Monday, 6 April 2015

The Christadelphian magazine and evolution. Part 2 - Robert Talbot

The second attack by The Christadelphian on evolutionary biology that focuses primarily on the science comes from Robert Talbot, a retired scientist from industry whose professional background, given his references to having worked in peroxide chemistry, would appear to be in chemistry or biochemistry. As with too many Christadelphian anti-evolutionists, his defence of special creation is based on the special creationist staple of the argument from personal incredulity, as well as misrepresentation of the basics of scientific epistemology, and allegations that the theory of evolution has been promoted fraudulently.

Underlying this, as with the attack by science educator Allan Harrison, is a failure to differentiate between evolution as fact and evolution as theory, and a conflation of evolution and abiogenesis. Furthermore, there is the implicit appeal to personal authority as a scientist, one which carries no weight given that scientific truth is not determined by mere appeal to authority. Given that the overwhelming majority of life scientists who have examined the evidence agree that it supports an evolutionary reading of natural history, one is entitled to ask why Talbot’s minority opinion should be given credence.

“How Little We Know” does not translate to a defence of special creation

Talbot begins his article with a brief autobiographical sketch, followed by the entirely appropriate comment that what we do not know still dwarfs what we do know. No scientist would deny this, particularly given that in science, there is no such thing as received truth, with all conclusions being subject to revision in the light of further evidence. Where Talbot makes his first major errors is to claim that
How, then, can scientists be dogmatic about our origins when they were not there to see it happen?
Here Talbot neglects to properly define evolution, fails to properly define basic scientific epistemology, and echoes YEC Ken Ham's "were you there?" attack on "historical science". The latter is particularly egregious given that it would rule out forensic pathology, history, astronomy, archaeology, and other scientific disciplines which have a historical component. This substantially undermines the credibility of Tablot's article.

I've stressed many times that one of the fundamental errors made by evolution denialists is their apparent misunderstanding over what mainstream science means by evolution. Evolution is used by scientists to refer to the fact of common descent and large-scale evolutionary change, the theory of evolution, that is, the theoretical explanation for how evolution occurred, and - given its historical element - the historical details of natural history such as the date, timing, and details of speciation and extinction.

That evolution has occurred is no longer in doubt, and Talbot is wrong to imply otherwise. Evolutionary biologist T.R. Gregory notes that:
Over the past 150 years, this initial list [of evidence Darwin compiled] has been supplemented by countless observations in paleontology, comparative anatomy, developmental biology, molecular biology, and (most recently) comparative genomics, and through direct observations of evolutionary change in both natural and experimental populations. Each of thousands of peer-reviewed articles published every year in scientific journals provides further confirmation (though, as Futuyma notes, “no biologist today would think of publishing a paper on ‘new evidence for evolution’ ... it simply hasn’t been an issue in scientific circles for more than a century”). Conversely, no reliable observation has ever been found to contradict the general notion of common descent. It should come as no surprise, then, that the scientific community at large has accepted evolutionary descent as a historical reality since Darwin’s time and considers it among the most reliably established and fundamentally important facts in all of science. [1]
While the fact of evolution is not doubted by credible, mainstream scientists, the theoretical explanation for how evolution occurred remains an active area of research and debate. Darwin's proposed mechanism of natural selection fell out of favour due in no small part to the lack of a robust theory of inheritance, and only with the forging of the modern synthetic theory did natural selection return to favour. During this "Eclipse of Darwin", alternative theories such as orthogenesis, mutationism, and neo-Lamarckianism held sway. It needs to be emphasised again that what was in doubt was Darwin's theory of evolution, not the fact of evolution, and as Darwin pointed out in The Descent of Man:
Some of those who admit the principle of evolution, but reject natural selection, seem to forget, when criticising my book, that I had the above two objects in view; hence if I have erred in giving to natural selection great power, which I am very far from admitting, or in having exaggerated its power, which is in itself probable, I have at least, as I hope, done good service in aiding to overthrow the dogma of separate creations. [2]
Scientists, contrary to Talbot's assertion do not dogmatise about evolution, a point that the National Academy of Sciences of the USA emphasises:
Scientific explanations are tentative. Explanations can and do change. There are no scientific truths in an absolute sense. [3]
Having said that, scientific theories are not wild guesses, hunches, or speculations. Considerable misunderstanding has been created by the failure to appreciate that a scientific theory is something with far more support than the popular concept of a theory:
As with all scientific knowledge, a theory can be refined or even replaced by an alternative theory in light of new and compelling evidence... However, ideas are not referred to as "theories" in science unless they are supported by bodies of evidence that make their subsequent abandonment very unlikely. When a theory is supported by as much evidence as evolution, it is held with a very high degree of confidence. [4]
Again, it is critical to stress that we are referring to evolution as a theory. The fact that all life shares common ancestry and that there had been large-scale evolutionary change in the fossil record is not in doubt as it can be readily demonstrated via comparative genomics, the biogeographic distribution of species and the fossil record, to name just three lines of evidence.

