The perception and reconstruction of the apt-organism

The perception and reconstruction of the apt-organism

J. Social Biol. Smci. 1988 II, 221-233 The perception and reconstruction apt-organism of the Peter D. Dwyer Zoology Department, University ...

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J. Social

Biol.

Smci.

1988

II,

221-233

The perception and reconstruction apt-organism

of the

Peter D. Dwyer Zoology

Department,

University

of Queensland, St Lucia, Australia 4067

Brisbane,

Queensland,

The organism-environment relational notion of ‘adaptation’ has, for more than a century, dominated the thinking of English-speaking evolutionary biologists. If a science of form is to be renewed, then the idea of ‘adaptation’, as state of being (hereafter termed uptation), must be critically examined. It is argued that aptation, as perceived, may lie anywhere on an ideal continuum between a ‘perfect fit’ of organism to environment and a ‘random walk’ of organism in a near infinite environment. Aptation as reconstructed by evolutionary biologists has been consistently positioned toward one end of this continuum. Currently accepted evolutionary models motivate the prevailing experience of aptation and, indeed, critics of the ‘adaptationist programme’ differ from those they criticize not in the way they view aptation but in asserting a plurality of originating mechanisms. Different expressions of aptation-as perceived, not as reconstructed-may be underlaid by differing constellations of extrinsic and intrinsic constraints on organismal form. As the proportion of extrinsic to intrinsic constraints on form shifts from ideal ratios of I : 0 to 0 : I, so functionalist methodologies will be less useful, and structuralist and transactionalist methodologies will be more useful, as aids for understanding form.

Introduction The thing is prior to the ideas men form of it, though the idea, once formed, can exert a profound influence in changing the shape of things, and in bringing new combinations of things into existence. Throughout human history, things and ideas ceaselessly interact, but never so as to upset the primacy of things. For, in order to become a force in history, the idea, which is derived from things, must be made flesh, and become a thing (Cole, 1964; p. 17). Darwin, for all his intellectual daring and reinterpretation of facts, and for all the challenge he proffered to the religious outlook of his contemporaries, did not directly challenge their commonsense image of natural law, which was that of a statue set up by God and obeyed by nature. As he viewed the vast array of plant and animal forms with which he was familiar, what aroused his scientific wonder was just what had always aroused people’s religious wonder-the special fitness of each kind of organism to cope with the conditions of its existence (Langer, 1970; p. 363). The expectations of theory color perception to such a degree that new notions seldom arise from facts collected under the influence of old pictures of the world. New pictures must cast their influence before facts can be seen in different perspective (Eldredge & Gould, 1972; p. 83). ‘The discipline of morphology is currently undergoing a renaissance in evolutionary biology’. With these words Lauder (1982) introduced the reprint of E. S. Russell’s (1916) Form and Function. Gould (1970) has written in similar vein of a ‘science of form’ and (1980) that a new and general theory of evolution ‘will restore to biology a concept of 0140-1750/88/020221+13

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organism’. The newness of the interest in form is, of course, largely confined to Englishspeaking and writing evolutionary biologists; morphological inquiry did not abate or stagnate in Europe (e.g. Raup, 1972; Seilacher, 1973; Grass&, 1977; Riedl, 1978, 1983). Among English-speaking biologists, decline in the study of form was consequent upon the success of Darwinian and, especially, neo-Darwinian ideas (Lauder, 1982). These ideas produced powerful connections between genes, phenotypes and environments by arguing that natural selection was causal of both the process and state of ‘adaptation’. ‘Form’ as a concrete, even if historical, entity gave way to ‘adaptation’ as a relational, and certainly historical, state. Evolutionary inquiry, as a means of investigating relations through time, focussed on the latter. If a renewed science of form is to emerge among English-speaking biologists, then the notions of ‘form’ and ‘adaptation’ need to be critically examined. Their connections need to be re-established. One approach to this would be to position ‘adaptations’ as a class of possible concrete entities and ask, first, how these entities have been conceived by evolutionary biologists and, secondly, how they might be studied to retrieve ‘organism’, and hence ‘form’, from the insistent environmentalism of neo-Darwinism. This is the purpose of the present essay. To achieve my aims, it is essential that ‘adaptation’ as state of being be unambiguously separated from ‘adaptation’ as process of becoming. From the former, I delete the prefix ad( = towards) to remove the connotation of genesis. Thus, I use the term apt&ion for the state of being and retain adaptation for the process of becoming. This decision is influenced by, but differs from, Gould & Vrba (1982) and Harper (1982). The essay is structured as follows. First, I describe the relational phenomenon of aptation such that the description matches the perception. Secondly, I show how biologists have reconstructed an experience of aptation which does not match the full ambit of their perception. Thirdly, I explore the possibility that different expressions of aptation-as perceived, not as reconstructed-will be most usefully investigated from different methodological perspectives. What we see: perception of the apt When biologists observe nature they see individual organisms. These exist or act within contexts which we have grown accustomed to labelling their ‘environments’. At this level of perception, a distinction has been drawn between ‘organism’ and ‘environment’: that is, the perception arises within a prior dualistic frame. (Dualism may encourage us to separate the inseparable. For my purposes, the dualism is provisionally accepted; I return to this problem toward the close of the essay.) We observe ‘organism’ and ‘environment’ and perceive the former as existing or acting within the latter. We perceive a relation between the two. What is that relation? We perceive organisms as-and there are no easy labels for this-suited or sufficient or as apt. It is rare to observe an organism that is unsuited. We would recognize a fish suffocating on dry sand or a wind-blown waif as unsuited: we would know why they were unsuited and might feel for them. They are out of context. But these observations would not diminish our perception that most organisms most of the time are ‘sufficient’ within their environments. We have learned to call the relational phenomenon of ‘sufficiency’ aptation. Beneath the bark of trees there are insects whose body form is flattened. In deserts there are plants with thickened, moisture-holding leaves. In the sky the birds fly and are feathered. These are instances of aptation, of organisms being ‘sufficient’ within environments.

