A teoria evolucionária darwinista pode ser levada a sério???

quarta-feira, junho 01, 2016


Can Darwinian Evolutionary Theory Be Taken Seriously?

Stephen L. Talbott

This article is part of “RediscoveringLife.org”, a news portal for the Biology Worthy of LifeProject. Copyright 2016 The Nature Institute. All rights reserved.
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Posted: May 17, 2016 (Article 30)

This article is the initial offering in a projected trilogy. The other two articles are tentatively entitled, “Evolution as a Story of Extended Development” and “The Intentional Organism”. The three pieces are intimately intertwined and mutually supportive. None of the three is fully intended to stand by itself, but, for the time being, this one must do just that.

Evolutionary biologists today find themselves in a troubled relationship with the American public. Their great source of discomfort and wonder lies in the fact that the theory of evolution is “still under siege”1 by a substantial and sometimes aggressively disbelieving population — this despite being “an established and accepted scientific theory for 150 years”.2 “What are we doing wrong?” asks Jason Wiles, a biologist and educator at Syracuse and McGill Universities. His answer: “We do not know”.3 And, in light of the vast institutional support undergirding evolutionary science, another educator wonders why “those exposed to evolution education do not generally demonstrate mastery of the concept”.4

The usual claim is that at least half of Americans doubt the prevailing theory, if not the very fact, of evolution. Or, at least, they recoil from the theory’s standard presentation, which tells them that the entire sweep of evolution, from microbes to man, has occurred through natural processes.5 “Natural”, in this context, means something like “purely material, purposeless, and inherently meaningless”.

Of course, rejecting the natural looks rather like bad karma. But then, embracing strictly material meaninglessness is not an obvious key to enlightenment. Do the meanings and values we derive through our experience in the world really belong to the world, or are biologists merely inventing things when they deem the truth desirable and their own work worthwhile? Are mentality and purpose alien to nature? — and if not, can they be alien to fundamental evolutionary processes?

Actually, no one doubts that human culture, with all its purposes and meanings, now plays a large role, both in our own evolutionary development and in the extinction, preservation, and modification of other species. Can we believe that our cultural ideas andintentions, which so effectively re-shape the material world, arrive on the scene only through ruptures in the natural fabric of the universe?

But the problem of meaning and purpose runs through all pre-human evolution as well. To see this, we need only observe the remarkable display of wisdom and carefully coordinated, apparently goal-directed activity so evident in dividing cells, developingembryos, mating animals, and organisms seeking food. We can hardly dismiss the evolutionary relevance of these adroit, adaptive, and seemingly intentional performances.

Perhaps we should pause and take a fresh look at things.

I would like to suggest that if half of all American citizens have become (as certain arch-defenders of biological orthodoxy like to put it) “science deniers”, then something important is afoot, and it does not look good for science. At the very least — if we assume the denial to be as unreservedly stupid as it is said to be — it would mean that science has massively and catastrophically failed our educational system. Or, if it’s not that stupid, perhaps half the population simply refuses, with more or less understanding, to tune into certain tendencies and philosophical commitments that have grossly distorted the interpretive framework governing most biological science today.6

The organism as a pretender

Some things are too obvious to deny, and not many biologists will flatly dispute the intelligently purposive, or teleological, character of organisms. “It would make no sense to talk of the purposiveness or adaptation of stars, mountains, or the laws of physics”, wrote Theodosius Dobzhansky, a geneticist and leading architect of twentieth-century evolutionary theory. But “adaptedness of living beings is too obvious to be overlooked ... Living beings have an internal, or natural, teleology”.7

Philosopher of biology Robert Arp puts it this way:

Thinkers cannot seem to get around [evolutionary biologist Robert] Trivers’ claim8 that “even the humblest creature, say, a virus, appears organized to do something; it acts as if it is trying to achieve some purpose” ... Darwin’s biology does not deny — rather, it reaffirms — the immanent teleology displayed in the striving of each living being to fulfill its specific ends ... Reproduction, growth, feeding, healing, courtship, parental care for the young — these and many other activities of organisms are goal-directed”.9

Here, however, is where a strange ambiguity begins. For even if what Arp points out seems obvious, he cannot quite bring himself to accept it at face value. So he hedges those remarks with a crucial qualification: “with respect to organisms, it is useful to think as ifthese entities have traits and processes that function in goal-directed ways” (his emphasis). In other words, the organism’s purposive behavior is not quite what it seems.

This “as if” has long been a cliché of evolutionary biology. In 1909, the prominent German evolutionary theorist, August Weismann, said that “the principle of [natural] selection solved the riddle, how it is possible to produce adaptedness without the intervention of a goal-determining force”.10

The idea was simple: there is always variation among organisms, and the ceaseless culling of the less fit among them by natural selection leaves the field to those organisms bearing the most useful variations. These are the organisms most fit for survival and reproduction — best adapted for functioning successfully in their prevailing environments. They therefore appear to be goal-directed beings, whether the goal is survival or any lesser goal serving the purpose of survival. But Weismann wants to assure us that there is noactual goal-seeking going on — or, as he puts it, no “goal-determining force” at work.

