Sunday 18 February 2024
The mind contemplates itself?
Consciousness, a Hall of Mirrors, Baffles Scientists
To contemplate consciousness is, as professor of religion Greg Peterson put it, like looking into and out of a window at the same time. No surprise then that philosophers of science call it the Hard Problem of Consciousness. The inexorable progress of brain imaging was supposed to dissolve the conundrum but we spoil no surprise by saying that new information and insights only deepened it.
Among the many quests, one has been to discover the seat of consciousness. An image rises unprompted. Seat? Does consciousness have a seat at the table? Wait a minute. Isn’t consciousness the table? You see the difficulty, of course. At any rate, the search is for the specific bit of the brain that spews out the unthinking electrical charges that create consciousness.
It’s been a long and winding road. Brain imaging has not turned out to be a road map of the mind. For example, functional MRI imaging only tells researchers where blood is traveling in the brain. The problem is, as a Duke University research group pointed out, “the level of activity for any given person probably won’t be the same twice, and a measure that changes every time it is collected cannot be applied to predict anyone’s future mental health or behavior.”
Rise and Fall of the Lizard Brain
The most widely popularized theory of mind — the triune brain theory — depends on organization rather than imaging. Originally developed by Yale University physiologist and psychiatrist Paul D. MacLean (1913–2007) decades ago and promoted by celebrity skeptic Carl Sagan (1934–1996), it divides the brain into three parts. The reptilian brain controls things like movement and breathing, the mammalian brain controls emotion, and the human cerebral cortex controls language and reasoning.
This approach resulted in immensely reassuring ideas; for example, a widely disliked boss or politician morphed into a “dinosaur brain.” In 2021, Jeff Hawkins, inventor of the PalmPilot (a smartphone predecessor) even claimed to have figured out how human intelligence works, relying on his model of the mammalian brain.
The human brain was bound to disappoint pop culture in this matter because key functions are distributed throughout. Also triune brain theory doesn’t square with the high animal intelligence recently found in (non-vertebrate) octopuses. Claims for the mammalian brain in particular don’t square with the high intelligence found in some birds. Let alone with the fact that human consciousness remains an absolute outlier.
But MacLean’s idea has proven much too culturally satisfying to be spoiled by mere neuroscience. As one research team notes, “despite the mismatch with current understandings of vertebrate neurobiology, MacLean’s ideas remain popular in psychology. (A citation analysis shows that neuroscientists cite MacLean’s empirical articles, whereas non-neuropsychologists cite MacLean’s triune-brain articles.)”
It’s All in the Connections
Never mind, the exciting new world of -omes (genomes, epigenomes, biomes…) beckons. The connectome — essentially, a complete “wiring diagram” of the brain, might possibly identify human consciousness. In 2010, computational neuroscientist Sebastian Seung told humanity, “I am my connectome,” a thought on which he expanded in his 2012 book, Connectome: How the Brain’s Wiring Makes Us Who We Are. In 2012, National Institutes of Health director Francis Collins was thinking along the same lines: “Ever wonder what is it that makes you, you? Depending on whom you ask, there are a lot of different answers, but these days some of the world’s top neuroscientists might say: ‘You are your connectome.’”
That moment has passed. Harvard neuroscientist Jeff Lichtman, who is trying to map the brain, surveys the awful complexity nearly a decade later and sums up,
…if I asked, “Do you understand New York City?” you would probably respond, “What do you mean?” There’s all this complexity. If you can’t understand New York City, it’s not because you can’t get access to the data. It’s just there’s so much going on at the same time. That’s what a human brain is. It’s millions of things happening simultaneously among different types of cells, neuromodulators, genetic components, things from the outside. There’s no point when you can suddenly say, “I now understand the brain,” just as you wouldn’t say, “I now get New York City.”
GRIGORI GUITCHOUNTS, “AN EXISTENTIAL CRISIS IN NEUROSCIENCE,” NAUTILUS, JANUARY 22, 2020
In short, once we are into abstractions, we are no longer dealing with the concrete substance of the brain.
It’s All in the Electricity
But what about the bioelectric fields that swarm throughout the brain? Bioelectric currents, unlike electric currents, rely on ions rather than electrons but they are still electricity. Evolutionary biologist and lawyer Tam Hunt tells us, “Nature seems to have figured out that electric fields, similar to the role they play in human-created machines, can power a wide array of processes essential to life. Perhaps even consciousness itself.” That’s a remarkable idea because it includes the notion that our individual cells exhibit consciousness: “Something like thinking, they argue, isn’t just something we do in our heads that requires brains. It’s a process even individual cells themselves, and not requiring any kind of brain, also take part in.”
This sounds cool but gets us nowhere. We have no reason to believe that our individual brain cells are conscious; what we know is that we are conscious as whole human beings. We could say the same about claims that everything is conscious (panpsychism) or that nothing is (eliminativism). Whatever else the claims do, they shed no light on the conundrum at hand.
Consciousness as an Undetected State of Matter
Max Tegmark, MIT physicist and author of Our Mathematical Universe: My Quest for the Ultimate Nature of Reality (Knopf, 2014), goes still further. He suggests that consciousness is a so far undetected state of matter, perceptronium, “defined as the most general substance that feels subjectively self-aware.” Which, again, gets us precisely nowhere.
Prominent neuroscientist Christof Koch notes more mundanely that physical distance in the brain matters: “A new study documents an ordering principle to these effects: the farther removed from sensory input or motor output structures, the less likely it is that a region contributes to consciousness.” And that’s about as far as neuroscience has got.
Koch has also written a book, The Feeling of Life Itself (MIT Press, 2019), where he tells us, among many other things, of dogs, Der Ring des Nibelungen, sentient machines, the loss of his belief in a personal God, and sadness, all seen as “signposts in the pursuit of his life’s work — to uncover the roots of consciousness.” And that is where we must leave the subject for now. We are back where we started — but we do have interesting books.
The ultimate Rube Goldberg?
Intelligently Designed Evolution? Sorry, Wrong Universe
Many in the intelligent design camp have considered the possibility that the evolutionary process was designed. Leading ID theorists such as Michael Behe, Stephen Meyer, and Jonathan Wells readily acknowledge that while natural mechanisms can’t produce all the complexity of life, they can produce some degree of complexity in organisms. One might even say that evolution is designed to effect small-scale changes within species.
