A Darwinian quiz
(Update Feb 9 1:38 p.m.: I’ve received quite a few reader responses, pretty much covering the gamut, which I have posted below.)
Please read the following passage from Richard Dawkins’s The Ancestor’s Tale, p. 592, then see the questions below:
Bombardier beetles of the genus Brachinus are unique, in Dr McGavin’s experience, in mixing chemicals to make an explosion. The ingredients are made and held in separate (obviously!) glands. When danger threatens, they are squirted into a chamber near the rear end of the beetle, where they explode, forcing noxious (caustic and boiling-hot) liquid out through a directed nozzle at the enemy. The case is well known to creationists, who love it.
They think it is self-evidently impossible to evolve by gradual degrees because the intermediate stages would all explode. I enjoyed demonstrating the error of this argument during my Royal Institution Christmas Lectures for Children, shown on BBC television in 1991. Donning a Second World War helmet, and inviting nervous members of the audience to leave, I mixed hydroquinone and hydrogen peroxide, the two ingredients of the bombardier explosion Nothing happened. It didn’t even get warm. The explosion requires a catalyst. I raised the concentration of catalyst gradually, which steadily increased the hot whoosh to a satisfactory climax. In nature, the beetle provides the catalyst, and would have had no difficult in gradually, and safely, increasing the dose over evolutionary time.
What do you think of Dawkins’s disproof of the anti-Darwinians’ argument that the Bombardier beetle’s explosive device could not have evolved by gradual, Darwinian processes of minute random mutations and natural selection? Do you think his demonstration and reasoning are persuasive, and, if so, why? Do you think his demonstration and reasoning are not persuasive, and, if so, why?
Please mail your answer to me here, putting “Darwinian quiz” in the subject line.
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Terry Morris writes:
It’s not persuasive because Dawkins is working in a controlled environment seeking a known, or a desired result. In other words, Dawkins’s successful experiment did not happen by chance occurrences and random mutations. It required intelligence and design; knowledge and purpose.
Mark P. writes:
So how does natural selection through random mutation know when to mutate and add a catalyst at just the right mixture of hydroquinone and hydrogen peroxide to result in an explosion? The matter simply shifts away from the potentially lethal experimentation of two chemicals to the certainly lethal experimentation of three chemicals.
Alan M. writes:
The key flaw in his argument in my opinion is that, by his own model, there would have to be an evolutionary benefit in the “pre-explosive” quantity of catalyst. Not only the absolute amount but in the increasing amount of it. Otherwise, through random genetic mutation, the amount of catalyst would be a random walk rather than an increasing amount.
Another flaw is assuming a designer who somehow continually experiments with more and more catalyst until there is enough for an explosion.
In his experiment, again, he ignores the designer of the experiment.
Finally, his explanation is only a story with no proof that it could have happened that way.
Dan McCulloch writes:
Not persuasive. Dawkins seems to think that creationists are arguing that the rapidity of combustion proves this process couldn’t have developed gradually, when they are saying (I hope), that without purposeful direction the combustion of chemicals as a defense mechanism can neither be effective, controlled in any way, nor reproduced. But most of all it certainly can’t be anticipated or desired as a defensive end, because there’s no one there that wants it. Since there’s no intelligence there that desires a flame-thrower for defense, there’s also no one there who knows that getting blown up by his own juices is a great start to producing one, and ought to be reproduced a billion more times until it gets perfected, as opposed to something simpler, like excretion of a mere bio-hazard chemical.
Mark K. writes:
Problem #1: What exactly are the stages of this evolution and how does Darwinism explain them step by step in detail? In other words Dawkins describes the phenomenon of the beetle’s weapon and demonstrates its usage but NEVER himself invokes Darwinism to explain the actual evolutionary pathway that these components came to be assimilated into the beetle’s biological structure (organs).
Problem #2: Even if the two components mixed together do not explode, how did the beetle develop the appropriate catalyst in his gland to engender the precisely needed chemical reaction? Chemical reactions are based on accurate proportions of chemicals through catalysts. How did the beetle’s internal organs determine the right catalyst for a proportionate mixing of the other two chemicals?