Julian Huxley, who coined the phrase “Modern Synthesis” to describe the now canonical, twentieth-century formulation of what is also called “neo-Darwinism”, wrote in 1942:

It was one of the great merits of Darwin himself to show that the purposiveness of organic structure and function was apparent only. The teleology of adaptationis a pseudo-teleology, capable of being accounted for on good mechanistic principles, without the intervention of purpose, conscious or subconscious, either on the part of the organism or of any outside power”.11

Here, again, we are said to be saved from the “intervention” of an alien force, as if real purpose and intelligence would be an offense against the natural world.

And, several decades later, the author who gave us the “selfish gene” warned us how hard it can be to escape illusion: “So overwhelming is the appearance of purposeful design that, even in this Darwinian era when we know ‘better’, we still find it difficult, indeed boringly pedantic, to refrain from teleological language when discussing adaptation”. And yet, Richard Dawkins is ever ready to remind us, “the theory of natural selection provides a mechanistic, causal account of how living things came to look as if they had been designed for a purpose”12 (emphasis added).

Dawkins’ formulation has the virtue of making explicit the fact that the organism of the long-running cliché is a designed artifact, or machine. The purposes posing the original problem — purposes that seemed to arise from a live sensing of the requirements of the present moment and a directional striving — have been quietly assumed away. They now become the functions of a machine-organism. So the question about the organism’s purposeful activity has disappeared in favor of this: “Was the design of the artifactual organism purposeful or not?”

Of course, Dawkins’ own strong predilection runs toward purposeless design by natural selection, a “blind watchmaker”13 who gives us an apparent purpose that — no need to worry! — isn’t quite the real thing. On the other hand, many of the opponents Dawkins commonly has in mind prefer an intelligent designer. What seems to have fallen out of the argument on both sides is the organism itself, which has vanished into the automatisms of engineered machinery. Its living powers have been transferred to a mysterious designer, blind or otherwise, who, having messed around with everyone’s ancestors, remains conveniently obscure for current scientific investigation.

Pursuing an illusion is hard to do

A rather odd urgency sounds through all this earnest insistence that, while organisms certainly look as if they possessed intelligent agency, we should not be so foolish as to be compelled by the evidence of our own eyes. And the claim is curiously vague. How, after all, might we distinguish between an organism capable of expressing wise intention, and an organism capable of conjuring an overwhelming illusion of wise intention? Is there, in fact, evidence that can properly override the judgment of our own eyes?

Suppose, having watched a powerful drama in which the players improvise on Shakespeare’s Hamlet, we were told that its meaningfulness — all the evident thought and intention of the players, all the unpredictable, yet coherent and directed storytelling activity — was somehow an illusion. What could we possibly make of this? Isn’t an appearance of meaningful dialogue already meaningful dialogue — and wouldn’t it remain so even if we subsequently found that it came to us, not as we thought, but in a ghostly vision? Pointing to a ghost that speaks meaningful words to us does nothing to banish the problem of meaning.

The same would be true if a cleverly programmed, artificially intelligent robot spoke those words. We would recognize a real — not a pseudo — intelligence somewhere behind the production of the meaningful speech. The question would not be whether we were seeing evidence of real intelligence, but where was its live origin.

It is easy to believe that the ubiquitous and casually spoken aphorisms about as ifteleology have never clearly been thought through. They may serve mainly as a convenient smokescreen for covering theoretical confusion — or, perhaps, a means of self-reassurance in the face of a powerful awareness of one’s own interior life, an awareness virtually impossible to shake off. “Yes, we are sometimes moved by profound meaning, and we pursue our own intentions; but that’s okay because none of this is quite what it seems to be”.

Or, which is much the same thing: “Darwin assumed only variation and natural selection, resulting in adaptation. The ‘results’ are the same as if they had been ‘intended’”.14 We might want to ask, “If the results really are the same as if they were intended, what makes them not really intended?” But perhaps it’s not worth the bother.

The thing to hold onto in all this is natural selection. If there seems to be real purpose in organisms, so we’re told, then natural selection explains it, or explains it away, in non-purposive terms. If there is only an illusion of purpose, natural selection is the responsible agent behind the illusion. Just as we trace the machine’s intelligence and intentions to a human designer, we must trace the organism’s intelligence and intentions, such as they may be, to natural selection, the blind, mindless, unintelligent, yet wondrously effective designer whose existence Darwin exposed.

