In explicating this feature of broad generality for the legitimate realm of physical imposition and predictability, Kauffman (pp. 13-14) draws an apt analogy that cannot be denied, but that also identifies the limits of his favored approach:
There is no doubt that our awareness of historical contingency is proper. The question we must address is whether there might be statistical order within such historical processes. A loose analogy makes this point. Imagine a set of identical round-topped hills, each subjected to rain. Each hill will develop a particular pattern of rivulets, which branch and converge to drain the hill. Thus the particular branching pattern will be unique to each hill, a consequence of particular contingencies in rock placement, wind direction, and other factors. The particular history of the evolving pattern of rivulets will be unique to each hill. But viewed from above, the statistical features of the branching patterns may be very similar. Therefore, we might hope to develop a theory of the statistical features of such branching patterns, if not of the particular pattern on one hill.
An ironic solution to controversy between this form of timeless structuralism and historical particularism could emerge from a treaty that rigidly relegated each domain to its proper space within the analogy. But such a clearly defined and well-patrolled truce would also deprive biology of much interest and legitimate skirmishing, for our deepest puzzles and most fascinating inquiries often fall into a no-man's land not clearly commanded by either party — while we must also admit (and treasure) our human inclination to expand the domains of personally favored explanations (“pushing the envelope” in a favored cliche of our times). Historicists do claim that much of what we have often interpreted as timeless and predictable generality (with evolutionary “progress” towards some form of consciousness as a prominent example) truly falls into the domain of contingent, but still fully explainable, good fortune in the particular history of this specific planet (whatever the percentage of inhabited worlds that eventually evolve consciousness in some form). [Page 1213]
Similarly — for the subject would otherwise evoke no interesting debate — D'Arcy Thompson, Kauffman, Goodwin, and all biologists attracted to this view of life have extended their putative realm of predictable generality based on universal physical structure into examples coveted by historicists as central features of their domain. For example, I have no quarrel with Goodwin's (1994, p. 132) attribution of patterns in phyllotaxis, particularly the transition from distichy to spiral ordering, to simple constraining geometries of necessary spatial filling based on the size and rate of origin for new units at the generating center — if only because the promiscuous phyletic scattering of these transitions, and their consequent correlation to immediate rates and sizes rather than to historical context, points to physical automaticity rather than to genealogical constraint. “The frequency of the different phyllotactic patterns in nature,” Goodwin writes, “may simply reflect the relative probabilities of the morphogenetic trajectories of the various forms and have little to do with natural selection.”
But I balk when Goodwin then wishes to extend this claim for physical generality to such a phyletically localized, complex, and historically particular structure as the tetrapod limb (whereas I acknowledge, of course, the fascination and utility of recent data from evo-devo — see Chapter 10 — on general rules that this historical particular then uses to craft its uniquenesses). I don't deny Goodwin's following statement about generation from rules (1994, p. 155), but I would maintain that these particular rules originated as consequences of contingent events in vertebrate history (now expressed as regularities in the development of limb buds), and not as simple properties of the universal order of geometry: “Tetrapod limbs are defined as the set of possible forms generated by the rules of focal condensation, branching bifurcation, and segmentation in the morphogenetic field of the limb bud. All forms are equivalent under transformations that use only these generative processes. With this we arrive at a logical definition of tetrapod limbs that is independent of history. The idea of a common ancestral form as a special structure occupying a unique branch point on the tree of life ceases to have taxonomic significance.”
Several colleagues have complained that phrases like “adaptation to the edge of chaos,” while incorporating some currently fashionable imagery and terminology, lack clear scientific definition and operational utility. I regard this judgment as overly harsh and would argue to the contrary, that Kauffman and his colleagues at the Santa Fe Institute for the study of complex systems are groping towards something important. If we have been unable, thus far, to achieve a rigorous formulation, we should at least recognize that science itself has been so tuned to other, largely reductionist, modes of thought, that the basic conceptual tools have never been developed. I welcome this exploration in terra largely incognita and would only like to point out, in ending this section that the implications for evolutionary theory may extend even further than the major protagonists have recognized.
In particular, and for its engagement with a dominant theme of this book (the hierarchical reformulation of selectionist theory as the first leg on a tripod [Page 1214] of Darwinian central logic), if species gravitate to a position of best possible balance between optimization for the moment and flexibility for future change, then Darwinian organismic selection cannot directly fashion such adaptations with advantages only measurable in terms of capacity for success in the face of future environmental changes, a central component in Kauffman's concept of benefits provided by residence at the edge of chaos (p. 409): “Selection, I shall further suggest, by achieving genomic systems in the ordered regime near the boundary of chaos, is likely to have optimized the capacity of such systems to perform complex gene-coordination tasks and evolve effectively.” A Darwinian can argue that flexibility linked to future capacity for change arises exaptively as a lucky consequence of features actively evolved for immediate organismic advantage. But such capacities can also evolve by direct selection, at a higher level, for species-individuals who win differential reproductive success by their propensity for living through external crises that consign closely related species-individuals to extinction.
