Inheritance and the Whole Organism

In 1923 Wilhelm Johannsen, the Danish plant physiologist and pioneering geneticist who had earlier given biologists the word “gene”, expressed concern about the way genes were being conceived as neat, cleanly separable causal units. He made the following curious remark, which remains today as intriguing as ever, despite its never having had much effect on the direction of genetic research:

Personally I believe in a great central ‘something’ as yet not divisible into separate factors. The pomace–flies in Morgan’s splendid experiments continue to be pomace–flies even if they lose all “good” genes necessary for a normal fly–life, or if they be possessed with all the “bad” genes, detrimental to the welfare of this little friend of the geneticists (Johannsen 1923, p. 137).

Nevertheless, disinterest in this all too obvious and fundamental fact of life took over evolutionary biology as if the disinterest were somehow a prerequisite for the preservation of the discipline. Genes came to be seen as discrete and particulate entities, making them nicely definable and easily trackable, fit to be considered primary causes of the organism.

The consequence for the organism was that it lost its unity, becoming instead an aggregate of discrete parts and traits mapped to genes. Holistic, contextual understanding was severely downplayed. The organism’s interior agency became alien to the biologist’s manner of thinking — displaced by the informational gene, where the idea of information, with its inescapable connection to meaning, was conveniently conflated with material entities. With the aid of information one could import meaning into biology “under the table”, thereby making biological description tolerable, while pretending that one’s reference was really only to inherently meaningless matter. And so, as far as explicit theorizing went, the unifying play of organizing idea and intention through all biological activity (Chapter 6, “Context: Dare We Call It Holism?”) could no longer be mentioned in decent circles.

On his part, Johannsen realized that the new genetic work, based as it was on the assumed existence of separate and independent causes of traits, left untouched what might easily be seen as the central problem of inheritance: the faithful reproduction of kind, or type — that is, the maintenance of the materially perplexing, integral unity that harmonizes all the particular traits and parts of an organism and expresses a species’ characteristic way of being. While mutated genes might result in (typically pathological) differences in certain narrowly conceived traits, this sort of change never reached through to the fundamental identity (“that great central something”) defining an organism as this kind of organism. Whatever the artificially induced and disfiguring mutational horrors, the pomace flies always remained pomace flies.

Johannsen’s problem arises because we can hardly help recognizing the distinctive unity of a living being — a unity we cannot equate to any particular parts. Rather, the unified whole seems in some way responsible for its parts which, in turn, always appear to be expressions of the whole. We never see an organism being constructed or assembled from already-existing parts. In its development it works to bring them about — to differentiate them out of a prior and continuing unity. Every organism is the power to do this work, and the power is not derivable from its material results. If some of its parts become deformed, the organism works out of its unity to compensate for the deformities as best it can, doing so according to the way of being of its own kind.

In other words, biologists have long been forming their idea of heredity against the backdrop of carefully selected, inessential, experimentally accessible traits that scarcely touch the problems presented by every organism’s essential unity and inalienable character. They have not been asking themselves, “How can we begin to think about the organizing power by which a mammal differentiates and maintains in its proper place the indivisible uniqueness of a whole liver cell (and every one of its billions or trillions of other cells) as long as it is needed?”

The distinction between a fundamental, shared nature, on one hand, and individual peculiarities incidentally distinguishing organisms sharing that nature, on the other, has practical implications for genetic research:

The broad general resemblances of type give no hold for experimental or statistical treatment, and have accordingly on the whole been ignored. But it is this general hereditary resemblance which constitutes the main problem. [The gene theory] deals only with differences between closely allied forms, and with the modes of inheritance of these differences; it leaves the main problem quite untouched as to why, for example, from a pair of Drosophila only Drosophila arise. It takes for granted the inheritance of Johannsen’s “great central something” — the general hereditary equipment of the species (Russell 1930, pp. 269-70).

Every organism is thoroughly holistic (contextual). Its entire business might be seen as the continual, total reorganization of its own part-relations, or causal interactions, in response to different environments — all in harmony with its own essential way of being. Given this organization, harmony, and unity of being through which the organism’s central, governing character is expressed, it seems perfectly reasonable to surmise that this character could never be dissected or analyzed into a sum of causal relations between separate parts. Rather than being causal in the sense of “resulting from the impact of discrete thing on discrete thing”, it is interpenetrative, much as ideas are interpenetrative. Changing one significant word in a text can change the shade of meaning of many other words. It is not a matter summing up a set of isolated and discrete semantic impacts. We are always looking at a transformation of the meaning of a whole.

