Limit to Lifespan Will Limit Human Knowledge
John Richard Schrock, Emporia State University
There is a long-term tension between the need for science to continue to specialize, and the calls for more interdisciplinary education.
In the late 1700s, study of medical science could be merely a matter of apprenticing under a master and passing an oral examination. There was no college coursework in the preparation of the famous doctor, William Beaumont (1785–1853). He saved the life of French fur-trapper Alexis St. Martin who accidentally shot himself in the stomach. Beaumont proceeded to study the functions of St. Martin’s stomach by dangling food on a string through the fistula left by the wound (Kelly and Burrage). His pioneer work was often featured in biology textbooks.
By the time doctor Samuel Mudd (1833–1883) repaired the broken leg of John Wilkes Booth, the assassin of President Lincoln, Mudd had spent only two years in college medical study (Mudd). It has been one of my joys in biology teaching to inform my biology sophomores that they were nearly finished with the education needed to be a medical doctor…over 150 years ago.
Today, of course, a medical education extends far beyond a college bachelor’s degree. Depending on whether a specialty is pursued, a medical doctor today may not complete training until he or she is nearly 30 years old.
Learning Takes Time
This need to learn ever more will not stop. Learning is not instantaneous; you cannot simply take a pill and immediately understand. “Meaning” is dependent upon experience, and experience takes time. A baby suspended in a sensory deprivation chamber from birth can learn nothing. Despite the assertions of Carl Sagan in his classic program “Cosmos” that the library at ancient Alexandria held a vast amount of “knowledge,” that is not knowledge but mere “information” (Sagan et al.). When a librarian hands you a book, they are handing you information, not knowledge. Whether you will understand what is in that book will depend on whether it is related to your experiences, directly or indirectly. And that is the job of a teacher and others involved in our learning. Life experiences and associated learning are the Rosetta Stone that allows us to understand, to convert the information learned by those before us and by our contemporaries into our knowledge. Simply: no experience, no meaning. And for every new discovery we add to the edge of our growing paradigms, it also gives rise to even more new questions. The universe has a complexity that extends far beyond our current understanding and there is no current evidence that we will eventually “know everything.”
New concepts also result in more new terminology. In the 1800s, the disease “consumption” referred to a sinking in of the chest; it was one generalized entity. After the new germ theory of Pasteur and Koch, and additional discoveries since then, the word “consumption” has disappeared and been replaced by over two dozen different well-defined ailments that are now recognized, from various lung cancers to viral and bacterial pneumonias to emphysema and black lung disease (Davis). Another example is infection of the liver or “hepatitis.” And, when a second cause of infection was discovered, it was separated into Hepatitis A and Hepatitis Non-A. This process of discovery advanced into Hepatitis A and B, and Hepatitis Non-AB, and continues to expand much further down the alphabet today (Kahn). Scientific terminology expands as scientific research further reveals the complexity of the real world. Our science dictionaries will continue to expand.
But we have come to see the various persons who knew everything that was known about their broad field of study die in the 1700s and 1800s. The last polymath in entomology, the study of insects, was probably Johan Christian Fabricius (1745–1808) (Tuxen). Insects are divided into many orders, and probably the last polymath for just the order Hymenoptera—the last person to know everything that was currently known about ants, bees, wasps, etc.—was John Lubbock (1834–1913) (Lubbock). And in the study of just bees (mellitology), that would be Charles Michener of the University of Kansas, who died in 2015. “There is no single individual today, and perhaps never shall be again, who has had as much firsthand experience with every lineage of bees in the field and who commands such an all-encompassing knowledge of our world’s bees” (Engel 5). Thus Michener is likely the last person who knew all there was to know at his time about bees. Now there is simply too much for any one person to learn in one lifetime about bees.
Thus, it is an absolute certainty that in the future, in order to learn more about a specific science field, the future student must narrow their focus. It will take a longer time for them to learn the expanding body of what is known and to arrive at the forefront of their specialized knowledge to conduct new research to expand their paradigm. Therefore the medical doctors of tomorrow will take longer and longer to learn their specialty. And there will be ever more narrower specialties. Just having stockpiles of information available in a print or digital library does not solve the problem of knowing enough to ask the correct question or to understand the ever more complex answers we get.
That brings us to an interesting dilemma. Despite various proclamations by various biologists that human life can be extended in the future by maintaining telomere length or otherwise manipulating factors that cause senescence (decline with aging) over time, it remains fairly certain that there is a set lifespan limit that is roughly between 115 and 120 years maximum. This is the “Hayflick limit” named for Leonard Hayflick who has carefully documented the many factors of aging (Hayflick). Unless you are a cancer or germ cell line, the number of your various body cell’s divisions is limited, and that in turn limits our lifespan. While we live under the impression that humans are living longer, in fact a few humans in ancient times lived to our maximum old age. With improvements in nutrition and human living standards, a larger percentage of us are living closer to that upper limit today. But that upper limit has not changed.
This fact of a set maximum lifespan, combined with a necessary minimal time to learn, leads to an ultimate limit to human progress. Considering that from the earliest time in childhood we detect the intellectual desires of a child, and then customize their learning into ever-narrowing fields of specialization, some future day will come when it will take a full lifetime of learning to finally master the knowledge of a specialized field to the point that would allow the specialist to propose one new experiment before reaching their Hayflick limit. This limit on lifetime therefore would in turn set a limit beyond which further scientific advancement will not be possible.
Can Group Cooperation Overcome Individual Specialization?
