Evolution Icon Evolution
Medicine Icon Medicine

Against “Darwinian Medicine”

Randolph_M._Nesse.jpg

Darwinist Randolph Nesse has been peddling “Darwinian Medicine” for years. He laid out his vision of medical science informed by Darwinian speculations two decades ago in a book, Why We Get Sick: The New Science of Darwinian Medicine, co-authored with Darwinist George C. Williams. He pointed out (correctly) that Darwinism has no current role in medical education and medical research. He means to change that. He argues for integration of Darwinian science into medical school curricula, and he argues that the light cast by Darwinian insights will significantly advance medical education and research.

That is a dubious claim. The very admission that Darwinism has had no role in medical science is a telling argument not for its inclusion, but for its irrelevance. Medical science is remarkably successful. Antibiotics, cybernetics, cancer chemotherapy, bone marrow transplants, hip replacements, heart transplants, and a host of near-miraculous advances have greatly extended our lifespan and improved the quality of our lives — all without Darwin.

Whether or not Darwinian hypotheses can be teased out of some medical advances, it is simply a fact that doctors and medical researchers pay no attention to Darwinian speculations in their work, and their work has been astonishingly successful. Would heart transplants work better if cardiac surgeons speculated about the Darwinian origin of the four-chamber heart? Would chemotherapy for leukemia be more effective if oncologists speculated about the adaptive benefits of bone marrow proliferation in Pleistocene apes? Would antibiotics be more effective if microbiologists applied the Darwinian observation that antibiotics kill bacteria that are killed by antibiotics? The questions answer themselves.

Evolutionary biologist Ernst Mayr observed many years ago that there are two ways to understand biology: proximate explanations and evolutionary explanations. Proximate explanations are the actual explanations for the disease process. Malaria is caused by eukaryotic protists of the genus Plasmodium, which are sensitive to certain anti-parasitic drugs. The biochemical basis for the infection and the pharmacological basis for the treatment of the infection are reasonably well understood. In other words, proximate explanations in medicine are explanations for the cause and treatment of the disease.

Evolutionary explanations are speculations about how natural selection supposedly gave rise to adaptation and to disease. Some speculations are of some interest (e.g., the speculation that sickle cell trait confers some protection from malaria), while other speculations are more akin to stand-up comedy (e.g., the Darwinian speculation that malaria renders the patient prostrate so more mosquitoes can land more easily on the motionless body). Evolutionary explanations for diseases are fanciful. To wit:

  • We become obese because our primate ancestors on the savanna had to suffer prolonged periods of famine, causing us to adapt by storing more energy as fat.

  • We resist exercise because it served no purpose on the savanna when we weren’t being chased by predators.

  • Anxiety disorders are caused by our prehistoric fight-or-flight mechanism, which served adaptive purposes for our simian ancestors but are of little use in today’s society.

  • Symptoms of disease such as fever, cough, shaking, chills, etc. are useful from a Darwinian standpoint (rallying the body’s defenses, expelling pulmonary secretions, etc.).

Whatever the value of these Darwinian stories to evolutionary biology, there is no discernable value of to medical practice or research. For example, the role of fever in fighting infection is a topic of genuine and important medical research. All of the actually useful information gathered from this research is gleaned from the proximate explanation for fever and infection, not from the evolutionary explanation. Does fever help the immune system fight infection? When is the negative effect of fever more of a danger to the patient than the positive effect? What are the biochemical and physiological substrates of the fever response, and how can they be modified therapeutically?

These are the important questions for medical research and treatment. The role of fever in illness in apes in Africa 3.5 million years ago is a fine topic for speculation by evolutionary biologists (if they have some extra time on their hands), but is of no discernable use to actual medical treatment or research.

Evolutionary medicine is to medicine as evolutionary psychology is to psychology. Medicine and psychology are flourishing disciplines of clinical practice and basic research. Evolutionary medicine and evolutionary psychology are disciplines of evolutionary biology that contribute nothing of tangible value to the medical and psychological sciences. There is no justification for the use of scarce resources in medical education and research on storytelling.

Evolutionary medicine is a jobs program for evolutionary biologists, and an effort by Darwinists to polish the reputation of an increasingly discredited Darwinian paradigm. There’s money and prestige in medical science. Ergo — Darwinian medicine!

Is Darwinism an increasingly discredited paradigm, you may ask? Well, yes. Nesse in an article asks and answers ten questions about Darwinian medicine. I ask Nesse an eleventh question. His book, published in 1996, is subtitled “The New Science of Darwinian Medicine.”

Nesse now admits:

… Darwinian medicine was the more accurate designation… Over the decades, however, evolutionary medicine has become the standard term…

Why did evolutionary biologists drop “Darwinian” medicine and replace it with “evolutionary” medicine? By Nesse’s own admission, “Darwinian medicine” remains the accurate designation for the strategy to inject Darwinian stories into medical science. The fact that the evolutionary biologists and even the founder of “Darwinian medicine” recognizes the need to drop “Darwinian” from the name suggests that storytelling predicated on Darwin’s theory is losing cachet, another hint that Darwinism is headed for the dustbin of discredited pseudoscience, where it belongs.

Photo: Randolph M. Nesse, by Panek (Own work) [GFDL or CC BY-SA 4.0-3.0-2.5-2.0-1.0], via Wikimedia Commons.