The Saturday Morning Lectures series recently featured an excellent presentation by Dr. David Sivak, Associate Professor in the Department of Physics at Simon Fraser University, titled “Evolution Is an Engineer — The Ingenious Nano-Machines Inside All Living Things.” Sponsored by Canada’s particle accelerator centre, the University of British Columbia, and Simon Fraser University, the Saturday Morning Lectures are a wonderful effort to share hot science topics with high school students and a general audience. I encourage readers to check out the lectures for the Spring series here.
The first in the Spring 2021 series, Sivak’s lecture was billed as a “dive into the variety of natural machines, strange properties resulting from their microscopic size, and how living things take advantage of these properties.” Just as humans have engineered systems to do useful work, Sivak noted, nature has “evolved many diverse nanoscale machines for similar purposes.”
Starting Out Strong
Sivak’s lecture was well-organized and thoughtfully presented. He provided a reasonably good overview of various molecular machines, and I particularly appreciated that he mentioned the thermodynamic challenges facing life, as well as physical constraints of the micro-environments in which nano-machines operate. He had clearly put a lot of thought into his presentation and overall did a good job of bringing what can sometimes be a challenging topic down to the lay level. Thus, I have no desire to dispute minor technical points, given the target audience and the 45-minute time constraint he had to work with.
As background to his presentation, Sivak spearheads a small team carrying out very interesting research that for all intents and purposes sounds like it could be right out of the pages of an engineering in living systems monograph. Sivak’s website says that the group “combines approaches from statistical physics, molecular biophysics, and information theory to elucidate the physical limits placed on biological systems by their operational imperatives….” Moreover, they hope to “identify fundamental design principles for effective biological function, with special emphasis on transduction of energy and information.” This is truly good stuff — where do we sign up! If that weren’t enough, the last sentence really caught my eye: “Our theoretical flights of fancy are tethered to reality through close experimental collaborations.”
Combining approaches from various disciplines to understand the operation of biological systems, identifying fundamental design principles, and watching out for theoretical flights of fancy? I couldn’t have said it better myself. As a result, other than a minor quibble about one aspect of Brownian motion Sivak mentioned in his presentation (perhaps a topic for another time), I have no disagreement with the work he is doing and I eagerly look forward to many exciting research results from his group in the coming years.
What I would like to do is modestly suggest one area where the presentation he gave, and the work his team is doing, might be strengthened by sticking with the facts and adhering more closely to his own group’s mantra of tethering any “theoretical flights of fancy” to reality.
Theoretical Flights of Fancy
Sivak discussed a number of remarkable molecular machines found in nature, including ATP synthase, the bacterial flagellum, kinesin, DNA polymerase, and more. A listener could scarcely avoid thinking of Darwin’s Black Box and Behe’s argument for the purposeful design of the molecular wonders found in the cell.
One of the things that jumped out at me throughout the presentation, however, was Sivak’s liberal use of the word “evolve.” This was not wholly unexpected, given the title of his talk, but it came across as rather gratuitous, even strained at times. An example will illustrate.
Time and again, Sivak referred to the evolution of these amazing molecular machines, yet provided no evidence that they had evolved. At best, such pronouncements came across as little more than a declaration of faith, without adding anything of substance to his lecture. Worse, these statements actually distracted from the substantive focus of his message about the function of these systems and the engineering work he and his team are doing to elucidate their operation.
Yet notwithstanding the title of the presentation, not once was any evidence provided that evolution was in fact “an engineer” or had any involvement whatsoever in the formation of these machines. Indeed, when an audience member asked during the post-presentation Q&A (47:21) whether scientists had found “primitive versions of these nano-machines” that could speak to the evolutionary history of how they “evolved by natural selection,” as Sivak had claimed, all Sivak could offer was the observation that “these machines are so widespread that the evidence is very, very strong that there were common ancestors that diversified… to accomplish different tasks.”
In other words, because these machines are widespread in many different organisms, and because the way we get different organisms is through evolution, then these machines must have evolved. Or something like that…
This is of course not an explanation of how these machines evolved, or whether they in fact did. Indeed, it is not an explanation at all, just a circular restatement of the theory: We think these machines evolved, because, well, that is how evolution tells us fancy biological systems like these come about.
Sivak went on to note that there are a few variations of ATP synthase that have “a different gearing ratio, a different leverage between the voltage and the chemical energy that it produces, which actually appear to have evolved to essentially match the strength of the voltage [across the membrane] in different organisms.” Sivak acknowledged that he couldn’t point to specific examples of primitive machines to provide an evolutionary history, but suggested that “you can certainly see how nature has used essentially modular architecture of these machines to create different versions to accomplish different goals.”
