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Chapter 21

Teleology and Evolution:

Why Can’t We Have ‘Evolution on Purpose’?
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This is a preliminary draft of one chapter of a book-in-progress tentatively entitled, “Evolution As It Was Meant To Be — And the Living Narratives That Tell Its Story”. You will find here a fairly lengthy article serving as a kind of extended abstract of major parts of the book. This material is part of the Biology Worthy of Life Project. Copyright 2017-2020 The Nature Institute. All rights reserved. Original publication: November 6, 2020. Last revision: November 22, 2020.

Tags: development (ontogeny); evolution/and development; inwardness (intention, idea, meaning)

To begin this chapter I will briefly consider some of the difficulties evolutionary theorists are likely to have with the idea that purposiveness, intention, and agency play a role in evolution. Then I will assess the nearly universal conviction among biologists that natural selection explains away the apparent purposiveness in the lives of organisms.

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Every organism is continually dying in order to live. Breaking-down activities are prerequisites for building up. Complex molecules are synthesized, only to be degraded later, with their constituents recycled or excreted. In multicellular organisms such as vertebrates, many cells must die so that others may divide, proliferate, and differentiate. Many cancers reflect a failure to counterbalance proliferation with properly directed tearing-down processes.

You and I have distinct fingers and toes thanks to massive cell death during development. The early embryo’s paddle-like hands give way to the more mature form as cells die and the spaces between our digits are “hollowed out”. In general, our various organs are sculpted through cell death as well as cell growth and proliferation. During development the body produces far more neurons than the adult will possess, and an estimated ninety-five percent of the cell population of the immature thymus gland dies off by the time the mature gland is formed (Rich, Watson and Wyllie 1999).

Despite all this life and death, I doubt whether anyone would be tempted to describe an embryo’s cells as “red in tooth and claw”. Nor do I think anyone would appeal to “survival of the fittest” or natural selection as a fundamental principle governing what goes on during normal development. The life and death of cells appears to be governed, rather, by the form of the whole in whose development they are participating.

But this has been a truth hard for biologists to assimilate, since it has no explanation in the usual causal sense. One way to register the problem is to ask yourself what you would think if I suggested that organisms in an evolving population thrive or die off in a manner governed by the evolutionary outcome toward which they are headed — that the pattern of thriving and dying off becomes what it is, in some sense, because of that outcome. It is not a thought any evolutionist is likely to tolerate.

But perhaps the occasional intrepid researcher will be moved to inquire: “Why not?” After all, we can also ask about the cells populating our bodies: do they thrive or die off in a manner governed, in some sense, by the forthcoming adult form? And here the answer appears to be a self-evident “yes”.

Perhaps, when we have come to accept what we see so clearly in individual development, we will find ourselves asking the “impossible” question about evolutionary trajectories: Does natural selection really drive evolution, or is it rather that the evolving form of a species or population drives what we think of as natural selection? Are some members of an evolving species — just as with the cells of an embryo’s hands — bearers of the future, while other members, no longer being fit for the developing form of the species, die out?

What makes this idea seem outrageous is the requirement that inheritances, matings, interactions with predators, and various other factors in a population should somehow be coordinated and constrained along a coherent path of directed change. Unthinkable? But the problem remains: Why — when we see a no less dramatic, life-and-death, future-oriented coordination and constraint occurring within the populations of cells in your and my developing bodies — do we not regard our own development as equally unthinkable?

Few would imagine that our own well-directed development from embryo to adult is owing to an external guiding power or to a conscious “aiming” or planning. Nor need we think that the “developmental path” of evolution is owing to guidance such as an external breeder might supply. Rather, the idea would be that the evolutionary narrative, like the developmental one, arises from the agency and developmental powers of cells, organisms, and communities of organisms, as they express their own character and realize their potentials in the presence of the prevailing environmental challenges and opportunities.

So the question is this: do we have any less reason to expect a coordinating agency at play in a population of organisms pursuing an evolutionary trajectory than we do to expect a coordinating agency at play in a population of cells pursuing a developmental trajectory?

Our answer will depend on our willingness to take seriously a plain fact of our experience — a fact stressed throughout the first half of this book: agency and intention, wisdom and meaning, are given expression by organisms in a way that belies our expectations for collected bits of inanimate matter.

Are there obvious reasons to reject
agency and teleology in evolution?

Every living activity we actually observe is purposive, or “teleological”, or, as I will often call it here, “telos-realizing”. It always has a holistic dimension, and it always represents a further addition to a life story. We find ourselves watching, not necessarily a conscious planning (as in the human case), but rather the self-expression, or self-realization, of a living being. Physical events and causes are coordinated in the interests of a more or less centered agency that we recognize in cell, organism, colony, population, species, and perhaps even in ecological contexts.

This coordination, these interests, this agency — they are already assumed, consciously or otherwise, by all biologists in the case of the individual organism’s development. They are assumed, that is (as I have frequently been pointing out), insofar as one is doing biology, and not merely physics and chemistry.

I tried to suggest in the opening section of this chapter that the agency and purposiveness so clearly manifest in the development of individual organisms could just as well manifest itself in evolution. But, to most biologists, this is bound to seem a mere conjecture, and an impossible one at that. Let’s listen to a few of the possible misunderstandings that can so easily disturb our thinking about the role of agency — and, indeed, any sort of meaning — in evolution.

How can you jump so casually from the hypothesized agency of a single, developing individual to that of vast, co-evolving populations?

When one speaks, not about physical processes as such, but rather about an underlying biological agency, intention, and purposiveness, then the distinction between an individual animal as a collection of molecules, cells, and tissues, on the one hand, and an entire population as a collection of organisms, on the other, becomes an open question. The whole business of telos-directed biological activity, wherever we have observed it, is to bridge radically different physical processes. That is, it brings diverse and complex physical phenomena — for example, in the brain, heart, liver, intestines, and skin of a developing mammal — into integral unity and harmony, making a larger whole of them. When we have seen this purposeful coordination and harmonization in one organic context, it is only natural to look for it in other contexts.