As for the ultimate question of origins, namely abiogenesis, it is critical once again to point out that abiogenesis and evolution are related but ultimately separate disciplines. Talbot greatly weakens his case by neglecting to point out that while mainstream scientists rightly regard common descent as something no longer in doubt, they recognise that abiogenesis is still yet to achieve the rigour of a theory. Biochemist Larry Moran pithily notes that "[w]e don't know how life began" and regards the primordial soup argument as "one of the more fanciful hypotheses" [5] while evolutionary biologist Eugene Koonin notes that "we still do not have even a plausible coherent model, let alone a validated scenario, for the emergence of life on Earth." [6] Talbot's claim that scientists are "dogmatic about origins" is difficult at best to reconcile with what those with a professional interest in abiogenesis actually say.

Having said that, the fact that there is no universally-accepted theory of abiogenesis does not impact on the reality of common descent, any more than the inability of general relativity to explain gravity at the quantum level means gravitational phenomena such as planetary motion, gravitational red shift, and gravitational lensing suddenly cease to exist. We don't yet know how life began from prebiotic precursors, but we have overwhelming evidence for the reality of common descent, and a theory of evolution that has been remarkably effective in its explanatory and predictive power.

Talbot's assertion that we cannot be dogmatic about origins because we weren't there unfortunately shows the malign influence of YEC organisations such as Answers in Genesis, whose leader Ken Ham makes a point of indoctrinating young children to mindlessly blurt out "were you there" in response to any mainstream scientific statements about natural history. [7]

The problem with the "were you there" retort is that one can easily use it to dismiss forensic pathology, archaeology, history, or any discipline which examines the evidence in order to make inferences about the past. Fundamentally, the "were you there?" claim is based on the bogus YEC attempt to divide science into 'historical' and 'observational', a distinction which does not exist in mainstream science. The National Center for Science Education points out:
The problem with these attempts to divide science neatly into two piles is that, as Sober observes, a given science, and even a given scientist, can switch between approaches in the quest to address a single question. Geologists can plumb the oldest rocks on earth for evidence of the first life, but they can also go to the lab and recreate the conditions of early earth to test predictions of hypothesis about events billions of years ago. And those results from a modern laboratory will send researchers back to the field to test predictions about historical events generated in the laboratory. 
Similarly, physicists at the Large Hadron Collider in Switzerland are testing theories about the origin of the universe
At the earliest moments of the Big Bang, the Universe consisted of a searingly hot soup of fundamental particles - quarks, leptons and the force carriers. As the Universe cooled to 1000 billion degrees, the quarks and gluons (carriers of the strong force) combined into composite particles like protons and neutrons. The LHC will collide lead nuclei so that they release their constituent quarks in a fleeting 'Little Bang'. This will take us back to the time before these particles formed, re-creating the conditions early in the evolution of the universe, when quarks and gluons were free to mix without combining. The debris detected will provide important information about this very early state of matter. - Science and Technology Facilities Council (2008) "The Big Questions" page on "The Large Hadron Collider" website. Accessed September 18, 2008. 
Which category of science does this belong to? Clearly, it is both historical science and experimental science. Other such historical claims can be evaluated using modern experiments. Another example of this approach can be found in the episode of Mythbusters in which claims about the destruction of the Hindenburg are tested using modern models of the combustible zeppelin. If a television show can accurately navigate these philosophical waters, it is entirely appropriate to expect a textbook to handle them responsibly as well. [8]
Special creation is not science, but special creationist claims have been refuted by science

Talbot's ignorance of the fundamentals of scientific epistemology - a damning fact for a man with a background as a scientist - is further highlighted by this comment in which he complains about science's dismissal of creation:
Remarkably, creation is usually discounted on the assumption that only science has all the answers.
There is nothing remarkable about it. Science to a first approximation is the search for natural explanations for natural phenomena. As there is no way to test for the supernatural, science can say nothing about its existence. The moment one allows the supernatural as an explanation, then science ceases, and with that, any chance of being able to understand how our world works. For example, if we declared that a sudden outbreak of cholera was caused by God's wrath, then any further attempt to stop cholera outbreaks ceases. However, if one traces where people who suffered cholera were shortly before they became ill, find that they all used water from a contaminated well, hypothesise that drinking the well water caused the disease outbreak, then we can test that hypothesis by closing down the well and sourcing drinking water from elsewhere. Postulating divine intervention or special creation does nothing to tell us how things work, or how things began. It is the ultimate science stopper, which is why science discounts special creation as an explanation.

