I spent most of my working life as a computer programmer. One of my favorite jokes about software programming goes like this:
Manager: What have you been doing lately?
Programmer: I've been very productive. I've been busy replacing the crummy old code with crummy new code.
I am reminded of this joke when studying biologist Michael Levin's attempts to sell the notion of a "bioelectric code" as an explanation for morphogenesis, the mystery of a how a tiny speck-sized zygote progresses to become the vastly organized state of a full human body. Like more than 25 other science and medical authorities I quote in the "Some Scientists and Doctors Who Told the Truth About DNA " section of my post here, Levin has recognized that the old story that we arise from the reading of a body blueprint in DNA is just plain false (DNA has no such blueprint, no such specification of how to make a body). Levin has attempted to suggest a new story, using the term "bioelectric code." Unfortunately Levin's new story seems like some new baloney that is just as much bunk as the old "your DNA made you" baloney.
Let's take a look at Levin's 2018 paper "The Bioelectric Code: An Ancient Computational Medium for Dynamic Control of Growth and Form," co-written with Christopher J. Martyniuk. I will attempt to "throw a yellow flag" on all of the main dubious or incorrect statements he makes. The first paragraph makes a big mistake by claiming that we know something from "first principles" that we do not at all know. We read this:
"DNA simply encodes specific proteins – there is no direct encoding of anatomical structure. Thus, it is clear from first principles that pattern control involves a code: the encoding of anatomical positions and structures within the egg or other cell type, and the progressive decoding of this information as cells implement invariant morphogenesis (Fig. 1B)."
No, such a thing is not all "clear from first principles," nor is it even obviously likely. From the fact that DNA does not have any code specifying the organization of a human body, we are not entitled to deduce that there must be some other code in a fertilized egg that specifies such things, particularly since no such code has been found. Always be very suspicious of either a scientist or a philosopher who attempts to make gigantic claims on the basis that they are "clear from first principles." Levin's next sentence is: "It should be noted that the current understanding of these codes is in its infancy and many fundamental questions remain to be addressed." When you hear statements like that, alarm bells should go off in your head, and you should suspect that you are about to hear some cobwebs of speculation that are not even half-baked, but much less than tenth-baked.
In the next paragraph Levin states this: "The mainstream consensus is that there is no overall encoding of the target morphology: the process is controlled by local events, and the resulting complex pattern is the result of emergence and self-organization." Since "emergence" and "self-organization" are just empty phrases that don't amount to anything, if this statement is true, it is a shocking truth, for it would mean that scientists have no credible tale to tell of how a zygote is able to progress to become a full human body. The truth is that rather than presenting so vacuous a tale -- telling us that a human body arises from mere "emergence and self-organization," sounding like they were very empty-handed -- very many scientists keep telling us the old lie that a body arises from a DNA blueprint. The current situation can be described like this: the left hand of biology is still telling us the lie that our bodies result from a reading of a DNA blueprint or program, but the right hand of biology is telling us that such a claim is false. When biology can't get its story straight on how morphogenesis occurs, we should note that discrepancy, and not claim that there is any such thing as a "mainstream consensus" on this topic. See my post here for a discussion of how the old lie about DNA as an anatomy blueprint continues to be told on US government web sites (the same post contrasts such statements with many opposing statements by biologists and doctors).
Levin discusses some anomalies of biology, such as amphibians that can regenerate a limb after it was cut off. At the end of page 4, Levin makes this very shaky-sounding claim:
"Here, we argue that it is time to consider the possibility that the known emergent features of cell behavior are augmented by a complementary set of top-down controls in which at least some aspects of target anatomical states are encoded within tissue properties (Pezzulo and Levin, 2015). If tissues must somehow remember at least some aspect of a target state in their physico-chemical properties, then encoding and decoding is necessary, since living tissues are storing information about a future (counterfactual) state in their current structure – this is the quintessential context of a code."
Sounds like Levin hasn't discovered any body organizing code, but he's arguing that there must be such a code. Rather than saying "here is the code I found," he says, "encoding and decoding is necessary." This is more arguing from "first principles," which resembles the reasoning of neuroscientists who claim that since a brain must store ideas, there must be a neural code by which ideas are stored in brain states. That isn't good reasoning, for we only know that minds create ideas, not that they are created or transmitted by brains; and no sign of such a neural code can be found.
My suspicion that Levin is arguing like a metaphysician is confirmed by the next sentences in his paper, where he keeps arguing from alleged "first principles," rather like some Hegel-style metaphysician trying to deduce the nature of Being from first principles:
"What mechanisms could underlie such a morphogenetic code? Based on the observed examples of stable yet re-writeable anatomical structure, it would have to be a system that supported long-term but labile memory, with capability to sense/measure large-scale spatiotemporal signals. It would also have to have holographic properties (storing information about the whole in individual pieces) and be able to harness individual cell activities toward grouplevel goals. While many architectures could in principle support this kind of control system, two well-studied examples do all of the above: cognition in the living brain, and engineered artificial information-processing devices (computers)."