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I have illustrated aptation by commenting that the birds fly and are feathered, yet the origin of feathers may have had nothing to do with flight (Bakker, 1975; Thulborn, 1984). Originally, feathers may have had a thermoregulatory function or even-it is possible-no function at all. As Gould & Vrba (1982) put it, feathers may have been co-opted for flight. A crucial distinction is needed. It is the one between ‘aptation’ as a state of being and ‘adaptation’ as an historical process of becoming. Although many writers (e.g. Weiss, 1949; Williams, 1966; Stern, 1970; Lewontin, 1978; Bock, 1980) have been careful to acknowledge or even direct attention to this distinction, it has remained inadequately drawn in the literature. The inadequacy has arisen because, nearly always, the single word ‘adaptation’ is used for both the state and the process.+ When we observe nature we perceive aptation. We do not and cannot perceive the historical process through which aptation came into being (cf. Langer, 1970; pp. 364-365). That process is outside the range of possible perception. Thus, if in birds, feathers and flight go together, if they are part of the sufficiency of birds, then no matter how or when they were linked they remain part of the aptness of birds. We all know this because it is what we all perceive. In Langer’s words it is ‘common-sense’.t The fact of aptation is just that. It is a perception of organisms within environments. It may call for explanation but does not make a necessity of any class of explanation. If organisms are apt-if we have got that much correct-then in no way does this inform us that evolution occurred. The multiple models of evolutionary mechanisms represent only one interconnected cluster of ideas that accounts for aptation. The ideas are connected because they are evolutionary. Because most biologists conflate the state and the process in the single word ‘adaptation’ they tend, even against their own best intentions, to incorporate an historical (or originating) dimension into aptation-a dimension which it does not and cannot have. An example may be useful. In a recent paper, Mayr (1983; p. 327) suggested that ‘the ubiquity of extinction’ was sufficient proof that aptation was not perfect.8 He was wrong. The historical process of extinction is irrelevant to the meaning of aptation. Aptation is an a posteriori state of being. The dinosaurs were not less apt than their recent counterparts. Allowing, then, that we perceive ‘sufficiency’, it is fair to ask what ‘sufficiency’ could be. It is a perception of a relation between organism and environment. How might we substantiate this relation? t The contrast between state of being and process of becoming is important but the word ‘state’ is slippery. ‘State’ is, itself, processual; all life is process. The distinction is of scale. The sorts of processes which comprise ‘state of being’ were not necessarily implicated in the process of origin (cf. Bock, 1980). Indeed, failure to appreciate this at the root of the functional fallacy. t Is the perception of the ‘apt’ restricted to particular cultures or to people steeped in dualism? Perhaps not. In Papua New Guinea I was told that, in the past. cassowaries had large wings and flew, while hornbills had small wings and walked on the forest floor. The cassowaries, being large and heavy, regularly fell to the ground and the hornbill, with its enormous beak, was often caught in the undergrowth. The birds solved their dilemmas by exchanging wings-the cassowary received the small wings and remained on the forest floor, the hombill received the large wings and joined the flying birds. The people who recounted this tale were not committed to dualistic models of the world yet had, it would seem, a clear perception of the apt. The theme of the tale recurs in stories from across the globe. §Mayr (1983; p. 327) wrote: ‘. other evolutionists remained fully aware that selection cannot give perfection, by observing the ubiquity of extinction and of physiological and morphological insufficiencies’. The context was of ‘state of being’, not ‘process of becoming’. In the same paper, he made the contrary and (to me) unobjectionable suggestion that, ‘Considering the strictly a posteriori nature of an adaptation, its potential for the future is completely irrelevant, as far as the definition of the term adaptation is concerned’ @. 324).

