The “Botched” Human Body, Revisited
I recently posted some thoughts about a Wall Street Journal article on the “botched” design of the human body. It was written by biologist Nathan Lents as a teaser to his recently released book on the subject.
Not surprisingly, Dr. Lents disagreed with my views, and devoted a lengthy blog post to his response. But Lents seems to have misunderstood virtually every point I made. Since Lents raises some questions that may be of concern to others as well, I’ll ignore his ad hominem attacks and focus here on further exploring my argument.
My previous post was about principles of good and bad design, and how design professionals assess the designs that they observe, or that they’re creating or modifying. These principles apply to all complex man-made systems, and they appear to be just as true for living systems.
As a systems architect, I’ve spent decades designing and implementing large and complex systems of information systems — often involving thousands of individual systems. Such systems are normally embedded in complex processes that may span days, months, or even years. They integrate information systems with human activities, often across multiple organizations. These systems have a lot of moving parts.
It turns out that a number of key design principles are essential for building and modifying complex systems of systems. Get the design principles right, and everything works better. Mess up the design principles, and everything is harder — and sometimes impossible.
A few years ago I realized that these same design principles apply to living systems. So, my insights into systems design may offer an unconventional perspective into how living systems work, and how they change over time.
So, Lents is right — I’m a non-biologist talking about (and working in) biology. But what I wrote was from the perspective of design, and this is exactly my area of expertise. In contrast, I see no evidence that Lents has formal training or work experience in the design of complex systems. So, he is a non-designer talking about design.
Biology is complex. It defies simple explanations, from either side. Maybe it’s time for all hands on deck if we ever hope to figure out what’s going on in living systems. The plain fact is that in research, as in most areas of human endeavor, multi-disciplinary approaches work best.
I should also address a few of the demonstrably false assertions Lents makes, either to discredit his critics or to prop up his narrative (or both). Consider the following (from his blog):
There is basically one truly credentialed and accomplished biologist who supports the theory of intelligent design, Michael Behe. [Emphasis added.]
Seriously, Michael Behe is the only credentialed and accomplished biologist that supports intelligent design? Maybe Lents needs to get out more. Other scientists like Scott Minnich, Douglas Axe, and Günter Bechly are certainly credentialed and accomplished. And each has paid dearly for his open support of intelligent design.
Or this one:
[Evolution News] is exceptionally and intentionally deceptive, especially in its portrayal of a scientific debate about evolution versus intelligent design, when no such debate exists in the scientific community.
There is, in fact, quite a robust debate taking place in biology. In large part, it’s about the causal sufficiency (or the lack thereof) of neo-Darwinian mechanisms to explain the observed properties of living systems (interestingly including their design properties).
This was the main topic at the 2016 Royal Society meeting in London, which was convened to discuss the fundamental explanatory deficits of neo-Darwinian theory. A contingent of my colleagues attended, and as one of them put it, others at the conference “recognized the problems of information and the appearance of agency, but they had no explanations for these challenges.”
Talk of design is all over the place in biology. Dawkins noted “the appearance of design.” Design was mentioned often at the Royal Society meeting (but only as an analogy). Lents (in his blog) mentions the amazing capabilities of unintentional design — almost as if this is a thing.
But talk of a designer is not allowed.
So biology faces a causal conundrum. As I’ve previously written,
Materialist biologists are thus pressed to find a third class of causal force — one that works without purpose (required to adhere to materialist philosophy), yet produces purposeful outcomes (required to adhere to the observed world). As yet no reasonable candidate forces have been proposed.
Darwinists need a causal force capable of producing large quantities of information, fantastically improbable molecular machinery, and stunning functional coherence — all without meaning to.
Clearly, this debate is ongoing, and heated.
The Bad Design Argument
It’s not clear that Lents fully understood my previous comments on the “bad design” argument. In saying that the bad design argument is inherently weak, I was talking about the class of argument rather than specific instances of the class.
There are five ways the bad design argument can (and often does) go wrong:
- Not understanding the relevant design goals and constraints.
- Not accounting for design tradeoffs, which are necessary in all complex systems.
- Failure to acknowledge degradation over time — degradation can occur in heritable ways, leading to offspring with defects not present in the parents.
- Logical fallacy — “bad design” ≠ “no design.”
- Aesthetic considerations — which usually translate into some variation on, “I wouldn’t have done it that way.”
There is, in fact, a discipline and methodology for critiquing designs. It takes serious work to demonstrate that you’ve not made errors in evaluating a design, and this work must be done for each purported instance of “bad design.” This is true for man-made things and for living things.
Of course, with biology such critiques are more difficult than they would be if you were reviewing the design of an Atlas V rocket. Biology is much more complex. Much of how it works remains to be discovered, so evaluating the design of any living system is normally done in the absence of sufficient knowledge.
