On Monsters: An Unnatural History of Our Worst Fears (29 page)

In Darwin’s time high stakes were involved in issues of teratology. Every animal was seen as an example of God’s designing acumen, and
because God was thought to be omnipotent, his animal designs should be absolutely perfect. Recall that it was difficult for medieval theologians to reconcile the existence of monsters with the omniscient, omnipotent, and omnibenevolent God. In that era, the problem was mostly about how to reconcile evil and evildoers with God’s obvious authority over the cosmos. Now, in Darwin’s era, the evil had largely gone out of the monster concept, but monsters continued to challenge assumptions about God’s ultimate authority over nature. Why would the perfect craftsman create (or allow) the imperfect craftsmanship implied by teratology?

The natural theologians tried to show that nature was elegant, economical, and rational, a perfect incarnation of God’s blueprint. During the 1830s a popular series of books called the Bridgewater Treatises endeavored to show how nature’s beautiful adaptations proved the existence of a divine architect. But it was becoming increasingly difficult to maintain this optimism when paleontology was uncovering massive evidence about extinct genera. Why would God retract whole orders and families of his beautiful creation? Were these “mistakes” in God’s overall plan? Was it even possible for God to make a mistake?

In addition to the theological threats from paleontology, the new work in embryology and morphology was also discovering some disconcerting truths about ontogeny. Natural theologians had built a professional industry on the demonstration of useful traits: the eye is designed perfectly for seeing, the canine tooth for tearing flesh, the neck of the giraffe for reaching higher foliage, and so on. For a mole, which lives underground, digging through dirt, normal eyes would only create an unhealthy nuisance; lo and behold, the Designer has seen fit to perfect the mole by withholding its eyes. But to this cheerful party of hand-in-glove correlations between structure and function came uninvited observations from anatomy. On closer analysis there appeared to be many structures that are
not
perfectly adapted to function. Recall Geoffroy’s and Hunter’s recognition that many animals with radically different life conditions nonetheless seemed to have similar structures; one finds a common pentadactyl forelimb structure, for example, in humans, whales, moles, and bats. Why would the Designer use the same structure for flying, digging, swimming, and grasping?

Homologies between different kinds of creatures did not sit well with natural theologians who saw each species as independently created by God. By the time Darwin was writing in his notebooks, the atheistic implications had been fully drawn out and emphasized against the more pious adaptationists. Significant anatomical structures did not have any obvious purpose in nature, and these anomalies threw doubt on the more general assumption that nature had been divinely designed. The morphologists, in
contrast to the adaptationists, argued that a mole’s paws, a whale’s flippers, a human’s hands, and a bat’s wings all had similarities because nonpurpo-sive materialistic laws of embryological growth were shaping them. Radical anatomists, taking their start from Geoffroy’s ideas, began referring to the theologically minded Bridgewater Treatises as the “Bilgewater Treatises.”
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Monsters became part of the rallying cry of the radical atheists against a perfect, purposeful nature. Mutants and homologies theoretically conspired to undermine the Panglossian adaptation ideology of natural theology. Against this growing tide of atheism, Darwin’s colleague Richard Owen hatched two “curative” solutions. Owen argued that the structural homologies, emphasized by the morphologists, should not be seen as evidence against a divinely designed nature. Rather, these deeper unities underneath diverse species are actually transcendental archetypes: God’s blueprint plans for the animal kingdom. Owen eventually described an ideal vertebrate archetype that could be detected like a Platonic Form embedded in every snake, fish, monkey, and man. This clever move allowed natural theologians to concede that not every structure is perfectly adapted, but now this counterevidence that morphologists claimed as blind, nonpurposive laws could be seen as just
more
evidence of a divine hand in nature.