The fact is, we do not currently understand the nature and origin of the observed powers of coordination in living organisms, just as we do not understand the nature and origin of physical law. Nor do we know which of these is more fundamental. We can only assume that the teleological dimension of an organism’s performance comes into play at the very root of its material being, just as does the play of physical law. If anything, an inherent power to orchestrate physically lawful activity in a purposive manner, however poorly understood, would seem higher or more fundamental than the physical processes being orchestrated.1

Given our ignorance of the ultimate nature of things, the most immediate path forward when the teleological question arises in a particular context, is simply to observe whether the adjustment of means toward the fulfillment of needs and interests is actually occurring in that context.

But this much can be said already. When we consider our experience of telos-realizing entities bound together in some way, we see one example after another where the more comprehensive entity or context manifests in its own turn a teleological character. Whether it is all the molecules in a cell, or all the cells in an organism, or all the organisms in an insect colony or mammalian social group, we always find a weaving of lower-level narratives into the fabric of a larger story.

So we can hardly help asking the teleological question in an evolutionary context: Does a species have its own sort of “developmental” potentials? And then we must be willing to look.

“You speak of a harmonization in tune with meaning and purpose. But how can physical processes be harmonized without relevant causal connections between them? We can see such connections clearly in a developing organism. But huge numbers of different organisms in radically different species, often scattered over a large geographic area, are a different matter.”

Yes, a very different matter. And certainly any purposive coordination of physical events does require causal connections between them. Those connections are precisely what must be coordinated. But the members of evolving populations of organisms have no fewer or less relevant causal connections than the aggregated cells in an individual. Eating and being eaten are surely causal! And, of course, not only predator-prey relations, but also mating choices (including hybrid ones), territorial movements, learning experiences, lateral gene transfer mediated by microorganisms and viruses, and many other causal interactions already figure importantly in conventional evolutionary theory.

Isn’t the entire body of evolutionary theory today concerned with physical causation? And don’t we find that ancestral species are in fact transformed into descendent species? Surely conventional theory is a physical theory and gives us all the relevant causal interactions we need. The question about purpose, intention, and meaning is a question about the organization and coordination of the organically transformative processes already identified by evolutionary biologists.

Moreover, when considering causal interactions among evolving organisms, we shouldn’t forget the special role of cognition. We can hardly help acknowledging the highly intentional causal connections between all those organisms possessing specialized sense organs. And today we know that specialized senses exist even at the level of single-celled organisms, who display a sophisticated agency at both the individual and collective levels.

When speaking of “sensing”, we always refer to something more than “being impinged upon by external forces”. We refer to a perception of that which has meaning for the cell or organism, and this is linked to a meaningful response by the organism. If there were no detectable, purposive response to a particular feature of the environment, we would have no reason to believe that perception had occurred.

In a play of meaning (as in a poem, novel, or any worthy line of thought) we always find a coherent movement toward — toward an end, or completion, or a greater fullness of expression. So, too, every organism is continually bringing its own distinctive life story toward fuller realization. It does so in the first instance merely by passing through all the major phases of life. But every sensing and responding becomes an integral “utterance” within that same story.

Actually, the reality of a coordinating power weaving through and governing large, scattered populations of organisms is already put on display for us before we even think about evolution. It is displayed, for example, in instinctual behavior such as that of migrating monarch butterflies, many of whom gather together from throughout a wide area and travel thousands of miles over multiple generations to a precise spot in Mexico — all this along aerial pathways they have never traveled before.

Or consider the sophisticated collective behavior of a wolf pack, an ant colony, or even the cells — bacterial and otherwise — of a biofilm. The latter has been termed a “city for microbes”, and the complex, teleologically rich organization of a city is not an unapt picture of the life of a biofilm. In all these different sorts of collectives, the power of end-directed coordination, whatever we take it to be, seems to work across the relevant communities, and all the way down to the molecules that actively participate in the performance of the various organisms.

So I come back to my initial line of thought. Suppose, for the sake of argument, that an animal’s mating choices and its preparation of inheritances for its offspring are guided, or end-directed, in a manner leading to coherent evolutionary change. How would this be more problematic for our physical understanding than all the cellular inheritances within the many proliferating and radically diverging cell lineages in a complex, developing organism. These, too, are guided in a manner leading to coherent developmental change — that is, leading toward the integral, overall unity of the mature organism.

Yes, the particular principles of coordination in evolution must in some ways differ from those in individual development, as we will see shortly. In fact, they will not be the same in any two, distinct contexts. But whatever the principles are, we will not discover them by looking at the laws of physics and chemistry. We will begin to grasp them only when we are able to read each particular context in terms of its own meanings, self-realizing powers, and directions of movement. We are already pretty good at this in the case of individual development. There is no reason not to try looking in an analogous way at evolving populations.

“It sounds as though the myriad forms of your wonderful ‘agency’ can accomplish just about anything. The different agencies of individual organisms can somehow blend together so as to become the telos of a species or larger group, just as the telos of the larger group can fragment into subunits — all in order to vitalize and give identity to everything from the smallest bacterium to the entire biosphere as a single whole. Do you have any idea how all this works?”

I pointed out above that we no more understand the nature and origin of the observed power of coordination in living organisms than we do the nature and origin of physical law. But I would add: just as, through observation, the physicist can learn about the working of ideal (immaterial) laws and forces, so the biologist can learn about the working of the teleological activity of living beings. In general, biologists do not have a particularly difficult time of it. Nor does any pet owner or observer of nature.

It is true that, in the organism (and in all biology), diverse processes are coordinated toward a common end. And it is also true that this is understandable only because a principle of interpenetration is universal in biology. The general rule is that we always find ourselves looking at wholes embedded within still larger wholes, and contexts overlapping other contexts. This is clearly evident when we consider the integrated unity of a physical body with all its cells, tissues, and organs. It may take some effort, but we have to learn to think in terms of this embeddedness of wholes and overlapping of contexts.