It is understandable, then, that genetic analyses in which we try to isolate the effects of specific genes can never solve for us the puzzle of the pomace flies that always remain pomace flies.

You might think that, given the broad fact of infertility between different types, biologists would have cast around for new approaches to the problem of an organism’s inherent governing nature, even if it required quite different methods from those they were trained in, and even if those methods included an artistic component. (See Chapter 12, “Is a Qualitative Biology Possible?”, for examples of alternative methods.) What is at stake, after all, is our understanding, not only of the organism, but also of evolution. We certainly cannot answer all the questions we have about fundamental evolutionary change — for example, questions relating to the origin of basic body plans — merely by looking at how specific gene variants correlate, under the right conditions, with inessential differences between closely allied forms of the same general type.

The picture I have been developing in this book shows us that organisms are in fact agents telling their own story — coherent, qualitative wholes that inform and define their own parts. The parts, being so informed, share in each other’s identity and become inseparable features of a larger unity. Some such picture has been acknowledged by many biologists throughout the history of their discipline. If the picture is accurate, then the power to maintain this larger unity across generations — which also suggests a power to transform the unity — would seem to be central to our understanding of heredity and evolutionary change.

This is truly decisive. Have biologists in our day lost sight of the whole organism because of their fixation upon the molecular parts known as genes? And have they lost sight of evolutionary dynamics because of their fixation upon the hereditary transmission of genes rather than the activity of entire living cells?

And there is a third question we might ask here. Biologists freely resort to the word “organization”. This is healthy. But it is not so often realized that organization only has meaning in light of whatever organizing ideas one is referring to. Except in terms of organizing ideas, there is no organizing to speak of. The term becomes absolutely empty. So the question is this: might the problem with genetics as we have had it till now be that biologists have tried to substitute a one-dimensional, abstract, mathematized, and de-meaned notion of genetic information for the full-fleshed meanings (intentions, ideas, morphological and behavioral forms, purposes, needs, and interests) manifested in the story of every animal’s life?

We cannot understand a story by adding together material causes and effects. We cannot understand it with physical and chemical analyses. We have to take up the story in its own narrative terms. But this will not seem to be science to most biologists and geneticists, who have been trained to think that the causal essence of their discipline is physical and chemical. And, yes, it certainly does make sense to think of physics and chemstry as subdisciplines of biology. But that still leaves biology as such.

Biology as such is always a matter of meaningfully functioning wholes. If it is truly the case that the organism as a whole, with its needs and interests, plays a governing role whereby it continually informs its parts with its own character and “catches them up” within its own narrative purposes, then the performance of this whole, as Russell says, “can be [hereditarily] transmitted only by a whole, i.e. by the egg in its entirety, which already at the very beginning of development is the new individual” (Russell 1930, p. 283).

Amid this diversifying whirl of cell lineages in a human embryo, where our genomes are simultaneously being summoned into the service of wildly different cellular phenotypes, we can hardly help asking: What is the unifying and coordinating source, or power, through which all the radically diverse differentiating cells are formed into coherent tissues, organs, organ systems, and the stable, functional unity of an entire human body?

To get a grip on the scale of the organizational challenge, think first of the “humble” yet extremely dynamic and context-sensitive “hair follicle niche” we looked at in Chapter 6. Then consider the unthinkable number of distinct niches, many of them microscopically small, in the liver, or in the kidney, or in the brain, pancreas, bone marrow, and every other part of the body. They are all extraordinarily complex, more or less in the manner of the hair follicle niche. Vast numbers of such interpenetrating contexts, while mutually shaping each other, must somehow come under a global coordinating power reflecting the form and life of one human being.

The interactions within and between all these niches, organs, and organ systems look as though they are virtually infinite. Further, environmental conditions and bodily activity are continually changing in an endlessly varying manner. As a result, those “virtually infinite” interactions, including the patterns of gene usage in billions of cells, are only momentary. They must be capable of being reorganized minute by minute and hour by hour.

Still further, the task of global coordination goes far beyond what we normally think of as coordination. For the parts being coordinated are always in the process of becoming more or less different parts. We are never speaking merely about the coordination of existing parts, but also about their transformation — and, often, their coming into, or passing out of, existence. There are also the mind-numbing facts of wound healing, where molecules in a local region of the body — comprising muscle, nerve, and blood cells — find a way to restore the normal bodily structure of that region. (See the description of wound healing in Box 10.1 of Chapter 10 , and also the one related by C. S. Sherrington in Chapter 2.)