Exapting the Rich and Inevitable Spandrels of History
NIETZSCHE'S MOST IMPORTANT PROPOSITION
OF HISTORICAL METHOD
A. N. Whitehead famously remarked (see previous citation on p. 57) that all later philosophy might well be described as a footnote to Plato. How often, indeed, must any decent scholar invent a formulation with pride in systematic analysis, and with hope for originality — only to discover that one of history's truly great thinkers had established the same principle, recognized its importance, and even specified its full range of application. I described a case of this ultimately humbling experience (see p. 51), when I discovered that, for all the struggles of several macroevolutionists, none more intense than my own, to define a workable concept of species selection in the 1970's, Hugo de Vries had formulated the idea, and even applied the same name, in his 1905 book, written in English and therefore scarcely qualifying as light hidden under a bushel for anglophonic readers.
I knew that a claim for originality could never be asserted for my various writings on the key structural and historical principle of inherent differences between current utility and causes of origin, and on the consequent impossibility of inferring reasons for evolutionary construction only from current adaptive roles (Darwin, after all and as we shall see (pp. 1218–1224), invoked this principle to disperse a theoretical objection that he regarded as the most potent challenge to the central logic of natural selection). I have written about this subject for more than 30 years, and with a growing attempt at systematization, moving from my naive, albeit accurate, distinction of “immediate” and “retrospective” significance in Ontogeny and Phylogeny (1977b), to the spandrels of San Marco (Gould and Lewontin, 1979), to the codification of exaptation as a missing term in the science of form (Gould and Vrba,
1982). Only my work on punctuated equilibrium has attracted more citations, [Page 1215] and I ventured to hope that I had, at least, presented a richer and more systematic analysis to demonstrate the centrality of this underappreciated principle, which operates so effectively as a bulwark for structuralist perspectives in evolutionary theory — thus setting the location of the topic within this book. (I wrote in 1982, epitomizing the meaning of this theme for the general subject of constraint as a structural channeler of adaptation (Gould and Vrba, 1982, p. 13): “Exaptive possibilities define the 'internal' contribution that organisms make to their own evolutionary future.”)
Then, in 1998 and thanks to the broader vision of my (then) graduate student Margaret Yacobucci, I discovered that Friedrich Nietzsche had brilliantly elucidated this principle, with its full spate of implications, in one of his most celebrated works, The Genealogy of Morals, first published in 1887.
Throughout his career, Nietzsche (1844-1900) struggled to identify and define the root motives behind our conventional beliefs about morality, philosophy and religion in Western traditions. He viewed these beliefs as secondary and functional expressions of a primary, generating source: “the essence of life, its will to power” (1967 edition, p. 56). And he recognized that we would never understand the nature and character of this primary source if we only analyzed the current utility of its secondary manifestations.
Nietzsche has received a bum rap from history, and for reasons clearly beyond his intention or control. In identifying traditional beliefs as secondary expressions of a will to power, he did not wish to deny their potency or their value, but only to make a proper logical separation so that their sources of origin, which we must also understand if we wish to achieve a full appreciation of their history and status, might be disentangled from their current utility. The later fascist misreading of Nietzsche did try to validate the worth, and to promote the pure expression, of a will to power on no basis beyond its mere existence — the very illogical step that Nietzsche analyzed so clearly in the work discussed in this section.
Nietzsche became mentally incapacitated in 1889, and lived the last years of his life under his sister's care. She later became an ardent Nazi, and used her control over Nietzsche's literary estate to further her own purposes, including the publication of notes that Nietzsche had discarded, and even some minor forgeries of her own. We owe Nietzsche far more respect and admiration than he receives from those who know him only for a common misunderstanding of his concept of the “Ubertnensch” or “superman” (not a Hitlerian defense of domination by the more powerful, but Nietzsche's ascetic description of a person who could accept complete repetition (“eternal recurrence” in his terms) of life, with all its horrors, rather than wishing for an edited version); and from those who may feel ambivalent towards Richard Strauss' tone poem on Also Sprach Zarathustra (Nietzsche's treatise on the tibermensch), the source for the stunning opening theme of Stanley Kubrick's film 2001, and a bit scary in its apparent glorying of a transcendence that might not always be kind to the majority left behind.
In the Genealogy of Morals, Nietzsche addresses the differences between historical origin and current utility in section 12 on the nature and meaning [Page 1216] of punishment. He begins by outlining the various opinions of moral philosophers on the function or purpose of punishment in current society — “for example, revenge or deterrence” (p. 55), or more specifically (p. 57) “as a means of rendering harmless, of preventing further harm ... as payment of a debt to the creditor in any form (even one of emotional compensation)... as a means of isolating disturbance of balance.”