Problem #3: Dawkins claims that the beetle “would have had no difficult in gradually, and safely, increasing the dose over evolutionary time.” How long is this evolutionary time because during any lengthy development of the appropriate dosage, the beetle could have been ravaged by his enemies and gone extinct.
Problem #4: An incoherent mixture of chemicals in any body can result in biological damage. The three components carried by the beetle do not result in any internal damage to the beetle’s organs. What statistically are the odds that the beetle was able to develop, through random processes, this precise relationship of chemical reactants, harmful to others but not itself? This betrays a self-awareness of the beetle, a consciousness of internal cohesion of chemical relations!
Problem #5: In what year did the first beetle to achieve this magnificent defense mechanism hold a seminar to instruct others of its kind to learn about and adopt this mechanism? Dawkins doesn’t say so we don’t even get a historical overview of this development.
Jon W. writes:
My top of head reaction from my admitted profound biological/chemical ignorance (which you will likely confirm) is this: I believe there is a concept called teleology which, stating it as crudely my knowledge of it, goes something like this. Teleology is the concept that a natural process is goal directed, i.e., its progression of changes in state are moving toward a goal—implying there is a design and a designer.
Here we have the independent development (uh, “evolution”) of the three exact required chemicals, the combination of them in exact right proportions over time, the mixing of them in a suitable chamber, the development of a well formed gun that can be fired in the appropriate direction, all this just exactly in time to keep the beetle’s natural predators at bay. The chemicals are probably toxic to the creature and held within well suited chambers. Quite a lot going on here with all of it just resulting from random operations over time, I’d say. Bunk!
Also, in demonstrating the need for the catalyst the Darwinians exponentially increase the implausibility of their argument. Dawkins’s argument, in effect, was merely one of shouting louder with no addition of credible evidence for his refutation argument.
Dawkins fails to refute the creationist by adding a third “bug juice” component to be evolved at the right time in the right place. (I’m not sure, but seem to recall that catalysts are analogous to keys for locks.) Forget the improbability of concurrently evolving with the chemicals the unique anatomical components, the gun and chemical storage chambers. Forget the vanishingly small individual probabilities of evolving any one of the three requisite chemicals or its organic or inorganic precursors. Forget the vanishingly small probability the three required chemicals (especially the chemical “key,” the catalyst) would ever come together anywhere by accident. The demand is overwhelming; temperature, place, timing, raw materials, concentrations, and proportions have to be “just right.”
Paul K. writes:
It seems obvious to me that there can be no explanation for what it would profit the bombardier beetle to evolve this faculty when it serves absolutely no purpose until all elements are in place. It would be like someone building a television before electricity was harnessed.
I recently listened to Bill Bryson’s “A Short History of Nearly Everything” on CD. He discusses some of the challenges to evolutionary theory and addresses them. He began with the observation that for life to have evolved randomly is akin to a cake being baked by the random interaction of the contents of a kitchen; and not merely a cake, but a cake that reproduces itself. But, he explains, this is in fact what happened.
With this image in mind, I could not join hands with him and make the leap of faith to Darwinian theory.
Robert C. writes:
I think Dawkins’s defense falls short. He appears to assert too much from his example. That is, because he can demonstrate an example of a gradual change that, eventually, causes a reaction, the validity of the theory of gradualism is also true, not just that Behe’s example can conceivable occur once—but by purpose directed action. I don’t think Behe would deny that by gradual changes, you could eventually reach a point where changes will cause a functional change. Even water freezes suddenly at 32f. Only that all change up to that point are useless. Also, Dawkins himself did not rely upon an actual example of gradualism and chance to reach that point of functional change. he used an intelligent and purposeful action, an observation not missed by Behe.
Also, if ongoing gradual change is really the nature of things, why did the process then abruptly stop, right at the point of the mixture reacting, instead of continuing to evolve. (Obviously a reproductive advantage if all evolutionary change is abruptly stopped at precisely that point.) But if gradualism is true, there should be evidence a well of proto or post models that fell short or went too far. He did not offer almost blaster beetles I’ll bet, which should also be found in nature’s record if gradualism is accurate. One may by chance reach a point where all of the tumblers in a safe line up so that one can open the safe. The wonder is that nature has stopped just there and decided to stop and returned to the already acknowledged realm of variety within a species, such as the example (Cited by Darwin I think) of birds changing color to their surroundings.
