Teleological Evolution
Teleological Evolution
Most modern accounts of evolution dismiss the idea that the process is in any way teleological, that is, directed toward a goal. Evolution is a blind, mechanical process, they say, that just happened to produce all the complex forms of life we know today, including human beings. There was no foresight or intention to do so. But Steve Talbott, Senior Researcher at The Nature Institute in upstate New York, disagrees. He thinks evolution does show foresight and intention, as does life in general. This essay examines the issue in some detail. This one is a bit longer than usual, but bear with me. It gets positively cosmic at the end.
I. Two kinds of explanation
There is an explanatory tension between teleological explanations, which look toward the future, and causal-mechanical explanations, which look toward the past; and that tension reveals fundamentally different ways of viewing the world.
Causal-mechanical explanations apply to the realm of the non-living, where desires and beliefs about the future play no part. That a gas expands when heated has nothing to do with its desire to keep its temperature constant, even though that is just what happens, nor its belief that by expanding it can do so. The standard approach to physical explanation is by appeal to physical laws, regularities of behavior that are so universal that we depend on them. In technical terms, this approach is called the deductive-nomological method of explanation. It accounts for particular events by showing how they can be deduced from law-like regularities that pertain to them. (The Greek word nomos means law.)[1] The law is that when gas is heated it always expands if it has room to do so. We heat some gas and confidently expect it to expand because that’s what gas always does. No agency is involved, and no view toward the future. The cause of the expansion, the heat we applied to it, lies entirely in the past.
Teleology looks toward the future. The word “teleology” comes from a Greek root, telos, that literally means end or conclusion, and by extension means goal or purpose, what is to be achieved at the end of striving toward something. A teleological account of an activity or behavior explains it by citing its purpose or goal. Such an explanation cites a future state of affairs toward which behavior is directed rather than an antecedent state that caused it.[2]
Teleology is most easily understood in human affairs. We act for reasons directed at the future all the time. We go to the store in order to buy some things we need or want. We go to work in order to earn money. We go to school in order to learn things. We study philosophy because we seek wisdom, or at least some intellectual entertainment. Our actions are based on our desires—to get some goods, some money, an education, wisdom, etc.—and our beliefs about what will bring our desires to fruition. We look to a future state of affairs to explain what we are doing. In a word, we are agents with desires, beliefs, goals and intentions.
We explain physical behavior causally and mechanically, and we explain human activity teleologically. Philosophical discussion abounds about whether human activity can be explained causally and mechanically as well. Do our beliefs and desires cause our behavior? In other words, is human activity caused by events in its past, just as physical movement is? In this essay I bypass that question, noting only that for practical purposes, teleological explanations do, in fact, succeed in accounting for a great deal of human behavior.
So far, so good. But what about biology—living organisms and systems—in general (of which humans are but one example)? It seems quite natural and appropriate to use teleology, or goal-directness, employing language such as “in order to,” to explain biological activity and function. A person goes to the kitchen in order get a drink; a cat climbs a tree to get away from a dog; a spider runs across its web in order to get to the prey ensnared there. “In order to” seems quite natural as an explanation for all these activities. A mammal sweats in order to keeps its temperature down; a polar bear has white fur in order to camouflage it against the snow; a heart beats in order to pump blood. All these functions seem to be designed to accomplish an end. “In order to” sounds reasonable here as well. But is that phrase a mere metaphor, or is there something real going on?
II. Function
It used to be thought that it is more than a metaphor. We understand function as a result of deliberate design from our experience as agents. The function of a carburetor is to mix fuel and air so they can burn in a controlled way, and it has that function because someone designed it so. For much of human history, people saw what looks like design in living organisms and thought it was evidence of a grand designer, God or at least a demiurge. But now we think that mechanical causality can account for the evolution of biological function with no need to appeal to a conscious designer. We think so because mechanical causality explains so much of the physical world, and organisms are, undeniably, physical entities. But in order to avoid appeal to a conscious designer, we need something to take its place. In recent years philosophers of biology have come to something of a consensus on the details of how causal-mechanical explanations can account for function.[3] That account contains two pieces: what something does and how it came to be.
