more specimens. His belief in continua forced him to explore virtually every square foot of suitable territory for
Cynips
in North America—for whenever he found large gaps, he strongly suspected (usually correctly) that intermediate forms would be found in some geographically contiguous area.
In the end, Kinsey’s antiessentialism became almost too radical. He was so convinced that species would grade into other species that he began to name truly intermediate geographical variants
within
a single species as separate entities, and established a bloated taxonomy of full names for transient and minor local variants. (Kinsey decided that species arose by the spread through local populations of discrete mutations with small effects. Thus, whenever he found a local population differing from others by mutations of the sort produced in laboratory stocks, he established a new species. But local populations within a species often establish small mutations without losing their central tie to the rest of the species—the ability to interbreed.)