Darwin and medicine, redux

The summer 2006 edition of Stanford Medical Magazine has devoted their issue to “The evolutionary war.” Being the alumni magazine of a medical school, of course they have an article on “Darwin in medical school.” It’s a nice overview, discussing a bit of the history of “Darwinian medicine” and the pros and cons of teaching it in an already over-scheduled medical school curriculum. More after the jump…

Randolph Nesse, who I mentioned in this post and is considered one of the fathers fo “Darwinian medicine,” argues for the inclusion of evolutionary medicine in med school curricula:

…They know that deans feel beleaguered by demands to add new subjects to the already crowded schedule — nutrition, alcoholism and aging to name a few. “But still, it’s preposterous that evolution is not a part of medical education,” says Nesse. “Evolution offers a broad framework on which you can organize and understand all kinds of facts and principles. It ties together medical education instead of leaving it hanging as 50,000 discrete facts.”

Stanford’s assistant dean for medical ed largely agrees, but notes that much of the evolution discussion is integrated into the classes themselves.

“It is impossible to be a good physician without understanding the evolutionary process,” says Julie Parsonnet, MD, senior associate dean for medical education. She notes the importance of evolutionary explanations for antimicrobial resistance and the emergence of new infectious diseases, as well as more complex chronic diseases, such as the cardiovascular problems that piqued Yun’s interest years ago.

Stephen Lewis of the University of Chester in England, a proponent of evolutionary medicine, notes one reason for hesitation to include specific courses on the topic:

Add to this the fact that the field has failed so far to provide clinically useful findings and you see why medical schools lack interest, says Lewis. “There is much about explanation and understanding but little about treating and curing,” he says.

(This is along the lines of what was discussed by commenters in this previous thread).

They do, however, note that two Stanford docs take the idea seriously enough to apply evolutionary concepts to the creation of new medical devices:

Of the billion dollars under management, the firm has invested $350 million in health care, much of that in companies that produce devices that make sense from an evolutionary standpoint. In other words, stents are out; gentler procedures that don’t escalate the trauma response are in. Drug-delivery systems for treating kidney disease intravenously are out; delivering the drugs directly to the kidneys to bypass the trauma response is in.

So even if evolutionary considerations aren’t being taught up-front, at least they’re being applied.

Finally, in the sidebar to the article, they also note some other applications of Darwinian principles to medicine, with some “myths” and evolutionary insights that shed light on treatment:

Myth: Bacteria and viruses become less virulent the longer the interaction with the host species has been going on.

Myth: Aging happens because parts wear out.

Myth: Annoying responses to infection — such as fever, anemia and diarrhea — are unnecessary and should be alleviated with drugs.

I’ll leave it up to y’all to check out the article and see how they apply evolutionary biology to those claims.

Comments

  1. #1 Leon
    June 8, 2006

    It’s great that someone’s pushing to include evolution education in medical training. There’s way too many creationist physicians out there, which is ironic for a field that benefits so much from evolutionary theory. Evolution may be integrated into many courses, but I’m sure the bits of evolution there are easily missed or ignored; putting a spotlight on it would be a great idea.

    But…again with the “Darwinian” references. No one believes in Darwinian evolution any more–the field has advanced considerably since Darwin’s day.

  2. #2 Tara C. Smith
    June 8, 2006

    That’s just what they chose to call the field. Nesse’s book, for example, is called Why We Get Sick : The New Science of Darwinian Medicine.

  3. #3 Vasha
    June 8, 2006

    “Darwinian” seems to be the obvious name for evolutionary theories which include a prominent role for unguided natural selection. There certainly are ideas of evolution which don’t — Lamarckism, for example, or a New-Age-type idea I heard once which, as far as I understood it, posited that evolution just happens because of overflowing abundance of energy (from the sun or whatever) and its innate tendancy to maximum diversity. So perhaps it makes sense not to just say “evolutionary” but further specify as “Darwinian”.

  4. #4 Joseph j7uy5
    June 8, 2006

    I attended some seminars by Randy Nesse, in the late 1980’s. It seemed as though everyone took him seriously, but it does not appear that there has been much progress in getting the material added to medical school curricula.

    The seminars I attended were for residents, not medical students. It seems that medical school curricula are already pretty well packed with material, and I can see that it would be difficult to get anything added at this point. However, residency education programs have a lot more flexibility. I’d bet that if there is to be any progress in adding evolutionary concepts to medical education, it is going to start at the residency level.

    (Note: medical school is the first four years, after which one is granted a medical degree; residency comes after that, and leads to qualification in a medical specialty.)

  5. #5 Mesk
    June 9, 2006

    …companies that produce devices that make sense from an evolutionary standpoint. In other words, stents are out; gentler procedures that don’t escalate the trauma response are in. Drug-delivery systems for treating kidney disease intravenously are out; delivering the drugs directly to the kidneys to bypass the trauma response is in.