However, it is possible to use science to test the claims made by special creationists, and here science has comprehensively falsified these claims. Talbot asserts:
How can we be so sure that there is no being in the Universe that is  capable of designing and creating  living creatures within the six-day  framework described in the Bible?
His first comment goes beyond science which is silent on the existence of the supernatural. However, it is more than capable of testing the special creationist claim that all life was created six thousand years ago within a six day period, and what it has found runs counter to Talbot's claims:
  •  The age of the Earth is around 4.6 billion years. [9]
  • The first single-celled life appeared 3.45 billion years ago. [10]
  • Metazoan (animal) life first appeared around 665 million years ago. [11]
  • Fish first appeared around 525 million years ago [12]
  • Tetrapods first appeared at least 360 million years ago [13]
  • Birds first appeared at least 85 million years ago. [14]
  • Mammals first appeared at least 164 million years ago[15]
  • Humans first appeared [16]
The special creationist claim that life was created recently in a six thousand year period has been comprehensively falsified. Furthermore, the idea that all life has been created separately, and does not share common ancestry likewise has been falsified, given the considerable evidence for common descent from areas as disparate as palaeontology and comparative genomics. [17]

Talbot's attempt to bolster the standing of special creation as a valid explanation for the origin of the diversity of life crashes into logical fallacy when he declares, after a thumbnail sketch of what we are able to perform in the field of molecular biology declares:
If man can do these things, is it not logical to consider the Bible creation account as a serious possibility? If man can do these things, is it not logical to consider the Bible creation account as a  serious possibility?
It does not logically follow that if humans can manipulate the genome, then special creation is a fact. No one denies that an infinite deity is capable of speciality creating all life instantaneously. However, the question is not whether God could have done that, but whether he did, and a careful examination of all the evidence comprehensively rules out recent special creation.

Misunderstanding basic scientific epistemology - proof is for mathematics, not science

Talbot's next remark manages to compress four major errors into a single sentence:
As a scientist, I am not aware of any scientific evidence that proves the theory of evolution.
He commits the argument from authority by appealing to his status as a scientist. That is irrelevant. The truth or falsity of evolution is not determined by his opinion, and invoking his status as a scientist, particularly given that it is a minority opinion, is irrelevant. He ignores the fact that scientific theories are not proved. A theory can be falsified, but no matter how well attested it is, it is never proved true. Proof is only for theorems in mathematics. Finally, he fails to properly define what he means by evolution. Is he referring to common descent (evolution as fact) or he modern synthetic theory of evolution? Finally, he is betraying a profound ignorance of the fact that common descent is one of the best-attested facts in science. As evolutionary biologist T.R. Gregory points out:
Conversely, no reliable observation has ever been found to contradict the general notion of common descent. It should come as no surprise, then, that the scientific community at large has accepted evolutionary descent as a historical reality since Darwin’s time and considers it among the most reliably established and fundamentally important facts in all of science. [18]
No, it's not a case of differing presuppositions. The evidence does support evolution

Talbot's following remarks unfortunately betray more evidence of special creationist distortion of basic scientific epistemology:
In this context, we need to be clear what constitutes ‘evidence’. Frequently, I hear scientists confusing ‘evidence’ with ‘the interpretation of evidence’.
The 'differing presupposition' argument is one that is commonly invoked by YEC extremist groups such as Answers in Genesis. Ignoring the fact that the YECs are not viewing the evidence through a Biblical worldview, but rather a view championed by Seventh Day Adventist pioneer Ellen G. White, Talbot again illegitimately smuggles in a supernatural explanation into an area where it simply does not belong, given that science is the search for natural explanations for natural events. Furthermore, given that as we've already seen, the features of the natural world that we would expect if the early chapters of Genesis were a scientifically accurate account of origins are simply not present, any attempt to justify a special creationist reading of the evidence has already been ruled out. The only way that such a reading can be justified is by starting with an assumption, and forcing the evidence to fit the mould.

Talbot's attempt to justify the 'same evidence, different interpretation' argument betrays a considerable lack of understanding of the subject about which he speaks:
For instance, you can always point towards the evidence of physical similarities between, e.g., monkeys and mankind, and we cannot (and would not want to) deny that. However, this similarity is capable of more than one interpretation. One interpretation is that mankind descended from monkeys; another is that both mankind and monkeys were created by the same Creator. The fact that we share certain DNA sequences could logically mean that the Creator used the same code because it is a successful sequence that works.
There is of course the egregious blunder about 'descending from monkeys' which is nonsense. Humans, apes, and monkeys share a common ancestor. We did not evolve from contemporary monkey species. Remarks such as this simply reinforce Talbot's utter unfamiliarity with paleoanthropology, and show why his attack on evolution is not worth taking seriously.

If common descent was true, then we would expect to see all life naturally fall into a nested hierarchy. Descent with modification is the only known process that will generate a nested hierarchy, which means that the taxonomic classification system is not an arbitrary means of classifying animals, but also one that allows us to make predictions. We would expect every new species discovered to fit into the existing evolutionary classification tree. Conversely, we would never expect to see birds that lactate, or mammals with feathers, even though these would definitely provide an advantage.

