Evolution Intelligent design/creationism Medicine Pseudoscience Science Skepticism/critical thinking

Medicine and Evolution, Part 10: “Intelligent design” creationists misrepresenting the role of evolution in medicine

If there’s one undeniable aspect of “intelligent design” creationism advocates, it is their ability to twist and misrepresent science and any discussions of evolution to their own ends. Be it Dr. Michael Egnor‘s twisting of history to claim that eugenics is based on Darwinism, rather than the artificial selection (or, as we snarky ones like to call it, intelligent design), claims that “Darwinism” is a tautology and irrelevant to the question of antimicrobial resistance, or blaming evolution for atheism, the decline of Western mores, and, if you believe the ID advocates, bad breath, key to the ability of ID advocates to get their message across is to quote mine. Rarely do we see a better example of this than Sal Cordova’s recent piece in Uncommon Descent, entitled Darwin dissed by doctors, but a design revolution continues at MIT, in which he misrepresents an article in PLoS Biology entitled, Does Medicine without Evolution Make Sense? Let’s just say that Sal subjects this article to yet another bit of the “Darwin beats puppies“-style dishonest quote-mining that he’s become so well known for.

I had originally been planning on blogging about the PLoS article when it first came out, with the intention of devoting at least a little bit of my piece to my prediction that creationists would be quick to misrepresent the article. (You’ll just have to take my word for it, although I did commit this prediction to type in an e-mail discussing the article.) It turns out that my prediction was correct, although it took longer than I had expected (two weeks) for someone from Uncommon Descent to get around to it. Sal Cordova starts out bad and gets worse in quote-mining:

In the recent editorial Does Medicine without Evolution Make Sense? MacCallum writes:

Charles Darwin, perhaps medicine’s most famous dropout, provided the impetus for a subject that figures so rarely in medical education. Indeed, even the iconic textbook example of evolution–antibiotic resistance–is rarely described as “evolution” in relevant papers published in medical journals. Despite potentially valid reasons for this oversight (e.g., that authors of papers in medical journals would regard the term as too general), it propagates into the popular press when those papers are reported on, feeding the wider perception of evolution’s irrelevance in general, and to medicine in particular.

Wow. This does sound like a really damning admission, doesn’t it? Except for one thing: Sal left out the closing sentence to the paragraph, which reads:

Yet an understanding of how natural selection shapes vulnerability to disease can provide fundamental insights into medicine and health and is no less relevant than an understanding of physiology or biochemistry.

That certainly changes the meaning and tone of the paragraph being quoted by Sal, don’t you think? This isn’t even subtle quote-mining. Come on, Sal! You can do better than that. Or maybe he can’t. For example:

Darwinists claim how important Darwinism is to science, but MacCallum’s editorial makes an embarrassing admission of Darwinism’s irrelevance to medicine. She also reports on the protests from medical students who find themselves forced to study Darwinism for no good reason.

Here’s what the article really said about this alleged “protest” by medical students regarding having to study evolution:

Even at a very basic level, medical students can draw insights from evolution they cannot obtain from other core sciences on their course. Paul O’Higgins (Hull York Medical School) noted that it is much easier for medics to learn the nerves involved in the brachial plexus (the nerves supplying the arm) if they first understand the origin of the pentadactyl limb.


Ironically, the hardest task in adding evolutionary/Darwinian medicine to medical curricula may well be soliciting support from medical students. Although Paul O’Higgins thought a comparison of the brachial plexus to the pentadactyl limb was helpful, not all his students agreed–complaints were lodged that he was forcing evolution on them. That lack of support was also reflected in the participation of only three medical students at the York meeting (albeit enthusiastic ones), despite being widely publicized. It is not clear whether this is because medical students are more overburdened than most or because of a more deep-rooted resistance to the subject, reflecting wider political and religious prejudice against evolution.

If you read Cordova’s piece and the PLoS article, you’ll note that Cordova left out important parts of the quote in order to attribute to the article a different impression than it in fact gives in his eagerness to paint the article as saying that evolution is not important to medicine. Actually, the article was more about how many physicians do not perceive its importance, even though evolutionary science is becoming more and more important to medicine:

The most obvious examples of evolutionary biology’s importance to medical understanding are related to infectious disease [7]. As Jon Laman (Erasmus University, The Netherlands) pointed out at the meeting, the immune system provides the perfect platform to explain the medical relevance of the exquisite evolutionary relationships between pathogens and their hosts. Understanding how virulence evolves, for example, can help predict the potential, sometimes counterintuitive (and controversial) negative consequences of imperfect vaccination [8,9]. But evolution can also tell us that the origin of HIV was precipitated by a jump across the primate species barrier [10] and enables us to predict the imminent arrival of avian flu and the mutations most likely to be responsible for that evolutionary leap from birds to humans [11]. Where epidemiological and population genetic processes occur on the same time scale, the emerging field of “phylodyamics” can also inform us about the timing and progression of pathogen adaptation more generally [12].

The relevance of evolution to medicine is, however, much broader. Participants at the York meeting discussed not only how vulnerability to cancer is an inevitable but unfortunate consequence of imperfect human engineering and natural selection (Mel Greaves, Institute of Cancer Research, UK) [Ed. note: Orac discussed Mel Greaves’ recent article in Nature Reviews Cancer about this very topic while refuting Dr. Egnor.], but how life history theory can potentially explain patterns of pregnancy loss (Virginia Vitzthum, Indiana University), how a comparative approach applied to different human cultures and different primates can improve rates of breastfeeding (Helen Ball, University of Durham), whether clinical depression has an adaptive origin (Lewis Wolpert, University College London), and if suicide attempts are really just evolutionary bargaining chips in intense social disputes (Ed Hagen, Humboldt University).