Environments 0000

Organisms 00..

Modes

of aptotion 0000 Perfect

Figure

I.

Possible chosen

fit

Programmed

expressions of aptation. (The left-right to avoid an unlzwnted. though potential,

walk

Random

walk

orientation on the jigure political metaphor)

was

In Figure 1, the possible manifestations of the relation are represented as a continuum. At the extreme left of the figure, ‘sufficiency’ is represented as a ‘perfect fit’ of organism to environment. The universe represented as environment prescribes a unique form of organism; a complete description of the former completely codes specifications of the latter. Any change to either environment alone or organism alone will jeopardize the state of organic ‘sufficiency’. At the extreme right of the figure, ‘sufficiency’ is represented as a ‘random walk’ of organism within a secure environment. The universe represented as environment does not prescribe the form of organism, it merely proscribes a class of potential forms as candidates for ‘sufficiency’; i.e. there is no possible description of environment that can code specifications of a unique apt-organism. Any change to either environment alone or organism alone is unlikely to jeopardize the state of organic ‘sufficiency’. Between the extremes of ‘perfect fit’ and ‘random walk’ the relation of ‘sufficiency’ is represented as a ‘programmed walk’ of organism within environment. The organism is free to wander but not so free that its movement relative to environment should not be bound by rules. From left to right across the figure the relation of environment to organism shifts from prescriptive to proscriptive. The possibility that a complete description of environment may code specifications of organism is progressively and, beyond the limits of the figure, ultimately reduced to zero. When we observe an instance of aptation, our perception lies somewhere on a continuum between ‘perfect fit’ and ‘random walk’. And that is all. We have no way of knowing or, at present, of measuring where on that continuum the observed expression of aptation falls. We cannot measure it because we have not tried; we have not recognized the continuum and, therefore, have not considered the need. Organisms exceeding the limits of the environmentally possible are ‘unsuited’; they are fish out of water or wind-blown waifs, but those which do not transgress these limits are sufficient. That is all we can perceive. We do not and cannot perceive some degree of sufficiency. I doubt that there is any one organism for which we know where on the continuum it is situated. It is no argument to assert that the mode of aptation called ‘random walk’ is improbable. for this is neither more nor less probable than the mode called ‘perfect fit’. There is no a priori reason to suppose that the location of all organisms will coincide, or that the entire continuum is not occupied. The continuum is of all possible expressions of aptation and each expression we perceive lies somewhere on it.

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What we get: reconstruction of the apt