To me, the maddening argument of the materialists—but outside of your example and confirmed by a black robed tyrant sitting on a federal district court in Pennsylvania—is that the mere assertion of an alternative hypothesis is religious and therefore not an allowable hypothesis at all.
Paul T. writes:
I don’t know much about this, but if it’s difficult to accept that precisely the two chemical components required for the explosion evolved by chance in the same organism and in just the right way, surely it’s even more difficult to accept that just the right chemical catalyst also evolved with them? Instead of removing the difficulty, Dawkins seems to have increased it.
Right—instead of two chemicals to account for, he has to account for three!
Paul T. replies:
Gosh, what do I have to do to become an intellectual leader like Richard Dawkins?:)
Eric H. writes:
This passage is NOT persuasive.
Dr. Dawkins falsely assumes only “creationists” doubt Darwinism.
He states the non-Darwinian critique in the case of the bombardier beetle as “[I]t is self-evidently impossible to evolve by gradual degrees because the intermediate stages would all explode.” First of all, the onus probandi is on him, the one proposing a scientific account of phenomena, not on the skeptics who point out that he has not accounted for the phenomena. We do not need to prove that it is “self-evidently impossible”; he has to provide plausible accounts of how it could have happened, responses to our objections, and some evidence that it actually did happen.
Second of all, he misstates the critique. Darwinism says that some minute random mutations provide a benefit to the organism. Sometimes that benefit is useful enough for natural selection to increase that organism’s reproductive success. The non-Darwinian critique is nothing so simple-minded as, “the intermediate stages would all explode.” The critique is that each one of the changes leading to this complex system must have been of such benefit that each one spread by natural selection through the population of hypothetical pre-bombardier beetles.
He helpfully points out an additional element of complexity, the catalyst, weakening the Darwinian position still further. The hypothetical pre-bombardier beetles must now evolve at least the following complex structures:
1) organs for making hydroquinone
2) organs for making hydrogen peroxide
3) organs for making the catalyst
4, 5, (6) organs for storing the above
7, 8, (9) organs for delivering them simultaneously to the explosion chamber
10) the explosion chamber
11) the aiming nozzle
12) the instincts to spin round, point its rear end at an enemy, and fire an explosion
A Darwinian account of the evolution of the bombardier beetle from hypothetical pre-bombardier beetles must sketch a path in which every one of these complex structures is produced by minute random mutations, every step of which provides a reproductive advantage to its possessor. It is not evident what benefit any of these structures provides its possessor until all twelve are in place and functioning together.
Dawkins’s final line, “the beetle … would have had no difficulty in gradually, and safely, increasing the dose over evolutionary time,” assumes a proto-bombardier beetle in which all the innovations above have already been evolved and function together, but do not function at their maximum possible efficiency. His “demonstration” only even attempts to demonstrate the possibility of an Darwinian path from the hypothetical proto-bombardier beetle which sprays some kind of hypothetical tepid and mildly irritating liquid to the actually existing bombardier beetle which sprays “caustic and boiling-hot” liquid. This is a response to the supposed creationist objection “the intermediate stages would all explode,” but has nothing whatsoever to do with the real critique, which points out the absence of a Darwinian path between the hypothetical pre-bombardier beetles and his hypothetical proto-bombardier beetle. He is begging the question.
Dawkins insults his critics, distorts, misstates and misunderstands their objections, knocks down a straw man, and assumes his conclusions. The burden of proof rests on him, the proponent of an all-encompassing theory, not on me, the skeptic. I remain unconvinced.
Peter B. writes:
I believe in Darwinian evolution, but even to me this explanation appears wrong, or at the very least woefully incomplete.
What he has failed to explain is where the advantage in the intermediate stages are and what the starting point could have been. If the hydrogen peroxide and hydroquinone were produced for defence purposes on their own (they are caustic after all) then it’s possible a mutation to produce some form of catalyst would provide incremental advantage but it’s really difficult to say without more evidence. As Dawkins himself has explained each successive mutation has to have comparative advantage. Would a slightly warm fluid be more advantageous than one at beetle body-temperature? If not the mutation would not be successively more common in each successive generation. There is no target end-point for the process—mutations are not selected for because they might come in handy later.
