Tuesday, June 21, 2011

Jerry Coyne and Darwinian medicine

Jerry Coyne has a post on Darwinian medicine, which is a new branch of evolutionary biology that studies the evolutionary causes of disease and claims to provide evolutionary insights that are of therapeutic value.

I'm a professor at a medical school and I have several decades of experience teaching medical students. As you might imagine, I am quite skeptical about the value of Darwinian medicine in medical education. In this post and in posts to follow, I'll briefly summarize my reasons for skepticism about Darwinian medicine in the medical school curriculum:

1) Darwinian medicine is not new.

During the first half of the 20th century, Darwin's theory played a central role in medical education in the United States, as well as in continental Europe, primarily in Germany. Eugenics is the application of breeding principles to human biology based on the Darwinian understanding of man. The term eugenics was coined by Darwin's cousin Francis Galton (the concept, but not the word, appeared in Darwin's Descent of Man).

Eugenics is the original Darwinian medicine. According to Darwin's understanding of human origins, man evolved by a long brutal process of natural selection, and man's highest qualities were evolved by a process of millions of years of often violent struggle. As man became civilized, the weakest members of the species-- the ill and infirm, the handicapped, the mentally deficient-- were unnaturally preserved in the population through man's charitable instincts. Darwinists cautioned that compassion for the weak was diluting the human species, allowing defective humans to breed and spread their deficiencies. The solution to this Darwinian crisis seemed obvious: human beings must be bred, like farm animals, to produce the strongest individuals and preserve the species.

Eugenics (Darwinian medicine 1.0) was a central principle in American medicine from 1900 through the late 1930's. It was 'consensus science', opposed only by a few deniers (mostly Christians and especially the Catholic church, which strongly opposed eugenics in any form) who insisted on respect for human dignity despite illness and infirmity. Eugenics was taught in medical schools and in biology programs, and was embraced by major medical and scientific organizations in the United States. Eugenics was endorsed by the National Academy of Sciences, the American Medical Association, the Birth Control League (later renamed Planned Parenthood), and countless universities. It was mainstream consensus science. Compulsory sterilization laws were passed, and 50,000 Americans were sterilized against their will in the first half of the 20th century.

The Germans deeply admired and emulated the American eugenics program, and took Darwinian medicine a step further. In the late 1930's the Nazis organized the T4 program, which was an explicitly Darwinian approach to cleansing the German gene pool of weak people, most of whom were handicapped. Citizens were encouraged to report handicapped people to government authorities, who would take them into custody for medical evaluation. If they were deemed a genetic impediment, they were euthanized. By 1945, German doctors, acting on an explicitly Darwinian understanding of man, killed 250,000 handicapped people, a large number of whom were children.

At the Doctor's Trial following the war, 23 doctors and administrators were tried for various crimes against humanity. Seven doctors, including doctors involved in the T4 program, were hanged.

Dr. Coyne:

[there are] few evolutionary biologists ...on medical school faculty: almost none...

After WWII, eugenicists on medical faculties in the United States were generally shown the door, and eugenics, the first Darwinian medicine, disappeared as a explicit component of medical education.

Coyne is right: there are virtually no evolutionary biologists on medical school faculties in the 21st century. Part of the reason is mundane: evolutionary biology plays no significant role in medical science and practice. Medicine depends on actual scientific understanding of disease mechanisms and therapeutics, and speculation about evolutionary origins is of no tangible value to the medical profession.

There are also a few members of each medical school faculty who know enough about the history of medicine in the 20th century who greet the topic of Darwinian medicine with widened eyes.

More on Darwinian medicine in ensuing posts.


  1. L. M.F. Merlo, J. W. Pepper, B. J. Reid, and C. C. Maley, "Cancer as an evolutionary and ecological process," Nature Reviews Cancer 6, 924 (2006).doi:10.1038/nrc2013.

    The introductory paragraph: "Neoplasms are microcosms of evolution. Within a neoplasm, a mosaic of mutant cells compete for space and resources, evade predation by the immune system and can even cooperate to disperse and colonize new organs. The evolution of neoplastic cells explains both why we get cancer and why it has been so difficult to cure. The tools of evolutionary biology and ecology are providing new insights into neoplastic progression and the clinical control of cancer."

  2. R. M. Nesse and J. D. Schiffman, "Evolutionary biology in the medical school curriculum," Bioscience 53, 587 (2003). doi:10.1641/0006-3568(2003)053[0585:EBITMS]2.0.CO;2.

    Abstract: "The principles of evolution are finding new applications in medicine, but little is known about the role of evolutionary biology in medical curricula. To determine which aspects of evolutionary biology are included in medical curricula and the factors that influence this, a questionnaire was sent to all deans at North American medical schools who are responsible for curricula. The questionnaire asked about content areas in the curriculum, their perceived importance, and the factors that influence the amount of coverage given to those areas. Forty-eight percent of the deans who responded considered evolutionary biology important knowledge for physicians. Only 32 percent of the respondents reported that their schools covered at least 8 of 16 core topics in evolutionary biology, and only 16 percent of the schools reported having any faculty with a PhD in evolutionary biology. Lack of time in the curriculum and lack of faculty expertise are the main perceived impediments to increased teaching of evolution. We conclude that the role of evolutionary biology as a basic medical science should be carefully considered by a distinguished group of biologists and medical educators. In the meanwhile, undergraduate educators need to recognize that, for now at least, most future physicians must learn evolutionary biology as undergraduates if they are to learn it at all."

  3. The term Darwinism is often used in the United States by promoters of creationism, notably by leading members of the intelligent design movement, as an epithet to attack evolution as though it were an ideology (an "ism") of philosophical naturalism, or atheism.[17] For example, Phillip E. Johnson makes this accusation of atheism with reference to Charles Hodge's book What Is Darwinism?.[18] However, unlike Johnson, Hodge confined the term to exclude those like Asa Gray who combined Christian faith with support for Darwin's natural selection theory, before answering the question posed in the book's title by concluding: "It is Atheism."[19][20][21] Creationists use the term Darwinism, often pejoratively, to imply that the theory has been held as true only by Darwin and a core group of his followers, whom they cast as dogmatic and inflexible in their belief.[22] Casting evolution as a doctrine or belief, as well as a pseudo-religious ideology like Marxism,[23] bolsters religiously motivated political arguments to mandate equal time for the teaching of creationism in public schools.

  4. "Eugenics (Darwinian medicine 1.0) was a central principle in American medicine from 1900 through the late 1930's. It was 'consensus science', opposed only by a few deniers (mostly Christians and especially the Catholic church, which strongly opposed eugenics in any form) who insisted on respect for human dignity despite illness and infirmity."

    Unfortunately, it seems this was not uniformly true. Martin S. Pernick's The Black Stork records James Cardinal Gibbons support for Dr. Harry Haiselden's high-profile campaign of infanticide against disabled newborns.