“Evolutionary Medicine Needs Engineering Expertise”
by Randolph M Nesse,
The National Academy of Engineering “Perspectives.”
“Engineering has made vast contributions to health and medicine, from designing water and sewer systems that have saved millions of lives to optimizing healthcare delivery systems and creating ever more sophisticated medical devices. New applications of evolutionary biology to medicine are now giving rise to new opportunities for engineering to enhance understanding of disease. Projects that bring engineering expertise to bear on the questions addressed by evolutionary medicine promise major advances.
What Is Evolutionary Medicine?
Evolutionary medicine is the field that uses the principles of evolutionary biology to better understand, prevent, and treat disease. Medicine has made great progress by viewing the body from a mechanic’s point of view—asking how it works, what has gone wrong, and how to fix it. Evolutionary medicine adds an engineer’s point of view by also asking why natural selection left so many aspects of the body vulnerable to disease.
Naïve attempts to answer such questions sometimes suggest that diseases like cancer, schizophrenia, and diabetes somehow give advantages, but such explanations are almost always wrong. Diseases are not adaptations shaped by natural selection, so they do not have direct evolutionary explanations.
The correct objects of evolutionary explanation are traits that leave humans vulnerable to diseases and problems. Why is the windpipe located where food can block it? Why is the birth passage obstructed by a narrow ring of bone? Why hasn’t natural selection provided better protection against infection? Can an answer to that question help to explain the prevalence of excessive inflammation that causes autoimmune diseases, atherosclerosis, and Alzheimer’s disease? Why are pain, anxiety, and depression often excessive? Why are people vulnerable to obesity, eating disorders, and addiction? And why hasn’t natural selection provided better protection against cancer?