I have described what biologists see-the perception of aptation. Here, I describe what they get-the reconstruction of aptation. I show how biologists construct an experience of aptation from their perception of ‘sufficiency’ and, further, how they incorrectly assume the experience to be coincident with perception. My argument commences with the pre-Darwinian trinity of aptation, species fixity and God as creator? Before Darwin, people saw what you and I see and, like us, called it aptation. They saw a relation of ‘sufficiency’ between organism and environment. What they saw they explained by ‘theorizing’ (or believing) that species were fixed and immutable and were specially created. Species were designed by a Designer. The perception of organisms as being sufficient is transformed by belief in design and a Designer. Under this belief, ‘sufficiency’ is necessarily experienced as ‘perfection’. To think otherwise would be an affront to God (cf. Mayr, 1983; p. 327). How else would He have rendered them? Thus, before Darwin, the quality called aptness was experienced as a ‘perfect fit’ of organism to environment. The notion of aptation was bound by the theory of God as Designer and was positioned at one extreme of the range of the possib1e.t By Darwin’s day, the idea of species as fixed was coming apart at the seams. The variety of individuals was being impressed upon peoples’ thoughts, and recognition of variety called to question the idea of species as immutable. God Himself was taking a back seat. His explanatory power was diminished as belief in immutable species dissolved. The self-reinforcing trinity of aptation as perfect fit, fixed species and God as Creator was reducing (in the domain of the natural) to a single experience-that of aptation. This, at least, people experienced each day: organisms were suited to the places where they lived. What people did not appreciate was their theory-bound translation of ‘suited’ to ‘perfect’. Darwin did not appreciate this either. For him, aptation was given, it was out there in nature, it called for explanation and the people were ready for his explanation. They were ready for his explanation because, in large part, it was a translation of current and popular ideas from other areas into natural history [see, for example, Bernal (1971), Schwartz (1974) Schweber (1977)]. Darwin’s experience of aptation was of achieved perfection within the constraint of observed variation. [This argument must be put because some writers protest that Darwin did not claim ‘perfection’ for Nature; e.g. Mayr (1983); see Ospovat (1981) for an account of changes in Darwin’s thought regarding ‘perfection’.] Darwin wrote: t The historical notes in this essay are, because of their brevity, constrained to be caricatures. Changes in ways of seeing the world have never been abrupt and, for example, new insights attributed to the rise of Darwinism were sometimes not accepted until well after Darwin himself had died. In this sense, like many other writers, I use ‘Darwin’ and ‘Darwinism’ in rather metaphorical ways. Useful and detailed historical accounts are provided by Ghiselin (1969) Ospovat (1981). Ruse (1979) and Russell (1916). One historical transition excluded from the body of this essay-needs brief mention. Many morphologists before Darwin’s time sought to discover the ‘unitv of plan’ that underlav the diversitv of forms (Lauder, 1982). This unity, or class of ‘unities’. could be regarded as an expression of ‘perfection’ ht nature and, hence, as the epitome ofGod’s ‘plan’. Questions concerning the relation between form and function in the environment transformed the idealistic notion of ‘perfection’ into the relational notions of ‘design’ and ‘perfect fit’. This happened into the relational notions of ‘design’ and ‘perfect fit’. This happened for scientists and theologians alike. The religious quarrel with the Darwinians centred on causes of the relational notion, and this is the place at which the historical notes of this essay commence. Present-day fundamentalist Christians have accepted environmentally motivated descriptions of organismal form (i.e. as aptations) while vigorously protesting the causal explanations of evolutionary biologists. $According to Popper (1959) and others, all observation is theory-bound. Although this idea has its detractors, it is rather generally accepted by scientific biologists. Within the context of Popper’s assertion, statements about theory-boundedness in this essay refer to theories within theories; i.e. the observation of aptation is bound by dualism, its reconstruction is bound in other ways. I am concerned with the latter.

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. . . such a conclusion, even if well founded, would be unsatisfactory, until it could be shown how the innumerable species inhabiting this world have been modified, so as to acquire that perfection of structure and coadaptation which justly excites our admiration. . . . it is preposterous to attribute to mere external conditions, the structure for instance, of the woodpecker, with its feet, tail, beak and tongue, so admirably adapted to catch insects under the bark of trees (1872; p. 2).

Darwin withdrew from an assertion of ‘perfection’ in as much, and only in as much, as the mechanism he proposed seemed incapable of giving the products that he wanted. Because he generously devoted five chapters of The Origin of Species to ‘the most apparent and gravest difficulties in accepting the theory’ (1872; p. 3), it has been easy for later authors to select passages which declare ‘perfection’ as improbable or unattainable. But-though this will emerge more forcefully below-had Darwin not experienced aptation as ‘perfect’ (or at least near perfect), had he experienced it merely as ‘sufficient’, why did he commit himself to an hypothesis of mechanism which could produce nothing less than an approximation to the ‘perfect’? Darwin withdrew from strong assertions of ‘perfection’ in nature only in as much as his hypothesis required it. In this sense, inadequacies in his own hypothesis, and his inability to devise a ‘better’ one, encouraged him to see the world somewhat differently.7 Darwin’s hypothesis set in train the idea that pursuit of perfection, not perfection per se, might be the name of the game. He wrote, ‘. . . Natural Selection almost inevitably causes much Extinction to the less improved forms of life . . .’ (1872; p. 3). Like Mayr, more than a century later, Darwin got it wrong; he had confounded state and process and left a persistent legacy. Darwin showed how the variety of individuals might provide the source of variety between species. This, I think, was the raison d’gtre of his genius. In one breath, he rationalized the observation of variety with a notion of evolutionary transformation. He gave us a different experience of reality. His theory of Natural Selection explained aptation not merely as the reality of ‘sufficiency’ but as attained perfection within the bounds of available variation. He left the experience-the construction-of aptation intact and chained it to a different theory. Had he not done this, I doubt his theory would have changed our minds. How could he have promoted the idea of a ‘perfecting’ mechanism if he did not believe the perfection was there? How could he have argued for mere sufficiency when people experienced perfection, when, indeed, perfection was all that remained of their ‘trinity’? To be convincing, even to convince himself, Darwin had to devise a mechanism for evolution which could approximate all that God had done before. God’s power had, after all, been very great. He had rationalized an experience of aptation which would stay intact long after He had left centre stage. The neo-Darwinian experience of aptation is not at a far remove from Darwin’s own. The neo-Darwinians concede imperfection and have named it.1 They acknowledge lag -a tiny temporal mismatch-between organismal and environmental change, use metaphors from Alice in Wonderland (i.e. the Red Queen hypothesis) and speak of the opt-organism. Natural selection optimizes, it deals in multivariate states and pursues 7 Da&n said that natural selection might not be the only mechanism of evolutionary change (Darwin, 1872; p. 395; Gould & Lewontin, 1979). He did so when he could not use his hypothesis to explain certain observations; e.g. sterile castes in bees. The concession allows the thought that he entertained the idea of other mechanisms which might lead to ‘perfection’. Some of the observations Darwin regarded as problems have subsequently been resolved in terms of expanded versions of his own model (e.g. as in sociobiology). $ The bestowal of a name upon a collective of things is a very powerful and interesting act of communication. The name explains (i.e. those included in the name are now linked by virtue of the name), but the explanation is instantly reduced to description (i.e. the abstract is made concrete, the idea becomes a thing). Except in ceremonies of naming, the decay of explanation to description usually takes a long time.