But theologian Rope Kojonen, at the University of Helsinki, wants to go much further. In his book The Compatibility of Evolution and Design, he offers a model in which evolution succeeds because it is intelligently designed. It’s a thoughtful book, and I regard Rope as a friendly critic of ID. According to Kojonen, mainstream evolutionary theory is true — and it’s not just “compatible” with design, as he says in the title of his book, but biological phenomena even exhibit evidence for design. Let’s take a closer look at this idea.
Serendipity Required
Kojonen argues that evolutionary mechanisms produced the complexity of life. But there’s an intriguing assumption implicit in this: on its own, blind evolution is very unlikely to produce the complex features we see in living organisms. Thus, Kojonen envisions that the evolutionary process receives help from above in the form of the fine-tuning of the initial conditions and natural laws that allow evolution to get the job done.
Kojonen proposes that our universe might be finely tuned to allow for otherwise unlikely evolutionary events, such as life suddenly co-opting proteins to evolve new functions and evolve into irreducibly complex systems:
Suppose for the sake of the argument that Behe is partially correct: complex machinery exists in nature and is difficult to evolve. Nevertheless, suppose that his critics are also correct, and the evolution of such complexity through Darwinian mechanisms actually happened. Given these premises, a theistic evolutionist could well argue that the irreducible complexity argument merely shows how demanding the conditions for evolvability are, and how much fine-tuning evolution actually requires. In a universe designed to allow for evolution, such serendipity could be expected, rather than being unlikely. Hence, Behe’s argument could simply reveal the extent to which fine-tuning is required by evolution.
PP. 118-119
Kojonen states that the conditions for evolvability are “demanding,” and unless there is “fine-tuning” which causes “serendipity” to be “expected,” then evolution is “unlikely.” In short, he concedes that evolution only works “in a universe designed to allow for evolution.”
He says the same about that the evolution of molecular machines like the flagellum. That will only happen if there is “fine-tuning of the landscape of forms” which makes it possible to move from one functional state to another during a blind, trial-and-error evolutionary process:
According to this view, then, the possibility of evolution depends on the features of the space of possible forms, where all the forms must be arranged in a way that makes an evolutionary search through it possible. This argument shows how the preconditions for the working of the “blind watchmaker” of natural selection can indeed be satisfied by nature in the case of protein evolution, despite an extreme rarity of functional forms. According to this view, then, the possibility of evolution depends on the features of the space of possible forms, where all the forms must be arranged in a way that makes an evolutionary search through it possible. This argument shows how the preconditions for the working of the “blind watchmaker” of natural selection can indeed be satisfied by nature in the case of protein evolution, despite an extreme rarity of functional forms. Behe (2019, 112) argues that Wagner does not yet solve the puzzle of evolving irreducible complexity, arguing that “it doesn’t even try to account for the cellular machinery that is catalysing the chemical reactions to make the needed components. ” However, suppose that, in the case of the bacterial flagellum, though the vast majority of possible arrangements of biological proteins are non-functional, there nevertheless exists a series of possible functional forms, little “machines” that happen to contain increasing numbers of the flagellum’s vital parts while still serving some other function. This then would allow for the seamless transition from no flagellum to a flagellum over time, through small successive steps. In this manner, by moving through such a suitable library of forms, the blind process of evolution would have the ability to produce even the most complex structures without the intervention of a designer. This is the kind of fine-tuning of the landscape of forms that seems to be required to evolve the kind of biological order described by Behe.
It seems, then, that defending the power of the evolutionary mechanism requires assuming that the landscape of possible biological forms has some fairly serendipitous properties. [Emphasis added.]
P. 122
Which Universe Are We In?
There’s a great irony here in the structure of Kojonen’s argument: He implicitly concedes that evolution is very unlikely to work in your average universe that isn’t finely tuned. He says if evolution is going to work, that’s only because natural laws and initial conditions are specially “fine-tuned.”
Thus, the universe has some pretty lucky properties. The question then becomes: Are we in Kojonen’s universe? His argument for the feasibility of evolution requires a great degree of “fine-tuning” of nature where functional forms are “arranged in a way” such that it is easy to move from one functional state to another functional state via blind evolutionary mechanisms. Are we in a “universe designed to allow for evolution” in this manner? Or are we in a universe where evolutionary mechanisms don’t seem capable of producing the complexity of life — meaning that they didn’t?
As my colleagues and I have shown both in a review of Kojonen’s book and in an occasional series of posts here, from protein evolution (here, here, and here) to the origin of irreducibly complex molecular machines like the flagellum (here and here), the universe we live in does not seem to allow evolutionary mechanisms to produce the complexity of life. We live in the wrong universe for Kojonen’s proposal.
But there’s a problem with the structure of Kojonen’s argument that goes even deeper.
How Do We Detect Design in Kojonen’s Universe?
One of the potential strengths of Kojonen’s thesis is that he wants to join evolution with design. And it’s very important to his argument that he preserves our intuition of design in nature because he wants to attract what he calls the “theist on the street” to his position. See Stephen Dilley’s article yesterday on that. Kojonen says that the “theist on the street” rightly looks at life and sees that it was designed. I would say that life contains a form of complexity that this average theist knows, from experience with the world, does not arise by on its own and requires the input of intelligence.
Kojonen differs with me. He seeks to preserve and defend the theist on the street’s intuition that life was designed. But in his mind this is not because natural processes are incapable of producing life. In fact, he thinks they are capable of that. That is, while evolutionary processes are inadequate on their own, natural processes in general are capable of producing life. Kojonen thinks this reflects the fact that the laws of nature and the initial conditions of the universe themselves are fine-tuned and designed to make the origin and evolution of life possible — by natural processes.
But if natural processes are capable of producing the complexity of life, then isn’t the “theist on the street” wrong to conclude that life was designed in the first place? On what basis can this theist know that the natural laws are “fine-tuned” to allow life to evolve? The theist must have some background knowledge that natural laws can’t produce living systems. But if Kojonen’s thesis is correct, then in our universe the theist ought not to have such background knowledge. After all, natural laws are capable of producing such complex systems!
A Gambling Analogy
In our paper “On the Relationship Between Design and Evolution,” responding to Kojonen’s thesis, we present an analogy from gambling that helps explain the self-defeating nature of this method of fusing evolution and design:
Imagine a jury being asked to try a court case about an allegedly fraudulent casino that was accused of rigging slot machines to yield winning jackpot combinations far less than they should, statistically speaking. On these particular slot machines, there are four reels with 10 symbols on each reel. The machines will pay out a jackpot when the symbols on all four reels line up with an identical symbol — a cherry — something that should happen, on average, 1 in every 104 spins, or 1 in every 10,000 spins.