Is this dynamic unity, or wholeness, not one angle from which to view Johannsen’s “great central something”? Yet, a century after his comment few have gained the courage to contemplate this coordinating/creating power so evident in every organism, let alone to ask whether it must not be closely related to the power through which inheritance comes about.

At present, with our reigning tendencies of thought, we scarcely know how to speak about such matters. But we shouldn’t have difficulty at least holding on to the observationally sound idea of a unifying power capable of maintaining the distinctive character of every organism.

On the face of it, the failure of biologists to explore the explanatory potentials of the organism’s more-than-genetic, whole-cell and whole-organism capacity for directed change seems to reflect one of the most egregious and crippling blockages of thought in all the history of science. You may recall the question put forward in Chapter 17 (“Evolution Writ Small”) when we were reckoning with the facts of cell differentiation: Why should a forward-looking, transformative, and adaptive capacity, manifest in all organic activity and vividly demonstrated in all the cell lineages of our bodies, cease altogether at just one decisive point: namely, the point where (in sexually reproducing animals) the germ cell lineage — a lineage that lives under the same governing and coordinating power as all the other cell lineages — contributes a gamete to the next generation? Why should the whole gametic cell forfeit its ability continually to re-organize itself and all its resources, including its DNA, in pursuit of the organism’s inherent and adaptive developmental potentials?

Of course, it is well understood that two gametes joined in a zygotic cell do retain all the potentials for cell differentiation we observe in the new organism. But the question is why, if this species happens to be evolving, the transformative powers of that zygote should be thought unable, in their wholeness, to be potent bearers of the directive evolutionary impetus, just as they are already known to be bearers of the typical unity characterizing members of the species. It is, after all, this entire unity that must be transformed, not merely some material parts of it (and certainly not merely its DNA).

Actually, it is rather hard to distinguish a zygote’s power of transformative activity from its power to preserve its own type — especially if its type is understood as a forward-looking, adaptable, and dynamic way of being. The tendency to draw a strict line between these two aspects of an organism’s life — the power to preserve and the power to transform — may have resulted from our materialistic reconceptualization of the organism as an unliving, machine-like thing.

When we look at a machine, we see either the same machine that was there yesterday, or a re-engineered and re-designed machine. But when we look at an organism, we are seeing neither the same one that was there yesterday, nor one that has been arbitrarily reconfigured from outside itself. We are seeing instead a more fully realized being — a being entering ever more fully into its own potentials, however hidden they may be to our present insight. These potentials — presumably already there with the first living cell — might in general need to be understood from the vantage point of the immediate population, or from the “point of view” of an ecological setting, or from the broad perspective of the entire sweep of evolutionary history on earth.

In any case, there is always transformation, and no form of life stays always in the same place, even if there is no evolution in the usual sense. We are not in a good place today to judge the idea or meaning or context of the transformation; but once we have opened ourselves to the fact of meaning in the life of organisms, we realize that our questions have no localized bounds — actually, no spatial or temporal bounds at all. (What is the “location” of a meaning?) The nature of the potentials for change, and how far they may reach, are matters about which we currently have little insight — which is one reason why we need to learn everything we can about evolution.

Our ignorance may be part of the difficulty of holism. And, to be sure, there is difficulty. Whenever anything like the question of Johannsen’s “great central something” is raised, biologists have a strong tendency to plead the impossibility of carrying out their usual analyses if in fact they are up against organic wholes. I have never heard an evolutionary biologist acknowledge even the possible legitimacy of an evolutionary inquiry into the whole-cell, heritable, and transformative powers associated with gametes and zygotes. And, consistent with this, I have never heard of a major research program aimed at tracking how whole-cell inheritance might play into evolution. The most obvious possibility is the least considered — not because it is faulty, but only because it is difficult.⁵

It may have been a recoiling from this difficulty that led evolutionary biologists at mid-twentieth century to embrace so heartily a gene-centered view of organisms that spared them any need to deal with the problems and obscurities of whole organisms. We will look at this retreat into the conveniences of molecular biology in the next chapter. It’s been a retreat whereby organisms themselves have almost disappeared from evolutionary theory.

But, before that, it would be good to note the way in which (1) the seeming inaccessibility of the problem of wholeness has been used in attacks against the very idea of holism in biology. And also the way in which (2) the inescapable fact of holism has created seemingly insuperable problems for the theory of natural selection.