In other words, dear listener, no, there isn’t good evidence of evolutionary precursors. Yet somehow nature itself has created machines, using “modular architectures,” to match the needs of different organisms and to “accomplish different goals.” It’s amazing what nature can do!
If the inquiring audience member wanted another reason to marvel at the remarkable coordinated functionality found in life, great. On the other hand, if he was hoping for a good evolutionary explanation for these machines, Sivak’s answer surely provided no confidence.
Nature Evolves Machines?
Then there is the awkward use of evolutionary terminology generally. Multiple times Sivak stated that “nature evolved” this and “nature evolved” that. This use of the transitive form of “evolve” is not unknown in the English language, but it strains the trained ear in this context. This transitive verb suggests that nature, as some kind of active agent (in a suspiciously vague and undefined sense), “evolved” molecular machines, meaning that nature produced, built, or constructed these machines. But what does it even mean to say that nature constructed something like, say, ATP synthase? Indeed, what could it possibly mean?
Careful readers will recognize that this assignment of the role of skillful engineer to nature is the same approach Darwin took with his rhetorically effective though intellectually empty anthropomorphizing of natural selection as some kind of wise and beneficent force that goes about “scrutinising, throughout the world, every variation, even the slightest; rejecting that which is bad, preserving and adding up all that is good…” In both cases, such anthropomorphizing is unquestionably colorful, definitely memorable, but hardly the stuff of solid science.
On the theory that two wrongs make a right, Sivak tied these two incomprehensibles together for his audience, shifting from “nature’s” creative capabilities to stating more than once that “natural selection has evolved” these molecular machines. This assuredly does not add up.
Even if we swallow Darwin’s evolutionary tale hook, line, and sinker, it can’t possibly be true in any substantive sense that natural selection produced a molecular machine. After all, even under the evolutionary narrative natural selection doesn’t actually create anything. Like the annoying middle manager at work, natural selection lifts nary a finger during the long hours of toil, swooping in only after the fact to take credit for all the hard work that was already done. For the actual creative effort, we must look elsewhere.
Presumably what Sivak means by the statement that “natural selection evolved” something like ATP synthase is that a long series of hypothetical, unknown, accidental copying errors happened to produce ATP synthase one happy day. Yep. Just stumbled upon this remarkable machine by sheer dumb luck.
Under Darwin’s story, once ATP synthase accidentally came on the scene through sheer dumb luck, then, yes, natural selection would be so kind as to let ATP synthase hang around, blessed by the approving stamp of natural selection’s personified scrutinizing efforts. Yet even under Darwin’s story, natural selection cannot be the force that “evolves” a remarkable molecular machine. For that, evolution must rely on dumb luck.
Suddenly, the evolutionary story doesn’t sound quite so impressive when we strip out the obscuring rhetoric and state things in direct terms. Want to know how it happened? You’re out of luck. Want to understand which mutations are actually required? We can’t say. Want to run some basic population genetics calculations to see if this is reasonable within the available timeframe, even in principle? No need to worry about such details. We’ve got a story to tell…
In fairness to Sivak, he is not an evolutionary biologist, so perhaps the extraneous and strained evolutionary terminology was sprinkled throughout an engineering lecture to pander to his evolutionary-minded colleagues. Or perhaps he was too easily impressed by the problematic arguments put forth in some of the books he recommended at the end of his presentation, such as those by Nick Lane and Jeremy England (45:03).
In any case, what we can conclude is that it makes little sense to say that evolution “engineered” these sophisticated molecular machines. Unfortunately, beginning one’s presentation with an announcement that “today we’re going to discuss some of the amazing machines that accidentally came about by sheer dumb luck through a string of copying errors,” tends to throw a wet blanket on whatever gravitas one is hoping to bring to the stage.
So rather than stating the evolutionary claim clearly, the evolution part of the story is couched in vague terminology and gratuitous references to unknown and speculative processes obscured by the mists of deep time. It comes across as more believable that way.
Yet why burden the listener with this intellectual baggage at all? If the goal is to improve our understanding of the operation of molecular machines, then why drag the discussion into the muddy and highly questionable waters of evolutionary theory? This is just one more example of the way in which evolutionary theory casts its opaque and diminishing shadow over the light of scientific endeavors.
It is easy to avoid this intellectual baggage; we just need to be aware of it. Instead of saying, “Now we’re going to examine another remarkable machine that nature evolved,” just say, “Now we’re going to examine another remarkable machine found in nature.” Leave the “theoretical flights of fancy” out of the conversation.