The prosecution presents evidence that the casino’s machines are producing jackpots far less than they ought to. In fact, the prosecution’s team of experts tested the slot machines and found they only pay out a jackpot 1 in every 100,000 spins — an order of magnitude less frequently than they should.
The defense then takes its turn and makes a counterargument: “Actually, we live in a very special universe where the physical laws that govern slot machines (and their statistical odds) are fine-tuned such that things always happen about an order of magnitude less frequently than you’d expect. In fact, the ‘weird’ behavior of these slot machines proves our theory is true!”.
But how did the defense know that in our “special” universe, “things always happen about an order of magnitude less frequently than you’d expect”? They could only know this based upon background knowledge of how often things ought to happen (in this case, that there ought to be a win 1 in every 10,000 spins) and then, on this basis, compare the behavior of the slot machines to show that winning was occurring actually far “less frequently than you’d expect”.
The problem for the defense’s argument is that if we if we really lived in their universe, then all our knowledge of physical laws and statistics and slot machines would be based upon our experience in that universe. And if the defense’s argument was true then, based upon our experience in that universe, we should “expect” a win 1 in every 100,000 spins — not 1 in every 10,000 spins — and thus the slot machines at stake in the case should appear to be behaving perfectly normal. Thus, in the defense’s universe, we could never know that things were happening “an order of magnitude less frequently than you’d expect”.
The defense must answer this question: If we lived in their universe, how could they possibly “know” that the slots were producing wins less likely than they should? In their universe, the slot machines should behave exactly as experience would suggest — so they could never argue that things were behaving in a weird way. But the fact that the slots are behaving weirdly suggests that the defense’s “fine-tuned universe” argument cannot be true.
Damaging Design Detection
Kojonen wants to preserve the ability of the “theist on the street” to detect design — but we explain in our paper that this doesn’t seem possible even if we did live in his universe:
This analogy invites us to consider the epistemological effects of living in a universe described by Kojonen’s model (in which evolution is true, design is confined to the advent of the laws of nature, and biological data are in view). In this universe, it is not clear that humans (including theists on the street) would have the basic epistemological dispositions or beliefs that Kojonen believes undergird our ability to detect design in biology. For example, people who grew up in this universe would not likely believe that nature (i.e., non-agent processes) have only limited ability to build biological complexity. After all, in this universe, the continuity of non-agent processes across the advent of everything from bacteria to blue whales seems to suggest that non-agent causes are quite creative. Similarly, people who grew up in this universe would not likely believe that our own experience of creating complex things is at all relevant to the claim that ‘minds have greater creative power than nature does’. Instead, they would likely believe that our minds are simply a manifestation of nature’s creativity (or the creativity of non-agent causes). A similar line of thinking applies to the other elements of design detection discussed above. The bottom line is that human cognition would likely be significantly different in Kojonen’s universe than we actually experience it to be. Conversely, the fact that we have the particular cognitive dispositions and beliefs that we currently possess — instead of the ones we’d have in Kojonen’s universe — suggests that we live in a world notably different than captured in Kojonen’s model. Thus, in a particular sense, Kojonen’s model is inconsistent with the lived experience of some humans, including some theists on the street. This seriously harms the plausibility of his proposal, including its defense of everyday theists.
Thus, even if Kojonen’s argument were correct and the laws of nature were capable of producing living systems, then his “theist on the street” should not be able to detect design in living systems in the manner he suggests. If the laws of our universe are rigged to produce life, then such an event would be fully natural and should not trigger a design inference. We would see no reason to invoke anything other than normal natural processes to explain life’s complexity. The very fact that life does trigger a design inference for Kojonen’s theist suggests that our experience teaches us such events don’t happen due to natural laws. That means Kojonen’s thesis is self-defeating and cannot be true.
Saturday 17 February 2024
Yet more on one of our planet's other civilization.
Ants “Think” Differently from Humans
There are some 20 quadrillion ants living in the world today. John Whitfield offers an essay at Aeon on the factors underlying the successful spread of vast colonies from, say, South American to Europe — by piggybacking on human journeys.
Whitfield, author of Lost Animals: The Story of Extinct, Endangered and Rediscovered Species (Welbeck 2020), resists the temptation to compare ant dominance to human dominance of the globe, in part because, well, ants think differently. Here are a couple of the questions he answers in his sparkling and informative essay:
Why Do Ants Work So Well Together?
Recognition looks very different for humans and insects. Human society relies on networks of reciprocity and reputation, underpinned by language and culture. Social insects — ants, wasps, bees and termites — rely on chemical badges of identity. In ants, this badge is a blend of waxy compounds that coat the body, keeping the exoskeleton watertight and clean. The chemicals in this waxy blend, and their relative strengths, are genetically determined and variable. This means that a newborn ant can quickly learn to distinguish between nest mates and outsiders as it becomes sensitive to its colony’s unique scent. Insects carrying the right scent are fed, groomed and defended; those with the wrong one are rejected or fought.
JOHN WHITFIELD, “ANT GEOPOLITICS,” AEON, FEBRUARY 16, 2024
As Eric Cassell notes in Animal Algorithms: Evolution and the Mysterious Origin of Ingenious Instincts (2021) , all species of ants are social; there are no known solitary ants.
How Different Is Ants’ Way of Thinking?
The more I learn, the more I am struck by the ants’ strangeness rather than their similarities with human society. There is another way to be a globalised society — one that is utterly unlike our own. I am not even sure we have the language to convey, for example, a colony’s ability to take bits of information from thousands of tiny brains and turn it into a distributed, constantly updated picture of their world. Even ‘smell’ seems a feeble word to describe the ability of ants’ antennae to read chemicals on the air and on each other. How can we imagine a life where sight goes almost unused and scent forms the primary channel of information, where chemical signals show the way to food, or mobilise a response to threats, or distinguish queens from workers and the living from the dead?
WHITFIELD, “ANT GEOPOLITICS”
Cassell suggests that colony communication is somewhat like a computer algorithm: The ant processes pheromones (scent signals) as if they were AND gates and STOP in a computer system (p. 91). Thus, the ant is not judging the situation and deciding whether to go along with the group or not — as a human might — but rather, processing a signal. Stanford entomologist Deborah M. Gordon calls the resulting communication without personal understanding the “anternet.”