In Chapter 6 (“Context: Dare We Call It Holism?”), we heard how the botanist Agnes Arber described the relative character of organic wholes:

The biological explanation of a phenomenon is the discovery of its own intrinsic place in a nexus of relations, extending indefinitely in all directions. To explain it is to see it simultaneously in its full individuality (as a whole in itself), and in its subordinate position (as one element in a larger whole). (Arber 1985, p. 59)

From flocks, herds, and schools, to bee and ant colonies, to parasitic and symbiotic pairs, to more or less closely aggregated communities of cells, to the highly differentiated and elaborately integrated cells of our own bodies — there are many different contexts of agency. The one thing we can know directly is that we discover agency and intention wherever we find participants bound together in more or less centered activities that unfold along a continuous and well-directed pathway according to their own distinctive meanings.

The honey bee hive functions, in this sense, as a (relative) whole with its own agency. We have no difficulty recognizing this agency in the hive’s pattern of coherently directed activity. The participants in the hive have no absolute discreteness or wholly independent identity. But neither do they lose all identity. It is a matter of one identity participating in a greater one.

If, as Arber suggests, biology presents us with interpenetrating wholes, then we should also expect to see interpenetrating agencies expressed in those wholes. The distinctive character of, say, a mammalian genus (or any other taxonomic group) is not silenced by, but rather informs, the character of each species within the group.

This sort of interpenetrability is exactly what we find in language — that is, in different contexts, and even in different words and phrases. We can put words together in infinitely varying ways. Any two words or ideas or philosophies, no matter how different, can be brought into meaningful relation, thereby modifying each other. A word is given its meaning in part by the character of the larger thought in which it participates, just as a heart receives its meaning in part from the larger organism in which it participates. Neither word nor heart thereby suffers a loss of identity, but rather gains in the richness of its meanings and its relational potentials.

If there is one thing we must expect to discover in the wise and diverse, narrative-spinning agencies of life, it is this thoughtful, profoundly integrative, and unifying potential.

“Isn’t the idea of agency, when applied to organisms in general, a rather disastrous anthropomorphism?”

Anthropomorphism is indeed a supreme danger in biology. Think, for example, of all the human activity we rather blindly import into the organism when we analogize it to a machine. (See below.) Similarly, it would be highly misleading to think of biological agency as if it were like the directive activity of a sovereign and individual human agent.

To begin with, human agency itself is not as neat and unambiguous as we may be inclined to suppose. A fully sovereign individual does not exist. Who among us can say that he is motivated solely by his own will? Who does not at times yield gladly to internalized and inspiring “voices” — for example, of teachers and mentors, or religious figures, or uplifting texts. And who does not also wrestle with lower, less worthy urges? What young child subjected to extreme abuse does not carry into adulthood the burden and unfreedom of a psychic complex expressing some of the disastrous ideational and volitional powers of his abusers? Or again, which of us is absolutely immune to the collective ecstasy, hysteria, or rage of a massive crowd “rooting for the home team” or submitting to the spell of a charismatic leader?

It is true that, when we speak of agency, we speak of a capacity we ourselves routinely exercise. But at the same time we must admit that our experience of our own agency is closely bounded on all sides by mystery. We do not fully understand where our thoughts and actions come from, or how our intentions move our bodies. It would be a mistake to clothe the mystery of biological agency in the imagined form of a grandly sovereign, all-knowing human individual.

And if we cannot be entirely clear about the sources of agency in our own lives, we can hardly be dogmatic about the nature of the agency — or diverse agencies — at work in a single bee colony, a particular species of rodent, or the biosphere as a whole.2 In the chapter, “Mysteries”,3 I looked at certain puzzles about agency and purposiveness in biology. But this much can be added here:

Nothing prevents us from being good observers of biological activity, which is also to be observers of the actual working of biological agency. In this way we become familiar with the complex and perhaps many-voiced character — the way of being — of particular organisms. We learn to know “from the inside” one species as distinct from another. And we can try our best to bring the same disciplined observation to bear on ecological settings, communities of organisms, or the entire historical panorama of evolution.

We do not need to understand the “ultimate nature” of agency in order to describe its immediate manifestations. This is a truth familiar to us, for we have no difficulty describing with more or less insight the character of a friend, even though we do not know the ultimate nature of the human being.

“But the simple fact is that evolution is not individual development. Don’t you need to reckon with this fact?”

Yes. As I remarked above, the principles of coordination in one context must differ in one degree or another from those of a different context. They are what make each context what it is.

One obvious difference between development and evolution is that cycles of individual development are endlessly and reliably repeated, so that no one can avoid at least unconsciously recognizing their teleological character. Time and again, amid all the inconstancies of life and environment, mouse zygotes develop into adult mice.

Evolution, by contrast, encompasses the totality of life on earth, and occurs only once. No more than in reading a good novel can we predict, mid-way through the story, its later outcome, even if that outcome turns out to be the end toward which everything was tending.4 This non-repeatability of evolution makes it all too easy, for those bent on doing so, to “forget” everything they know about the creative and end-directed character of all the life processes through which evolution occurs.

There are, of course, other distinctions between individual and evolutionary development. In the latter case we see (in those organisms reproducing sexually) a continual merging of separate hereditary lineages. There is also the fact of hybridization across species, genera, and even families. None of this commonly occurs among the cells of a developing organism. And some evolutionary features figuring strongly in current theorizing — symbioses of various sorts, cultural inheritance, and lateral gene transfer — also serve to remind us that, while communities of organisms can be vitally important even for individual development, they become central in evolution.

We have no reason to assume that the play of purposiveness across all the cells of a complex, developing organism is exactly analogous to its play among the members of a species or population. Nor need we asume that the more or less fixed stages through which individual development passes give us a neat roadmap for the course of evolution.

We do, however, have at least one foundational principle: whether we are focused on genes or traits, nothing can become a fact of evolution that was not first a fact of individual development. The very substance of evolutionary transformation must first of all occur within individual organisms.

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The current unwillingness of biologists to reckon with the possibility that evolution gives us a coherent, telos-realizing narrative does not appear to be explained by the differences between individual development and evolution (which are very real), but rather by a refusal to take seriously the problem of active biological wisdom and agency in either case.