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compromise solutions. [Harper (1982) and Patten (1982) make much the same comment, though in different ways.] But the new synthesis has been subject to many assaults upon methodology (e.g. cladistics) and the understanding of mechanism (e.g. neutralism, punctuationism and epigenetics). In as much as the neo-Darwinians have bowed to these assaults-though their protests have often been vigorous [e.g. Cain (1979); Stebbins & Ayala (1981); Berry (1982)]-so they have reconstructed their experience of aptation. Where mechanism dictates the neo-Darwinians have followed-this is the Red Queen hypothesis revisited upon the evolutionists! They withdraw from perfection, but only insofar as the logic of current and acceptable theory insists.+ Like Darwin before them, but even more so, they experience aptation as an imposition of acceptable theory onto observed and observable reality: cf. Bock’s (1980) suggestion that aptations should be defined relative to specific environments of selection; this, of course, begs the question of origins by forcing organisms, to the best of our ability, into neo-Darwinian straitjackets. What the neo-Darwinians see is suitedness; what they get lies toward the ‘perfect fit’ end of a wide-ranging continuum. They have positioned themselves within the dilemma of Pangloss in believing that all is for the best in a not very good world; that aptation is the best necessary in a world of competitors or the best possible within the limits of the possible. Phylogenetic legacy may define those limits (e.g. Raup, 1972). Two recent and important papers appear to offer a way out. These are Gould & Lewontin’s (1979) expose of the ‘Panglossian paradigm’ and Gould & Vrba’s (1982) dissection of the idea of aptation. Gould & Lewontin (1979) criticize the ‘adaptationist programme’. They depict the literature of biology as being littered with exemplars of the functional fallacy. They show that excessive reliance upon neo-Darwinian thinking has blinded biologists to other possible, or actual, interpretations of the world. They catalogue the part non-Darwinian factors and mechanisms might play in change and show how some of these could mean that organic form is not always, or primarily, underlaid or driven by conventionally accepted processes of selection. In particular, through the use of powerful metaphor (i.e. the spandrels of San Marco) they seem to show that ‘design’ and ‘function’ in organisms is built within prior architectural constraints on form; that the domain upon which selection acts is contained or legislated by, for example, epigenetic processes. Gould & Vrba (1982) want to expand our hold on aptation. (They use ‘adaptation’ to refer to the state of being apt. I shall write of adapted features, or constellations of features, where they write of adaptations. I shall italicize terms, modified or not, which are used in their sense.) Early in the paper, they distinguish two meanings of apt features in evolutionary biology. These are (1) features ‘built by natural selection’ for the functions they now perform, and (2) features which ‘in a static, or immediate way’ enhance ‘current fitness, regardless of historical origin’. Presumably, the second meaning includes the first. They suggest restricting the term adaptation (i.e. adapted feature) to only those features whose historical genesis was through Darwinian or neo-Darwinian processes. (cf. Mayr, 1974; p. 107; ‘Adaptive means simply: being the result of natural selection’.) They propose the new term exaptation (i.e. exapted feature) for all those features whose contribution to the organic whole is exactly like that of an adapted feature, but whose historical genesis was not through Darwinian or neo-Darwinian processes. (Taken together, adapted and exapted features are, in my modification of their terminology, apted features.) Finally, they argue that exapted features originate by t Note that organisms may not be ‘running as fast as possible to stay in the same place’. Evolutionary change could sometimes alter the expression of aptation in the direction of ‘random walk’. According to this argument, the Red Queen hypothesis is, itself, part of a reconstruction of aptation as near perfect.