Whitfield tells the story of Biosphere 2, a giant terrarium in Arizona, designed in the 1980s as a self-sustaining living system with no connection to the outside world. Developed to test the design of biospheres for space exploration, it fell victim in 1996 to the southeast Asian black crazy ant, which turned it into a honeydew factory.
So sometimes, sheer numbers and a viable social algorithm win out over high individual intelligence. But, in fairness, the eight humans who lived inside Biosphere 2 for two years did not seem to enjoy it much:
In pursuit of a third way? II
Denis Noble in Nature: “Time to Admit Genes Are Not the Blueprint For Life”
Last November I reviewed an article in BioEssays which declared a Kuhnian “paradigm shift” away from the concept of junk DNA. That article compellingly argued that we need to abandon the notion that genes only make proteins because our genome is full of “RNA genes” that produce RNAs which perform vital functions. Now another groundbreaking article in Nature by Oxford emeritus biologist Denis Noble is calling for a major “rethink” of biology by charging that “It’s time to admit that genes are not the blueprint for life” because this “view of biology often presented to the public is oversimplified and out of date.” Noble is reviewing a new book, How Life Works, by Philip Ball.
This is not to say that genes aren’t important for life — of course they are. It’s that they aren’t the fundamental blueprint that controls an organism. In fact, in a surprising twist, Noble argues that it’s the organism that controls the genome! Before we get there, we must review some of Noble’s striking discussions of the complexity of life.
Life is Complicated
Those who travel in the intelligent design (ID) community know that we have often compared biological systems to machines. Now we have never intended to say that living organisms literally are machines — but rather that machine-like structures exist within living organisms, alongside many other features which may or may not be comparable to machines. The idea that life contains machine-like structure was explained eloquently by former U.S. National Academy of Sciences president Bruce Alberts, who famously wrote in the journal Cell:
[T]he entire cell can be viewed as a factory that contains an elaborate network of interlocking assembly lines, each of which is composed of a set of large protein machines.… Why do we call the large protein assemblies that underlie cell function protein machines? Precisely because, like machines invented by humans to deal efficiently with the macroscopic world, these protein assemblies contain highly coordinated moving parts.
Noble’s current Nature paper seemingly disagrees with Alberts’s use of machine-metaphors for biology. I think the metaphor still works in many cases, but before we explore Noble’s view, it must be understood that the reason for Noble’s disagreement with machine-metaphors isn’t because life is less complex than machines, but rather because it is MORE complex and the machine comparison fails to capture the true nature of life’s incredible complexity. Here’s what Noble writes:
For too long, scientists have been content in espousing the lazy metaphor of living systems operating simply like machines, says science writer Philip Ball in How Life Works. Yet, it’s important to be open about the complexity of biology — including what we don’t know — because public understanding affects policy, health care and trust in science. “So long as we insist that cells are computers and genes are their code,” writes Ball, life might as well be “sprinkled with invisible magic”. But, reality “is far more interesting and wonderful”, as he explains in this must-read user’s guide for biologists and non-biologists alike.
I don’t think that Noble is saying that the comparison between life and computers or machines is entirely inappropriate or completely irrelevant to anything we find in biology. Rather, I take him to be saying that life is “far more interesting and wonderful” than the idea that life is merely a computer or machine. If that’s what he’s saying, then I agree completely.
Proteins More Complex than Initially Thought
Another area where Noble argues that biological systems are more complex than often appreciated is “intrinsically disordered proteins” (IDPs) — proteins that don’t have a stable three-dimensional shape. Brian Miller and I wrote about IDPs in a response to critics of Douglas Axe posted last year:
Venema (2018) cites intrinsically disordered proteins (IDPs), noting they “do not need to be stably folded in order to function” and therefore represent a type of protein with sequences that are less tightly constrained and are presumably therefore easier to evolve. Yet IDPs fulfill fundamentally different types of roles (e.g., binding to multiple protein surfaces) compared to the proteins with well-defined structures that Axe (2004) studied (e.g., crucial enzymes involved in catalyzing specific reactions). Axe (2018) also responds by noting that Venema (2018) understates the complexity of IDPs. Axe (2018) points out that IDPs are not entirely unfolded, and “a better term” would be to call them “conditionally folded proteins”. Axe (2018) further notes that a major review paper on IDPs cited by Venema (2018) shows that IDPs are capable of folding — they can undergo “coupled folding and binding”; there is a “mechanism by which disordered interaction motifs associate with and fold upon binding to their targets” (Wright and Dyson 2015). That paper further notes that IDPs often do not perform their functions properly after experiencing mutations, suggesting they have sequences that are specifically tailored to their functions: “mutations in [IDPs] or changes in their cellular abundance are associated with disease” (Wright and Dyson 2015). In light of the complexity of IDPs, Axe (2018) concludes:
“If Venema (2018) pictures these conditional folders as being easy evolutionary onramps for mutation and selection to make unconditionally folded proteins, he’s badly mistaken. Both kinds of proteins are at work in cells in a highly orchestrated way, both requiring just the right amino-acid sequences to perform their component functions, each of which serves the high-level function of the whole organism. (Axe 2018)”
Noble’s essay provides a direct vindication of our view of IDPs as dynamic, multi-functional systems. Yes, IDPs can adopt different three-dimensional structures, but that isn’t because their shape doesn’t matter but rather because they can switch from one shape to another — like miniature transformers — to perform different functions. And the shape is undoubtedly vital to their proper function in each case. Noble’s description of IDPs is striking:
Another metaphor that Ball criticizes is that of a protein with a fixed shape binding to its target being similar to how a key fits into a lock. Many proteins, he points out, have disordered domains — sections whose shape is not fixed, but changes constantly.
This “fuzziness and imprecision” is not sloppy design, but an essential feature of protein interactions. Being disordered makes proteins “versatile communicators”, able to respond rapidly to changes in the cell, binding to different partners and transmitting different signals depending on the circumstance. For example, the protein aconitase can switch from metabolizing sugar to promoting iron intake to red blood cells when iron is scarce. Almost 70% of protein domains might be disordered.
In other words, IDPs can switch from one shape to another in response to environmental cues or signals they encounter, and this allows them to perform multiple vital functions. Once again, the complexity of life appears to be greater than we expected.
But what are the implications of all this for evolution?