As a result, any claim that a biological system or subsystem is poorly designed must be done with a healthy dose of humility, else the proponent risks coming across as presumptuous.
Therefore, my argument stands:
Absence of sufficient knowledge + presumptions = ignorance + arrogance
While Lents took my comment along these lines as a personal attack, it was meant simply as a general assessment of this class of argument.
The bad design argument is weak in two additional ways.
First, it’s usually possible (and sometimes easy) to find counter arguments. When the argument consists mainly of story-telling, someone is bound to come up with counter-stories. Almost inevitably the conversation devolves into a spitting contest over who’s telling the best story. Regardless of which side better represents the truth of the matter, at some point the cost-benefit ratio gets too high, readers move on, and the argument peters out.
A case in point is what Lents describes as “eight [bones] in our wrist, like a useless pile of rocks, good for nothing but sprains and strains” (emphasis added). Even on its surface, this casual and dismissive assessment seems to illustrate several of the five ways the bad design argument can go wrong. Given the enormous range of capabilities of the human hand — from the subtle touch needed to play a violin to heavy physical labor, from fine dexterity to absorbing heavy impacts — it’s clear that the hand must be both strong and flexible. The obvious way to engineer this is with small, solid components (bones), with suitable shapes to allow the correct range of motion(s), with suitable connecting and separating tissues (ligaments, tendons, cartilage) in just the right places between and among all those parts, and the whole thing wrapped tightly (in ligaments) to bind it together. Given the human hand’s impressive performance against such diverse capabilities, it doesn’t seem like such a bad design.
Minimally, an assertion of this kind requires that all the relevant stresses and forces have been considered against the observed range of movements, and that the design in some way or other doesn’t stand up to the tasks required of it.
If Lents has a better design in mind, there’s a fortune waiting for him in the robotics industry.
Second, arguments made in the absence of knowledge are vulnerable to new knowledge as new discoveries are made. Case in point: Lents tells stories about early man’s struggle to survive in the harsh ancient African climate, but recent findings (here and here) suggest that the long-accepted “out of Africa” hypothesis may be due for a rethink.
(I can hear the Darwinists shouting at this point that intelligent design is an argument from the absence of knowledge, but this is not the case. ID is not a God-of-the-gaps argument, but rather an inference to the best explanation — namely, that intelligence is the only causal force currently known that can generate coherent, information-based systems of systems.)
None of this means that everything in biology is perfectly designed. Since design always involves tradeoffs, it’s normally not possible to even define “perfect design” for any specific complex design problem, much less in general. Any call for perfect design is likely a red herring.
Nor am I suggesting that evaluating biological design is a pointless exercise. In fact, there is much to be gained from doing so (think biomimetics). My point is simply that the bad-design class of argument cannot prove (or disprove) anything.
But maybe Lents is not trying to prove anything. Maybe he’s trying to persuade people via a grand evolutionary narrative that ties together a panoply of presuppositions, assumptions, hypotheses, educated guesses, (selected) empirical evidence, and miscellaneous factoids. He somehow manages to tie all of this to a few sketchy conclusions about how evolution has resulted in global warming and the threat of nuclear war. All overlaid with a smooth and well-written veneer (Lents does have a fluid and engaging writing style).
This may sell well to the Darwinian faithful, but in the end, most open-minded people will note that there’s just a lot of story-telling going on here.
Finally, focusing on examples of bad design leaves the most important (and interesting) questions in biology on the cutting room floor.
For example, why are there any good designs in nature? Why does every living thing contain so much coherent design?
For the human body, why do the millions of parts work, and why do they just happen to make up a whole that can accomplish tasks that none of the parts can do by themselves?
Anyone who examines the design of the human body without considering such questions in some depth has simply missed the mark.
It’s a bit like diligently reading and rereading War and Peace, looking specifically for grammatical errors, typos, and other mistakes. Of course, you’re likely to find examples, whether real or contrived. But in the process you may have missed the point of the book.
Yes, it’s a flawed analogy. For one thing, the human genome contains roughly 150 times more information than does War and Peace, one of the longest and most profound novels in all of human literature. For another, War and Peace can’t generate its own power by eating paper, or maintain a chemical equilibrium different from its environment, or make a copy of itself. But the human body (and each of its cells) does these things handily.
To understand human anatomy and physiology it’s essential to carefully examine the whole system before declaring the parts badly designed. It’s essential to consider how the parts relate to and interact with each other — the kinds of tolerances, stresses, forces, ranges of motion, capabilities, and overall dynamics that are required.
And, for goodness sakes, it’s essential to note that it works.
Lents contends that the forces of neo-Darwinism can generate profoundly complex and elegant designs, and they do this all the time. This is the heart of the debate. It has not been resolved by Nathan Lents.
Image: Bone structure of a human hand, by Henry Gray (), Anatomy of the Human Body, [Public domain], via Wikimedia Commons.