God could have readily designed creatures in such a way that they would not be able to be classified in a nested hierarchy, and that would have neatly falsified common descent. Instead, special creationists have to postulate common design as an ad hoc explanation for the evidence which is far more readily explained by common descent. 

Common design particularly fails when we consider the examples of flawed design shared by animals that fall into a monophyletic group, that is, one which shares a common ancestor. The concept of descent with modification means that we would expect to see sub-optimal anatomical features in members of a group that have a common ancestor. We see this with vertebrates with the inverted retina, a suboptimal design which results in a blind spot, increases the risk of retinal detachment, and leads to visual impairment from retinopathy and haemorrhage, given that the blood vessels are between the source of light and the light sensors. We also see this with the tetrapod recurrent laryngeal nerve, which bypasses the larynx, makes a pointless detour down into the chest, then back up the neck to innervate the larynx. In the giraffe, this results in several metres of wasted nerve:

Common design fails here as it means that an intelligent designer not only has created a demonstrably flawed design, but done this repeatedly, and done so exclusively in a way that would be expected if that original suboptimal design first occurred in an ancestor of that monophyletic group.

The power of this argument becomes even more apparent when we look at the genomic level. Conversely, this is where Talbot's argument falls apart. I've commented on this point extensively, so there is no need to re-invent the wheel, but once again:

  • The redundancy in the genetic code means that for even a protein around 100 amino acids long, there are around 5x10^47 possible ways to code for the exact same protein. Given that this redundancy means neutral mutations can accumulate without changing the amino acid sequence, we'd expect that animals sharing a recent common ancestor would differ by fewer mutations than those with remote common ancestors. Conversely, there is no reason under a model of special creation for this to be true. What we see when we examine the genomes of organisms is what common descent would predict, Furthermore, the evolutionary family trees constructed from molecular data are consonant with those from morphological data.
  • Humans and apes share many identical genetic 'errors' such as broken genes (pseudogenes), retrotransposons, endogenous retroviral elements, mitochondrial DNA elements in nuclear DNA, ectopic telomeric DNA, and scars of DNA repair at the same places in their genomes. This is exactly what we'd expect from common descent - the inheritance in a common ancestor of a genetic 'error'. There is no credible special creationist explanation, unless the creator was deliberately creating animals with genomes in such a way as to exactly simulate common descent.
Talbot makes another classic creationist error by his conflation of abiogenesis and evolutionary biology when he launches into a discussion on the chemistry of life. 
One of the most significant problems with the current theory of evolution is that it cannot explain how some of the essential mechanisms in cellular chemistry came about.
Abiogenesis is not evolution. Common descent is true irrespective of the status of abiogenesis

The origin of life is a separate question from the fact of common descent. Irrespective of whether the original cell was specially created, or the product of abiogenesis, the reality of common descent stands independent of the question of abiogenesis. As I mentioned earlier, biologists freely acknowledge that the origin of life is a major unsolved problem, with no universally accepted theory and a number of competing hypotheses. However, as cell biologist Kenneth Miller notes, the basic theory of evolution is anything but a 'theory in crisis':
I don't think there are basic “gaps” in the theory of evolution, which has proven to be a remarkably flexible scientific framework, brilliantly accommodating new data and even new fields of science, like molecular genetics. However, the most profound unsolved problem in biology is the origin of life itself. We know a great deal about the creative chemistry of the early Earth, but not yet enough to solve this problem. [19]
Miller's careful differentiation of evolution and abiogenesis (note his reference to the most profound unsolved problem in biology, as opposed to evolution) makes clear what Talbot completely failed to do, point out that abiogenesis and the fact of evolution are two separate areas, and problems in the former do not invalidate the considerable evidence demonstrating the reality of the latter.

