In the consciousness literature, Darwin is king.  Whatever consciousness is (and there is plenty of disagreement about that), every one in the conversation accepts that consciousness must be a product of a Darwinian process of evolution.  There are various competing versions of an evolutionary narrative for the arrival of consciousness on the scene.

In its most extreme versions, panpsychism tries to avoid the sticky problem of identifying the “before” from the “after” moment.  The problem for any Darwinian account: once consciousness did not exist, but at a certain point in time it emerged, it arrived.  By saying something (just what is unclear) fundamental to consciousness was always already there, the panpsychist tries to sidestep the before/after conundrum; but even the panpsychist has to have a story about how the originating germ of consciousness develops into the full-blown consciousness of humans, higher primates, other mammals, and other creatures.  No one is claiming mollusks have a consciousness as fully elaborated as that in chimpanzees. Or that chimpanzees were there at the origins. There still needs to be a story about the elaboration of consciousness from its primitive beginnings into the sophisticated forms displayed in life forms that arrive on the scene at a much later date.

There are two things it would seem any plausible Darwinian account must provide.  First, it must provide a plausible bio-chemical account of a) how variants are produced for a process of selection to choose among, and b) the physiological/chemical processes that create consciousness itself.  Genetics (most directly random genetic mutations) is assumed to provide most of what is needed to answer the variant question.  As for b, a bio-chemical explanation for the phenomenon of consciousness, that such an explanation must exist is generally assumed in the literature, although everyone (with a few exceptions, as always) agrees that we are still a long way away from possessing anything like a complete and satisfactory bio-chemical understanding of consciousness.

I am going to leave these bio-chemical questions aside in this discussion—as do Veit and Humphrey in their books.  [Nicholas Humphrey, Sentience: The Invention of Consciousness (MIT Press, 2023) and Walter Veit, A Philosophy for the Science of Animal Consciousness (Routledge, 2023).]  Instead, I want to focus my attention on the second requirement of any Darwinian account.

Namely, such an account must identify the “advantage(s)” that consciousness would provide to an organism.  Only if there are such advantages would consciousness be “selected” for.  Since (of course) we don’t get to see the competition between creatures possessing different types and/or degrees of consciousness in real time, we must (as both Veit and Humphrey explicitly state in their books) “reverse engineer” the account of how one possible variant is “selected” over another.  Those more skeptical of Darwinian explanations call “reverse engineering” “just-so stories.”  Lacking direct evidence, a narrative is produced that assumes the mechanism of natural selection. 

Essential to such accounts is functionalism.  The writer must identify what consciousness does, what functions it performs, and from that basis argue for those functions as providing advantages in a struggle for existence understood in Darwinian terms.  Veit is what might be called a Darwinian fundamentalist.  He flatly states “the goal of biological systems is ultimately reproduction” (54); and identifies “the real purpose of the organism, which is to maximize its representation in future populations” (55).  Armed with this fundamental and overriding purpose, he can then assess how consciousness would provide a leg up in the effort to “maximize” an organism’s chances for reproductive success.  That such an account of “purpose” seems awfully reductive in the face of the wide variety of behavior exhibited by animals and humans does not seem to bother him a bit.

More interesting is Veit’s holistic understanding of the dynamic nature of the organism.  He calls his approach “teleonomic”: “organisms are goal-directed systems,” that “evolve to value states and behaviors that increase their own fitness and avoid those that are detrimental to their health” (9).  This approach falls in with other recent accounts that rehabilitate an Aristotelean notion of teleological or final causes.  The organism is directed toward something—and that something acts as one cause in the action of natural selection.  As Veit strongly puts it: “the external factors that matter to the evolutionary trajectory of the organism are themselves causally dependent on the organism” (8).  In other words, the organism is not a merely passive recipient of what external environmental and genetic factors produce.  The organism’s active pursuit of reproductive advantage guides its own selection process; the organism evaluates what the larger ecological scene makes available and works to exploit the elements in that scene that will serve its purpose(s). 

Of course, this approach still must posit an overriding purpose present (innate to) all organisms: the drive for reproductive success.  So one complaint I have about such Darwinian theorizing is that natural selection does not get off the ground unless there are randomly produced variants.  If we only have clones, then there is no range of actual variants for selection to choose among.  Yet the theory allows for no variance in the fundamental purpose of organisms.  Everything walks in lock step to the Darwinian command to maximize reproductive success.  And that leads to the absurdities of the endless worries about altruism, music, laughter, and play.  More and more implausible stories must be told about all of these behaviors to make them serve the overriding Darwinian purpose.  Reductionism doesn’t simply haunt Darwinian thought; it appears as absolutely central to such thinking.

Veit cheerfully accepts the hard-core utilitarianism of his approach.  “It is thus not unreasonable to treat them [organisms] as economic agents maximizing their utility (i.e. fitness).  Each individual within a species is fundamentally faced with a resource allocation problem. . . . This is the economy of nature” (19).  Casually swept aside are all the frivolous and downright counter-productive behaviors on view every day in the natural world.  The failure of humans and other animals to be reasonable resource maximizers must be ignored or subjected to torturous (and implausible) explanations.  Surely the simplest approach here would be to concede that the struggle for life and reproductive success doesn’t consume all of the organism’s time and energy—and the surplus is devoted to activities that don’t further Darwinian goals.  But very few of the Darwinian advocates take this easy way out.  Of course, it has been a commonplace that it is rich societies (Renaissance Florence, Elizabethan England etc.) that witness a flourishing of the arts.  The problem is that, in fact, we don’t know of any societies without music and dance. Variety, activities that are hard to account for by a strict Darwinian logic, appear baked in from the beginning.