Now we can appreciate Owen’s second theoretical move: the idea, contra Geoffroy, that monsters are triggered by
internal
germ causation. Owen revitalized Hunter’s theory of monsters as an alternative to the blind view of nature that the radicals were preaching. If monsters, or pathological structures, are caused by anomalous conditions in their external environment, then changes in nature are accidental. Chance and contingency are the distressing implications of an exogenic theory of monsters. In other words, one child is born with two arms, but if we dial up the heat significantly (according to an exogenic view), we might end up with another child having four arms. Pure chance, not purpose, seems to be behind nature’s processes. To combat this accidental view, Owen argued that monsters resulted from preset changes in the germ, and this made room for the idea that monsters were purposefully caused.
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Owen offered a clever rescue, one that made sense out of the increasingly undeniable empirical data of transmutation, but also saved a role for God’s design. The rounded jigsaw skulls of vertebrate animals, for example, may originally have been a monstrous deviation from an ancestor, a tera-tological alteration of rostral vertebrae. But, according to Owen, such a monstrosity was preprogrammed by God and had led to an evolutionary jump, called
saltation
, a new kind of genus or order. The logic of monsters is synthesized with the idea of morphological archetypes if we consider that the homologies we see (the common body plans) are like footprints
of the previous saltational monster jumps. God uses monsters to install his evolutionary designs over time, and the archetypes reveal to us some of those installation points.

Darwin’s
Origin of Species
was published in 1859, but long before that he was privately scribbling his theories in red notebooks. After his long journey on the HMS
Beagle
(1831–1836) he returned to London with a veritable treasure trove of exotic specimens, preserved animals, and strange fossils. At the same time that he was secretly writing notes to himself about transmutation, he was working with a variety of British naturalists to analyze, describe, and name his specimens. One of these new London friends, introduced by the famous geologist Charles Lyell, was the curator and anatomist Richard Owen. At the time, Owen was in charge of John Hunter’s collection, which was housed in the Royal College of Surgeons. Owen worked to describe Darwin’s specimens (including a giant sloth species that Owen named
Mylodon darwinii
), but he also exposed Darwin to the teratological interests of Hunter’s work.

It is clear from Darwin’s notebooks of the late 1830s that he became fascinated with the monsters in Hunter’s collection and Hunter’s opaque teratology theories. One idea that he underscored, even calling it “Hunter’s Law,” was that monsters varied according to laws.
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In particular, specific anomalies seemed to happen during certain times of gestational development. The unnatural positioning of limbs or organs happened during a certain week range, and the addition of digits or limbs happened during another range, and so on. These correlations were both species-specific and more generic. Darwin agreed with Owen, Hunter, and the Geoffroys that monstrosity had a law-like logic, but he was more interested in the implications of this for evolution than for embryology.
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Remember, Hunter thought monsters were already malformed in the germ code, but Geoffroy claimed they were the result of external mechanical influences of temperature or pressure. Owen sided vigorously with Hunter.
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At first, Darwin absorbed this whole debate and, following Owen’s suggestion, entertained the idea of monsters as launching points for species transmutation. But how, he still wondered, could such a launching point produce the amazing fit between a species and its environment? The theological solution seemed too incredible.

In Darwin’s notebooks we see him sifting his way through these teratological issues, keeping the workable bits from his predecessors but ultimately
finding his own way. He starts from the premise, pushed for by William Lawrence and other forerunners, that monsters are part of a larger biological phenomenon called
variation
.

