October 2, 2023 | Jerry Bergman

Evolutionary Medicine Will Not Help Medical Research

Why evolution has nothing positive
to offer medical science


by Jerry Bergman, PhD

What is evolutionary medicine?

Most modern medical research focuses on the physical, chemical, and psychological causes of disease. Conversely, evolutionary medicine attempts to understand “why we might have evolved to be susceptible to [disease] conditions in the first place, and how we can use evolution to fight them.”[1] Also known as Darwinian medicine, this theory applies evolutionary theory to questions about human health and disease.

The phrase “why we might have evolved” admits that evolutionary medicine is based on speculation and guesswork. It is far more productive to focus on what causes certain diseases, how they can be prevented, and how they can be treated. Likewise, attempting to guess how we can use evolution to fight disease moves us into speculation and away from empirical analysis. To support this conclusion is the goal of this review.

Case Histories Comparing Animal Behavior with Human Behavior

A typical example of the behavior medical evolutionary claims to explain can be found in Bruce Bagemihl’s 1999 book, Biological Exuberance: Animal Homosexuality and Natural Diversity. In his 751-page book, Bagemihl argues that homosexuality is widespread in the animal world. Therefore, he concludes, it is biologically caused and normal for humans.[2] One reviewer of his book wrote that it is a:

scholarly, exhaustive, and utterly convincing refutation of the notion that human homosexuality is an aberration in nature . . . Focusing primarily on mammals and birds, and citing only strictly documented case studies, he firmly establishes in part one of this work that homosexual and transgendered behaviors occur widely in the animal world. … homosexuality occurs freely and frequently in nature.[3]

Thus, since he claims that since homosexuality appears to be common in the animal world that humans evolved from, it must be normal and appropriate behavior for humans.

A major problem with Bagemihl’s book is that he defines homosexuality to include a diverse range of activities, and not specifically in the way people normally think of the term.  Most people think of homosexuality as sexual activity involving someone of the same sex, instead of the normal sexual function between members of the opposite sex (heterosexuality). In contrast to this definition, Bagemihl defines the term to include what he interprets as courtship, affection, sex, pair-bonding, and parenting.

Anyone who has a pet dog or other pet knows that animal sexual behavior is clearly not a model for human sexual behavior. Of note is that his PhD is in linguistics, not biology.

Human beings should not model their behavior on animals. For example, chimpanzees (and other mammals) commonly invade areas which are inhabited by other chimpanzees and then attempt to slaughter them, including their young. When living in groups that consist of a single dominant male and multiple females, the dominant males have a reproductive monopoly within the group. To reproduce, subordinate males normally attempt to take over the dominant role within a group, usually by an aggressive struggle with the existing dominant male. If successful, infants born by females fathered by another male are then killed. This infanticidal period is normally limited to shortly after the group is taken over.[4] Obviously, this behavior is strongly disapproved of by society for several good reasons. When it occurs in humans, strong societal condemnation, as well as severe punishment, results.

Evolutionary biology’s “poor design” way of looking at the human body makes its value to medicine dubious at best.

Claimed Benefits of Evolutionary Medicine

Supporters of evolutionary medicine claim that this new discipline is making strides in the fields of cancer treatment and antibacterial resistance. They claim to provide new understanding about how cancers, autoimmune diseases, and antimicrobial resistance develop. In practice, traditional researchers have been studying these conditions for many decades. In my work at the medical school, we used the common Norwegian white rat for research. Obviously, researchers must understand the differences and similarities between rats and humans, but in my experience the concern was similarities and differences that had nothing to do with evolution. Evolution was never mentioned, ever.

Cancer Treatment

Cancer cell clusters can change to allow tumors to grow and flourish. Gallagher outlined the large number of ways in which a tumor can evolve (actually, adapt). The number of cells that exist in a late-stage tumor could be several hundred billion.[5]  The so-called evolution of cancer cells is not evolution, but part of the cell’s designed ability to adapt. Those cells that are less vulnerable, or immune, from the effects of the cancer treatment survive to pass on their genetic traits to other cells. Thus, some highly successful cancer therapies eventually stop working in many patients because the cancer cells develop resistance to the treatment. They can then multiply, growing their population size.

Currently, the main way of treating cancer cells is using radiation to cause more mutations, killing the cells. This works because cancer cells in general have lost their ability to repair damage mostly because, by definition, cancer cells divide, then reproduce again without going into the cell cycle pause stage where cell damage is repaired. Thus, radiation disproportionately kills cancer cells, in contrast to non-cancer cells, which most often repair the damage caused by radiation.

For the last 50 years cancer treatment has involved applying the same drug, or combination of drugs, in cycles. This approach allows the majority of the cells that are resistant to the drug to increase. By continuing with the same therapy, the oncologist allows the cancer cells to proliferate so their population becomes larger, the opposite of the goal, which is to cause the cancer cells to shrink.