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co-option of either features that were originally adapted for other functions (e.g. feathers for flight as a co-option of feathers implicated in, perhaps, temperature regulation), or features that were non-apted(i.e. features whose origin did not entail the action of natural selection). The two meanings of apt feature identified by Gould & Vrba differ in that the first includes an explanation of the observed phenomenon and the second does not. The first meaning is more restrictive than the second because the historical explanation used (i.e. origin via natural selection) may not account for all relevant observations.+ The difficulty with Gould & Vrba’s classification of apted features is that both adapred and exapred categories are defined by reference to their genesis. The consequences of this are twofold. First, it means we cannot place any feature (or constellation of features) of any organism into an appropriate category until we know the process underlying its origin: we may seldom be able to use either term. Secondly, it means that all apfed features of organisms are viewed by Gould & Vrba as being part and parcel of an expression of aptation lying toward the ‘perfect fit’ end of the continuum of possible expressions. That is, apted features, according to Gould & Vrba’s reasoning, are either built for a current use by natural selection or, although not built by selection, are used as though they were. With the exception of so-called non-apred features, Gould & Vrba leave us with nothing which might contribute to alternative expressions of aptation. (I return to the problem of non-apt features below; see also Gould & Vrba, 1982; p. 12.) Taken together, the papers of Gould & Lewontin (1979) and Gould & Vrba (1982) do not constitute a radical overhaul of our understanding of aptation. There is, in fact, no overhaul except in the sense that they want to restrict the scope of the word to only those expressions of ‘sufficiency’ whose origins have been underlaid by natural selection. (In the same way, ‘adaptation’ as process is reduced to its neo-Darwinian modes.) Expressions of ‘sufficiency’ underlaid by different processes are to be given different names, but they are not regarded as being different in kind (i.e. as states) to the others. Even non-apted features join the fold, for they ‘establish an enormous pool for potential’ co-option as exapted features (Gould & Vrba, 1982; p. 13): as features, in other words, whose use is precisely like that achieved under a regime of selection. The contributions of these authors do, however, revise our understanding of the processes which produce aptation. They say these processes are diverse but, in the final analysis, their attack on the Panglossian paradigm amounts only to an assertion that there are many paths to the same end. If we are to agree that many exapted features were once adapted (in their restricted sense), how should we view the past status of current architectural constraints-these, too, may have originated through the action of natural selection? The definitional world these authors offer may prove the undoing of aptation. Their efforts may confine the notion to just one part of the possible and place the full scope of the possible beyond our grasp. Like the neo-Darwinians before them, Gould, Lewontin and Vrba have reconstructed their experience of the relation between organism and environment as a statement of the allowable; and they have defined the allowable in terms of current models of evolutionary mechanism. The result is that what they allow as ‘sufficient’-as state-is not much more than those they criticize have always allowed. + In contrast to Gould & Vrba (1982; p. 4). 1 do not accept that pre-Darwinian usage of aptation necrssari/~ included an explanatory dimension. My understanding is that before Darwin, aptation was perceived as given and all modes of aptation were explained by reference to a Creator. This argument does not founder merely because most participants would not have separated the perception and the explanation. This failure of separation is, after all. my argument regarding scientific biologists.

The Apt-organism I have shown that when biologists look at nature what they see is not what they get. They see ‘sufficiency’ but they get an approximation to ‘perfect fit’, an approximation which they variously label the ‘pursuit of perfection’, the ‘opt-organism’, etc., or which they construct as a near replica of one of these (e.g. the phylogenetically constrained organism). The mismatch between the ‘seeing’ and the ‘getting’ occurs because biologists are committed to acceptance of certain models of evolutionary process. It is only in as much as these models show the way that biologists withdraw from their construction -their experience-of aptation.