Now we consider the proposal to promote interdisciplinary education. While the 2020 COVID-19 pandemic has slowed overall efforts in both education and general science research, a concept I refer to as Years of Potential Intellectual Life Lost (Schrock), it has greatly expanded research related to the narrow field of the coronavirus disease agent and its origin. On January 22, 2020, a journal in virology published a paper by five authors investigating similar codon usage proposing that the coronavirus had passed from its bat origin through a snake before infecting humans. On April 14, 2020, another author in a journal in molecular biology published research asserting that the lack of a specific dinucleotide indicated that dogs were the intermediate host between bats and humans. This “finding” in particular sent fear through many dog owners. Both journals supposedly use peer review. But the broader biological and medical community was very skeptical from the beginning. While I do not know who the peer reviewers were, there was concern that both the authors and the reviewers were all molecular biologists with little understanding of snakes or dogs, an understanding of organismic biology that molecular biologists generally do not have. Finally a deeper analysis of “Susceptibility of ferrets, cats, dogs, and other domesticated animals to SARS-coronavirus 2” (Shi et. al.) was published in the journal Science on May 29, 2020 and it was co-authored by 21 researchers, some with expertise in molecular biology and some with organismic specialization, all working together. This research is better accepted, while those prior two papers are mostly disregarded.
Here we have an example where interdisciplinary research goes beyond the expertise of any one specialist and relies on each researcher understanding the mission in generality and contributing their unique expertise as a partial contribution to the whole effort. Today, we no longer educate one biologist to be expert in the molecular biology of viruses, the complexities of immune systems, and the host biology of a wide assortment of mammalian hosts. But it appears that both the authors and peer reviewers of the articles in the first two journals were so narrowly specialized that they failed to understand their limitations. But the third Science article, and similar studies since, have succeeded in combining the expertise of different specialists to perform a cross-disciplinary investigation.
This then poses the question: Can cooperation among different specialists overcome the limitations imposed by the Hayflick limit? There is no question that as scientific fields of study become narrower in the future, the solution to problems of complexity requiring a range of different expertise will require the cooperation of a variety of experts. Here the difficulty will be the ability of specialists in one branch of study to communicate in sufficient depth with specialists in another branch of study, both converging upon a shared problem, just as the molecular and zoological biologists had to understand each other in the above example. But that need for “co-understanding” does not solve the problem insofar as it takes time away from the specialization.
Breadth Prevents Depth
This problem grows greater because research is not done in a vacuum. It takes funding and political and institutional support. Folks in government therefore have to understand enough to make judgements on research funding and policy. In the case of the speculative snake and dog-intermediate host papers, a consequence to the China government was to require pre-approval of any further studies on origin of the coronavirus (Gan et al.). And unnecessary fear by dog owners was certainly a valid reason for insisting on better review. But then government officials have to be knowledgeable enough to understand their science advisors and the potential and limitations of proposed science research. And that complexity will expand. The science understanding of governmental, medical, corporate and other partners will have to grow to remain adequate to understand the expanding complexity of science. This cross-communication requirement does not solve the problem of reaching a limit to our knowledge due to the Hayflick limit. Already university administrators are relying on “bibliometrics” that merely counts citations and journal ratings in order to make decisions far beyond their ability to otherwise understand and judge the research (Biagioli and Lippman, Gingras).
That is not to deny that a broader education of an individual will bring important understanding from one area of study into solving a problem in another specialized field. My doctoral training in entomology, specifically in systematics and ecology, is critical to my functioning as an English editor to a journal on insect taxonomy. But part of my position at my university was the training of secondary biology teachers. And teaching is very much based on understanding semantics. Communication is the paradigm of education, and semantics is the central study of associating the meaning of language with experience (Hayakawa). The earlier examples used in this essay explaining experience as the basis for knowledge, and common experience as the basis for communication between teacher and student, draws directly on my accidental but fortunate participation in a college semantics class. I doubt if any science professors worldwide have any semantics course required in their background. Therefore, my ability to advance this very thesis is a result of interdisciplinary education. The extra study of semantics provided the examples above and has been essential to teaching future biology teachers over the years. Yet while that breadth of education allowed me to parse this problem in a unique perspective, I have forfeited the depth to move to the cutting edge of research in entomology. Breadth prevents depth.
We do not have an endless lifetime. The more we trim education in one growing field of specialization in order to provide more interdisciplinary education, the less time there will be to advance in the narrowing fields of specialization. One answer to this would be to carefully separate those students whose mission is to assist general society in fuller general literacy from those designated to advance a specializing field of science, realizing that any time spent with interdisciplinary learning with this second lineage will merely delay humanity eventually reaching the maximum knowledge limitation imposed by the Hayflick limit.
Biagioli, Mario; Alexandra Lippman (eds.). 2020. Gaming the Metrics: Misconduct and Manipulation in Academic Research, MIT Press.
Davis, Charles Patrick (ed.). 2021. “Medical Definition of Consumption.” MedicineNet. https://www.medicinenet.com/consumption/definition.htm
Engel, Michael. 2020. Bees in Kansas. Kansas School Naturalist, December.
Gan, Nectar; Hu, Caitlin; Watson, Ivan Watson. 2020. April 16. “China adds Restrictions to Covid-19 Research and Publication.” CNN News. 4:10 AM ET
Gingras, Yves. 2014. Bibliometrics and Research Evaluation: Uses and Abuses; MIT Press.
Hayflick, Leonard. 1994. How and Why We Age, Ballantine Books.
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Kahn, April. 2017. “What is Hepatitis.” Healthline.com. https://www.healthline.com/health/hepatitis
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