Thus, to the extent that development is holistic, the more complex the organism, and the more it has been elaborated over evolutionary time, the less significant further change there can be in that lineage. The point that adaptive change would be impossible if development were holistic has been made before. Lewontin, for example, has pointed out that such change requires traits to be “quasi-independent” … (Sterelny 2001).

But there is something strange here. The argument starts by assuming that, in holistic organisms, the effects of a genetic change are likely to conflict with each other and be unhealthy. In other words, the assumption is that organisms cannot function (with respect to the assembly of inheritances) integrally, coherently, and holistically. But if this is the starting assumption, then there is only brute assertion and no argument at all. The argument, such as it is, becomes possible only because of this assumption that organisms cannot really adapt in a holistic manner. And it overlooks what we considered earlier in the chapter — namely, the interior wisdom through which the hundreds of cell lineages in humans and other “highly evolved” organisms are, amid unfathomable complexity, orchestrated into a harmonious and intricately differentiated whole where accidents, injuries, and unexpected circumstances are commonly overcome.

So we haven’t heard much of a case against holism — especially given how often it is admitted that we don’t presently have the tools (let alone the inclination) even to begin investigating the possiblities of holistic inheritance and evolution. As Lewontin himself put it:

If a change in a trait as a solution to one problem changes the organism’s relation to other problems of the environment, it becomes impossible to carry out the analysis part by part, and we are left in the hopeless position of seeing the whole organism as being adapted to the whole environment (Lewontin 1978).

This is the “hopelessness” that applies to any attempt to verify the theory of natural selection, which we will consider below. But the truth of our observations remains. If an organism’s life and development is in fact holistic, why should we suddenly lose sight of this holism as soon as we turn our attention to its management of mutations and inheritance, or its participation in a species-wide pattern of evolutionary change?

Why, for example, should we ignore the fact of an organism’s holistic capacities when it comes to its management of naturally occurring genetic mutations (as opposed to arbitrary mutations inflicted by unnatural processes in the laboratory), or when it comes to the preparation of a coherent inheritance for its offspring? And why should we lose sight of the developing organism’s remarkable capacity to integrate and reconcile as far as possible its various physical resources — or, for that matter, the even more stunning capacity of two gametes to organize their separate lineage inheritances into a single, viable zygote?

When Lewontin spoke of quasi-independence, saying a trait must be changeable (subject to mutation) in at least some ways that do not dramatically alter other traits, he was apparently accepting the particulate view of inheritance and the random view of mutations.⁸ He therefore overlooked the possibility that an organism caught up in the evolving destiny of its kind might, by virtue of that very fact, be capable of coordinating the elements of its hereditary bequest to the next generation — and doing so, as we saw in Chapter 19 (“Development Writ Large”), by participating in the winding, “mosaic”, perhaps unexpected pathway leading indirectly yet coherently from the past of its own kind to the future. But, insightful as he was in so many other regards, Lewontin did not seem to consider this possibility even to be on the table, despite his familiarity with the highly complex, coordinated, and directive aspects of individual development.

It seems that the very idea of holism is so alien to biologists that the attempt to think it is aborted before it gets very far. This is all the more odd given that many of those repelled by the idea of holism in general are also (and with justification) enamored of the inescapably holistic idea of phenotypic plasticity — the individual organism’s ability to alter itself in order to adapt to a particular environment. If organisms are phenotypically plastic, then their different internal systems — for example, those involved in bone growth, muscle growth, and nerve growth — must be tightly integrated, so that they can respond adaptively and mutually to changes in each other. “Phenotypic plasticity”, we read in one enthusiastic author, “pre-adapts lineages to evolutionary change, by connecting the development of distinct organ systems”:

Limb development requires simultaneous and co-ordinated development in other organs and tissue systems: cartilage, muscle tissue and attachment points, innervation of soft tissues; circulatory connections to tissues and bone marrow. If bone structure or muscle mass is plastic, responding to signals from the environment, co-ordinated systems must be plastic too, responding to signals from the systems developing with them … This same sensitivity of integration to the contingencies of development will make functional integration possible in the face of genetically-caused changes in crucial organ systems.

The author of these remarks (Sterelny 2009) happens also to be the author of the comment above about the problem holism presents for evolutionary change. It’s as though, when one’s attention turns to evolution, one is obligated to begin thinking of change as if it were brought about, not by the plastic and adaptive character and agency of the organism and its kind, but by random disturbances to a mere aggregate of particulate genes that somehow (in their separation and relative isolation) map to and determine the organism’s phenotype.