What can we do? Modes of enquiry Here, I explore the possibility that different modes of inquiry, different methodological perspectives, may be best suited to the understanding ofdifferent expressions of aptation. Imagine a situation where the relation between organism and environment was expressed as perfect fit. Given dynamism as inherent in the world, given that environments do change, it might, if we exclude a Creator, be hard to go beyond a vulgar neo-Darwinian model to account, in historical terms, for the observed fit and its ongoing reaccommodation to the changing environment. What would this mean? It would mean that each and every attribute of the organism was ‘fluid’, was prone to undirected variation and subject to the inevitability of environmentally directed selection. Each attribute taken separately would be fitted; together the fit would be perfect. It would mean, in other words, that the form of the organism (mutations aside) was subject to only those constraints which impinged from the environment in which it was situated. For us, as researchers, the environment would be a precise map of the organism. We could translate literally from environment to organismal form-there would be no ambiguity. Imagine a second situation where the relation between organism and environment was expressed as a random walk in a near infinite universe. Now our attempts to understand organismal form could not be aided by environment because the latter would not provide a map of form. Nor could our attempts be helped by evolutionary theory because, currently, there are no general models allowing the possibility which we are considering. Only one argument may help and this uses analogy and concerns constraints. If at the extreme of ‘perfect fit’ the form of the organism was subject to only extrinsic constraints, so at the extreme of ‘random walk’ the form of the organism must be subject to only intrinsic constraints. If the environment impinged on the organism, the walk could not be ‘random’. If it does not impinge, then all constraints are intrinsic and we may sustain our speculative possibility. From one end to the other of the continuum of aptation we may be observing an ever-altering, probabilistic assembly of constraints on form. With a shift from ‘perfect fit’ to ‘random walk’, organismal form may be decreasingly subject to constraints from without (i.e. environmental whim) and increasingly subject to constraints from within (e.g. epigenetic processes). But, of course, under this model something else happens. At the place where all constraints on form are intrinsic, so ‘environment’, as that term has been used in the argument, is irrelevant. It is irrelevant because the organism has become its own environment and the dualistic model of the world with which we started has collapsed. It is no longer appropriate.+ +To suggest that a dualistic model is inappropriate to resolution of certain observations (i.e. that the organism may be its own environment) does not collapse the earlier argument founded in dualism. Even if the organism was its own environment, ‘it’ (i.e. the unity) would be, and we would perceive ‘it’ as, apt within some extrinsic, although analytically irrelevant. environment.

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The gamut of expressions of aptation might be represented as a series in which the ratio of extrinsic to intrinsic constraints shifts between 1 : 0 and 0 : 1. (An assumption here is that the sum of all constraints or all attributes is very large.) At one extreme, none or few of the constraints on form are intrinsic. If we want to understand form then, here, it is both proper and useful to perform as functionalists, to seek correlations between organism and environment, avoid functional and genetic fallacies, and scan the correlations for acceptable, i.e. explanatory, causes (cf. Dwyer, 1984). This is what most twentieth-century English-speaking biologists have been doing. The methodology has given us the neo-Darwinian model and the ‘selfish gene’ to account for the genesis of these modalities of form; it has given us optimal design ‘theory’ and sociobiology to describe extant forms (i.e. states) of this kind. Toward the middle of the series, there are many intrinsic constraints on form; the ratio of extrinsic to intrinsic constraints approaches 1 : 1. Here, it may be possible to locate (or envision) an environmental grid which provides a metaphor for organic form. The metaphor will be unlikely to yield a literal translation; e.g. the programmes of neo-Darwinism, optimal design ‘theory’ and sociobiology will not be very helpful. To understand form, then, here, we must first be confident that the metaphor is apposite (i.e. it is crucial not to confound process and product) and, secondly, dissect out the objective base of the metaphor (i.e. to discover what it is about the organism which makes our preliminary metaphor seem so good; cf. Dwyer, 1984). This methodology is called structuralism. It was practised by many pre-Darwinian morphologists (cf. Webster & Goodwin, 1982), is familiar to biologists in Europe where interaction with the human sciences has been sustained (e.g. Riedl, 1978, 1983) and has recently undergone a re-awakening or rediscovery among some English-speaking evolutionary biologists (e.g. Gould & Lewontin, 1979). For obvious, though unfortunate reasons, it has made little impact upon the science of ecology-the science which has restricted its focus to functionalist modes of inquiry but which should be concerned to understand all states of the sufficient. At the other extreme of the continuum of aptation, most or all constraints on form are intrinsic. Here, the organism is its environment and the appropriate methodology is transactionalism. The methodology is accessible from the work of some students of human-environment relations and some psychologists (e.g. Tibbets & Esser, 1973; Spiegel, 1971). Within biology it is seldom practised. Patten’s (1982) analysis of ‘environs’ as a ‘relativistic elementary particle for ecology’ is the single instance known to me unless, perhaps, the same perspective underlies Shelldrake’s (1981) work. My own prejudice is, with one exception, against finding this state of being manifest in the biological world. The exception is mind, which has been described succinctly as a hologram reflecting upon what may be, after all, only a hologram (i.e. the physical universe), and which I regard, rather less poetically, as an internalization of the aggregate of relationships of which the mind’s bearer is a part. Mind is internalized environment and, hence, its own environment (cf. Bateson, 1979). The methodological perspectives I have described as functionalist, structuralist and transactionalist are, themselves, parts of a continuum. This may be mapped onto the continuum of expressions of aptation. It shows ways in which we might profitably investigate different modalities of form. But this solves nothing. It would seem that we cannot apply a method until we know what we have got. We must first position an expression of aptation upon the continuum of the possible before we can begin to study it. There are two solutions to this dilemma. First, we could try. We could see what was learned by understanding and using other methodologies de novo. The ultimate test of such experiments, of course, would be other