Whilst I used to admire Dawkins, his extreme anti-religious stance and his apparent inability simply to state “We don’t know” about something (when that simple phrase ought to be the starting point of all really interesting science) has discredited him in my eyes.
Laura W. writes:
Dawkins does not explain in your account what purpose the hydroquinone and hydrogen peroxide served before the catalyst was added.
What a fantastic Christmas lecture for kids! Reminds me of Dawkins publicized letter to his daughter. He told her she must never trust three things: authority, tradition and revelation. She must prove absolutely everything anyone told her by experiment and independent verification. (Logically, she couldn’t take anything even on the authority of a scientific Dad though he doesn’t mention that. Poor tyke, she would have to prove by experiment that you can take anything except by experiment!) She must be exhausted by now. I wonder if she ever got past Newton’s Law of Gravity.
Steven Warshawsky writes:
Not persuasive in the least. I am no scholar of Darwinian evolution, but it seems to me that folks like Dawkins like to come up with explanations for how different life forms could “gradually” evolve without demonstrating how each step in this alleged process provides the life form with an evolutionary advantage. As I understand it, Darwinian evolution is based on the fundamental idea of fitness, that is, life forms that are able to reproduce and survive in greater numbers than others “win” the evolutionary struggle and evolve over time. But in this case, how would the allegedly gradual development of the bombardier beetle’s defense mechanism provide any evolutionary advantages until it was fully formed? Dawkins’ “explanation” offers no reason to believe it would. Hence, the alleged evolutionary process, as I understand it, never would have taken place.
Alan Roebuck writes:
The most obvious response is that having non-explosive chemicals in its body would confer absolutely no “evolutionary advantage” on the beetle possessing them. In other words, having the non-explosive chemicals would not be any sort of defensive weapon, in which case there would be no reason for the Darwinian process of natural selection to select the many intermediate stages required for the whole defensive system to “come online.” In fact, the intermediate, non-functional stages would be a disadvantage, as the beetles possessing them would be squandering precious resources of energy and body tissue on a worthless set of organs.
There is only one Darwinian rejoinder that I can think of: The intermediate stages somehow conferred an advantage, even though we cannot say what it might have been. In other words (and this is the Darwinists’ basic position), if we know a priori that an Intelligent Agent could not have been responsible, even a conjectured naturalistic explanation for which no confirming evidence exists is always to be preferred. Once again, it all comes down to presuppositions.
I thank readers for contributing their thoughts on this. Many points have been made that had not occurred to me. My own main criticism of Dawkins’s argument, prior to reading everyone else’s (which have influenced my thinking), was as follows:
Dawkins thought that he had hit the bullseye when he revealed to his audience—a national television audience—that the two chemicals do not explode in the absense of a catalyst. Whicn means that he thinks the entire anti-Darwinian argument comes down to the idea that the two chemicals would combine and explode, thus killing the beetle, before the ability to target the explosion at an enemy had evolved. Therefore he thought that the need for the catalyst sufficiently refuted the anti-Darwinian objection. But as commenters have pointed out, the main problem is not a pre-mature explosion killing the beetle, the main problem is how the entire multi-part apparatus got put together at all.
Also, what Dawkins’ doesn’t realize is that the need for the catalyst, far from making the Darwinian evolution of the explosive device plausible, makes it more complicated and harder to explain.
However, the most interesting thing to me about Dawkin’s explanation is not that it is inadequate, but how obviously inadequate it is, and, further, that Dawkins smugly believes that this obviously inadequate answer wipes the floor with the anti-Darwinists:
“The case is well known to creationists, who love it. They think it is self-evidently impossible to evolve by gradual degrees because the intermediate stages would all explode. I enjoyed demonstrating the error of this argument during my Royal Institution Christmas Lectures for Children shown on BBC television in 1991.”
It is Dawkins’s sense of his complete superiority over the other side, combined with the fact that his argument is in reality embarrassingly weak, that reinforces the impression of the Darwinian orthodoxy as a Wizard of Oz, creating a show in which he puffs himself up to gigantic and terrifying proportions, intimidating all who would dare approach, when the reality is a little man behind a curtain pulling levers.