We recognize function by what an element does to contribute to the larger system of which it is a part. If an element contributes in some way to the ongoing health, operation or maintenance of the system, we call that contribution its function. The carburetor, by enabling controlled combustion of fuel, enables the vehicle to move. The heart, by pumping blood, keeps the organism alive.
A thing’s function is more than just its effects. A heart both pumps blood and makes noise. Why do we say that pumping blood is its function and making noise is not? Because pumping blood contributes to the well-being of the organism, but making noise is just a byproduct. A silent heart would contribute to well-being just as well as a noisy one, but a heart-like organ that only made noise and did not pump blood would not.
Not all function is designed function. Take for example a piece of debris that lodges in a small stream, blocking the flow. As time passes, other bits of leaves, twigs, larger branches and so forth lodge there as well. After a while the pile of stuff has formed a check dam, not only impeding the flow but forming a small pond. In turn, grasses and other plants grow there, using the moisture for sustenance. We can say that the debris functions as a check dam and that its contribution is to nurture the plant life, but we don’t say that it is or was designed to do so. To fully attribute function to something, we need to take into account not only what it does but how it came to be. Mere accident does not suffice.
For agential functions, the history is obvious: someone decided what the element needed to do and designed it that way. For biological functions, the history is how the element contributed to the survival and reproduction of the organism’s ancestors, and thereby to its own continued existence. Primitive multi-celled animals had some way to move fluid around in their bodies. As time progressed and animals became more complex, the heart emerged as an organ to pump blood. Those animals with more efficient hearts had more offspring than those with less efficient hearts. Over aeons of time, the human heart as we know it came to exist.[4] In place of deliberately designed function, we have function produced through natural selection. By analogy, we can call this process design by natural selection, but no conscious, deliberate designer is postulated.[5]
The causal-mechanical explanation of biological function parallels the account of intentional design of an artifact by a conscious agent. Each has two parts. The agential account is this:
- An element has a function if it contributes in some way to the ongoing operation or maintenance of the artifact of which it is a part; and
- It came about by deliberate design.
The causal-mechanical account is this:
- An element has a function if it contributes in some way to ongoing health, operation or maintenance of the organism of which it is a part; and
- It came about through a process of natural selection such that its operation gave a selectional advantage to the organism’s ancestors.
(To be more precise, the element must have contributed to the differential fitness of the organism’s ancestors rather than to a specific existing organism. Evolutionary psychologists Tooby and Cosmides say “… the function of a design refers solely to how it systematically caused its own propagation in ancestral environments” and not to what it contributes to an existing organism’s well-being.[6] But in most cases the existing organism is similar enough to its ancestors that the distinction is moot.)
In both kinds of explanation, we can understand the function of something by asking three questions:
- What contribution does it make to the whole of which it is a part?
- What brought it to this state? How did it get here?
- What does it aim at?
Only the third of these is specifically agential and properly called “teleological.” The causal-mechanical account of biological function reduces its apparent teleology to the kind of causality familiar to the physical sciences. We recognize the success of the physical sciences in explaining things and giving us the means to control them. We apply the same method to biology in hopes of replicating that success.
III. Biological teleology
But does the causal-mechanical account really explain biology sufficiently? Talbott thinks not. He argues that living beings are quite different from non-living things. Although some speak of plants and animals as sorts of machines, they are not like machines at all.
When we consider machines, we find parts arranged in certain ways to form wholes. Each part has a function that enables the machine as a whole to perform a function external to it, a function assigned by its designer. When we consider living organisms, we also find parts, i.e. organs, arranged to form wholes. Each organ contributes to the life of the whole, but each whole has functions that are internal to it. As Aristotle noted, the primary function of living beings is to stay alive. Without being alive, they cannot do anything else. (Plants, non-human animals and humans have different ways of staying alive, but that is a different topic.)