But do we have any possible grounds for taking natural selection seriously as a designer of organisms and explainer of their intelligence? Before answering that question, we need to clarify some terminology by distinguishing between machines and organisms. The issues are fateful; they make or break the entire theoretical structure underlying modern biology.

Of machines, organisms, and agency

When we build a machine, we manipulate materials of the world so as to configure a set of causal physical relations adequate to our purposes. Following this configuration, the machine’s performance is shaped by those causal relations, yielding a result that is in some regards predictable so long as outside factors do not interfere. Everything “rolls along” within the preestablished physical constraints. Engineers and philosophers speak of the “initial conditions” of the system — its original, designed arrangement — which then constrains the subsequent performance.

Organisms are not machines.15 They are not endowed with a set of initial conditions, after which they carry forward the mechanistic implications of those conditions. The organism is, moment by moment, establishing new “initial” conditions. It is as if a machine were being redesigned at every moment — or would be like that if the organism were machine-like. In reality, the organism’s life is a continual “self-redesigning” — or, better, a self-expressing, or self-transforming. Its parts are not assembled once for all; they aregrown on the spot during development, so that the functional unity of the organism — the way its parts play together, and even what the parts are — obviously must be changing all along the way. If the organism were machine-like, it would be a different, newly constituted and redesigned machine each time you looked at it.

So the organism possesses, or is, a power of origination. It constantly brings about something new — something never wholly implied or determined by the physical relations of a moment ago.16 We could also think of it as a power of self-realization. The “design work” accounting for the organism is an activity inseparable from the organism’s own life. It is an expression of that life rather than a cause of it.

Machines and organisms have this in common: whatever is responsible for orchestrating causal arrangements — initially, in the case of machines, or continually, in the case of organisms — cannot itself be explained by those arrangements. This single fact calls into question the entire habit within biology of trying to explain the present purely as the consequence of material forces playing out of the past.

Biologists speak incessantly of mechanisms and of machine-like or programmed activity in organisms. But this is empty rhetoric. No one has ever pointed to a computer-like program in DNA, or in a cell, or in any larger structure. Nor has anyone shown us any physical machinery for executing such program instructions. Nor, for that matter, has anyone ever explained what constrains diffusible molecules in a watery medium to carry out intricate and elaborately sequenced operations, such as DNA replication or RNA splicing.

So, then, how do the organism’s self-designing, or self-expressing, intentions compare to our own purposive, engineering activity in designing machines? There is a crucial difference between the two. We do not cause the parts of a machine to grow together; we put them together. Our designing activity impinges on the machine “from the outside”. This is best understood by comparison with organisms.

As we have seen, the life of the organism is itself the designing power. Its agency is immanent in its own being, and is somehow expressed at the very roots of material causation. It brings forth this or that kind of growth with no need for the artifice of an alien hand arbitrarily intervening to arrange parts and causal relations this way or that. The choreographing is brought about, it would appear, from that same depth of reality where the causal forces themselves arise, not from “outside”. However we conceive this “inner” place, it is, at least for now, inaccessible to our own engineering prowess.

At the same time, we ourselves possess varieties of conscious activity that other organisms do not. When I refer to the organism’s intelligent agency, or its purposiveness, or its directed coordination of means to serve particular ends, I do not imply anything equivalent to our own conscious purposing or planning. But neither do I suggest somethinginferior to our particular sort of wisdom and power of action. If anything, we must consider organic life — for example, the life of our cells — to be an expression of a higher sort of intelligence and intention than we ourselves can yet imagine consciously achieving in the technological realm.

Rather than over-defining terms and transgressing the boundaries of my own understanding, I am inclined to leave the matter there. I will tend to use words such as “intelligence”, “purpose”, “intention”, and “agency” in the way we commonly use them, with the understanding that the reader will keep in mind the above considerations. Given the scientific culture’s reflexive recoil from the psychic and voluntary in all its manifestations, I prefer to err on the side of anthropomorphism rather than to encourage the usual dismissal of interior reality.

It needs adding, finally, that our recognition of intelligent and intentional expressions does not require us to understand everything about their source. We would have no difficulty distinguishing the significance of letters on a page from that of pebbles distributed on a sandy shore, even if we knew nothing about origins in either case. We can declare a functioning machine to be a designed object, whether or not we have any clue about who designed it. And if we find live, intelligent performances by organisms, we don’t have to know how, or from where, the intelligence gains its foothold before we accept the testimony of our eyes and understanding.


Stephen L. Talbott
The Nature Institute; Ghent, New York

After many years working in the engineering organizations of computer manufacturers, Talbott joined The Nature Institute as Senior Researcher in 1998. He has long been concerned about distortions introduced in biology by technological thinking. He attempts to show how our understanding of the organism and its evolution is transformed once we recognize and take seriously the organism as an intelligent agent meaningfully (though not necessarily consciously) pursuing its own way of life.