Over and over, I have seen the Darwinian using two types of arguments:
(a) The argument from authority: We Darwinians are simply right and our critics are simply idiots.
(b) Some vague abstract explanation that does not at all answer the challenge to Darwinism, but the Darwinists act as though it does answer all challenges.
However, I just came upon an article at the TalkOrigins website that presents a 15-step scenario by which the author says that the Bombardier beetle could have evolved. I haven’t had time to take it in yet, but I will do later later and discuss it. This should be interesting. I hope it’s better than a supposed refutation of Michael Behe’s bacterium flagellum argument I read recently, in which the author said in essence, “Well, part X of the bacterium flagellum could earlier have had some other useful function Y, and therefore it was selected, and this explains how intermediate Darwinian mutations led step by step to the functioning 30-part bacterium flagellum! I have just refuted that idiot Behe who might as well be a dog catcher.” The author (like Dawkins above) evidently thought his argument was not only persuasive but definitive.
Sage McLaughlin writes:
I almost didn’t participate in your “quiz.” I’m not a scientist nor, for that matter, any good at science. But since what Dawkins proposes here isn’t science so much as pure speculation in search of some narrative that will account for the data, I’ve humbly concluded that I’m qualified to offer a critical appraisal of his reasoning. I’ve studied international relations theory in some detail, and I can tell you that this there’s nothing in it any less empirically based than the theory of macro-evolution—in fact, Kenneth Waltz’s Theory of International Relations is more parsimonious and clearly reasoned than anything I’ve ever read from uber-evolutionists like Richard Dawkins and John Derbyshire. So here are my admittedly amateur doodlings:
I don’t find his demonstration, nor do I find his use of it as some kind of analogy, especially persuasive. The problem I find with his account is that it seems—as is so often the case with advocates of his stripe—to depend on a kind of teleology that his own theory rejects. To be clear—his point is that by random mutations over many generations, the beetle could “gradually and safely” increase the dosage of the catalyst in order that some explosion could be directed at its adversaries. Well, I don’t see a problem with that if there is some reason that an increase in the catalyst over time—to say nothing of the chambering of two volatile chemicals in separate glands—should be selected for in the first place.
What advantage does an increase in the catalyst give at any intermediate stage that would make its beneficiary more likely to survive the rigors of the environment? It seems that the explosion is a pass/fail kind of thing. It’s absolutely useless until the moment it produces the desired effect. Too little of the catalyst, and you’re standing in a pool of hot fluid. Too much, too soon, or in the wrong anatomical location, and you’re blown apart by it. So again, how is it an advantage, let alone one that will be selected for over thousands of generations, to slowly increase the dosage of catalyst unless it is precisely in order that an explosion can safely and usefully be achieved? If that’s true, then the genetic proliferation of the mutation isn’t, strictly speaking, either random or purposeless—which is the whole point, after all.
Why should the active chemicals be stored separately within the beetle’s body, ever? Why would natural selection drive such a useless and potentially harmful process? What competitive advantage is produced by adding the catalyst? After all, if there’s no competitive advantage, it’s presumably not going to be selected for by the environment. It seems to me that Dawkins is making the claim that the beetle could safely increase the dose of the catalyst over time, and that that process could be driven by natural selection, even though there is absolutely no advantage to the current generation—only to some future generation who will receive the competitive benefits of the “finished product.”
Now, I haven’t done a lot of noodling on the question of evolution, so I’m sure there something I’m missing here, some answer that Dawkins might have at the ready. But this is the problem that a moment’s consideration presented to me, and I haven’t been able to work out a solution in Dawkins’ favor. I’m trying, but I can’t. Maybe you can tell me, since surely this objection has been anticipated.
Mr. McLaughlin continues:
Dawkins did a terrific job demonstrating how a designer who knows the certain outcome of mixing certain chemicals together can gradually produce a desired chemical reaction. He failed to demonstrate how those chemicals would have done so had he instructed everyone to walk out of the room with him and wait for it to happen on its own.
Posted by Lawrence Auster at February 08, 2008 09:32 PM | Send