Questioning Classic Views of Evolution
In his review, Noble comes right out and says that “Classic views of evolution should also be questioned.” Now Noble is an evolutionist and not an ID proponent to be sure. But he seems open to more rapid forms of evolution that, from our vantage in the ID community, seem preprogrammed to yield favorable results that benefit the organism. Here’s what he writes:
Evolution is often regarded as “a slow affair of letting random mutations change one amino acid for another and seeing what effect it produces”. But in fact, proteins are typically made up of several sections called modules — reshuffling, duplicating and tinkering with these modules is a common way to produce a useful new protein.
Noble also thinks there’s a place for “agency and purpose” in biology. He’s not talking about the intelligent design of life by an external agent, but he is acknowledging that much in biology is purposeful, noting that multiple experts now argue that “argue that agency and purpose are definitive characteristics of life that have been overlooked in conventional, gene-centric views of biology.” Again, this isn’t the modern theory of intelligent design, but once we begin to allow agency and purpose into our understanding of how life works, we’re taking important steps towards being able to recognize design in biology.
So, Where’s the Blueprint?
Noble offers various lines of evidence that the “blueprint” of life cannot be found in the DNA. He notes examples where hundreds of genes are involved in the development of certain diseases, suggesting that “It’s therefore a huge oversimplification … to say that genes cause this trait or that disease.” Moreover, rather than genomes controlling the organism, Noble notes that organisms themselves can “control their genomes” — suggesting genomes aren’t the foundation of life:
Ball is not alone in calling for a drastic rethink of how scientists discuss biology. There has been a flurry of publications in this vein in the past year, written by me and others. All outline reasons to redefine what genes do. All highlight the physiological processes by which organisms control their genomes.
If “organisms control their genomes” rather than the classical reductionist view that genomes determine organisms, then perhaps it is time for a radical “rethink” of how biology works. Here’s Noble’s vision of the future:
Ultimately, Ball concludes that “we are at the beginning of a profound rethinking of how life works”. In my view, beginning is the key word here. Scientists must take care not to substitute an old set of dogmas with a new one. It’s time to stop pretending that, give or take a few bits and pieces, we know how life works. Instead, we must let our ideas evolve as more discoveries are made in the coming decades. Sitting in uncertainty, while working to make those discoveries, will be biology’s great task for the twenty-first century.
Noble’s vision of biology is one where dogma is discarded, new ideas are considered, agency and purpose are acknowledged, cells are more complex than computers and machines, proteins are like miniature transformers, and organisms control their genomes, is highly compatible with intelligent design — certainly far more compatible than the biological thinking of the past hundred years. This means biology is moving in the right direction.
Friday 16 February 2024
More Darwinian appeals to engineerless engineering?
Fruit Fly Eyes and More Surprises for Darwin
Those tiny, pesky fruit flies have gotten no respect. Sprayed, swatted, and irradiated, the little flying machines have been treated by humans as better off dead. Hermann J. Muller got a 1946 Nobel Prize for blasting Drosophila melanogaster fruit flies with X-rays, finding that the barrage gave them lethal mutations. Scientists have manipulated their genes to make them grow legs out of their antennae or grow four wings, rendering them helpless. And worried farmers have convinced politicians to spray malathion over cities like Los Angeles to prevent invasions of fruit flies. But before killing off all these critters, it would be worth taking a closer look at their design.
Eyes’ Size
An adult fruit fly emerges from the egg and pupa in about two weeks. As the eyes are developing in a fruit fly embryo, an amazing process unfolds. A wave of signals sweeps across stem cells in the budding compound eye, switching on certain progenitor cells to stop proliferating and become unit eyes (ommatidia) and signaling others to undergo programmed cell death (apoptosis). The result is an “organ of extreme perfection” to call on Darwin’s phrase that is not only geometrically beautiful but functional for the fly — and it comes in matching left and right sides, like a pair of rubies.
Navarro et al. published a paper about how this works in PLOS Biology. In the same journal, Marco Milán from the Barcelona Institute of Science and Technology summarized the paper, explaining how the regulated process achieves “size precision” as the eye grows. Internal controls reduce “fluctuating asymmetry” (FA), a wobbly mismatch of size and shape. In effect, the growing cells of the eye do The Wave.
A new study unravels an organ-intrinsic mechanism of growth control in the developing fly eye that confers size precision through feedback interactions between proliferating and differentiating cells. This mechanismreduces eye size variability between and within animals, thus contributing to the symmetry between contralateral eyes and having a clear potential impact on eye functionality. In the growing eye primordium, a wave of differentiation moves anteriorly, whereby proliferative progenitors located anterior to the wave are recruited as differentiating retinal cells that exit the cell cycle (Fig 1). When the wave reaches the anterior-most region of the primordium, no remaining progenitors remain in the tissue, and the final eye size is attained. The movement of the differentiation wave relies on the activity of 2 morphogens [shape generators], the BMP homolog Dpp and Hedgehog (Hh), which are produced by differentiating retinal cells that signal anteriorly to nearby proliferating cells to recruit them as new differentiating retinal cells.
The Barcelona team calls this “feedback control of organ size precision mediated by BMP2-regulated apoptosis.” The result is a geometrically perfect oval-shaped eye with 800 ommatidia neatly arranged like hexagonal cells on a curved honeycomb. The curved shape gives the fly greater than 180-degree visibility on each side.
Much more must be going on, because bristles grow between each ommatidium to provide touch sensation for the fly, and each unit must be wired properly to the optic nerves going to the developing brain. What’s more, the two eyes must become exact mirror images of each other to prevent fluctuating asymmetry so that the fly can navigate with precision. The authors believe a similar process controls wing development so that the wings match. Imagine a pilot trying to maneuver a plane with one wing shorter than the other!
This one example illustrates an astonishing amount of control in an insect just a few millimeters in length. And they only investigated this in one organ — the visual system — while all the other body systems are also in the process of developing simultaneously: circulation, digestion, reproduction, muscular, flight, sensory, jointed appendages, and much more.
The authors, Navarro et al., make a logical mistake in how these controls came about:
Three features should have resulted in a strong evolutionary pressure to maximize the precision in eye size: First, size impacts vision directly, as image resolution and contrast sensitivity is proportional to the number of light sensing units in the eye; second, making and maintaining the eyes is energetically very expensive, so there is a pressure to match eye size to vision needs; and third, left and right eyes must survey a symmetrical part of the space, so eye asymmetry, which could be driven by developmental noise, should be minimized.