The other fundamental problem with his excursion into molecular biology is that his argument at heart is an argument from personal incredulity, and an invocation of the 'God of the gaps' explanation:
As with the enzyme situation, which came first: the generation  of electricity or the mechanisms which used the electricity? Surely,  it makes most sense to realise that  both (complex) mechanisms were designed by the same Creator at the same time!
Ignoring the fact that he makes the mistake of thinking that origin of life researchers believe that the earliest cell would have resembled even the simplest cell today, Talbot's inability as a retired scientist working outside of the highly technical area of origin of life research to imagine how enzymatic pathways evolved does not mean that the problem is forever insoluble to science. Talbot blithely asserted earlier, in his facile dismissal of evolution that  
History amply demonstrates that science has a bad record with theories and explanations of evidence; interpretations are frequently overturned in subsequent years.
Talbot's facile argument [20] can be readily turned on him. Special creationists who declare that a structure or organ or mutualism is too complex to have evolved have had those claims repeatedly debunked. For example, the claims of special creationists  that the evolution of snake fangs was a insoluble problem for evolution were neatly debunked by Vonk et al in a 2008 Nature paper:
In light of our findings, we put forward a new model for the evolution of snake fangs: a posterior subregion of the tooth-forming epithelium became developmentally uncoupled from the remaining dentition, which allowed the posterior teeth to evolve independently and in close association with the venom gland, becoming highly modified in different lineages. [21]
Similar examples of dogmatic special creationist assertions being overturned by scientific developments are trivial to find. With respect to his claims about the biochemistry of life, the current rate of scientific research into the problem alone should send a loud warning to Talbot about the wisdom of confidently declaring a problem insoluble for science.  For example. Lincoln and Joyce recently described the self-sustained replication of an RNA enzyme:
A long-standing research goal has been to devise a nonbiological system that undergoes replication in a self-sustained manner, brought about by enzymatic machinery that is part of the system being replicated. One way to realize this goal, inspired by the notion of primitive RNA-based life, would be for an RNA enzyme to catalyze the replication of RNA molecules, including the RNA enzyme itself. This has now been achieved in a cross-catalytic system involving two RNA enzymes that catalyze each other's synthesis from a total of four component substrates. [22]
Likewise, Kamioka et al describe the creation of a structure capable of both replicating itself, and catalysing chemical reactions. This is significant for origin of life research, not only because they provide a starting point for creating complex molecules, but because these synthetic replicators have the possibility of mutation. [23] This is not to say that the origin of life will be solved any time soon, or that any one of the current hypotheses (metabolism first, RNA world) will indeed be the basis of a robust theory of abiogenesis. Rather, it serves as a warning not to pontificate in areas well outside of professional competence and declare a problem insoluble for science. Such bold assertions frequently have a habit of backfiring, and if one's faith is predicated on the impossibility of science solving a particular problem, the implications are theologically hazardous.

Bombing out on the bombardier beetle

Talbot's reference to the bombardier beetle as an example of something too complex for evolution to have evolved is more than a little unfortunate, given the considerable volume of patently inaccurate material written by special creationist on this particular subject:
Whilst it has been claimed that this defensive mechanism evolved (but the entry in Wikipedia says, significantly, that “the true evolutionary path is still unknown ”), it does strain credibility to imagine that this is so! It makes much more sense to accept that a Creator designed all the complex mechanisms which work together so well in harmony and which need all their component parts together to make the system work.
By far the most common and embarrassing special creationist blunder made when appealing to the bombardier beetle is to claim that if there was one single error during the evolution of the bombardier beetle, the beetle would blow itself apart, thus making its evolution impossible. Talbot's assertion that the "explosion is so violent that, if it happened all at once, it would go off like a rocket and blow the insect off its feet" comes close to making this mistake. The truth, as ethologist Richard Dawkins points out is completely different:
Immediately after the section on the eye, for example, The Neck of the Giraffe goes on to discuss the bombardier beetle, which squirts a lethal mixture of hydroquinone and hydrogen peroxide into the face of its enemy. These two chemicals, when mixed together, literally explode. So in order to store them inside its body, the Bombardier Beetle has evolved a chemical inhibitor to make them harmless. At the moment the beetle squirts the liquid out of its tail, an anti-inhibitor is added to make the mixture explosive once again. The chain of events that could have led to the evolution of such a complex, coordinated and subtle process is beyond biological explanation on a simple step-by-step basis. The slightest alteration in the chemical balance would result immediately in a race of exploded beetles.

A biochemist colleague has kindly provided me with a bottle of hydrogen peroxide, and enough hydroquinone for 50 bombardier beetles. I am now about to mix the two together. According to the above, they will explode in my face. Here goes . . .

Well, I'm still here. I poured the hydrogen peroxide into the hydroquinone, and absolutely nothing happened. It didn't even get warm. Of course I knew it wouldn't: I'm not that foolhardy! The Statement that 'these two chemicals, when mixed together, literally explode', is, quite simply, false, although it is regularly repeated throughout creationist literature. If you are curious about the bombardier beetle, by the way, what actually happens is as follows. It is true that it squirts a scaldingly hot mixture of hydrogen peroxide and hydroquinone at enemies. But hydrogen peroxide and hydroquinone don't react violently together unless a catalyst is added. This is what the bombardier beetle does. As for the evolutionary precursors of the system, both hydrogen peroxide and various kinds of quinones are used for other purposes in body chemistry. The bombardier beetle's ancestors simply pressed into different service chemicals that already happened to be around. That's often how evolution works. [24]
The credibility of special creationist attacks on evolution made via the alleged impossibility of the evolution of the bombardier beetle defence are shredded just by the persistence of this asinine claim that 'one false step' would see beetle parts launched into orbit. More importantly, they are blunted by the failure to appreciate the power of small cumulative steps over time, with each step providing a selective advantage of the previous one. Mark Isaak's review article on the evolution of the bombardier beetle defence mechanism shows that plausible incremental pathways do exist, and that that examples of such intermediates exist today:
...a step-by-step evolution of the bombardier system is really not that hard to envision. The scenario below shows a possible step-by-step evolution of the bombardier beetle mechanism from a primitive arthropod.