And, yes, it is then very hard to imagine a set of scattershot changes that would, in harmony, alter the intricately interwoven, holistic way of being of an organism. But once we have acknowledged an organism’s holistic nature — and, in particular, its capacity for holistic, adaptive change — why should we so quickly forget it, especially when, in evolutionary theory, we are actually addressing the issue of holism?

I have not said anything about the degree of “quasi-independence” some organismal traits might have. I may indeed be inclined to start with the thought that organisms are far from being machines; they are not assemblages of independent, pre-fabricated parts. But if organisms consist of parts — cells and organs — that are relative wholes in their own right, then we would expect to see not only a principle of profound interpenetration among parts, but also manifestations of partial independence. This is worth a further look.

As for “quasi-independent” traits and holism, I think Samuel Taylor Coleridge, writing during the first half of the nineteenth century, put the question into the right perspective:

“The living power will be most intense in that individual which, as a whole, has the greatest number of integral parts presupposed in it; when moreover, these integral parts, together with a proportional increase of their interdependence, as parts, have themselves most the character of wholes in the sphere occupied by them” (Coleridge 1848).

Or, re-phrased: Life will be fullest in the individual that most fully integrates the greatest number of interdependent parts; and when those parts are themselves most like independent wholes.

Perhaps we can begin to glimpse the unity underlying these apparently contrary principles when we realize how, in human society, ever stronger and more centered selves are required if we want those selves to contribute ever more strongly and selflessly to the good of the larger society. Society becomes more complex and healthier to the degree the many movements toward a strengthened independent identity and toward interdependence are mutually reinforced.

Or think of your heart or brain. These wonderfully “perfected” organs, while possessing the strongest possible identity and wholeness in their own right, are — as an expression and extension of their wholeness — bound together with everything else that goes on in the body. No part of our bodies can be separated from the circulatory and nervous systems, just as the heart and the brain cannot meaningfully function in isolation from everything else in our bodies.

In other words, the potential for holism and the potential for a (relatively) independent perfection of parts are two sides of the same coin. An overall, deeper holism depends on a greater independence and perfection of parts in their own right, and a greater independence and perfection of parts depends on a deeper holism. The two principles, despite their contrary natures, are complementary in such a way that each exists only by grace of the other. This principle of polarity might almost be considered definitive of the organism. For example, every organism lives by distinguishing itself from its environment — and also lives only by virtue of what it takes into itself from its environment.

Coleridge’s remark derived, I believe, from a straightforward observation of living beings and required no evolutionary theorizing. He was, of course, writing before Darwin’s Origin. And he was willing to look at whole organisms as they actually presented themselves. As it happens, there is nothing in evolution that contradicts this profound holism of organic life. Holism, far from making evolutionary change more difficult, is what makes whole-organism transformation, and therefore evolution, possible.

At the same time, the “hopeless” situation Lewontin imagined, where we must see the “whole organism as being adapted to the whole environment” is not so hopeless after all. It’s not that our analytical tools are useless, since the parts of an organism are not only interdependent. They also manifest a certain analyzable independence. We need only avoid the usual temptation to see them interacting as the inanimate objects we imagine to be pushed and pulled by external forces.

An organism is able to act coherently as a whole because it is in fact a profoundly integral whole. But within that whole, each part is able, in its relative independence, to give its own intelligent and discriminating expression to the whole in which it participates so intimately. Yes, we have to learn to look with new eyes in order to see the integral unity of the organism. But it can be done, as we saw in Chapter 12 (“Is a Qualitative Biology Possible?”).

The theory is said to explain how genuinely new innovations can come about, resulting in the diversity of life from jelly fish to hippopotamuses — all presumably descended from a single, primordial cell. The theory holds that all this happens through a process whereby the fittest (best adapted) organisms of every generation are the ones most likely to survive, thanks to relatively rare, advantageous, and random (relative to fitness) mutations. This “survival of the fittest” is seen as the effective “mechanism” of natural selection.

If the theory really is key to understanding the evolution and origin of species, then we should, by looking closely at proposed examples of natural selection, be able to trace, not just how we imagine a general algorithm might have produced evolutionary transformation, but (in some cases, anyway) the actual causal processes by which one kind of organism evolves into a fundamentally different kind. That is, if we want a scientific test for the theory of natural selection, then the requirement is to explicate particular evolutionary changes and confirm natural selection as the decisive efficient cause accounting for them.