An unguided, blind process could not care about what “should” be done and is incapable of being pressured to do anything. Stephen Crane once quipped, “A man said to the universe: ‘Sir, I exist!’ ‘However,’ replied the universe, ‘The fact has not created in me a sense of obligation.’” Much less could molecules know about or care about “evolutionary pressure.” The authors are admittedly surprised how all these parts come together so neatly:
Biological processes are intrinsically noisy, and yet, the result of development — like the species-specific size and shape of organs — is usually remarkably precise. This precision suggests the existence of mechanisms of feedback control that ensure that deviations from a target size are minimized.
Right Flight
Here’s another fruit fly trick from recent news. How did the fruit fly make a sharp turn? This is not a joke. Sharp turns don’t just happen in a fruit fly because it has wings. They are controlled by specialized neurons.
This month, Ros et al. published their findings in Current Biology about “Descending control and regulation of spontaneous flight turns in Drosophila.” In the same issue, Matthieu Lewis summarized the research about how and why fruit flies make sudden zigs and zags while flying.
Upon detecting an attractive odor plume, a fly surges upwind, followed by crosswind casting separated by counterturns when the plume is lost. While the sensory control of turning and casting is shared across most animals, little is known about its neural underpinnings. In a paper in this issue of Current Biology, Ros et al. report the identification and functional characterization of a pair of bistable descending neurons that orchestrate casting during flight behavior in the fly Drosophila.
These neurons, Ros et al. explain, consist of “couplets of one excitatory and one inhibitory descending cell form functional units.” As with many systems in biology and in engineering, an accelerator is paired with a brake, providing fine control with a push-and-pull combination of systems responsive to input from the surroundings. Particular “command units” of descending neurons enable a fruit fly to make sharp turns called saccades. “An array of excitatory and inhibitory neurons provides input to the saccade network,” the authors say about one of their major findings.
Within the central nervous system of insects, descending neurons (DNs) constitute a critical stage in the transformation of sensory input in the brain into motor commands in the ventral nerve cord (VNC). Drosophila possess ∼650 pairs of DNs, some of which appear to function as specialized command neurons for specific behaviors, including courtship, walking backward, turning, take-off, and landing. Thus, DNs provide a logical starting point for investigating the circuits that generate and regulate flight saccades.
Stop for a moment to picture this little millimeter-range creature containing 650 pairs of descending neurons each programmed for specific commands. One fires, and the fly walks backward. Another fires, and the fly comes in for a landing. Another fires, and boy fly courts girl fly. This sounds much more astonishing than a computer-controlled robotic drone.
By ablating one or the other of the descending neurons (DNs) involved in saccades, the team supported their hypothesis that the couplet functions as a saccade-generating unit (SGU).
The altered saccade dynamics and temporal distribution after ablation support the hypothesis that each DN can produce saccades independently of the other but with different dynamics than those of control flies. The results support a working hypothesis that the two DNs play complementary roles by activating different components of the motor circuit in the VNC responsible for generating saccades. Together, functional imaging, unilateral activation, and ablation experiments suggest that two pairs of descending interneurons, DNae014 and DNb01, function together as saccade-generating units (SGUs) to execute commands for spontaneous turns during flight.
Louis gives examples in other animals, from insects to mammals, that use a similar “sector search” strategy during navigation. But why would a fruit fly need to make a sharp turn?
Saccades are thought to benefit flying animals in several ways. From a sensory perspective, saccades may restrict the deleterious effects of motion blur to brief moments interjected within longer sequences of gaze stabilization. Brief bursts of saccades in the same direction may aid local search strategy by allowing the animal to quickly scan the local environment for salient visual and olfactory features. More recently, it has been suggested that comparing sensory measurements immediately before and after each saccade might enable flies to estimate key parameters that are otherwise not directly measurable, such as the direction and magnitude of the ambient wind. For all these hypotheses, the timing between saccades is critical…
Critical timing, fine control, and convergent strategies between unrelated animals — such concepts defy Darwin’s bluffing notion of the creative power of natural selection. At one point, the authors acknowledge that this looks like engineering.
The activity levels between the left and right DNae014 cells followed an inverse, highly non-linear relationship, analogous to “flip-flop” components in digital electronic circuits (Figure 1J) and reminiscent of neurons identified in the steering behavior of male silkmoths. Further, the DNb01 cells synapse directly onto contralateral DNae014 cells. This is a simple reciprocal inhibitory motif, consistent with a network responsible for binary
More to Come
We’re not done with design in fruit flies. Next time, we will look at some of the sensory apparatus within these little insects. While fruit flies are convenient lab animals for study, undoubtedly similar systems can be found in even smaller flying insects like mosquitoes and gnats, all of which, being heavier than air, “evolved” powered flight and all their related systems because of “selection pressure.” Not.
In pursuit of a third way.
Bad News for the “Theist on the Street”
Is mainstream evolutionary theory compatible with a biology-based argument for intelligent design? That’s the argument of theologian Rope Kojonen’s book, The Compatibility of Evolution and Design (CED). Kojonen contends that evolution (and biology) rightly understood actually point to design. His book is perhaps the best treatment available of design and evolution from a theistic evolutionary point of view. But does it succeed?
Casey Luskin, Brian Miller, Emily Reeves, and I have published a peer-reviewed article that analyzes Kojonen’s proposal. Here I will provide an epistemological critique. We’ll see that Kojonen’s model undermines itself by raising obstacles to design detection — including the very design detection that he uses to undergird his own design argument.
Kojonen defends the perspective of what he calls the “theist on the street” — an everyday believer in God who accepts design based on direct perception or intuition rather than a rigorous design argument. Yet it turns out that his model actually undermines such a person’s design beliefs.
The Model
We summarize his model as follows:
The details of his proposal are manyfold, but the basic idea is straightforward: the locus of design is at the origin of the cosmos (or the laws of nature) (CED, pp. 164–67). God acts at the beginning of the universe, granting to it all that is necessary for biological complexity to eventually unfold. The deity creates the laws of physics and chemistry, which then give rise to preconditions — including “the library of forms” — that enable evolution to produce complex entities. Random mutations and natural selection alone are insufficient for the emergence of biological complexity; preconditions are required, and God ultimately stands behind these preconditions (CED, pp. 97–143).1
So God designed the laws of nature, which then give rise to laws of form and other processes, which eventually produce all flora and fauna. Thus, a person who sees, say, a hummingbird for the first time can rightly intuit (or infer) that it was designed. It’s just that the locus of its design was billions of years earlier and that natural processes transmitted and unfolded this design over time.