  1. Quinones are produced by epidermal cells for tanning the cuticle. This exists commonly in arthropods. [Dettner, 1987] 
  2. Some of the quinones don't get used up, but sit on the epidermis, making the arthropod distasteful. (Quinones are used as defensive secretions in a variety of modern arthropods, from beetles to millipedes. [Eisner, 1970])
  3. Small invaginations develop in the epidermis between sclerites (plates of cuticle). By wiggling, the insect can squeeze more quinones onto its surface when they're needed.
  4. The invaginations deepen. Muscles are moved around slightly, allowing them to help expel the quinones from some of them. (Many ants have glands similar to this near the end of their abdomen. [Holldobler & Wilson, 1990, pp. 233-237])
  5. A couple invaginations (now reservoirs) become so deep that the others are inconsequential by comparison. Those gradually revert to the original epidermis.
  6. In various insects, different defensive chemicals besides quinones appear. (See Eisner, 1970, for a review.) This helps those insects defend against predators which have evolved resistance to quinones. One of the new defensive chemicals is hydroquinone.
  7. Cells that secrete the hydroquinones develop in multiple layers over part of the reservoir, allowing more hydroquinones to be produced. Channels between cells allow hydroquinones from all layers to reach the reservior.
  8. The channels become a duct, specialized for transporting the chemicals. The secretory cells withdraw from the reservoir surface, ultimately becoming a separate organ.  This stage -- secretory glands connected by ducts to reservoirs -- exists in many beetles. The particular configuration of glands and reservoirs that bombardier beetles have is common to the other beetles in their suborder. [Forsyth, 1970]
  9. Muscles adapt which close off the reservior, thus preventing the chemicals from leaking out when they're not needed.
  10. Hydrogen peroxide, which is a common by-product of cellular metabolism, becomes mixed with the hydroquinones. The two react slowly, so a mixture of quinones and hydroquinones get used for defense.
  11. Cells secreting a small amount of catalases and peroxidases appear along the output passage of the reservoir, outside the valve which closes it off from the outside. These ensure that more quinones appear in the defensive secretions. Catalases exist in almost all cells, and peroxidases are also common in plants, animals, and bacteria, so those chemicals needn't be developed from scratch but merely concentrated in one location.
  12. More catalases and peroxidases are produced, so the discharge is warmer and is expelled faster by the oxygen generated by the reaction. The beetle Metrius contractusprovides an example of a bombardier beetle which produces a foamy discharge, not jets, from its reaction chambers. The bubbling of the foam produces a fine mist. [Eisner et al., 2000]
  13. The walls of that part of the output passage become firmer, allowing them to better withstand the heat and pressure generated by the reaction.
  14. Still more catalases and peroxidases are produced, and the walls toughen and shape into a reaction chamber. Gradually they become the mechanism of today's bombardier beetles.
  15. The tip of the beetle's abdomen becomes somewhat elongated and more flexible, allowing the beetle to aim its discharge in various directions.

Note that all of the steps above are small or can easily be broken down into smaller steps. The bombardier beetles' mechanism can come about solely by accumulated microevolution. Furthermore, all of the steps are probably advantageous, so they would be selected. No improbable events are needed. As noted, several of the intermediate stages are known to be viable by the fact that they exist in living populations. [25]
Special creationists also forget that the term 'bombardier beetle' refers to beetles in the family Carabidae of which there are around 500 species, and we do not find in each of these beetle species the same defence mechanism. Instead, some have decidedly primitive defence mechanisms, which is exactly what we'd expect if common descent was true (these beetles being descendants of early members of the bombardier beetle family that have retained the primitive defence mechanism). For example:
The bombardier beetle Metrius contractus discharges its defensive secretion as a froth that clings to its body. When attacked from the rear, it allows the froth to build up over the gland openings near the abdominal tip; when attacked from the front, it conveys the secretion forwards along special elytral tracks. M. contractus has two-chambered defensive glands typical of bombardier beetles, and its secretion, like that of other bombardiers, is quinonoid and hot. Its frothing mechanism, however, is unique for bombardiers and possibly illustrative of the ancestral glandular discharge mechanism of these beetles. M. contractus, thus, could be the least derived of extant bombardiers. [26]
From a special creationist point of view, it raises the question of why God did not equip each bombardier beetle with the same advanced target and spray defence mechanism. Far from providing evolution with an insoluble problem the bombardier beetles are perfectly explicable from an evolutionary point of view, and in reality provide special creationists with the problem of explaining the apparently capricious distribution of sophisticated and primitive defence mechanisms among the many members of the bombardier beetle tribes.