Nietzsche does not deny the force of these current utilities (and may well approve them as a matter of personal or public morality). Rather, he wants to resolve the different issue of the historical origin of punishment in human evolution (a quest highlighted in his book's title, The Genealogy of Morals). He recognizes that confusion between his question of historical origin and the unchallenged documentation of current utility poses the greatest barrier towards resolution. The opening sentences of this section outline the problem (p. 54): “Now another word on the origin and purpose of punishment — two problems which are separate, or ought to be: unfortunately people usually throw them together. How have the moral genealogists reacted so far in this matter? Naively, as is their wont: they highlight some 'purpose' in punishment, for example revenge or deterrence, then innocently place the purpose at the start, as causa fiendi [cause of making] of punishment — and have finished. But 'purpose of law' is the last thing we should apply to the history of the emergence of law.”
I would not, in this book, so highlight this crisp dissection of a key problem in evolutionary biology as well — the distinction between historical origin and current utility — if Nietzsche had not generalized the issue as central to all historical study, and if he had not so clearly explicated both the biological meanings, and the implications for adaptationist analysis as well.
Nietzsche labels the need to distinguish historical origin from current utility as “the major point of historical method” (p. 57). “There is no more important proposition for all kinds of historical research” (p. 55), he adds, just before presenting his clearest statement of the general issue: “Namely, that the origin or the emergence of a thing and its ultimate usefulness, its practical application and incorporation into a system of ends, are toto coelo [entirely, or literally 'to the highest heavens'] separate; that anything in existence, having somehow come about, is continually interpreted anew, requisitioned anew, transformed and directed to a new purpose.”
To resolve his particular issue, Nietzsche needs to make this separation because he wishes to locate the origin of punishment in the almost inevitable manifestation of a primal will to power. But if we make the mistake of equating an admitted and efficacious modern utility (in deterrence or resolution of debt, for example) with the ground of origin as well, we will never understand the genealogy of morals. Again, and contrary to the common misunderstanding, Nietzsche does not wish to advocate historical origin as a source of validation. Quite to the contrary, he argues that we need to understand the reasons for origin in order to analyze the source and strength of the underlying motivation (whatever the current utility), thus giving us better insight into our actions and natures. [Page 1217]
In a fascinating passage, Nietzsche then uses the biological example of eye and hand to assert his specific point about punishment, and to introduce a relative ranking, with the adaptation of current utility regarded as a secondary imprint upon a more fundamental original source:
No matter how perfectly you have understood the usefulness of any physiological organ (or legal institution, social custom, political usage, art form or religious rite) you have not yet thereby grasped how it emerged: uncomfortable and unpleasant as this may sound ... for people down the ages have believed that the obvious purpose of a thing, its utility, form and shape are its reason for existence: the eye is made to see, the hand to grasp. So people think punishment has evolved for the purpose of punishing. But every purpose and use is just a sign that the will to power has achieved mastery over something less powerful.
Two other aspects of Nietzsche's extraordinary analysis show how completely he had grasped this key principle of historical explanation with all its far-reaching implications, each of equal importance in evolutionary biology as well. First, he recognizes (as Darwin did) that the disengagement of current utility from historical origin establishes the ground of contingency and unpredictability in history — for if any organ, during its history, undergoes a series of quirky shifts in function, then we can neither predict the next use from a current value, nor can we easily work backwards to elucidate the reasons behind the origin of the trait. Note, in the following passage, how Nietzsche refers to the chain of secondary utilities as “adaptations”; how he specifies that the steps in the sequence of utilities follow each other “at random” (in Eble'
s (1999) sense of unrelated to, and unpredictable from, previous states and not in the strict mathematical sense); and how he clearly recognizes the significance of this principle for dispersing any hope that a phyletic history might be interpreted as a “progressus towards a goal,” another almost eerie similarity with Darwin's understanding of the meaning of contingency in evolution:
The whole history of a “thing”, an organ, a tradition can to this extent be a continuous chain of signs, continually revealing new interpretations and adaptations, the causes of which need not be connected even amongst themselves, but rather sometimes just follow and replace one another at random. The “development” of a thing, a tradition, an organ is therefore certainly not its progressus towards a goal, still less is it a logical progressus, taking the shortest route with least expenditure of energy and cost, — instead it is a succession of more or less profound, more or less mutually independent processes of subjugation exacted on the thing.
Second, Nietzsche promulgates an ordering of importance, with reasons for origin as primary in more than a merely temporal sense, and current utilities as sets of secondary “adaptations” (his description) with only transient status and less influence (than the persisting force behind the primal origin) [Page 1218] upon any future state. I would not defend this ranking for an application to evolutionary theory, if only because Nietzsche's formative “will to power” identifies a persisting force that must influence any subsequent adaptation as well, whereas the original context of an evolved phenotypic feature need not exert such a continuing hold upon later history. But I do appreciate Nietzsche's point, which can be translated into evolutionary terms as the source of constraint. The original reason does continue to exert a hold upon history through the structural constraints that channel later usages. Once feathers originate for thermoregulation, the form of any later utility for flight will be influenced by features built for the original context.
The Structure of Evolutionary Theory Page 193