I am hardly conversant with the vast literature about Darwinian evolution.  But I do know that whole books get written about the “problem” of altruism.  Whereas, as far as I know, no one takes up what seems to me the much more glaring problem of war.  After all, from the standpoint of reproductive success, war (which also seems endemic to all human societies of which we have any record) is a real puzzler.  Here’s an activity that places in danger precisely the (male) members of society who are in their prime years for passing on their genes.  And it would take a lot of ignoring of facts on the ground to claim that wars are primarily about securing resources necessary to life.  Despite the intuitive appeal of the Marxist notion that economics drives everything, wars are not only more often driven by issues of pique, status, and out-group hostility than by the scarcity of resources, but there is also the fact that wars destroy resources rather than augment them.  Wars are costly—more like potlatches dedicated to the wholesale destruction of goods and lives than a reasonable way to secure resources. (A side note: Engels realized that Marx and Darwin are at one in their appeals to economic reasoning and in identifying the pursuit of “interests” as the primary motive of “life.”)  In short, Darwinian reductionism (as well as its Marxist counterpart) offers little in the way of a plausible explanation for this all too frequent form of human behavior.

I want to end by moving on to more technical concerns about evolutionary accounts.  I will quote here from Humphrey’s book. “Since we are discussing evolution, we can assume three guiding principles.  First, there must have been a continuous sequence of stages with no unaccountable gaps.  Second, every stage must have been viable, at the time, on its own terms.  Third, the transition from one stage to the next must always have been an upgrade, adding to the chances of biological survival” (101).

I have trouble with both assumptions one and three. This may come down to semantics, to what exactly is meant by a “new stage.”  But let me state my worries.

On number one, I don’t see how unexpected and random genetic mutations (which are the engine of change, of movement from one stage to the next) are “continuous.”  It’s the discontinuity of mutations that seems much more obvious.  As I say, Humphrey might very well reply that I am misunderstanding the sense in which he is using “continuous.”  And, of course, various evolutionary theorists (most famously Stephen Jay Gould) talk of “punctuated equilibrium” to describe the sudden transformations that a genetic mutation can generate.  Still, Humphrey seems to think there will be an orderly “sequence” from one evolutionary stage to the next.  And that assumption will guide his “reverse engineering” account of the emergence of consciousness.  I think this confidence in an orderly sequence is misplaced—and thus makes the strategy of reverse engineering much more problematic.  It is harder to tell a story that, as Humphrey understands, has “gaps” that are not easily bridged.

The third assumption we might call the “things get better” thesis.  Each stage is an improvement over the last in terms of enhancing “chances for biological survival.”  But that way of stating things dismisses variants.  I had thought one goal of Darwinian theory is to explain diversity.  Variants are produced in the course of reproduction—and some of the variants (hardly all of them, but not just only one of them) prove viable (to use Humphrey’s term).  They are viable either because they exploit different ecological niches to secure the necessary resources to sustain life or because they are “good enough” to sustain life even as they differ from other variants.  Another way to say this: various traits get produced along the evolutionary track that do not undermine the ability to sustain life drastically enough to cause extinction of the organism carrying that trait.  A fairly obvious example is myopia.  Hardly a great asset in the “struggle” to survive, but apparently not enough of a deficit to have been discarded along the evolutionary pathway that leads to today’s humans.  In short, variants get produced all the time that are not “upgrades.”  They are simply not strong enough “downgrades” to prove fatal. 

By a similar logic, just as not all features of the organism necessarily make fully positive contributions to the effort to survive, not all features of the organism need be devoted to that effort.  The issue, once more, is surplus.  Just as the arts (in one reading) can seem irrelevant to the effort to sustain life, so various features of complex organisms may not be contributors to that effort.  A hard core Darwinian can consider them “free riders”—and that way of addressing the issue is fairly common in the literature.  Knowing how to read is not strictly necessary to survival—but humans get that extra ability because it develops from cognitive abilities that are essential to survival.  The problem becomes how do we identify (except by some seat of the pants appeals to what is necessary as opposed to what is “extra”) the abilities required by survival and those that free ride upon it.  Going back to war: perhaps we would want to argue that just like reading is a beneficial free rider, war is a disadvantageous one.  War, in other words, is an offshoot of some fundamentally necessary component of human physiology/psychology and thus can’t be jettisoned as evolution moves us toward “stages” where our chances our survival are enhanced. Even though war itself decreases chances of reproductive success.

I am hardly claiming that Darwinian evolution is a fundamentally mistaken theory.  But I am saying that the ham-handed, reductionist accounts of evolution overlook a number of puzzles that should give prevailing mono-causal biases some pause.  Furthermore, these puzzles should at least disturb any blithe confidence in “reverse engineering” stories.  Introducing a wider array of possible causes into such accounts, along with recognizing the random and disruptive effects of genetic mutations, would certainly complicate matters greatly.  But it also might yield more plausible accounts of how an evolutionary history got us the diversity and complexity of the animal and human worlds we can observe in the wide variety of behavior displayed in the present. 

Addendum (added January 19, 2024). I have just come across this relevant statement by Daniel Dennett on the error of thinking that evolution always produces enhancements of chances for biological success (quoted from Just Deserts: Debating Free Will, Polity 2021, p. 162):

“It is a fundamental mistake in evolutionary thinking to suppose that whatever ways (ideas, practices, concepts, policies) survived this process must have proven fitness-enhancing for the human species, the lineage, or even the individuals (or groups of individuals) who adopted them. Some, even many, of the established ways (of thinking, of acting) may have been cultural parasites, in effect, exploiting weaknesses in the psychology of their hosts.”