The uncomfortable truth is that biology has yet to come to terms with the physically puzzling fact of purposive biological activity — which is to say, all biological activity. To suggest that evolution is telos-realizing is not to suggest some new kind of problem. It is merely to say: let’s face up to the reality of teleological development and behavior that has already long been staring us in the face.

The shortest path to
confusion is circular

But haven’t I been committing an egregious sin of omission? Surely any reader with a conventional biological training will think so. After all, doesn’t everyone know that evolution by natural selection “naturalizes”, or explains away, the agency and purposiveness we observe in organisms? That is, explains it without appeal to any principles other than purely physical ones?

Biologists often think of purposiveness, or teleology, under the concept of function, as when they say that a trait is “for the sake of” this or that, or an organ exists “in order to” achieve a particular end. And so, as philosopher David Buller has summarized common usage, “the function of the heart is to pump blood, the function of the kidneys is to filter metabolic wastes from the blood, the function of the thymus is to manufacture lymphocytes, the function of cryptic coloration (as in chameleons) is to provide protection against predators”.

All this poses difficulties for a science that would honor its materialist commitments, since the concept of function, as Buller observes, “does not appear to be wholly explicable in terms of ordinary causation familiar from the physical sciences”. Whereas kidneys may continually adjust their activities and their own structure in order to do the best possible job of filtering metabolic wastes from the blood, no physicist would say that falling objects adjust their activities and their own structure in order to reach, as best they can, the center of the earth. More generally, organisms may strive to live, but physical objects do not strive to maintain their own existence. Organisms, so it seems, have intentions of their own, whereas physical objects are simply moved from without according to universal law.

So the problem for biologists has been to explain, or explain away, their persistent and seemingly inescapable language of purpose, and to do so in a respectable, materialistic manner — that is, to explain it without having to acknowledge that organisms really are purposive beings.5 But this problem — so we are told — has been fully solved in recent decades.

Buller, who was writing at the turn of the twenty-first century, was able to point to a “common core of agreement” representing “as great a consensus as has been achieved in philosophy” — an agreement that “the biological concept of function is to be analyzed in terms of the theory of evolution by natural selection”. More particularly, “there is consensus that the theory of evolution by natural selection can provide an analysis of the teleological concept of function strictly in terms of processes involving only efficient causation” — the kind of “purposeless” causation physical scientists accept as applicable to the inanimate world (Buller 1999).

So we no longer need to think of organisms as having genuine intentions, purposes, or aims of their own — no longer need to struggle with the problem of teleology, or end-directed activity. Teleology, we must believe, has been tamed, leaving biologists safe in their world of lifeless thought.

To put the most common version of the idea very simply (and not many working biologists seem worried about the need for a more sophisticated formulation), organisms are said to possess teleological, or purposive, features because those features are present by virtue of natural selection. That is, they were selected for the very reason that they effectively serve the organism’s crucial ends of survival and reproduction. And since natural selection is supposed to be a perfectly natural process — meaning that it involves nothing “mystical” like real purpose, intention, or thought — we can know that the functionally effective traits given us by natural selection are straightforward exemplars of physical lawfulness and nothing else, whatever they might look like.

If this feels as though it is cheating a bit, then you might want to trust your intuition — for more than one reason. I will briefly touch the issue from three different angles.

(1) The problem of the “arrival of the fittest” remains

To say that natural selection preserves traits promoting the survival of organisms does nothing to explain how the teleological character of those traits might be compatible with materialist thought. The preservation of an already existing trait is an entirely different matter from its nature and origin. Claiming that teleological features or activities already existed at some time in the past and then were preserved by natural selection merely pushes the problem of their origin and nature back to an earlier time, without solving it.

We heard about this in Chapter 19, where prominent figures in evolutionary biology over the past century and more complained that natural selection — even if it explains the survival of the fittest — cannot explain the arrival of the fittest. The arrival of traits is simply assumed, with natural selection then playing a role in their preservation and their spread throughout a population. Yes, purposive features conduce to the survival of organisms, and therefore may be preserved. But how does this bare fact make these features, in Buller’s words, “explicable in terms of ordinary [physical] causation”?

Given the historical persistence of the complaint by leading biologists about natural selection and the arrival of the fittest, it is remarkable that the arguments today about how natural selection explains teleology generally proceed without so much as an acknowledgment of the problem.

(2) The explanation assumes what it is supposed explain

It is important to realize that purposiveness runs through all biological activity. It is reflected in the coordinating principles that account for the integral, interwoven unity of the organism’s life. The complexity theorist and philosopher of biology, Peter Corning — who appears to hold a conventional, materialist view of life — was nevertheless gesturing toward this purposive unity when he wrote that living systems “must actively seek to survive and reproduce over time, and this existential problem requires that they must also be goal directed in an immediate, proximate sense … Every feature of a given organism can be viewed in terms of its relationship (for better or worse) to this fundamental, in-built, inescapable problem” (Corning 2019).

Rather than being just one more discrete trait that might have been neatly evolved at some particular point in evolution, the telos-realizing capacity of organisms reflects their fundamental nature. It is what “living” means. We are always looking at a live performance — a future-directed performance, improvised in the moment in the light of present conditions and ongoing needs — not a mere “rolling forward” of some blind physical mechanism set in motion eons previously.

Here we encounter a staggeringly obvious problem. You will recall from Chapter 19 that natural selection is supposed to occur when three conditions are met: there is variation among organisms; particular variations are to a sufficient degree inherited by offspring; and there is a “struggle for survival” that puts the existing variants to the test. But — and this is the crucial point — all the endlessly elaborate means for the production of variation, the assembly and transmission of inheritances, and the struggle for survival just are the well-regulated, end-directed activities whose teleological character biologists need to explain. So the basic conditions enabling natural selection to occur could hardly be more thoroughly teleological.