When philosophers or biologists claim that some hypothesized code "would have to have holographic properties," it is rather clear that we are not in the midst of careful scientific reasoning. The reasoning about the brain is unsound. We do not know that the brain is the cause of cognition, and have very good reasons for doubting that it is (discussed in the posts of this blog).
The next three pages of Levin's paper are mainly just a discussion of various electrical events going on in different parts of the body. None of that discussion does anything to substantiate Levin's claim that the structure of our body comes from some "bioelectric code." Yes, electricity is very important in the body, but that does nothing to support Levin's claims. Similarly, if I were arguing that human memories are stored in cell membranes, I would do nothing to substantiate that erroneous idea by filling up three pages telling you how cell membranes are very important in the human body.
On pages 9 and 10 Levin discusses some research he and others have done involving electrically zapping developing organisms to try to get them to change their form. Such experiments seem to have been done only with less-advanced organisms such as amphibians and reptiles and worms. It seems rather that he is trying to persuade us that you were built by a bioelectric code, because the development of some organisms can be changed by zapping them with electricity in certain ways. The line of reasoning is not a sound one. For example:
(1) You could change the structure of a developing amphibian by applying hammer blows, but that does not mean that the organism's form arose because of hammer blows.
(2) You could change the structure of a developing amphibian by zapping it with gamma ray radiation, producing some weird mutant, but that does not mean that the organism's form arose because of gamma ray radiation.
On page 11 Levin refers to "the bioelectric code model." In science a model means an exact mathematical speculation. From what I have read of his papers, Levin has not produced any model of a bioelectric code, but merely made some vague sounds about a "bioelectric code." Claiming that you have a model when you don't have a model is a common sin of scientists. Typically when scientists have a model, they write papers including equations; but there are no equations in Levin's paper. Near the end of the paper Levin confesses "the encoding of pattern outcomes to bioelectric states is only known for a small handful of examples." That's pretty much a confession that this "bioelectric code" idea is not well substantiated by observations. Levin has not at all advanced any theory of how hierarchically organized three-dimensional structures could be represented by some electricity code. What he has mainly done is just handwaving, decorated with irrelevant talk about various ways in which the body uses electricity. None of this amounts to a detailed theory of how the structure of a human body could arise from electricity or a bioelectric code.
There is no real substance involved when Levin makes statements like this: "The main point is that biological pattern regulation is a combination of emergent features that fill in local features and top-down controls that make decisions about large-scale patterning." That's just hand-waving. And the idea that we can explain the growth from a speck-sized zygote to a full-grown human by some concept of "patterning" is just another example of reductionist nonsense. The human body is no mere pattern, but a case of mountainous levels of organization all over the place, with the organization occurring in an extremely hierarchical manner, resulting in a dynamic three-dimensional system of mind-boggling complexity. Atoms are organized into small molecules such as amino acids, which are organized into very large molecules such as proteins, which are organized into teams of protein molecules called protein complexes, which are organized into much larger units called organelles, which are organized into hundreds of different types of fantastically complex cells, which are organized into tissues, which are organized into organs, which are organized into organ systems such as the digestive system or the nervous system, which (along with the skeletal system) are organized into a full organism body like the human body. You do not explain such organization by some mere two-dimensional idea of "patterning." What is needed is a theory explaining gigantic amounts of three-dimensional hierarchical organization and stratospheric heights of systemic coordination and component interdependence, but Levin has not presented one.
The word "code" has different meanings. The word "code" refers to software instructions written in some particular programming language. Hallmarks of software code are things such as local variables and if/then logic and control structures such as loops. We know of no software code of this type in the human body. DNA is not at all code in this sense of the word. There is also another meaning of the word "code": a system of representations under which particular symbols (called tokens) stand for other things. Two examples of such codes are below: the Morse Code used to transmit information by telegraph, and the genetic code used by DNA, under which nucleotide base pairs represent amino acids used by proteins.
Talking repeatedly about a "bioelectric code," Levin has failed to specify any such code, and fails to give us any code-specifying diagram anything like the ones above. He hasn't even specified some hypothetical arrangement such as an arrangement under which different types of electrical pulses represent particular movements a cell should make. If someone talks about a code without mentioning any specifics, without giving a simple example of "this particular combination represents this particular thing," then they haven't provided any model or theory of a code, and such a person is merely engaging in vague hand waving that uses the word "code."