Adaptive therapy, by contrast, tweaks the dosage of drugs for a tailored approach, using enough treatment to keep the tumor as small as possible without eliminating the sensitive population completely. Then therapy is withdrawn. This allows the cells that are sensitive to treatment to continue jostling for space within the tumor, preventing other drug-resistant cells from dominating due to their adaptive advantage. Proponents of evolutionary medicine claim this treatment comes via insight from evolutionary theory. The evolutionary medicine

research group, which is arguably the most advanced in the field, have already shown this technique works in a small pilot trial involving patients with prostate cancer. Patients who underwent adaptive therapy received half the normal dose of a chemotherapy drug over the course of the trial, during which they spent 46% of the time receiving none at all. The time from starting the therapy to when the cancer stopped responding to treatment was 19 months longer in the group who received this adaptive therapy compared to those who underwent the standard course of chemotherapy. The patients who had adaptive therapy also had an overall survival that was 2.26 years greater than those on the standard treatment.[6]

Is adaptive therapy a benefit derived from evolutionary medicine? No. It came from experimental results described above. The researchers admit that

Maybe evolutionary medicine really is the most likely scientific perspective on dealing with big questions like these… but doctors still have to treat patients every day by working with solutions they know, tried-and-tested best practices, and little room for hypotheses.[7]

Antibacterial Resistance

The other examples cited by proponents of evolutionary medicine illustrate the same flawed rationale. For example, one of the fastest-growing problems today is antibacterial resistance:

As modern medicine has developed powerful antibiotics to annihilate harmful bacteria that infect humans and causes diseases, their widespread use has also inadvertently led bacteria to evolve through natural selection resistance to these drugs. It is estimated that antimicrobial resistant bacteria killed more people than HIV/Aids or malaria in 2019, taking more than 1.2 million lives. Currently, doctors combat diseases caused by antimicrobial-resistant bacteria by switching to other medications in the hope they will get around the bacterial defenses against other drugs. But this practice risks continuing the cycle of resistance rather than stopping it – in fact, bacteria are evolving to become more and more genetically resistant to medication.[8]

By evolution they are not referring to the normal use of the term, such as in the expression ‘the universal common ancestry of humans from bacteria by natural selection,’ but are referring to the proliferation of resistant forms of the same species. These resistant forms can often acquire genes for resistance from other species by horizontal gene transfer, not by mutation and selection. Horizontal gene transfer is a form of information sharing, not evolution.

They admit, adding: “Bacteria also develop resistance in a whole range of ways – from swapping genetic material to accumulating random mutations. As a result, evolutionary scientists are testing various different approaches to break down these pathways.”[9] This is no different from how non-evolutionary scientists work to break down these pathways. Evolutionary theory, in short, offers no new treatment advantages.


Applying the term evolution in the phrase ‘evolutionary medicine’ is nothing more than an attempt to use modern in-vogue terminology to make the research sound more impressive. Darwinists will twist words to advance their agenda: for instance, saying that the recognized 360 dog breeds ‘evolved’ from the wolf when it is more accurate to state that humans have artificially selected 360 dog breeds from the wolf by intelligent design. The examples of so-called evolutionary medicine I reviewed have nothing to do with evolution as the word is normally used. Nor do their research protocols differ from those used for the past century in doing medical research.

Evolutionary theory devalues human life. Why would doctors pay any attention to it?

Editor note: Given the awful history of social Darwinism, eugenics and racism, the last person a patient should want by the bedside is a Darwinist.


[1] Quaglia, S. “How Darwinism is changing medicine.” BBC Future;
https://www.bbc.com/future/article/20230905-how-darwinism-is-changing-medicine, 6 September 2023.

[2] Bagemihl, B. Biological Exuberance: Animal Homosexuality and Natural Diversity. St Martin’s Press, New York, NY, 1999.

[3] Kirkus Reviews, “Biological exuberance: Animal homosexuality and natural diversity;” https://www.kirkusreviews.com/book-reviews/bruce-bagemihl/biological-exuberance/, 1 November 1998,

[4] Pusey, A.E., and C. Packer. “Infanticide in lions.” In Parmigiani, S., F.S. vom Saal. (eds.). Infanticide and Parental Care. Harwood Academic Press, Chur, Switzerland, 1994.

[5] Gallagher, J. “Study reveals cancer’s ‘infinite’ ability to evolve;” https://www.bbc.com/news/health-65252510, 12 April 2023.

[6] Gallagher, 2023.

[7] Gallagher, 2023.

[8] Gallagher, 2023; emphasis added.

[9] Gallagher, 2023.

Dr. Jerry Bergman has taught biology, genetics, chemistry, biochemistry, anthropology, geology, and microbiology for over 40 years at several colleges and universities including Bowling Green State University, Medical College of Ohio where he was a research associate in experimental pathology, and The University of Toledo. He is a graduate of the Medical College of Ohio, Wayne State University in Detroit, the University of Toledo, and Bowling Green State University. He has over 1,300 publications in 12 languages and 40 books and monographs. His books and textbooks that include chapters that he authored are in over 1,800 college libraries in 27 countries. So far over 80,000 copies of the 60 books and monographs that he has authored or co-authored are in print. For more articles by Dr Bergman, see his Author Profile.

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