So what, in Sal Cordova’s quote-mining mind, is the real situation? Laughably, it’s this:

Engineers, those who make a living studying the science of design are now invading biology in larger and larger numbers. The emerging discipline of Systems Biology, a design-friendly discipline which investigates biology from a design perspective, will eventually dominate the way biology is done from now on. In contrast, the discipline of Evolutionary Biology (with the exception of fine fields like Population Genetics) will possibly decline in prominence.

Systems biology, design-friendly? Only in Cordova’s warped ID dreams! Systems biology does not investigate from a “design” perspective. In fact, as I discussed in a long post a month and a half ago about Leroy Hood, one of the most prominent systems biologists there are, systems biology shows that biological networks are redundant. In fact, they are so functionally redundant many of these networks (with overlayered “circuit” design and interlocking redundant networks of regulatory genes) that they go against the very definition of “irreducible complexity.” Components can be removed from many of these systems and, thanks to redundant pathways that take up the slack, the overall network still functions nearly as well. Sal Cordova probably thinks systems biology is “design-friendly” because it uses the language of engineering (“circuits” and “systems,” for instance) and because, ID advocate that he is, he probably can’t see how these interlocking networks of regulated genes could possibly have evolved. Unfortunately for him, as complex as these circuits are, it is not difficult to imagine selection pressure acting both at the level of the individual genes and the individual modules of gene products that form the “subcircuits.”. After all, if gene duplication can lead to new biological information, as the duplicated gene, under selection pressure, gradually diverges from its original structure and acquires new functions, it’s not that hard to imagine a similar process happening to the “modules” of these biological networks. In fact, Leroy Hood, at least, directly mentions evolution as important to his work, because he works out these module designs in organisms other than humans and then infers information about the human networks based on this design and because evolutionary theory helps him determine how these networks evolved to become what they are in humans. Of course, we scientists make it easy for quote-miners like Cordova because we use the lazy figure of speech “design” all the time, and systems biologists are particularly prone to this.

To anyone reading the PLoS article, it becomes very apparent that the key point of the article is that physicians today do not perceive evolution as being important to medicine, and that is, as I’ve pointed out before, all too true. However, perception does not necessarily equal reality, and it is perfectly proper to campaign against an increasingly incorrect present perception. Cordova dismissively asks “Why is it that a campaign has to be waged to teach Darwinism in science classes?” and “Do we need campaigns to teach the theory of gravitation or the periodic table?” However, he seems to forget that, a mere 150 or so years ago, Ignaz Semmelweis elegantly showed that something as simple as physicians washing their hands between patients or between doing autopsies on patients who died of puerperal fever and then going to deliver babies dramatically decreased deaths in the maternity wards of his hospital in Vienna from puerperal fever from 10-35% to less than 1%; yet in many places in Europe his findings were not accepted for many years. Semmelweis’ findings were far simpler than the theory of evolution and how it illuminates our understanding of disease and treatments; it is not surprising that it would take time and explanation for the importance of evolution to modern medicine to start spreading from academic medical centers and permeating the rest of the medical profession, nor is it evidence of the lack of importance of evolution that this will take some effort.

As the PLoS article concludes;

But evolutionary medicine isn’t and shouldn’t be controversial, and the best way to challenge prejudice is through education. As the oft-quoted Theodosius Dobzhansky wrote in 1973, “Nothing in biology makes sense except in the light of evolution” [15]. The time has clearly come for medicine to explicitly integrate evolutionary biology into its theoretical and practical underpinnings The medical students of Charles Darwin’s day did not have the advantage of such a powerful framework to inform their thinking; we shouldn’t deprive today’s budding medical talent of the potential insights to be gained at the intersection of these two great disciplines.

Contrary to Cordova’s insinuations, advocating for more teaching of evolution in medical schools is neither nefarious nor evidence that evolution is irrelevant to medicine. Rather, it is simply a recognition of the fact that newer biomedical science is becoming more and more influenced by the findings of evolutionary biology, whose findings are leading to new and important insights into diseases as diffuse as infectious diseases, cancer, infertility, obesity, and heart disease, just to name a few. It is also a comment on how slow medical education is to change to reflect new findings in science. The same sorts of complaints about medical education and the perceptions of physicians about the importance of a new technology were made 20 years ago, when molecular biology was revolutionizing medicine but was hardly taught at all in medical school. I remember. That was when I was in medical school. Contrary to Sal Cordova’s deceptive quote-mining, it is most assuredly not an indictment of evolution’s growing utility to medicine.

More on this:

Sal Cordova’s Rank Dishonesty
Ed Brayton Exposes Sal Cordova’s Cherry-Picking

By Orac

Orac is the nom de blog of a humble surgeon/scientist who has an ego just big enough to delude himself that someone, somewhere might actually give a rodent's posterior about his copious verbal meanderings, but just barely small enough to admit to himself that few probably will. That surgeon is otherwise known as David Gorski.

That this particular surgeon has chosen his nom de blog based on a rather cranky and arrogant computer shaped like a clear box of blinking lights that he originally encountered when he became a fan of a 35 year old British SF television show whose special effects were renowned for their BBC/Doctor Who-style low budget look, but whose stories nonetheless resulted in some of the best, most innovative science fiction ever televised, should tell you nearly all that you need to know about Orac. (That, and the length of the preceding sentence.)

DISCLAIMER:: The various written meanderings here are the opinions of Orac and Orac alone, written on his own time. They should never be construed as representing the opinions of any other person or entity, especially Orac's cancer center, department of surgery, medical school, or university. Also note that Orac is nonpartisan; he is more than willing to criticize the statements of anyone, regardless of of political leanings, if that anyone advocates pseudoscience or quackery. Finally, medical commentary is not to be construed in any way as medical advice.

To contact Orac: [email protected]

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