In other words, the purposive performance of an organism is a pre-condition for anything that looks at all alive and capable of being caught up in evolutionary processes of trait selection. So the common form of the argument that natural selection explains the apparent purposiveness of all biological activity appears to assume the very thing it is supposed to explain. Purposiveness is built into the idea of natural selection itself, which therefore presents us with the problem instead of removing it. We are merely arguing in a circle. It would be truer to say that teleology explains natural selection than that selection explains teleology.

Although this problem regarding the explanation of teleology has been almost universally ignored among biologists, it has not been entirely overlooked. Georg Toepfer, a philosopher of biology at the Leibniz Center for Cultural Research in Berlin, has stated the matter with perfect directness:

With the acceptance of evolutionary theory, one popular strategy for accommodating teleological reasoning was to explain it by reference to selection in the past: functions were reconstructed as ‘selected effects’. But the theory of evolution obviously presupposes the existence of organisms as organized and regulated, i.e. functional systems. Therefore, evolutionary theory cannot provide the foundation for teleology.6

(3) The lure of the machine

Those convinced that natural selection explains teleological traits (rather than the other way around) do occasionally make at least passing reference to the problem of the origin of the traits. For example, Buller writes that “natural selection explains the presence of a trait by explaining how it was preserved after being randomly generated”. Organisms, he says, “are built by genes”, and genes undergo random mutation, whereby new traits arise.7

Of course, random activity does not by itself explain anything at all. So we can be sure that this activity is assumed to take place against a (perhaps largely unspoken) background that contributes essentially to the supposed explanation of teleology. A foundational feature of this background is the assumption that an organism is no more than a kind of material structure — preferably a machine, or mechanism, that we can imagine is controlled by a genetic program.

Evolution then “works” by tinkering8 with at least some part of this physical structure until, over geological time, entirely new sorts of structure take form. The tinkering works mainly upon randomly occurring variations — usually, it is said, genetic variations, or mutations. And, despite the word itself, tinkering is not admitted to be something the organism does. Nor does it reflect any sort of wisdom playing through living beings. Rather, the contriving of complex, sophisticated features is something that blindly happens to the organism.

But finding anything that blindly happens to the organism is hard to do.

The nonrandomness of mutation. To demonstrate that last point, we need only consider the unexpected reality of those genetic mutations upon which natural selection is supposed to work. The crucial observation was made by Oxford University biophysicist Norman Cook in 1977: far from being random, these mutations are actively managed by the organism. “Biological intervention through enzymes and enzyme systems is the principal mechanism of in vivo mutation”, he wrote. He went on to point out that if changes in the genetic material are indeed mediated by other cellular molecules, then the idea of randomness loses its meaning (Cook 1977).

Furthermore, as British radiologist B. A. Bridges remarked: even studies of radiation-induced mutation in bacteria have shown that cellular repair systems are “necessary for nearly all of the mutagenic effect of ultra-violet and around ninety percent of that of ionizing radiation” (Bridges 1969).

That is, outcomes depend at least in part on what the organism does with the influences impinging upon it. You might think that radiation mostly causes very local alterations in DNA, corresponding to the immediate location of damage. Yet the great majority of radiation-induced mutations involve large regions of DNA, often encompassing many thousands of nucleotide bases, or “letters”, of the genetic sequence (Elespuru and Sankaranarayanan 2006). This is greater than the length of many genes. The organism making such changes is apparently prepared to respond as best it can and in its own creative way when it engages the potentially harmful, mutagenic effects of its environment.

University of Chicago microbiologist, James Shapiro, in his book Evolution: A View from the 21st Century, presents a wide-ranging and authoritative case for the organism’s active role in modifying its own genome — an activity so pervasive and with such profound implications that he refers to it as “natural genetic engineering” (Shapiro 2011).

All this raises fundamental questions about the idea of an evolutionary process rooted in chance mutations. Where do we ever see random, undirected change as opposed to an organism’s response to its external and internal environment?

Activity precedes structure. The decisive issue goes far beyond responses to mutation. There remains the larger truth that every organism, in its entire being, is first of all an activity. Its structures are always results of activity — a truth we have seen amplified throughout the first half of this book. As American philosopher Suzanne Langer put it at mid-twentieth century: “Every discovery makes the living organism look less like a predesigned object and more like an embodied drama of evolving acts, intricately prepared by the past, yet all improvising their moves to consummation” (Langer 1967, p. 378).

When we look at an elaborately choreographed molecular activity such as RNA splicing (Chapter 8), the explanatory challenge lies in the fact that, unlike in a silicon chip, there are no precisely incised channels in the watery medium of the cell’s plasm. Likewise, there are no finely machined gears, switches, levers, springs, or hinges9 to forcibly shape the overall, carefully sequenced, and well-aimed activity of the hundreds of molecules engaged in the extended task of splicing. The fluid realm of the cell is one where movement and a kind of freedom reign. There is also a continual exchange and transformation of substances — which means there is little in the way of rigidly fixed structure of any sort.

This is why we have had to ask ourselves in that earlier chapter: What constrains and imposes end-directed order upon all the molecules involved in RNA splicing, DNA replication and repair, or gene expression?” What keeps these intricate processes — and countless others like them — “teleologically on track” to perform intricate and extended tasks despite what would be, in strictly physical terms, an overwhelming invitation to disorder? Can we possibly imagine that the cell’s living activity is controlled, step-by-step, by mechanistically enforced instructions issuing from the genome?

It’s not just that no one even pretends to have discovered genetically encoded instructions specifying what each of the molecules involved in RNA splicing should do, moment by moment. Even if there were such instructions, and even if they were so surpassingly complex and subtle that they could manage every moment’s need in perhaps trillions of differently contextualized cells throughout an organism’s unpredictable lifetime — still, these instructions would have no way of being continuously conveyed to the virtual infinitude of molecules needing them.

Nevertheless, even if they are not mechanistic, the constraints directing the organism’s activity are there. They are real. What helps to conceal this truth from us is our experience with the ubiquitous machines in our life. We see the solid, visible materials of a grandfather clock, a washing machine, or a computer, and we can’t help believing that those materials account for the activity we are watching. Of course, understood in the proper sense, this is true.

