Why would natural selection leave us vulnerable to disease? Exploring the evolutionary paradox at the heart of human health.
Why would natural selection, the process that crafted our remarkably resilient bodies, leave us vulnerable to cancer, infections, and debilitating back pain? This paradox lies at the heart of Darwinian medicine, a field that applies evolutionary principles to understand human health and disease. Also known as evolutionary medicine, this discipline challenges the conventional view of the body as a perfectly designed machine, suggesting instead that it's a bundle of compromises shaped by evolutionary pressures 5 .
The field gained formal recognition in 1991 when evolutionary biologist George Williams and physician Randolph Nesse published their seminal paper "The Dawn of Darwinian Medicine" 8 . They argued that we remain vulnerable to disease not because of design flaws but because evolution prioritizes reproductive success, not perfect health or longevity 5 . Despite this compelling framework, medicine has been slow to embrace its evolutionary heritage. As we'll discover, research suggests that medical science largely overlooks these evolutionary perspectives, potentially missing crucial insights into treatment and prevention .
Our bodies reflect trade-offs, not perfect designs
Understanding disease vulnerability through evolution
Evolutionary perspectives remain underutilized
Darwinian medicine uses evolutionary biology to answer fundamental questions about why we get sick. Rather than focusing solely on how diseases operate (proximate explanations), it seeks to understand why we've evolved to be vulnerable to them in the first place (evolutionary explanations) 5 . This approach provides powerful insights into five key areas:
Many modern ailments result from disparities between our current environment and the conditions in which we evolved. Our bodies adapted to environments where nutrient-dense foods were scarce, calories burned through daily activity, and threats were immediate physical dangers. In today's world of abundant processed foods, sedentary lifestyles, and chronic psychological stress, these same adaptations contribute to obesity, diabetes, and heart disease 5 8 .
The relentless arms race between pathogens and our immune systems drives much of infectious disease. Bacteria evolve resistance to antibiotics, viruses mutate to evade our immune defenses, and this evolutionary tango shapes the virulence and transmissibility of diseases from COVID-19 to malaria 5 . Understanding these dynamics is crucial for managing pandemics and developing long-term treatment strategies.
Evolution works with what's available, not with ideal designs. The narrow human birth canal, a compromise between bipedal locomotion and large-brained infants, creates obstetric challenges unknown in other primates 5 . Similarly, our backwards-wired retina with its blind spot represents an evolutionary constraint compared to the better-designed octopus eye 5 .
Cancers represent evolutionary microcosms within the body, where cells develop mutations that help them cheat the cooperative systems of multicellular life 4 . Viewing cancer through an evolutionary lens has inspired innovative approaches like adaptive therapy, which aims to manage rather than eliminate tumors to prevent resistant cells from taking over 4 .
"Many disease symptoms aren't problems themselves but evolved protections. Fever fights infection by raising body temperature to inhospitable levels for pathogens, while cough expels pulmonary secretions 3 . The 'smoke-detector principle' explains why we experience false alarms—the cost of excessive inflammation is minor compared to the cost of not mounting a defense when needed 5 ."
Just how prevalent are evolutionary concepts in mainstream medical science? A groundbreaking 2023 bibliometric study conducted by Brazilian researchers sought to answer this question by systematically analyzing how biological evolution concepts appear in medical literature .
The research team created two sophisticated databases to capture different aspects of medical publishing:
The researchers implemented an elaborate filtering system using PubMed to exclude non-biological uses of "evolution" (such as "evolution of surgical techniques" or "patient evolution") while retaining articles employing biological evolution concepts. Each identified article underwent manual textual analysis to confirm it genuinely incorporated evolutionary principles .
Top Medical Journals
Articles with "Evolution*"
Articles in Broad Medical Journals
The findings revealed a striking gap between the potential importance of evolutionary medicine and its actual presence in medical research:
| Database | Total Articles with "Evolution*" | Articles with Biological Evolution Concepts | Percentage |
|---|---|---|---|
| Top 50 Journals | 2,219 | 1,647 | 74.1% |
| Broad Medical Journals | 6,842 | 1,092 | 16.0% |
The data demonstrates that only a small minority of medical research incorporates evolutionary perspectives, with even the most prominent journals containing biological evolution concepts in less than three-quarters of articles that use the word "evolution"—and much less in broader medical literature . This scarcity is particularly pronounced in applied medical fields compared to basic science journals .
The researchers concluded that this omission potentially hampers the development of new ideas in treating human diseases and suggested that incorporating evolutionary concepts into medical curricula could better equip physicians to understand how evolution shapes human health .
Evolutionary medicine research employs sophisticated tools to unravel the deep evolutionary stories written in our genes, cells, and physiological responses. Here are some essential technologies driving the field forward:
Biomark X9 System 9
Automated analysis of genetic variations across populations for tracking gene frequencies, identifying mutations, and studying antibiotic resistance.
CyTOF/IMC 9
Detailed determination of cellular functional diversity for understanding distinct immune signatures and characterizing proteins for therapeutic development.
SomaScan Platform 9
Simultaneous measurement of thousands of proteins for identifying biomarkers and determining disease dynamics across half the human proteome.
3D cell culture models replicating human tissue complexity for drug testing, evaluating therapeutic responses, and understanding disease mechanisms.
Non-invasive, real-time tracking of biological processes for monitoring disease progression and therapeutic responses in pre-clinical research.
AlphaLISA 7
No-wash detection and quantification of specific proteins for precise measurement of viral vectors like AAV in gene therapy development.
These technologies enable researchers to move beyond theoretical speculation to rigorous empirical testing of evolutionary hypotheses about health and disease. For instance, mass cytometry helps unravel how immune systems have evolved different strategies across species, while genomic tools track the evolutionary arms race between pathogens and their hosts in real time 9 .
Darwinian medicine represents both a paradigm and a paradox—a framework with tremendous potential for sparking transformational innovation in biomedicine, yet one that remains underutilized in mainstream medical research and practice 4 . Its value lies not in replacing traditional medicine but in complementing it with deeper explanations for why we remain vulnerable to disease despite eons of evolution 8 .
Evolutionary concepts are rarely included in medical curricula
Limited resources allocated to evolutionary medicine studies
Requires changing how physicians think about disease causation
As the Brazilian bibliometric study revealed, the greatest challenge may not be generating evolutionary insights but convincing the medical establishment to embrace them . Perhaps the next dawn of Darwinian medicine will arrive when evolution becomes not just an optional perspective but a fundamental component of how we understand, treat, and prevent human disease. In the words of Theodosius Dobzhansky, "nothing in biology makes sense except in the light of evolution"—including the medicine we practice on our evolving bodies .