In machines, each part is exactly that, a part. It doesn’t do anything and does not make sense outside of the machine as a whole. But in living organisms, the parts are themselves wholes. We find, Talbott says, “wholes embedded within still larger wholes.”[7] Each cell is a whole of a sort. It has a boundary, the cell wall, and components within that boundary, such as the cytoplasm, the nucleus and so forth. Cells are contained within organs, such as the heart, the lungs, the liver and others. Each organ is also a whole of a sort, having a boundary that encloses the component cells. And organisms such as fungi, plants and animals are wholes, each having a boundary that encloses its component organs. Beyond individual organisms are ecosystems, which have boundaries that enclose their component organisms, and, still larger, ecozones, bioregions and the like. Wholes composed of other wholes are found throughout the entire web of life.
The operation of the parts of a machine can be described fully by reference to physical laws. The amount of fuel drawn into a carburetor depends precisely on the air pressure in the venturi tube. But the operation of the elements within living systems cannot be so precisely defined. We find uncertainty on several levels: the cell, the organ, the organism itself and, Talbott asserts, the evolution of generations of the organism over time.
The molecules within a cell move around in ways that would be extremely hard to predict in terms of physical law; they are functionally indeterminate. And even if we could determine them, the movements within each cell are so unique and nonrecurrent that no law-like regularity from cell to cell can be found. What does determine what they do is the cell as a whole. Talbott says
The cell as a whole exhibits its own specific character and regularity despite the virtually infinite degrees of freedom collectively possessed by its molecular constituents …. The detailed activity, with all its variability and lack of rigid constraint, turns out to be disciplined in a well-directed way toward fulfilling the needs of the cell. The details somehow participate in and reflect their larger context ….
And we find the same thing when we consider the embryonic development of organs. Again, Talbott:
If the experimentalist removes a limb bud from an embryonic amphibian, mixes up the entire cluster of cells, and then restores the now disordered group of cells to its proper context in the embryo, a normal limb will still develop. Extreme positional freedom among those cells is compatible with the ultimately reliable formation of the limb as a whole. In organisms more generally, an astonishing degree of cell-to-cell variation gives way to remarkably coherent results at the level of tissues and organs.
Similarly, a very young animal embryo contains relatively few different types of cells. They differentiate into hundreds of different cell types in the mature body: cells of the retina, of the heart, of the liver, the bones, the pancreas, the brain and more. What determines the ultimate destination of a specific stem cell? Not physical laws. Rather, says Talbott, it is the “power of the living organism as a whole.”
This power of the organism as a whole is central to Talbott’s conception of life. Following biologist Paul Weiss, he says “the character of a living context shapes and informs its parts, and cannot be understood as merely a deterministic result of those parts.” In other words, in living beings we find a top-down influence. What happens at a micro level is determined by the aims of the macro level, and not vice-versa. This happens at the level of molecules within cells, of cells within organs and of organs within organisms. And, says Talbott, it happens at the level of biological evolution as well.
Contrary to the usual causal-mechanical account of evolution, Talbott says that “organisms in populations thrive or die off in a manner governed by the evolutionary outcome toward which they are headed [and] the pattern of thriving and dying off … becomes what it is because of that outcome.” Somehow there is a species-level goal, and successive generations of organisms evolve toward it.
IV. Mentality
How can this be? The answer has to do with mind. First, note that the aims of the macro level are not the aims of an individual organism, but rather the aims of the type or form of the organism. The aims of an individual organism are things like chasing a particular prey animal for food or growing roots toward a particular source of water. The aims of the form of an organism are things like influencing stem cells to become the specific organs appropriate to that organism. Both types of aims involve envisioning something in the future rather than merely responding to things in the past. There is, fairly obviously, a mental component in each individual organism. Talbott asserts that a mental component is found in the form of the organism as well. He says,
We need to distinguish between the intelligence an organism possesses and that by which it is possessed—between the intelligence it consciously exercises (if any), and that which runs deeper …, between the intelligence employing a brain, and the still more profound intelligence capable of forming that brain.