But then we have been all too willing to ignore a more fundamental truth: the materials of the clock gained their functional order, such as it is, only by virtue of the creative thought and well-informed technique of the inventors and builders. In other words — and here is the decisive difference between a machine and an organism — the ideas governing the performance of the machine’s materials are imposed from without and are not, as in an organism, inherent in the materials themselves. This inherence is the difference that makes the materials of an organism living. When the materials of a machine are damaged, they do not naturally — out of their own nature and all the way down to the most detailed and complex molecular interactions — do their best to heal themselves in conformity with the larger purposes of the device.

Francis Crick, co-discoverer of the structure of DNA, once articulated a principle he called “the central dogma of molecular biology”.10 Despite its past influence, it has suffered much wear and tear with time, and need not concern us here — above all because there is a much more foundational principle (certainly not to be received as dogma) that we might offer in its place:

All material structure in an organism derives from, and must be maintained by, the organism’s activity. The structure, once originated, is put into the service of this activity — and in this sense becomes a constraining shaper of activity. But activity always precedes both structure and constraint.

Anyone who holds that natural selection is a “force” that tinkers with machine-like organisms so as to produce teleological capacities needs to tell us where we glimpse in the organism a truly machine-like object to begin tinkering with. Can one tinker with a power of activity? We do not even know what “tinkered with” could mean as an explanation of teleological activity, since tinkerable structures must first be derived — and continually maintained — through teleological activity.

We have heard a philosopher telling us that human hearts are “the product of randomly generated modifications to preexisting structures that were preserved or maintained by natural selection” (see footnote above). How easy it is to forget that there is no heart preserved down through the generations, waiting for the evolutionary Tinkerer to apply a few modifications now and then that can be accumulated over geological time. The heart disappears from the universe at every generational transition. It must then be created anew by a well-directed activity that is the primal source of change. This activity may be conditioned by existing physical structures, including chromosomes. But those structures were themselves the products of prior activity, and their present contributions can result only from further activity.

In sum: the first thing we require is not some way to explain how supposedly mechanistic structures, whether chromosomes or hearts, are progressively modified in an adaptive manner through the selection of random, heritable variations. Rather, we need a way to understand how all the heritable molecular structures — for example, in a reproductive cell — are teleologically formed and elaborated in the first place, and continually re-elaborated.

And once we gain that understanding, how could it possibly be anything less than decisive for our theorizing about evolution? Actually, we already know enough to grasp the truth of the matter, since we can clearly see that what plays through all the organism’s activity is a wisdom — creative thought — vastly beyond any thought we manage to invest in our dead machines. It is time to ask whether the development of species shows the same kind of creative thought we see at work in the development of individual organisms. Or perhaps to ask whether we can intelligently imagine such thought not being at work.

An aversion to
meaning

The theory of natural selection gives us no argument against the self-evident purposiveness of organisms. To the contrary, it confirms the theorist’s largely unacknowledged recognition of this purposiveness. For we can make sense of natural selection only after we have thoroughly internalized, from childhood on, a vivid awareness of the lively agency, whether of cats and dogs, birds and squirrels, worms and fish, or of the animals in our laboratories. The scientist can take this agency for granted without having to mention or describe it, since everyone else also takes it for granted.

And so one speaks ever so casually of individual “development”, or the “struggle for life”, or the “production of variation”, or “reproduction and inheritance” — all in order silently to import into theory the full range of the living powers that made biology a distinct science in the first place, but that few today are willing to acknowledge explicitly in their theorizing. In this way, amid contradiction, circular reasoning, and what I have called the biologist’s “blindsight” (Chapter 1, “The Keys to This Book’), the materialist preserves his preferred picture of a meaningless existence. All he needs to do is appeal to natural selection, that “universal acid” (Dennett 1995) capable of dissolving all objections to what one wants to believe.

The result is clear. Several decades ago the British biologists Gerry Webster and Brian Goodwin had already noticed that “the organism as a real entity, existing in its own right, has virtually no place in contemporary biological theory” (Webster and Goodwin 1982). Goodwin later elaborated the point in his book, How the Leopard Changed Its Spots:

“A striking paradox that has emerged from Darwin’s way of approaching biological questions is that organisms, which he took to be primary examples of living nature, have faded away to the point where they no longer exist as fundamental and irreducible units of life. Organisms have been replaced by genes and their products as the basic elements of biological reality.” (Goodwin 1994, p. vii)

The banishing of organisms from evolutionary theory was also an obscuring of biological purposiveness. It may even be that the banishing happened, in part, for the sake of this obscuring. Yet who can doubt that, if we ever do take the purposive organism into account at anything like face value, the results could be of explosive significance for all of evolutionary theory?

It is difficult to pinpoint whatever lies behind the extraordinary animus the biological community as a whole holds, not only toward teleology, but indeed toward any meaningful dimension of life or the world. But the animus seems as deeply rooted as it could possibly be. Michael Ruse, who might be regarded as a dean of contemporary philosophers of biology, once briefly referred to an article by the highly respected chemist and philosopher, Michael Polanyi, in this manner:

Polanyi speaks approvingly, almost lovingly, of “an integrative power … which guides the growth of embryonic fragments to form the morphological features to which they embryologically belong.”

And what was Ruse’s response?

One suspects, indeed fears, that for all their sweet reasonableness the Polanyis of this world are cryptovitalists at heart, with the consequent deep antipathy to seeing organisms as being as essentially physico-chemical as anything else … Shades of entelechies here! (Ruse 1979)

The real antipathy appears to be on Ruse’s part. One wonders exactly what violation of observable truth he saw in Polanyi’s reference to “an integrative power” that “guides” embryological growth. No biologist would dare deny that embryological development is somehow integrated and guided toward a mature state. And it is difficult to understand how any actual integrating and guiding could be less than the expression of an effective “power”, however we might end up understanding that term. Just think how much less justification there is for all the conventional references to the “power”, “force”, and “guidance” of natural selection! (On that, see Chapter 19.)