And when we talk about change in this way, we can’t allow ourselves merely to document the plasticity and adaptability that lies within a species’ unevolving nature. For example, we cannot talk about the famous peppered moths (Biston betularia) in England, whose darker forms prospered during the industrial age (because they were less visible to predators against the darkened, soot-covered trunks and branches of trees), and then reverted to lighter forms in the post-industrial age. This may indeed have illustrated some form of selectivity, but it was very far from convincingly illustrating evolution by natural selection.

So what is the difficulty in validating the theory of evolution by natural selection? Since fitness is the key parameter of the theory, the first task is to show how we might sort out and sum up the fitness contributions of all the interwoven parts of any given organism — an organism that always turns out to be an integral unity. And then there is the forbidding task of showing how the tracing of countless quantitative fitness values down through the evolutionary history of a species, can provide an adequate explanation of the qualitative transformation that occurs in the movement from one kind of organism to a different kind. We will not come to this second part of the task here, because we will find no way forward with the first.

As for the fitness parameter as such, the fact that we lack the means to formulate it reliably is not an ambiguous or doubtful matter. Even leading figures in the establishment of the reigning, neo-Darwinian theory of evolution have recognized the nature of the problem. For example, George Gaylord Simpson wrote that “The fallibility of personal judgment as to the adaptive [fitness] value of particular characters, most especially when these occur in animals quite unlike any now living, is notorious”.¹⁰ And Theodosius Dobzhansky wrote in 1975 that no biologist “can judge reliably which ‘characters’ [trait variants] are useful, neutral, or harmful in a given species” (Dobzhansky 1975).

In two crucially important papers,¹¹ the philosopher, Ronald Brady, cited these remarks by Simpson and Dobzhansky. The concern behind the remarks, as Brady also noted, was captured by the journalist, Tom Bethell, this way:

A mutation that allows a wolf to run faster than the pack only allows the wolf to survive better if it does, in fact, survive better. But such a mutation could also result in the wolf outrunning the pack a couple of times and getting first crack at the food, then abruptly dropping dead of a heart attack because the extra power in its legs placed an extra strain upon its heart … It is the overall animal that survives, not the individual parts of it.

And so we come back to Lewontin’s worry about the “hopeless” situation of the researcher faced with a holistic organism and with the problem of understanding how the whole organism is adapted to the whole environment. Darwin himself, in The Origin of Species, had emphasized what extraordinary thoroughness and subtlety must be brought to the problem. But nature, he thought, is adequate to the task: it “can act on every internal organ, on every shade of constitutional difference, on the whole machinery of life … Under nature, the slightest difference in structure or constitution may well turn the nicely-balanced scale in the struggle for life, and so be preserved”.

Darwin, in suggesting how far nature excelled the human breeder (who was generally concerned only about a narrow range of traits), did not illustrate or give examples of nature’s subtle, whole-organism “summing up” of fitness factors. Presumably he recognized that this was not possible in his day, and he assumed that the relevant research program would follow.

Brady responded by asking, “Has it followed?” And his answer, supported from many angles, as well as by the concerns we heard from Lewontin, Simpson, and Dobzhansky, was that we are still in no position to “read off” the fitness of the whole organism, and therefore are left to judge the matter by letting nature do the summing up for us. This has, in fact, become a common attitude: we simply declare surviving organisms the fittest, without really understanding what makes them the fittest.

But in giving up the effort to understand in scientific terms what it means to be one of the fittest who survives, we have given up the effort to understand causally how natural selection as currently defined might account for (if it actually does account for) evolutionary transformations. That is, we have given up trying to prove the validity of the theory of natural selection.

In fact, we have given up even having a theory at all. In simply accepting the record of survivors handed us by nature, we merely document the “natural history of life” (Langer 1967, p. 394) as it has actually occurred, which includes the diversification of species. But, as I pointed out in Chapter 16 (“Let’s Not Begin With Natural Selection”), this is the problem that our theory of evolution was meant to explain, not a solution to the problem.

It is not hard to recognize (1) our current inability to understand the almost unfathomable wisdom that plays through, and manifests as, the intensely integrated and well-adapted unity of the organism; and (2) our inability to analyze the vast range and subtlety of the organism’s interactions with its environment, adaptive or otherwise — an environment that cannot easily be defined, and doesn’t even exist for the organism except in relation to the organism’s activity in making its own environmental context what it is.