In a 2016 paper ("Reading and Writing the Morphogenetic Code") Levin had referred to a "morphogenetic code" which he defined like this: "the mechanisms and information structures by which cellular networks internally represent the target morphology, and compute the cell activities needed at each time point to bring the body closer to that morphology." No one has discovered any information structures by which cellular networks represent a target morphology.
On page 7 Levin makes this claim: "This body of work has revealed that in parallel with the genetic code (ideal for making sure the right protein components are available in the right place and time), and the epigenetic code (used for tweaking gene expression as a function of physiological history), there is also a bioelectric code – a dynamic distribution of electrical properties in somatic cell networks which mediates large-scale coordinated information processing in pattern homeostasis, orchestrating cell activity toward large-scale anatomical states." No such anatomy-orchestrating "bioelectric code" has been discovered, and pretty much the only people using this phrase are Levin and science journalists writing about his theorizing. And contrary to what Levin suggests in that statement, the genetic code does nothing to specify the time or place where any protein ends up (DNA not having any specification of when or where to use a protein).
On page 8 Levin defines this "bioelectric code" like this: "The 'bioelectric code' is defined as the mapping of real-time electric circuit dynamics among tissues to the pattern-regulatory functions that cells carry out." That doesn't sound like anything that could explain the mountainous mysteries of human development, which involves a thousand different things vastly beyond mere "pattern regulatory functions that cells carry out." One of the innumerable problems of explaining the growth from a speck-sized zygote to a full human body is explaining how cells themselves originate, and you don't explain that by appealing to some possibility that cells perform pattern regulation. That's like trying to explain the origination of your TV set by mentioning an "auto-off" feature in your TV set. "Circuit dynamics" is the kind of vaporous terminology that neuroscientists use to make it sound like they know something about things they do not understand. When you ask a neuroscientist something like "how could a brain without addressing or indexing ever be able to instantly retrieve a memory," a neuroscientist may say something, "Well, you know, it's some circuit dynamics at work." That doesn't really mean anything.
In his 2016 paper Levin predicts that "by year 2 we will be constructing quantitative models of the bioelectric code at several levels." But his 2018 paper about this "bioelectric code" does not have any such quantitative models, and I did not find any such quantitative model looking at Levin's papers written in the past five years. It seems that this idea of a bioelectric code controlling human development has yet to progress beyond a vague wooly catchphrase.
In a Youtube.com video entitled "The Electrical Blueprints That Orchestrate Life," we have Levin going way out on a limb of speculation. Here is part of the transcript:
Levin: "And so these cells are basically communicating with each other who is going to be head, who is going to be tail, who is going to be left and right and make eyes and brain and so on. And so it is this software that allows these living systems to achieve specific goals, goals such as building an embryo or regenerating a limb for animals that do this, and the ability to see these electrical conversations gives us some really remarkable opportunities to target or to rewrite the goals towards which these living systems are operating."
CA: "OK, so this is pretty radical. Let me see if I understand this. What you're saying is that when an organism starts to develop, as soon as a cell divides, electrical signals are shared between them. But as you get to, what, a hundred, a few hundred cells, that somehow these signals end up forming essentially like a computer program, a program that somehow includes all the information needed to tell that organism what its destiny is? Is that the right way to think about it?"
Levin: "Yes, quite. Basically, what happens is that these cells, by forming electrical networks much like networks in the brain, they form electrical networks, and these networks process information including pattern memories. They include representation of large-scale anatomical structures where various organs will go, what the different axes of the animal -- front and back, head and tail -- are going to be, and these are literally held in the electrical circuits across large tissues in the same way that brains hold other kinds of memories and learning."
There is no robust evidence for such claims, which seem to be made by hardly anyone other than Levin. The story above seems like a piece of blueprint mythology every bit as untrue as the "DNA as body blueprint" mythology. It sounds like some new bunk to replace the old bunk. In the rest of the video Levin mainly talks about weird behavior of flatworms, such as how they can regenerate their form when you've cut off a large piece of them. None of that backs up any of the claims quoted above. Ironically, at the end of the quote above Levin appeals to the theory that memories are held in the brain by storage in "electrical circuits" to try to bolster his theory of what is happening in cells outside of the brain. This is unsound for two reasons: (1) the theory of storage of memories in synapses (electrical connections between brain cells) is untenable because of 30 reasons discussed here; (2) between the cells below the neck (outside of the nervous system) there are no "electrical networks much like networks in the brain," because between such cells there are no electrical connections comparable to the synapses or axons that connect neurons. Trying to make us think that cells that are not wired together have networks like cells that are wired together, Levin speaks here as inappropriately as someone saying, "I can move super-fast in my town because the sidewalks are like subways." Beware of scientists using the word "basically" as Levin does twice in the quote above.