He speaks of organic forms possessing “meaning,” “intentional narrative,” “narrative significance” and “purpose.” He says “biological processes in the present are always in some sense—and in a meaningful (‘thoughtful’), non-machine-like manner—orienting themselves toward a not-yet-realized future.” They possess “active biological wisdom and intention.” All of these words and phrases have to do with mind.
And he extends this way of thinking to the whole process of biological evolution:
Evolution has a living, well-organized, well-coordinated, well-directed character analogous to that of individual development. … Instead of saying, “The most successful reproducers determine the future of the species”, we should say, “Those organisms representing the future of the species determine, over the long haul, what sort of individuals will become the most successful reproducers”.
In other words, just as the biological development of individuals is purposive, future-oriented and teleological, so is the whole process of biological evolution of species.
V. The big picture: Panpsychism and beyond
All of this no doubt sounds a bit mystical, as well it might. In this view, mentality pervades much more than individual entities. It is obvious that we humans have a mental aspect. We observe ourselves thinking private thoughts, feeling private feelings, envisioning past and future events, planning future endeavors and the like. It is not hard to imagine animals and even plants having similar powers. I expect Talbott would agree that indeed every living being down to the simplest single-cell organism has some degree of mentality, the subjective aspect of its ability to take into account its surroundings.
Going further—and it is not clear that Talbott goes this far, but I will—the metaphysical theory of panpsychism asserts that mentality extends to the most basic units of physical reality. Everything has both a physical and a mental aspect, an aspect observable by many and an aspect observable only by one, the entity itself. The attempt to reduce biological teleology to a causal-mechanical model is based on the desire for a unified explanatory theory of everything, and because the causal-mechanical model works so well in so many domains, people attempt to extend it to the biological. I have argued that it would make more sense to go the other way around, to base our model of reality on what is living rather than one what is not. I think Talbott’s view of the directedness of biological evolution is at least compatible with such a panpsychist view. And it suggests something even more.
If we say that evolution is purposive and oriented toward a future goal, it seems reasonable to ask whose purpose it is and to what end state it is aimed. Talbott is not a theist. He disclaims the existence of an external guiding power, and he denies any conscious aiming or planning by a deity. He speaks instead of “the agency and developmental powers of organisms and communities of organisms.” Unfortunately, that is a bit vague. How can the form of an organism have developmental powers? How can a community of organisms have the singleness of purpose that directs the evolution of species to some end?
The answer is to assume that individuals are not as separate mentally as we think. Mentality suffuses and pervades all beings; and it can “leak,” as it were, from mind to mind. Many of us have had mild psychic or telepathic experiences. A wife asks where her glasses are, her husband has a mental image of their location but does not say it out loud, and then she says “I bet they’re over here,” and so they are. One thinks of a friend, and then the friend calls or emails. Those who are talented with animals know that visualizing a desired scenario—that the animal be docile when approached, for instance—tends to make it happen.[8]
If the assumption that mentality leaks from mind to mind is true—and it is highly speculative, but it accords with Talbott’s view—then the mental image of the fully developed state of an embryo of a certain species could be physically based in the merged mentality of all the individuals of that species. And the end state of evolutionary progress, or at least its direction, could be physically based in the merged mentality of all beings.
The merged mentality of all beings has been called by many names: the One, the All, Brahman, the Void, Allah, the Tao, God, the Spirit-that-moves-in-all-things and many others. For now I will call it the Oversoul, a translation of the Sanskrit word Paramatman, which means Supreme Self. The Oversoul knows all beings from the inside, as it were, by a kind of divine telepathy. It knows the world through each being’s senses. It sees the world through our eyes and hears through our ears. And it is not just a passive observer; it animates all beings as well. It is not an external god, but an internal presence. Thus it can envision exactly the sort of forward-looking aims that Talbott ascribes to the form of organisms and communities of organisms.