The explanatory poverty and untestability of the theory of natural selection may help to explain the energy with which the theory has been defended as an empty algorithm, or play of logic. Recall some of what we have encountered in previous chapters:

• We have heard natural selection proposed as the solution to the problem of purposiveness in biology (Chapter 18) And yet, we saw that there was no concrete suggestion forthcoming as to how a mechanistically problematic dimension of purposiveness or end-directedness in biology — for example, the kind of purposiveness that governs the intricate, step-by-step, highly complex “surgery” of RNA splicing by scores of independent molecules in a fluid medium (Chapter 8) — might actually have been underwritten by natural selection.
• We have heard a prominent artificial life researcher (Christoph Adami) and a prominent philosopher (Daniel Dennett) arguing for the truth of natural selection while declaring that their faith is not dependent on the facts (or “little details”) of biology (Chapter 16).
• We have heard a science writer (Susan Blackmore) expressing her unqualified delight in the “inevitability” of natural selection, an algorithm that “just must produce design” — “design out of chaos without the aid of mind”. Apparently her enthusiasm did not require any explication of how selection theory actually works in producing design (Chapter 16).
• We also heard, in Chapter 19, that an informal poll of evolutionary biologists by Dennett suggested a consensus that there is no way to distinguish natural selection from artificial selection such as breeders carry out. So it appears that biologists who claim evolution is not a directive process have no basis for distinguishing a directive from a non-directive form of evolution.

But the entire problem of natural selection becomes still murkier when we realize that the fitness of the individual organism for survival, as I have remarked more than once, isn’t even the relevant criterion for evolutionary change. What matters, rather, is the contribution of the organism toward the meaningful outcome of the perhaps extremely complex evolutionary trajectory in which it is participating (Chapter 19, “Development Writ Large”).

Once we recognize this, the whole business of trying to quantify the fitness value of particular traits for the survival of the individual organism begins to look like an evolutionarily meaningless occupation. After all, the importance of a particular organism’s life for the evolutionary outcome may lie in the fact that it is going to die without leaving progeny, thereby contributing to the extinction of a lineage that might otherwise only hinder evolution because it represents the past rather than the future. Or it may lie in the fact that this organism is going to cross-breed with a member of a different species and produce only rather sickly offspring, one of whom will nevertheless introduce exactly the needed cellular feature into an evolutionary lineage bearing part of the future in itself.

To this we could add the fact that few if any biologists would want to defend the claim that multicellular organisms are fitter than single-celled ones in their reproductive success, or that dinosaurs were less fit than the extant organisms today. So the idea that superior fitness has been the key, guiding parameter for evolution requires severe qualification, at the least.

But the heavily abused concept of fitness is only part of the problem. There is also the mystery of the “arrival of the fittest” we encountered in Chapter 16 (“Let’s Not Begin With Natural Selection”). The theory of evolution by natural selection does not even take note of how organisms create the trait variants on which the theory builds. That is, it does not reckon with the problem, “How could it be that new, useful traits arise in the first place, and that when they arrive, they are already integral and harmonious participants in the the unified life of a particular kind of organism, thereby joining the chorus of all the other parts in giving expression to a distinctive way of being?”

Actually, natural selection is not a theory dealing with origins at all, but only with the spread of existing, unaccounted-for features through a population. And even that question is dealt with only insofar as the spread within a population can be correlated with a single feature of cellular life, namely, its genetic heritage. The always purposive organization of the whole zygotic cell, carrying the creative and evolutionarily relevant potential to differentiate into so many cell types — so many kinds of one-celled “organisms” — is ignored as a factor in inheritance.

And so we have only the travesty of a theory. It’s a theory misleadingly focused on the idea of individual fitness rather than on the evolutionary outcome that is the final object of explanation; a theory that has not even managed to define its pivotal parameter — the single organism’s fitness — with any scientific clarity; a supposedly causal, evolutionary theory that makes no effort to trace the genesis of the “ubiquitous variation” (crucial traits) it takes for granted; a theory that, when it does allude to these traits, says no more than that they somehow correlate with randomly generated mutations, where the appeal to randomness not only is the very opposite of scientific explanation, but also seems to contradict the infinitely complex, wholly intentional, thoroughly qualitative, interwoven unity of being of a shark or kangaroo or a dog or cat; and a theory founded aggressively and restrictively on the genome — that is, on a single aspect of the cell rather than on the whole-cell life, that so obviously governs the genome.

