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Starting From the End

Guest Commentary by Richard M. Plotzker, MD
July 5, 2018 | Comments


Editor’s Note: Richard M. Plotzker, MD works as an endocrinologist at Mercy Philadelphia Hospital.  He writes about endocrinology in contemporary practice. His Hormone Happenings series can be found HERE.Dr. Plotkzer is a regular commenter on Critica’s Facebook page and a fellow alum of the University of Pennsylvania.

        Reporting science accurately in a way that people understand it and, sometimes alter their beliefs or loyalty to authority, has been a challenge that probably predates Gallileo’s strained but ultimately successful challenge to geocentrism.  As a physician, some of what I was taught in medical school turned out to be wrong. When evidence shapes actions, abandoning the erroneous comes easily. When it challenges what your revered teacher taught you, whether about the nature and management of obesity in my medical practice or about the origins of man, those beliefs become more difficult to challenge.  I was taught a new version of the diabetic diet about every four years. By the fourth cycle I figured out that none were any good and just prescribed medicine rather than changing ingrained feeding behavior of individuals in a likely unsuccessful effort, though never ignoring the possibilities of what diet modification could do, but probably won’t happen. Science is ultimately about reality, or what the evidence leads us to think that reality is, subject to influence by more science and new evidence.  

        Today, scientists are much chagrined by those who deny the science of evolution in favor of something variously called “intelligent design.” We even decry the phrase “theory of evolution,” insisting that evolution is not theoretical, but settled science. Yet arguing in this way puts us up against people who hold fast to religious tenets of how the universe was created, even to the point of insisting that humans and dinosaurs once coexisted. Perhaps we are taking on this battle from the wrong end.

        Rather than starting by emphasizing the clash between science and religion, perhaps we should begin at the other end with facts both sides embrace. Since the resistance to accepting science often has a religious or political basis, I’ll start with the example of two religious and political opponents who took a different view of most of what they were asked to rule upon.

“and the Law is according to Hillel”

        For those who never had to endure Hebrew School, there is a traditional dispute between the followers of two Sages, Hillel and Shammai, which took place in Roman times. They disputed all sorts of practices but remained personally cordial.  Both positions were recorded in Talmud, much like we have majority and minority positions on Supreme Court rulings. But they could not both prevail. Ongoing practice nearly always went in the direction of the generally more lenient Hillel.

        We have perhaps rediscovered some of their traditional dispute in the realities of science and some of the organized opposition to it but natural law has to prevail, even amid its uncertainties. Immunization prevents diseases, the earth is warmer than it once was with natural consequences to follow, and gene mutations occur and are propagated, making a firm foundation for fighting diseases and enhancing food supply.  The law is according to science and the progress of our lives, accepted universally, depends of it, even among its most vociferous opposition.

        Rather than toss slogans or display placards, it may be more useful to work in the reverse direction, starting with those applications that are already accepted without controversy and working backwards to the original insight that had no proof at the time but turned out to be correct.  As one who treats diabetes professionally, the development of insulin illustrates the point quite well. All insulin deficient diabetics have their lives extended with daily insulin injections and accept their doctors’ judgment on this, hesitant at first sometimes, but loyal to that treatment once they start feeling good because of it.  The original insulins, used in routine care for about 60 years, were harvested from cattle and swine. It turns out that the insulin protein in the cow differs by three amino acids (the building blocks of proteins) from that of humans, and the hog differs by one amino acid. These variants occurred at some point in the evolution process and were propagated by each species from one generation to the next. Although lifesaving, even these seemingly small structural deviations from the human insulin protein caused some problems for patients who are insulin-dependent.

        By the mid 1980’s, armed with an understanding of how genetic mutations and evolution work, scientists were able to create yeast in the laboratory that make an insulin protein identical to the human sequence. Even that original protein has subsequently been changed, first in the laboratory and then on a commercial scale, to create insulin proteins not found in nature but with properties that are safer for patients and more useful medically.  

        This triumph of genetic engineering is, unfortunately, balanced by the challenge we now face by “superbugs,” microbes that were of no consequence when I attended medical school but devastate immunologically compromised patients now, including people with HIV infection and undergoing chemotherapy for cancer.  Superbugs are bacteria that have figured out ways of eluding antibiotics by undergoing genetic mutations. While these pathogens did not exist in the 1970’s, their emergence was predicted even before they began infecting people because scientists noticed that mutations of bacterial colonies in laboratory petri dishes made them resistant to the antibiotics being used. Our indiscriminate use of antibiotics, both those given to livestock we eventually consume and those mistakenly prescribed for viral illness, allowed bacteria ample opportunity to mutate to antibiotic-resistant species. Today, antibiotic-resistant bacteria make treating diseases once thought solved, including tuberculosis and gonorrhea, suddenly major clinical challenges to overcome.

        Fortunately, the pharmaceutical industry understands this process and continuously creates the more sophisticated antibiotics. It is an ongoing battle between rapidly mutating bacteria and laboratory scientists, but our  ability to stay one step ahead of the superbugs depends on an understanding of evolution at a microscopic level, not quite appreciated by Darwin at the time for what it was, but successfully applied by others later from the basic principle.

        The same is true about the food supply, where selective breeding of crops to produce higher yields and less loss at the farm goes back to the 19th century. Enjoying corn on the cob and whole wheat bread are not politically controversial or religiously suspect, even though the existence of these products depended on decades of cross-breeding based on genetic principles.

       While one’s beliefs are important, imprinted largely indelibly, typically with the same parent to child propagation as one’s genes, there is also an operating reality that sometimes diverges from what we are taught.  It may be better, as these realities of science are conveyed with some public resistance, to begin at the non-controversial conclusion and work backwards to the transforming insights that created those benefits that we have already accepted.  Evolution on a molecular or chemical level has been the way of the world, something observed in a hospital every hour, though not always recognized as an offshoot of evolution, applicable in both anthropology where it causes discomfort to some and in medical care where the consequences of that same principle are accepted with little opposition.

       Perhaps when confronting those who deny the science of evolution, we should start by seeking agreement that everyone is happy we have perfected the insulin we give to diabetics, understand how bacteria became resistant to antibiotics, and can enjoy corn-on-cob. From there we can point out that none of these innovations is possible without a thorough understanding of the way evolution shapes biology through the mutation of genes. Rather than starting out with first principles, evolution versus creationism, let’s consider starting at the other end.

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