When in doubt, claim evolution is a fraud

Talbot's attack on evolution as I've shown is nullified by his failure to properly differentiate between abiogenesis and evolution, as well as failing to appreciate the difference between evolution as fact, and evolution as theory. Of particular concern are his reliance on logical fallacies such as arguments from illegitimate authority and personal incredulity. The former logical fallacy pops up again in his conclusion:
In conclusion, as a scientist, I see many problems with the theory of evolution.
To be blunt, Talbot's opinion about what he thinks are problems for the theory of evolution is irrelevant as he is not an authority on evolutionary biology. Too many laypeople (and too may special creationists with science degrees) think that being a scientist in any area automatically bestows authority on any pronouncement they make, irrespective of whether that pronouncement is on a subject well outside their area of professional expertise. Replace the generic term 'scientist' with the precise name, and the fallacy becomes patently obvious:
  • In conclusion, as a geologist, I see many problems with the theory of general relativity.
  • In conclusion, as a botanist, I see many problems with the standard model of particle physics.
  • In conclusion, as a physicist, I see many problems with the germ theory of disease.
  • In conclusion, as a biochemist, I see many problems with the theory of plate tectonics
This is what we mean by argument from illegitimate authority. Unless Talbot is an evolutionary biologist, his assertion that the theory of evolution is false can be taken with a grain of salt. Furthermore, if he is referring to common descent, which is attested by lines of evidence from multiple independent areas, then his assertion is ludicrous. Common descent is attested by evidence from:
  • palaeontology
  • developmental biology
  • ecology
  • molecular biology
  • comparative anatomy
  • biogeography
  • comparative genomics
and it takes a lifetime of study and research to achieve the level of expertise required to comment with authority on each of them. For a special creationist to assert that the evidence from these fields does not support common descent is an implicit assertion that (1) they understand those fields in enough detail to be aware of all the evidence from them that is regarded as supporting common descent and (2) they have found it wanting. Needless to say, such an assertion is ludicrous. It is telling that those who declare the evidence does  not support common descent seem curiously reluctant to publish those findings in the scientific literature.

Talbot continues with the frankly outrageous assertion that mainstream scientists are engaged in fraud when promoting evolutionary biology:
I am well aware that the theory is being extensively promoted at the moment – in my opinion, often fraudulently.
No evidence for this accusation is made other than bald assertion, and given the dire nature of his attack on evolution to date, no confidence can be placed in this unreferenced, unverified accusation. Even if his claim is true - that the modern synthetic theory is a fraud - the facts of common descent and large-scale evolutionary change as evidenced in the fossil record remain, and any successor theory of evolution would need to explain these facts. It is hard not to see his appeal to wholesale fraud to explain away one of the best-attested scientific facts as a desperate attempt to evade the burden of proof.

Any doubt that Talbot is making poorly-informed arguments in areas completely outside of his area of expertise comes from this assertion:
Pieces of ancient bone are graced with an artist’s impressions of how the original animal looked. Common sense tells you that, on an important topic such as this, we cannot rely on an artist’s imagination.
Ignoring the fact that common sense is notoriously unreliable in science, Talbot single-sentence attempt to dismiss palaeontology is naive at best, and once again shows that he is out of his depth. Palaeontologists have considerable understanding of comparative anatomy, and are able to recognise animal types from bone fragments, just as comparative anatomists today are able to both recognise (for example) lumbar vertebrae from cervical vertebrae, and differentiate between bones from similar species. Furthermore, it is possible to infer details about an animal from one part of its body even in the absence of other fossil parts, given key anatomical details on bones which competent anatomists and palaeontologists are able to recognise. Reconstructions of extinct animals based on fossil remains contrary to Talbot's facile dismissal are anything but figments of the imagination. Certainly, when you have complete skulls such as this australopithecine specimen, the fact that it is neither modern human nor ape, but a transitional specimen is plainly apparent.


Ultimately, evolution denialism in our community is rooted in a fundamentalist distortion of the creation narratives based on the mistaken belief that a literal reading of the two creation narratives is the default exegetical option:
On the other hand, the Bible narrative is plain and simple. It describes a God with extraordinary powers and a completely plausible creation sequence.
We have of course already shown that a literal reading of the creation sequence in Genesis 1 is flatly contradicted by the evidence which shows that life appeared on this earth progressively over a 3500 million year period. The belief that life was created in six days six thousand years ago is impossible to reconcile with an avalanche of evidence from geology and biology, and no amount of appeal to literal reading of the creation narratives will change this.