But why do we recognize, he asked, that an albino is a monster variation, but a white-colored Arctic animal (e.g., an ermine hare) is an adaptational variation? Or similarly, why is a dwarf plant a monster in a temperate region but an adaptation in an alpine region? We have such variations as a six-fingered hand passed down from a parent (or even appearing de novo), but
not
related to the habit, function, or specific environment of the animal. Darwin says that some cases are obvious and easy to determine, such as when we discover nonfunctional traits: beetles, for example, “with wings beneath soldered wing-cases.”
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In those cases the oddities are inherited but they are not (at least currently) useful adaptations. But in the tricky cases, the only way of determining if a specific variation is an adaptation is to see if a subgroup of the larger family has a unique trait correlated with a unique habit of life. In other words, one would have to observe a subgroup of finches, say, with larger beaks, living successfully in a unique ecological niche away from the otherwise similar family of finches.
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Contrary to Owen, Darwin came to the conclusion that most monstrous variations were either too extreme for replication or just unrelated to environment (a characteristic they shared with most variations). However much Owen wanted to see macromutations as a first step toward new kinds of populations, empirical evidence from breeders and naturalists suggested otherwise.
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Darwin observed that hybrids either revert quickly to one of the parent types, or they do not reproduce at all. They fail utterly to spread their dramatic new traits to offspring; instead, such traits are lost in the next generation (if another generation is even possible). “An animal,” he writes, “is only able to transmit those peculiarities to its offspring, which have been gained slowly.” He continued to demonstrate his favorite rule,
Natura non facit saltum
(nature does not make sudden jumps), by pointing out that “mules have their whole form of body gained in one generation, so it is impossible to transmit them [to a subsequent generation].”
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Departures that are too far from the parents will always disappear quickly because “what has long been in the blood, will remain in blood.” Consequently, only slight variations, not monster jumps, will be passed down and possibly build up new populations gradually over time. So, although monsters are forms of variation, Darwin realized that they are not relevant variations for the transmutation issue. Monsters are either embryological mutants that
cannot reproduce, or they reproduce (like six-fingered men) but don’t fit as adaptations, or they result from hybridism but again fail to reproduce.

By provisionally entertaining the monster theory of species transmutation, Darwin was able to better hone his own thinking about evolution. It was shortly after considering the mechanism of monster jumps that he famously discovered the economist Thomas Malthus’s theory of population reduction and applied it “not only to population and depopulation, but extermination and production of new forms.”
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The idea that environmental pressures could slowly shape the distribution of minor mutations and thereby adapt the populations to their conditions of life led Darwin to his mechanism of natural selection. The year 1838 was the turning point for Darwin; before that, he thought of monsters as a reasonable catalyst for evolution, but after the discovery of natural selection he rejected the role of monsters.

Monsters continued to intrigue Darwin in his mature writings, including
Origin of Species
and
The Descent of Man
, but they never again seemed compelling as nature’s primary mechanism of transmutation. In fact, he often pointed out that the only way monsters continued to thrive, reproduce, and even become subspecies was through the reckless arts of human breeding (artificial selection). Considering the odd differences between the greyhound, the bloodhound, the bulldog, and the Chihuahua, Darwin wrote, “Domestic races of the same species…often have a somewhat monstrous character,” in the sense that “they often differ in an extreme degree in some one part, both when compared with one another, and more especially when compared with all the species in nature to which they are nearest allied.”
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The unfortunate creation of freak animals is because “man selects only for his own good; Nature [by contrast] only for that of the being which she tends.” Unlike natural selection, which results from multiple causes such as food supply, weather and geological conditions, disease, and competition inside and outside the species, humans breed animals in ways that do not maximize the health and fitness of the animal.
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The argument of the
Origin of Species
moves from conscious artificial selection to unconscious natural selection, but stylistic metaphors led some subsequent naturalists to try to put “consciousness” back into natural selection. Darwin’s occasional anthropomorphic or theomorphic metaphors got him into trouble because many people used them to justify their hope that a divine hand was guiding natural selection, and he had to denounce this interpretation for decades after.
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Remember that Owen’s monsters were possible mechanisms by which some design, some teleological direction, could be built into evolution. For Darwin, there is no teleological direction in nature. Once he hit on
natural selection of chance micromutations, he didn’t
need
any designing force in nature. He could explain the amazing adaptations of animals to environment without any need for conscious craftsmanship.
¹⁴
Darwin’s nature did not need a designer, nor did it need sudden saltational jumps to create new species. Additionally, Darwin was unimpressed by Owen’s ideal archetypes, and as the years wore on the two men grew further apart as naturalists and as friends. Suggesting that common body plans were the result of divine archetypes put Owen behind the times rather than in the vanguard.
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