The Problem: Part 1
What’s wrong with this picture is that it harms humans’ ability to detect design in the first place. This is for two primary reasons, which build on each other. The first is that it damages a human’s “direct design” beliefs. A “direct design” belief is a belief that a certain type of thing, like a hummingbird, was created by the immediate action of a designer rather than by mediated or secondary causes. As we explain:
In our lived experience, humans readily attribute direct design to various types of biological phenomena. (This is not only true of “theists on the street”, for example, but also of some other people as well.) For example, consider a person who sees a hummingbird for the first time. A natural reaction is to think that this type of bird was directly designed. (“Wow! That’s spectacular. Somebody made that!”) In fact, humans often experience things like hummingbirds as distinct entities — what Axe (2016, pp. 65–86, esp. 71) calls “busy wholes” or what one might call “natural kinds”. That is, humans often experience an entity like a hummingbird as a certain type of thing, and they naturally believe that this type is the result of direct design. By contrast, it is rarely the case that, upon seeing a hummingbird for the first time, a typical person would say, “Wow! That’s specular. Somebody indirectly created that by a process of secondary causes over millions of years”. Instead, many people believe that a designer directly crafted the first instance of a given specimen or feature. (“God made the first hummingbirds, then they reproduced”.) Whether rightly or wrongly, human beings routinely apprehend (or infer) direct design when they encounter the power, beauty, and complexity of organisms or organs.2
So how does Kojonen’s model affect this type of experience? Here’s how:
Yet in Kojonen’s model, these beliefs in direct design are uniformly false. In his view, there is no direct design of biological phenomena. All biological diversity and complexity are the result of indirect design. The locus of design was billions of years prior to the advent of life on Earth. (Indeed, even if Kojonen were to locate direct design at the origin of life, all subsequent flora and fauna would still be the result of indirect design.) This simply follows from Kojonen’s understanding of design (and of evolution). So, if Kojonen’s proposal were true, human beings who accepted his view would have a serious defeater for their ‘direct design’ beliefs about biological organisms and features. They would realize that they have little or no grounds to trust their minds in this context.3
So, in this model, a person would have lots of defeaters for her “direct design” beliefs about biological phenomena.
But on what basis does Kojonen know that the laws of physics are directly designed? After all, “direct design” beliefs in biology are unreliable and, on his model, biology (alone) has sufficient evidence for design. As we explain:
[H]ow would a person in this general situation know that the laws of physics and chemistry were directlydesigned, as Kojonen believes them to be? Recall that his argument for design is supposed to be based on biological phenomena. But if his model were correct, humans would have no cases of biological things that seemed to be directly designed actually turning out to be directly designed. So, if there are no such cases — and these cases are the basis for believing that the laws of nature are directly designed — then the ground for believing that the laws are directly designed is very poor indeed. If a baseball player strikes out in his first 23 plate appearances, what basis does he have to believe that he will get a hit at his next at-bat?4
The bottom line is that Kojonen undermines his own basis for saying that the laws of physics are directly designed. If so, then he has lost his case for design. The whole point of his model is that biology provides good evidence of design even if evolutionary theory is true. But his view of biology actually undermines his view of design. Whether a person is an expert or an everyday “theist on the street,” anyone who accepts Kojonen’s model can no longer locate design where Kojonen needs it to be.
The Problem: Part 2
A second problem, building on the first, likewise damages a human’s ability to detect design. A person who accepts Kojonen’s proposal would have significantly less ground for saying that biological phenomena provide evidence of design. This is because his model, to bring about all the flora and fauna in our world, relies on non-agent causessubsequent to the Big Bang. A non-agent cause is any cause that does not include the direct action of an agent. Most non-agent causes are physical in nature. They include, but are not limited to, evolutionary causes. Practically speaking, what does this mean?
For example, if Kojonen’s model were true, a person who accepted the model would believe that, despite her ostensible prima facie belief that, say, a designer directly crafted an eagle’s eye or the first hummingbirds, it is actually the case that each of these phenomena are proximately explained by non-agent causes. For each biological organism or feature, there would be continuity of non-agent causes from before that entity’s existence that led up to (and through) the advent of that entity. Indeed, this continuity would extend all the way back in time. (In fact, there might not be any particular reason, based in biology, to think there was a big bang.) A person who accepted this model would believe that non-agent causes gave (proximate) rise to case after case of biological complexity. The same would be true for human beings, too. An unbroken chain of non-agent causes from the ancient past would extend up to (and through) the rise of the first humans, whoever they happened to be.5
The problem is that “continuity” attenuates (or erases) evidence of design in biology. Given the continuity of non-agent causes to produce all biological phenomena, what basis is there in Kojonen’s model to say that any particular biological entity was designed? Recourse to fine-tuning in astrophysics or the Big Bang in cosmology is no help: the whole point of Kojonen’s model is that biological phenomena point to design. But if every biological entity arose from prior material causes (or non-agent) causes, on what grounds can one say that a mind was needed? Kojonen’s model destroys the detectability of design. There might still be ultimate design (at the beginning of the universe) but the evidence of design — based on biological phenomena — has been obscured.
Arguably, “mainstream” evolutionary theory — which rejects appeals to God in biology — expects strong continuity of natural causes in organic history: there’s no need to invoke God to account for the rise of any particular “kind” because natural causes are held to be sufficient. “Continuity” is just what one would expect if a non-theistic version of evolution were true — namely, that direct design beliefs are uniformly false and that, instead, natural processes appear to be capable of morphing one “kind” into another “kind” over time. Such a view is decidedly unexpected on the pre-theoretic lay theist’s default disposition toward direct design of biological kinds. Mainstream evolutionary theory pushes the theist on the street in precisely the wrong direction. Accordingly, it obscures the detectability of design for such a person. Insofar as Kojonen’s model accepts “mainstream” evolution (as he says it does), his model faces this significant epistemological difficulty.
An Eagle’s Eye
This means that Kojonen’s own biology-based design argument no longer works. After all, such an argument requires that biological design be detectable. If design cannot be detected, it cannot be parlayed into a rigorous argument. This same line of reasoning also undermines the ability of a “theist on the street” to detect design. Insofar as she accepts Kojonen’s model, she would have to regard her initial impression of direct design — of, say, an eagle’s eye — as mistaken. She’d now believe that God didn’t create the first instance directly; instead, it came about by an unbroken chain of material causes (or non-agent causes) throughout the entirety of organic history. For all that she can tell (based on biology), there is no need for recourse to a Mind. Thus, she no longer has grounds to trust her common-sense intuition of the design of the eagle’s eye — or for that matter of any other flora or fauna.