    In what sense does one require an “evolutionary standpoint” to develop these systems? These developments could just as easily have been based on basic physiology: treatments work better if you don’t trigger the body’s defence mechanisms. Well, duh.

  6. #6 Chris Noble
    June 9, 2006

    Bacteria and viruses become less virulent the longer the interaction with the host species has been going on.

    I wouldn’t say that this is a myth as such. Many bacteria and viruses do become less virulent after being introduced into a new host. The introduction on the myxoma virus to rabbits in Australia is a classic example.

    Different conditions can select for either less virulence or more virulence. Multiple rapid passage of a virus can select for higher virulence.

  7. #7 David Harmon
    June 9, 2006

    “…They know that deans feel beleaguered by demands to add new subjects to the already crowded schedule — nutrition, alcoholism and aging to name a few. ”

    The point of medical school is to teach prospective doctors what they need to know. If the list of necessary topics and information is genuinely overflowing the schedule — as opposed to getting crowded out by “Introduction to Crystal therapy” or the like — then, ipso facto, it is time to add another year to medical school.

    Also, the problem with having evolution “implicit” in the courses is that creationist students can just regurgitate the “official” answers when needed, and otherwise just “take the hit” to their grades, for failure to understand the underlying principles. If there were at least one required course specifically targeted on evolutionary principles and implications, that would sweep away the “deniability” question, and provide a red flag to alert professors and administrators.

  8. #8 DDS
    June 9, 2006

    I think Case Western is starting a 5 year MD program. I don’t know if they are including a course on evolution though.

    Even if they include a course on evolution I don’t think it would have any effect on peoples ability to deny evolution. Just read the comments on these boards.

    Finally, my personal opinion is that medical schools would be better off spending more time training doctors with various people and diagnostic skills. For instance, a course teaching empathy, interviewing and diagnostics skills would be much more valuable than a course on evolution. If you didn’t get it during 4 years as an undergrad and your first two years in Med school you are not going to get it.

    D

  9. #9 Tara C. Smith
    June 9, 2006

    I wouldn’t say that this is a myth as such. Many bacteria and viruses do become less virulent after being introduced into a new host. The introduction on the myxoma virus to rabbits in Australia is a classic example.

    Sure, but even that scenario isn’t as straightforward as some people tell it. The rabbit population evolved during that time as well, with more individuals selected who were genetically resistant to the virus. And it still causes death in ~50% of rabbits–not exactly avirulent.

    Different conditions can select for either less virulence or more virulence. Multiple rapid passage of a virus can select for higher virulence.

    Absolutely. But it’s still sometimes taught as conventional wisdom that low virulence = long evolutionary history with host, high virulence = new infection to species. That’s the myth portion.

    Finally, my personal opinion is that medical schools would be better off spending more time training doctors with various people and diagnostic skills. For instance, a course teaching empathy, interviewing and diagnostics skills would be much more valuable than a course on evolution. If you didn’t get it during 4 years as an undergrad and your first two years in Med school you are not going to get it.

    I agree that course would be valuable as well, but what I think is largely missing–especially in undergrad–is a course specifically focusing on how evolution applies to medicine. Will it “convert” creationist docs? Unlikely. But even for those who are just fine with accepting evolution, many simply don’t understand how some evolutionary principles apply to medical treatments–for example, the fever “myth” they mentioned.

  10. #10 DDS
    June 9, 2006

    I guess I’d have to see the syllabus of, or sit, through the kind of course your describing.

    The problem you could run into though is generating a lot of “just so” stories (http://www.boop.org/jan/justso/ or http://wiki.cotch.net/index.php/Just_So_Story) or ad hoc explanations. For instance, Yun’s hypothesis is intriguing and sounds good but that doesn’t make it true.

    I could propose one such as:

    “In the neolithic few peopled bathed regularly and personal hygiene was nonexistent. So, we must have evolved to live dirty lives. Therefore we should give up soap and water or at least wallow in the dirt occasionally”. (Yes, I know this is similar to the Hygiene Hypothesis).

    The problem here is assuming you know “all” of the factors that led to the evolution of certain phenotypes and characteristics. Evolution does an excellent job of explaining the origins, history and diversity of life. I am not sure it is a great experimental tool to make concrete predictions about physiology. It is too blunt a knife. For instance, although we know that bacteria will eventually become resistant to antibiotics after heavy use, evolution rarely lets us predict when resistance will arise and what the nature of the resistance will be.

    A final point, whether you believe Yun’s hypothesis is correct or not I think most physicians would agree that the less invasive a procedure is the better.

    D

  11. #11 Tara C. Smith
    June 9, 2006

    I guess I’d have to see the syllabus of, or sit, through the kind of course your describing.

    Ask and ye shall receive. (Click on the “courses” on the right).

    I agree about the “just-so stories.” They’re a peeve of mine as well (and I’ve written about them previously). But from the syllabi I browsed, I don’t see anything that suggested those type of stories were being used.

  12. #12 Lou FCD
    June 27, 2006

    Ahem noted.
    ;)

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