It's a situation similar to the groundless claims of neuroscientists that human memories are stored in neural circuits. No such memories can be found in neural circuits. Dissecting the brain of a newly deceased person, you cannot find anything at all about what that person learned or what experiences he had. Just as no sign of any learned information can be found by microscopically examining a brain, no sign of "representation of large-scale anatomical structures" can be found by searching for some "electrical network" between cells.
In the brain at least we know that there is some kind of electrical network, for neurons are connected by synapses that transmit electrical signals between neurons. Such signals are transmitted too slowly and unreliably to explain instant human recall and 100% accurate memory recall, such as when someone playing Hamlet correctly recalls all of his lines. But at least there is some kind of electrical network (a slow, very noisy and unreliable one) connecting the cells of the brain. Between the cells of a developing body outside of the nervous system, which are not wired together, electrical communication is maybe a thousand times more tenuous than in the brain. That makes Levin's claims extremely unbelievable.
In general, the idea that you can explain the origin of a human body by imagining some kind of signal code being transmitted between cells is an extremely misguided one. There are more than seven levels of organization that need to be explained in order for you to get a human body: (1) the formation of amino acid sequences into the 3D shapes of protein molecules, called the protein folding problem; (2) the formation of protein complexes from protein molecules; (3) the formation and correct positioning of organelles that are much bigger than protein complexes; (4) the formation and correct positioning of cells often built from many thousands of organelles arranged in a suitable way; (5) the formation and correct positioning of tissues from cells; (6) the formation and correct positioning of organs from tissues; (7) the formation of organ systems; (8) the formation of full organism bodies from organ systems and a skeletal system. Postulating signals between cells could never explain the first four of these things. If some stem cell were to receive coded signals telling it how to become a specialized cell and where in a body to go to, you would need to imagine both some miracle of coding allowing instructions vastly complex (unlike anything that can plausibly be passing between cells outside of the nervous system), and also another miracle of coding interpretation, under which simple microscopic stem cells would have powers of interpretation greater than a human mind, allowing them to act on fantastically complicated instructions telling them how to become super-complex specialized cells, and where to go to in a human body. Now you are in the nonsense of imagining microscopic cells with something like the interpretation powers of an Einstein.
Under the old "DNA as body blueprint" lie, there at least was an answer to the question of where the imagined blueprint came from: an answer of "the original zygote had such a blueprint in its chromosomes." Under this idea of a bioelectric code, there is no such answer. If cells are sending electrical messages to other cells telling them how to make the vast organization of the human body, why would such signal- transmitting cells be sending signals so precise and appropriate, just right for making a human body so organized? In Levin's speculation, there seems to be no answer to this question. We are left with the idea of cells that "just happen" to send exactly the right signals, which is as implausible as imagining that a star in a solar system without life would just happen to transmit radio signals telling how to make some extremely complex invention such as an interstellar spaceship.
In every attempt to explain the origin of a human by mere bottom-up mechanistic effects, there are problems such as these:
(1)The "blueprint would be too complex to ever form" problem. The human body is a state of such vast hierarchical organization involving so many billions of well-arranged parts that if you had a specification for making a human body, it would require something infinitely more complicated than a DNA molecule with its mere low-level chemical information such as linear sequences of amino acids; and it seems that anything that complex (vastly more complicated than a blueprint used to make a tall office tower) could never have arisen through accidental processes.
(2) The "blueprints don't build things" problem. Blueprints don't cause complex things to be built. Complex things can get built from blueprints only when intelligent agents study blueprints and get ideas on how to proceed. But there are no such constructive intelligent blueprint readers inside the human body below the neck.
(3) The "no Einstein to understand the super-complex blueprint" problem. The human body is such a state of enormously complex hierarchical organization (with 200 types of cells, each as complex as a factory) that if there were to exist in the human body a specification for making a human body, such a specification would be so complex that nothing in the human body (below the neck) could understand it, which would prevent such a specification from being part of a causal explanation for why human bodies appear.
We do not understand the great mystery of how a speck-sized zygote containing no specification for making a human is able to progress to become the vast hierarchical organization of a human body, consisting of billions of very complex well-arranged cellular components and protein complexes. We have every reason to doubt that mere mechanistic effects can explain such a progression. The old story told to try to explain such a thing (that a body blueprint is read from DNA) was a lie, a lie told for a particular reason explained here. No such blueprint or program for making a human is found in DNA, as dozens of scientists I quote (including Levin) have confessed. We should not be replacing that old bunk blueprint story with some new bunk blueprint story seemingly consisting of 97% hazy far-fetched speculation and a few bare threads of fact. Until we can credibly explain the great mystery of how a human body is able to originate, we should candidly confess that it is a mystery a hundred miles over our heads.
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