Furthermore, the creation narratives are nowhere near as "plain and simple" as Talbot asserts. C.C. Walker, who was hardly an evolutionary creationist (though not a YEC or even a gap theory OEC) pointed out that:
Moses’ testimony is not so “plain” that it cannot be misinterpreted or misunderstood. He speaks of “the heaven and the earth” as being in existence “in the beginning;” and therefore it does not seem to be inadmissible to suppose that “the host of heaven” was likewise then in existence... As to “the fourth day,” we do not know of any “day” in the literal sense apart from the sun and its motion. And, therefore, if the “days” of Genesis 1. are to be taken as literal days, we feel bound to admit the sun as the origin of the “light,” and “evening and morning” that were the characteristics of “the first day.” How can you have “evening and morning” without the sun? We must settle up “the plain testimony” of verse 5 with that of verses 14–19. As we said before (The Christadelphian, 1910, p. 269), “If we understand Moses as saying that the sun came into existence on ‘the fourth day,’ we make him contradict himself; we make him present us with day and night, evening and morning, without the sun upon which these things depend.”
A literal reading of the creation narratives not only forces them to conflict with the overwhelming scientific evidence for an ancient, evolving Earth, creates a contradiction between the two creation narratives in Genesis 1 and Genesis 2 when both are read as consecutive creation events, but in reality gives us a completely implausible creation sequence. Any reading where with plants are formed before the sun, and three 'evenings and mornings' appear before the creation of the very bodies that were made for 'signs and seasons' can hardly be described as 'plain and simple.'

There are many good reasons for belief. Evolution denialism is not one of them, and merely serves to bring our community into disrepute by linking the excellent case for Christianity with something as profoundly flawed as special creationism.


1. Gregory T.R. "Evolution as Fact, Theory, and Path" Evo Edu Outreach (2008) 1:49

2. Darwin C. The descent of man, and selection in relation to sex. ( London: John Murray; 1871)

3. National Academy of Sciences of the USA. Teaching about evolution and the nature of science. Washington, DC: National Academies Press; 1998. p 67

4. ibid, p 5

5. Moran L "NASA Confusion About the Origin of Life: Part II" Sandwalk July 27 2012

6. Koonin E.V "The Logic of Chance: The Nature and Origin of Biological Evolution" (2011 FT Press)

7. See here for an example of such indoctrination of young children by YEC extremist Ken Ham.

8. “Historical Science” vs. “experimental scienceNational Center for Science Education. September 24th 2008

9. Dalrymple, G. B. "The age of the Earth in the twentieth century: a problem (mostly) solved". Special Publications, Geological Society of London (2001) 190: 205–221

11. Maloof, A. C. et al  "Possible animal-body fossils in pre-Marinoan limestones from South Australia". Nature Geoscience (2010) 3: 653.

12. Shu, D. G. et al "Head and backbone of the Early Cambrian vertebrate Haikouichthys", Nature (2003) 421: 526–529

13. Clack, J.A. "Earliest known tetrapod braincase and the evolution of the stapes and fenestra ovalis". Nature (1994) 369:392-394.

14. Clarke, J.A.  Morphology, phylogenetic taxonomy, and systematics of Ichthyornis and Apatornis (Avialae: Ornithurae). Bulletin of the American Museum of Natural History (2004) 286:1-179

15. Ji, Q., Luo, Z-X, Yuan, C-X, and Tabrum, A.R. "A Swimming Mammaliaform from the Middle Jurassic and Ecomorphological Diversification of Early Mammals". Science (2006) 311:1123–7.

16. McDougall, I., Brown, F.H., Fleagle, J.G.  "Stratigraphic placement and age of modern humans from Kibish, Ethiopia". Nature (2005) 433:733–736

17. Theobald, Douglas L. "29+ Evidences for Macroevolution: The Scientific Case for Common Descent." The Talk.Origins Archive. Vers. 2.89. 2012. Web. 5 Apr. 2015 <>

18. See ref. 1

19. Evolution's Final Frontier" New Scientist (2009) 201:41-43

20. The facts that those theories were proposed to explain (which in this case are common descent and large-scale evolutionary change) may come and go, but those facts remain, and the theories which replace them not only need to explain the existing facts of evolution, but those phenomena which the previous theory could not explain. Again, Talbot's argument betrays a considerable lack of understanding of scientific epistemology.

21. Vonk F.J. et al  "Evolutionary origin and development of snake fangs" Nature (2008) 454:630-633

22. Lincoln T.A., Joyce G.R "Self-Sustained Replication of an RNA Enzyme" Science (2009) 323:1229-1232

23. Kamioka S et al “Autocatalysis and organocatalysis with synthetic structures” Proc. Natl. Acad. Sci. USA (2010) 541-544.

24. Dawkins, Richard. The Blind Watchmaker, (1991: Penguin) p 86-67

25. Isaak M. Bombardier Beetles and the Argument of Design TalkOrigins

26. Eisner, T et al (2000). "Spray mechanism of the most primitive bombardier beetle (Metrius contractus)". Journal of Experimental Biology (2008) 203:1265–1275.

27. Walker C.C. "Is it 'Wrong' to Believe that the Earth is a Sphere?" The Christadelphian (1913) 50:348