So much for the design intuitions of everyday theists. For more on Kojonen’s book, see here
Thursday 15 February 2024
Wednesday 14 February 2024
Tuesday 13 February 2024
Time for some much needed iconoclasm re: St.Darwin?
Does the World Need Another Book About Darwin?
Editor’s note: We are delighted to present an excerpt from the new book by Dr. Shedinger, Darwin's Bluff: The Mystery of the Book Darwin Never Finished. This article is adapted from the Introduction.
What can anyone say that has not already been said about this seminal figure, Charles Darwin, considering the wealth of literature written about him? To the question posed in the headline above, the simple answer is yes, we do need another book about Darwin, for there are aspects of his life and work that have surprisingly continued to evade the attention of his many biographers and interpreters.
The very human Charles Darwin has grown into a mythological figure — the paradigmatic example of a true scientist — without whom nothing in biology would make sense, in the words of Theodosius Dobzhansky. Unfortunately, this mythological figure would be scarcely recognizable to Darwin’s own contemporaries.
Happily for the present enterprise, the flesh-and-blood Charles Darwin is considerably more interesting than the two-dimensional Darwin of the hagiographies.
The state of his scientific legacy is also more intriguing than those same hagiographies would allow — intriguing because it is embattled in ways confessed to in some of the peer-reviewed literature and at high-level scientific conferences but rarely acknowledged beyond these specialized contexts.
Modern scientific advances in fields like molecular biology, genomics, epigenetics, paleontology, developmental biology, and more are raising significant questions about the power of the Darwinian mechanism of variation and natural selection to account for the evolutionary history of life on Earth. Some are calling for an extended evolutionary synthesis while others believe the entire Darwinian edifice needs to be overhauled. It is no longer clear that Darwin can be said to have answered the question of the origin of species. There is thus no reason to begin an investigation into his life and work with the assumption that he did.
Abstract Art
One effect of Darwinian mythology has been to downplay the 19th-century Englishman’s own characterization of The Origin of Species as a mere abstract of his species theory, a summary lacking much of the facts, evidence, and authorities he promised would follow in a later work. The Origin is usually treated as Darwin’s magnum opus, a characterization in keeping with Darwinian mythology but out of step with Darwin’s own view of his work. In truth, The Origin of Species was an abstract of a much larger book on species that Darwin was working on (and that was three-quarters complete) before events forced him to put the larger book aside and instead publish a mere abstract of it.
Once the Origin was in circulation, Darwin’s many correspondents anticipated that he would quickly follow up with the publication of his big book on species so they could better evaluate the argument for natural selection made in the Origin. Indeed, Darwin himself created this expectation both in the Origin and in his correspondence. Even early reviewers of the Origin noted the lack of empirical evidence for natural selection but gave Darwin the benefit of the doubt since the Origin was a mere abstract and therefore could not be expected to provide all the evidence. Given the anticipation among Darwin’s readers for the big book on species, anticipation that Darwin himself repeatedly stoked, why did he never publish the big book? This question is rarely asked.
A rough, handwritten manuscript of Darwin’s big book, titled Natural Selection, survived among his papers and was published by Cambridge University Press in 1975.1 Yet despite the easy access scholars now have to this work (I bought a copy on Amazon), there has been little detailed engagement with its contents or comparison of this work with its abstracted form in the Origin. Such a comparison proves enlightening, for it serves to highlight the secondary nature of the Origin as a hastily written abstract rather than a finely honed scientific treatise, thus challenging the iconic status of the Origin as the foundational text of the modern biological sciences. This, of course, may be precisely why the big book gets overlooked.
Missing Goods
Another reason the big book has been largely ignored, I hope to show, is that it does not deliver the promised goods. This, I will also argue, is the best explanation for why Darwin never brought the book to print. It wasn’t, as one might suppose, that he had made little headway on it and simply lacked the time or energy to produce it. Abstracts are usually distillations of longer works already in existence. So, if the Origin, as Darwin constantly repeats, is only an abstract, it would suggest the big book on species already existed in some substantial form prior to 1859. And in fact, this was the case. The manuscript contained nine chapters and was close to 300,000 words in length. It would likely have been around 400,000 words complete. Given that this book was nearly three-quarters complete, why did Darwin never publish it? And why did he instead turn to the study of orchids as a follow-up to the Origin? Because, as will become clear, he came to see that it did not answer some key criticisms that the Origin had elicited. So, he abandoned the project, even as he allowed anticipation of its publication to persist for many years.
To be sure, Darwin’s orchid book, which he called “a flank movement on the enemy,”2 did attempt to provide some of the evidence for natural selection missing from the Origin (and, as it turns out, missing from the big book as well). He tried to outflank his opponents by putting before them an entirely new work on the numerous contrivances (Darwin’s word) found among orchid flowers to ensure their cross-fertilization by insects. Surely this would impress his readers with the power of natural selection to evolve all these exquisite contrivances.
But Darwin’s strategy failed. Reviewers of his orchid book read it as providing evidence for natural theology, not natural selection. And surprisingly, even Darwin himself in one place likened his orchid book to the Bridgewater Treatises, a series of writings designed to extol the power of God manifest in nature! Could anything be more ironic than that Charles Darwin, the poster child for the triumph of scientific naturalism in biology, actually advanced the cause of natural theology in his day? This is an aspect of his life and work that has been entirely erased by the prevailing mythological Darwinian narrative.
For all these reasons, a more nuanced assessment of Darwin’s evolutionary writings is warranted.
An Enigmatic Victorian
In my engagement with Darwin, I will give pride of place to his voluminous correspondence as the evidentiary basis of this more critical portrait of a truly enigmatic Victorian figure. The argument that lies ahead cites more than 250 letters written by and to Darwin up to the year 1863, some never cited in Darwinian biographies. These letters represent Darwin’s engagement with more than seventy friends, family members, and scientific correspondents. I have elected to adorn the book with many direct quotations from these letters, since I think it is crucial for readers to hear Darwin’s own voice on the page as much as possible to truly encounter the thought patterns and rhetorical style of this fascinating individual.
Many of Darwin’s biographers take the reverse approach — providing their own paraphrases of Darwin’s words — which has the effect of subordinating Darwin to the mythological figure the biography exists to perpetuate. I have also elected, for authenticity’s sake, to retain Darwin’s spelling and punctuation rather than correct them to modern standards. We need to let Darwin speak for himself. It turns out that Darwin, given the opportunity, is quite capable of dismantling his own mythology.
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