It appears, then, that the contemporary theory of evolution by natural selection is not much of an evolutionary theory at all. Instead, it has veered off into various scientific research strategies that certainly have led to many profitable observations of organisms and their interactions, and certainly have produced a great deal of data about changes in relatively minor traits — changes that are often reversed later, as in the famous case of the coloring of peppered moths in England — all in the absence of anything we could call a fundamental theory of evolution. Perhaps it is no wonder that so many who would speak for science on the topic of evolution today, as we saw in Chapter 16, prefer to celebrate the “inevitable” logic of natural selection instead of demonstrating its explanatory contribution to our understanding of actual evolutionary transformations.

3. Figure 20.2 credit: From Ramster 2003

4. Hybridization does in fact sometimes occur between distinctly different species (within limits, but way more often than most biologists believed not long ago) and, as I mentioned in Chapter 19 (“Development Writ Large”), this can contribute to rather dramatic evolutionary change. But such hybridization is likely to generate massive genetic and cellular reorganization, far too extensive and global to allow for conventional genetic approaches. So one is still facing the unsolved “problem of the whole” — the problem that genetic analyses were designed to steer clear of by focusing on particular genes causing particular trait differences under well-defined conditions.

5. There is also a common claim that we lack any evidence for more-than-genetic, whole-cell inheritance. This claim usually reveals itself as spectacularly circular, being based on the fact that holistically inherited features can’t be clearly mapped to specific “causal” genes. The underlying assumption is that all heritable or evolutionarily significant change must arise from germline genetic mutations. This assumption is then used to refute the claim that there are more-than-genetic, whole-cell or whole-organism powers of change.

So no change can be talked about that isn’t linked to particular genes that get reliably inherited, and the argument against a more-than-genetic, whole-cell contribution to evolution is that it can’t be reduced to a particulate, gene-based theory. Something very like this argument is put forward, for example, whenever the question of epigenetic inheritance is raised in connection with evolution.

On the related claim that evolutionarily significant variation (mutations) must be stably maintained across many generations, see Chapter 22 (“A Curiously Absolute Demand for Stable Variation”).

6. See Lewontin 1978 and Levins and Lewontin 1985, pp. 79-80. Lewontin actually spoke of two requirements for adaptive evolution. In addition to the quasi-independence of traits and their variants, he also cited the need for continuity: “small changes in a characteristic must result in only small changes in ecological relations; a very slight change in fin shape [of a fish] cannot cause a dramatic change in sexual recognition or make the organism suddenly attractive to new predators” (Lewontin 1978).

7. Figure 20.3 credit: Museum of Comparative Zoology, Harvard University; copyright President and Fellows of Harvard College (CC Attribution-NonCommercial-ShareAlike).

8. On the supposed randomness of mutations, see the discussion in the concluding section of Chapter 17 (“Evolution Writ Small”).

Of course, apparently random events may figure in a scientific theory. But when the whole point of the theory is to explain evolutionary change, the assignment of change to random mutations doesn’t yet give us an explanation we can reasonably call “scientific”. It’s basically a way of saying, “We have no scientific explanation”. What we really want is an understanding of how we can characterize the origin or transformation of a trait that is present in the only way normal traits can be present — as part of the tightly organized unity of a living being. The relation between such traits and the genes in our cells — or, more relevantly, between such traits and the overall organization of our cells — has scarcely been approached in the modern era of biology.

9. German philosopher, Dieter Wandschneider, has commented that “In a world in which sickness can effectively be cured, clinics and spas are at people’s disposal, artificial limbs are applied, and replacement organs are implanted, the biological principle of survival has been ‘unhinged’. And that means, too, that natural evolution has come to an end”:

One could object that the human species changes biologically even today — for example, in muscle structure, susceptibility to sickness, and life span. That cannot be denied. But these changes are manifestations of the “self-domestication” of man and thus consequences of civilization, which as such are not the results of natural selection. On the contrary, they are expressions of an evolution that is now taking place under completely different conditions, namely those of cultural evolution (Wandschneider 2005, pp. 204-5).

10. Quoted in Brady 1982. The quotation is taken from Simpson’s 1953 book, The Major Features of Evolution.

11. The papers are “Dogma and Doubt” (Brady 1982) and ”Natural Selection and the Criteria by Which a Theory Is Judged” (Brady 1979). They attempt to show why the frequent charge of tautology leveled against the theory of natural selection is invalid, and why the real problem lies with the current impossibility of testing the theory. Because of the testing problem, Brady argues, we have as yet no evidence that natural selection can explain the origin of evolutionary innovations.

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Steve Talbott :: Inheritance and the Whole Organism