As for Ruse’s shuddering at the term “entelechy” (sometimes rendered as “soul”), the scholar who is perhaps the foremost interpreter of Aristotle today translates the Greek entelecheia as “being-at-work-staying-itself” (Sachs 1995, p. 245). What better characterization of an organism and its distinctiveness relative to inanimate objects could there possibly be? Every biologist who uses the conventional term “homeostasis” (a system’s maintenance of its own stability) or, better, “homeorhesis” (a system’s maintenance of its characteristic activity) is already saying something similar to “being-at-work-staying-itself”. It’s the way of being of any organism. The Aristotelian term is useful for reminding us that an organism is first of all an activity, and its activity is that of a centered agency possessing a remarkable coordinating and integrative power in the service of its own life and interests.

On our part, we will now do our best to read the organism and its activity back into evolutionary theory. In doing so, we will ignore the strange taboo against accepting living powers and purposiveness as relevant to the theory.

Where are we now?

Is Teleology Disallowed in the Theory of Evolution?

An animal’s development from zygote to maturity is a classic picture of telos-realizing activity. Through its agency and purposiveness, an animal holds its disparate parts in an effective unity, making a single whole of them. This purposiveness informs the parts “downward” from the whole and “outward” from the inner intention, and is invisible to strictly physical analysis of the interaction of one part with another.

Biologists in general have failed to take seriously the reality of the animal’s agency, and have considered it unthinkable that something analogous to this agency could play through populations of organisms in evolution, just as it plays through populations of cells in an organism. I have tried to suggest that there are no grounds for making a radical distinction between the two cases.

And then, addressing the idea that natural selection explains (or explains away) biological purposiveness, I focused on three closely related problems:

•  The preservation of purposive (functional) traits — or any traits at all — by natural selection neither explains their origin nor shows how they can be understood solely in terms of physical lawfulness.

•  Selection itself is defined in terms of, and thoroughly depends on, the purposive lives of organisms. This purposiveness must come to intense expression in order to provide the basic pre-conditions for natural selection. These conditions are the production of variation; the assembly and transmission of an inheritance; and the struggle for survival. Since the entire logic of natural selection is rooted in a play of purposiveness, it cannot explain that purposiveness.

•  Finally, the understanding of organisms in physical / mechanistic / machine-like terms offers no solid purchase for the evolutionary tinkering through which teleological traits are supposed to arise. An organism is first of all a characteristic activity, not a tinkerable machine, and its drive toward self-realization explains its developing structure at every level of observation much more than that structure explains its drive toward self-realization. In particular, genes have no way to guide the moment-by-moment, purposive activity of extended molecular processes such as RNA splicing and DNA damage repair.

All this has been to clear away some of the major stumbling blocks biologists inevitably feel whenever evolution is said to have a purposive, or teleological, character. There remains the question whether evolution does in fact show such a character. We will see that — just as with individual development — the question is answered as soon as it is asked. In both cases, once the metaphysical biases against the very idea of teleology are removed, all we need to do is look, and it’s as if our eyes themselves are enough to give us our answer.

Notes

1. This orchestration of physical processes occurs, as I said, at the root of their material being, which is very different from the human engineer’s arrangement of material parts “from the outside”. I make further mention of this difference in these two paragraphs. below

2. Owen Barfield once wrote a kind of fantasy novel (Barfield 1965) in which the protagonist had conversations with a higher being modeled after the “maggid” of Jewish mystical tradition. The final words of that being — and of the novel — depict an “interwoveness” of a hierarchy of living and guiding agencies that may perhaps be curiously, if somewhat remotely, suggestive in the present context:

Twice, answered the gentle but inexorable voice, twice now you have called me “Master”. But what you shall do shall be taught you not by me, neither by my masters. You may only receive it direct from the Master of my masters; who is also their humble servant, as each one of them also is mine; as you — if your “doing” should be only a writing — will strive to be your reader’s, and as
I am
yours.

3. As of this writing, the chapter, “Mysteries”, is not yet available.

4. Actually, the same unpredictability is true of individual development. If we were watching a developmental sequence for the first time, we would not be able to predict its mature outcome based on what we saw half way through. And yet we would recognize retrospectively that this outcome was the end toward which everything was tending all along.

5. Part of the worry about purposive activity has to do with the fact that it is future-oriented, and therefore seems to involve something like conscious human planning, which we can hardly attribute to an earthworm. Nor do we need to. I touch on this issue in the chapter, “Mysteries” (not available at this writing). The present chapter concerns mainly the relation between teleology and natural selection.

6. Toepfer 2012. There is also this from University of Toronto philosopher of biology, Denis Walsh. Natural selection, he says, occurs

because individuals are capable of mounting adaptive responses to perturbations. This capacity to adapt allows individuals to survive in unpredictable environments and to reproduce with startling fidelity, despite the presence of mutations. It is adaptation which explains the distinctive features of natural selection in the organic realm and not the other way round. (Walsh 2000).

Therefore, he adds, “the programme of reductive teleology cannot be successfully carried out”. Then there is the following succinctly stated criticism by the independent philosopher, James Barham:

Selection theory does nothing to help us understand what it is about functions that makes it appropriate to speak of their “advantage”, “benefit”, “utility”, etc. for their bearers. Natural selection is like a conveyor belt which transmits a biological trait or function from one generation to the next … But natural selection cannot explain how the capacity of biological functions for success or failure arose out of physics in the first place, for the simple reason that the selection process has no hand in constituting biological traits as functions. (Barham 2000)

Given my limited familiarity with the literature, I would not be surprised if there exist a few similar criticisms along the same line, at least among philosophers. But my own experience suggests that finding them amid all the conventional evolutionary thinking requires some serious digging.