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people’s acceptance of our fresh interpretations and the ultimate danger, perhaps, would be that we were too convincing and reconstructed the world in the shape of the tested methodology.+ We could apply other methodologies to either the problem of understanding extant states of being or the derivation of models which accounted for the origin of hypothesized states. The first is what Patten (1982) has tried with transactionalism; the second is what many biologists are now trying with structura1ism.t We could be less radical and attempt modest revisions of the notion of aptation by, for example, defining the environment of an organism to include transformations arising from organismenvironment relations and only then proceeding to an analysis of those re1ations.s There is, of course, one body of supposed biological facts which suggests the rewards from such attempts could be worth the effort. This is the totality of so called non-apt features (i.e. ‘non-aptations’ in the usage of Gould & Vrba, 1982); a totality which many biologists think is not inconsiderable. Gould & Vrba remark on the irony of the term non-apt. Non-apt features are conventionally viewed as ones ‘not now contributing to fitness’ (Gould & Vrba, 1982; p. 12); they may have originated as neutral features or they may have fallen from grace. The metaphor is itself apt. So-called non-apt features are those which we cannot accommodate within the prevailing functionalist mould; they are outside the ambit of neo-Darwinian models. But, on the argument of this paper, they cannot be non-suited features; if they were not part of suitedness they would be non-existent features. Thus, it is possible that many so-called non-apt features are at the core of intrinsic constraints-they may be the features which allow modes of aptation other than ‘perfect fit’. (Note also, that the term ‘non-apt’, of itself, contributes to the experience of aptation as near perfect.) The second approach is of evolution, not revolution. As our understanding of evolutionary mechanism has enlarged, through the past century, so our experience of aptation has both retreated from the perfect and expanded. We could, therefore, keep nibbling in the same way, puzzling about fragments of the world which do not seem to fit our explanatory models. (The danger here is that the explanatory models themselves change, carrying our constructions of the world with them; I am asking that both the models and the constructions are allowed to expand, cf. the footnote on p. 226) We could use the apparent facts of evolutionary mechanism as a yardstick against which we diagnosed expressions of aptation. This approach would yield results but the irony would not be + Analyses of the relation between ‘society’ and ‘language’ have, through the past century, shifted from reliance upon functionalist methodologies, through structuralist and post-structuralist methodologies to arrive, very recently. at transactionalist analysis (Parkin, 1982). Simultaneously, the perceived relation between ‘society’ and ‘language’ has shifted from seeing either one as functionally tied to, or causal of. the other, through the notion that each is a transformation of the other, to arrive at a perception of their unity. It is hard to know whether the existent relation (or, perhaps, varied expressions of that relation) has ever been experienced by the analysts. It seems, rather, that the preferred methodologies have entrained the experience. i Biologists who are experimenting with structuralist methodologies appear to encounter several difficulties. First, they are better critics of functionalism than they are constructive users of structuralism; i.e. they use. structuralism to greater effect in its destructive rather than its creative role. Secondly, their passion for structuralism often leads to unreasoned assertions that functionalism has no place in biology. The danger here is that they may leave no place for natural selection. Thirdly, they sometimes align themselves with the political ideology (in contrast to the methodology) of Marxism and, in this sense, can sacrifice the gentleness that ought to be the companion to assertive human discourse. These sorts of difficulties are all evident in two collections of papers published by ‘The Dialectics of Biology Group’ (Rose, 19820, 6) and, for example, by the paper Lambert & Hughes (1984) chose to call ‘Misery of functionalism’. 9 In Dwyer (1987) peopleeenvironment relations concerned with food-getting are analyzed ufier environmental attributes (e.g. dispersion, supply. particle size and lasting properties of food resources) have been defined to include manipulations of those attributes by the people. This procedure conflates some aspects of organism and environment and, by the standard of conventional ecological practice, is messy thinking!

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lost.+ We would be using evolutionary theory to construct the meaning and the limits of aptation. The theory which once explained what we saw would have become the technique which helped us to see. But, perhaps, after all, this would be fair. People experience apparently new theories in either or both of two ways. The new theory may reinforce prior experiences of the world as, indeed, Darwinism reinforced a prior experience of aptation. The new theory may also, or instead, reconstruct the real. Perhaps this last was Darwin’s gift to us all. He gave us evolution as a new reality. It would seem fair, therefore, to honour his name by applying this new reality to the task of discovering expressions of aptation which he had never conceived.1

Acknowledgements

I thank Glen Ingram and Monica Minnegal for their comments during the time when this paper was coming into being.

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