The great process panpsychist Alfred North Whitehead has a view of evolution quite similar to Talbott’s. He speaks of an “upward trend” of evolution toward increased complexity.[9] That trend is not driven by the past, but by a vision of the future. Whitehead says that the art of life is “first to be alive, secondly to be alive in a satisfactory way, and thirdly to acquire an increase in satisfaction.”[10] Given that the Oversoul animates all beings, that it is the source of life in all beings, it too has these aims. The evolutionary drive toward increased complexity and elegance of form is the Oversoul’s desire made manifest in the ongoing succession of generations of individual organisms. The Oversoul does not (I presume) envision a specific end state for each species. Instead, given the possibilities for change and adaptation at any given time, it acts as a lure, an attraction, persuading but not commanding new variations to emerge. We may say with the Sufi mystic that it aims at an increasingly rich state of love, harmony and beauty.
I am not a biologist and am not qualified to judge with authority Talbott’s assertions, but they certainly sound plausible. And, if my mystical speculations are correct, they have an implication for our conduct. If the aim of the Oversoul is increased satisfaction in love, harmony and beauty, then we can participate in that satisfaction ourselves by promoting love, harmony and beauty in all that we do.
Hempel, “Two Models of Scientific Explanation,” pp. 46-49. ↩︎
Sehon, Teleological Realism, p. 13. ↩︎
See, for example, Neander, “The teleological notion of function.” ↩︎
Stephenson, et. al., “The vertebrate heart: an evolutionary perspective.” ↩︎
Ayala, “Darwin’s greatest discovery: Design without designer.” ↩︎
Tooby and Cosmides, “Toward Mapping the Evolved Functional Organization of Mind and Brain,” p. 180. ↩︎
Talbott, “Evolution As It Was Meant To Be — An Overview.” All subsequent references to Talbott are to this article. ↩︎
This idea is elaborated in my “A Whiteheadian Solution to the Combination Problem.” ↩︎
Whitehead, The Function of Reason, pp. 7, 24. ↩︎
Ibid., p. 8. ↩︎
References
Ayala, Francisco J. “Darwin’s greatest discovery: Design without designer.” Proceedings of the National Academy of Sciences of the United States of America (PNAS) Vol. 104, Suppl. 1, 15 May 2007, pp. 8567–8573. Online publication https://doi.org/10.1073/pnas.0701072104 as of 10 August 2018.
Hempel, Carl. “Two Models of Scientific Explanation”. In Yuri Balashov & Alexander Rosenberg (eds.), Philosophy of Science: Contemporary Readings. Routledge. pp. 45-55 (2002). Online publication http://fitelson.org/woodward/hempel_tm.pdf as of 18 January 2018.
Meacham, Bill. “A Whiteheadian Solution to the Combination Problem.” Online publication https://www.bmeacham.com/blog/?p=1997.
Neander, Karen. “The teleological notion of function.” Australasian Journal of Philosophy, Vol. 69, No. 4, December 1991. Online publication https://doi.org/10.1080/00048409112344881 and http://www.sfu.ca/~jillmc/Neanderteleo.pdf as of 11 August 2018.
Sehon, Scott. Teleological Realism: Mind, Agency, and Explanation, Cambridge, MA: MIT Press, 2005.
Stephenson, Andrea, Justin W. Adams and Mauro Vaccarezza. “The vertebrate heart: an evolutionary perspective.” Journal of Anatomy, 14 September 2017. Online publication https://doi.org/10.1111/joa.12687 as of 11 August 2018.
Talbott, Stephen L. (2019) “Evolution As It Was Meant To Be — An Overview.” Online publication https://bwo.life/bk/thesis_34.htm as of 16 January 2022.
Tooby, John, and Leda Cosmides. “Toward Mapping the Evolved Functional Organization of Mind and Brain.” In Elliott Sober (ed.), Conceptual Issues in Evolutionary Biology, 3rd ed. Cambridge: MIT Press, 2006, pp. 175-195. Online publication https://pdfs.semanticscholar.org/0838/72f28332bf3454b818b5a54c17a20e7a6c99.pdf as of 15 February 2018.
Whitehead, Alfred North. The Function of Reason. Boston: Beacon Press, 1929.
How To Be An Excellent Human
Mysticism, Evolutionary Psychology and the Good Life by Bill Beacham, Ph.D.