7. Here is a more complete statement from Buller:

Consider how natural selection provides an explanation of why humans, for example, have hearts. The heart is a complex organ and all complex traits are the product of accumulated modifications to antecedently existing structures. These modifications to existing structures occur randomly as a result of genetic mutation or recombination. When they occur, there is variation in a population of organisms (if there wasn’t already) with respect to some trait. If one of the variants of the trait provides its possessor(s) with an advantage in the competition for survival and reproduction, then that variant will become better represented in the population in subsequent generations. When this occurs, that variant of the trait has increased the relative fitness of its possessor(s) and there has been “selection for” that variant. That variant can then provide the basis for further modification. Thus, humans have hearts because hearts were the product of randomly generated modifications to preexisting structures that were preserved or maintained by natural selection due to their providing their possessors with a competitive edge. So natural selection explains the presence of a trait by explaining how it was preserved after being randomly generated.

8. The idea of tinkering — that evolution is a tinkerer rather than an engineer — traces back to an influential article by the French biologist, François Jacob (1977). “Tinkering” is now one of the tropes of evolutionary theory.

9. I am, with more than a touch of irony, echoing a statement by the Harvard cognitive psychologist and evolutionist, Steven Pinker, where he says:

The stuff of life turned out to be not a quivering, glowing, wondrous gel but a contraption of tiny jigs, springs, hinges, rods, sheets, magnets, zippers, and trapdoors, assembled by a data tape whose information is copied, downloaded, and scanned. (Pinker 1997, p. 22)

We might hope that by now Pinker has awakened from his culturally induced trance and has realized that, as far as our current, rapidly expanding knowledge goes, the “quivering, glowing, wondrous gel” (if we discount the hyperbolic ridicule intended by the phrase) is actually closer to the truth than is the picture of all those wonderfully familiar, but terribly unbiological, machine parts.

10. Crick first put forward the “dogma” in 1958, and slightly re-formulated it in 1970. It concerns the one-way passage of information from DNA to protein. For perhaps most biologists the idea has been taken to mean (with some distortion) that DNA shapes and functionally determines proteins, rather than the other way around. But the central dogma is much less cited today than it was in the past, no doubt because its relevance to the actual life of organisms is so limited.

Tags: development (ontogeny); evolution/and development; inwardness (intention, idea, meaning)

Sources:

Arber, Agnes (1985). The Mind and the Eye: A Study of the Biologist’s Standpoint, with an introduction by P. R. Bell. Originally published in 1954. Cambridge UK: Cambridge University Press.

Barfield, Owen (1965). Unancestral Voice. Middletown CT: Wesleyan University Press.

Barham, James (2000a). “Biofunctional Realism and the Problem of Teleology”, Evolution and Cognition vol. 6, no. 1.

Buller, David J. (1999a). “Natural Teleology”, introduction to Function, Selection, and Design, edited by David J. Buller. Albany NY: SUNY Press, pp. 1-27.

Bridges, B. A. (1969). “Mechanisms of Radiation Mutagenesis in Cellular and Subcellular Systems”, Annual Review of Nuclear Science vol. 19, pp. 139-78. doi:10.1146/annurev.ns.19.120169.001035

Cook, Norman D. (1977). “The Case for Reverse Translation”, Journal of Theoretical Biology vol. 64, no. 1 (January 7), pp. 113-35. doi:10.1016/0022-5193(77)90116-3

Corning, Peter A. (2019). “Teleonomy and the Proximate–Ultimate Distinction Revisited”, Biological Journal of the Linnean Society, vol. 127, no. 4 (August), pp. 912-6. doi:10.1093/biolinnean/blz087

Crick, Francis H. (1958). “On Protein Synthesis”, Symposia of the Society for Experimental Biology no. 12: The Biological Replication of Macromolecules, pp. 138-63.

Crick, Francis (1970). “Central Dogma of Molecular Biology”, Nature vol. 227 (Aug. 8), pp. 561-3. doi.org/10.1038/227561a0

Dennett, Daniel C. (1995). Darwin’s Dangerous Idea: Evolution and the Meanings of Life. New York: Simon and Schuster.

Elespuru, R. K. and K. Sankaranarayanan (2006). “New Approaches to Assessing the Effects of Mutagenic Agents on the Integrity of the Human Genome”, Mutation Research vol. 616, pp. 83-9. doi:10.1016/j.mrfmmm.2006.11.015

Goodwin, Brian (1994). How the Leopard Changed Its Spots: The Evolution of Complexity. New York: Charles Scribner’s Sons.

Jacob, François (1977a). “Evolution and Tinkering”, Science vol. 196, no. 4295 (June 10), pp. 1161-6. doi:10.1126/science.860134

Langer, Susanne K. (1967). Mind: An Essay on Human Feeling vol. 1. Baltimore MD: Johns Hopkins University Press.

Pinker, Steven (1997). How the Mind Works. New York: W. W. Norton and Company.

Rich, Tina, Christine J. Watson and Andrew Wyllie (1999). “Apoptosis: The Germs of Death”, Nature Cell Biology vol. 1 (July), pp. E69-71. doi:10.1038/11038

Ruse, Michael (1979). “Philosophy of Biology Today: No Grounds for Complacency”, Philosophia vol. 8, (October), pp. 785–96. doi:10.1007/BF02379065

Sachs, Joe (1995). Aristotle’s Physics: A Guided Study. New Brunswick NJ: Rutgers University Press.

Shapiro, James A. (2011). Evolution: A View from the 21st Century. Upper Saddle River NJ: FT Press Science.

Toepfer, Georg (2012). “Teleology and Its Constitutive Role for Biology as the Science of Organized Systems in Nature”, Studies in History and Philosophy of Biological and Biomedical Sciences vol. 43, pp. 113-9. doi:10.1016/j.shpsc.2011.05.010

Walsh, Denis (2000). “Chasing Shadows: Natural Selection and Adaptation”, Studies in History and Philosophy of Science, Part C: Studies in History and Philosophy of Biological and Biomedical Sciences vol. 31, no. 1 (March), pp. 135-53. doi:10.1016/S1369-8486(99)00041-2

Webster, Gerry and Brian C. Goodwin (1982). “The Origin of Species: A Structuralist Approach”, Journal of Social and Biological Structures vol. 5, pp. 15-47. doi:10.1016/S0140-1750(82)91390-2

Steve Talbott :: Teleology and Evolution: Why Can’t We Have ‘Evolution on Purpose’?