Recent discussions surrounding aging and scientific innovation have raised important questions about how scientific creativity should be measured. A recent article in Science approached this issue primarily through bibliometric and disruption-based analyses, perspectives that were subsequently discussed and amplified in other outlets, including Nature.
Still, scientific creativity may not always be fully captured through disruption metrics or bibliometric patterns alone, a concern raised in recent responses discussing the limitations of citation-based interpretations of creativity and aging in science. Innovation in science rarely emerges entirely “out of the blue.” Many transformative advances develop gradually through continuity, mentorship, experience, and the transmission of ideas within scientific communities.
Senior scientists should not be viewed as a single, uniform category detached from discovery itself. Many remain closely connected to mentorship, interpretation, conceptual guidance, peer review, and the day-to-day intellectual life of research long after reducing their direct involvement at the laboratory bench. Scientific creativity is not one-dimensional. Disruptive breakthroughs are important, but so are continuity, judgment, technical refinement, and the transmission of experience through mentorship and scientific communities over time. Consequently, scientific influence may persist even when it becomes less visible through authorship patterns, citation-based measures, or other indicators of scholarly activity.
With time, scientists often develop an intuition for emerging questions and unexpected connections between fields. Responding to an advertisement in C&EN News in early 1990, I joined the laboratory of William Pryor as a postdoctoral fellow. Although this was an exciting moment in my early scientific career, I also realized that I would be working on ozone chemistry, a field about which I had virtually no prior knowledge apart from occasional references in the news and popular discussions of atmospheric pollution. I first learned how ozone was generated experimentally only after entering the laboratory.
A similar transition later occurred in studies of nitric oxide and peroxynitrite chemistry. Although I was familiar with the field and its emerging questions, I had not previously appreciated how insights gained from ozone chemistry might provide an entry point. That perspective changed when a visiting scientist brought to my attention a 1929 article by Gleu and Roell published in a German journal, illustrating how ideas separated by decades can unexpectedly converge. The paper helped me and my colleagues develop a practical method for preparing peroxynitrite solutions of low ionic strength and free of hydrogen peroxide. The method subsequently proved useful for investigations of peroxynitrite chemistry and biology both in our work and in studies conducted by other groups. Had I trained elsewhere, I might never have entered any of these fields, and whatever work I was later able to contribute was inseparable from the scientific environments, mentorship, and laboratory traditions that helped shape it.
One lesson that emerged from these experiences was that scientific advances often arise through the integration of ideas originating in different disciplines. In ozone chemistry, many studies at the time focused on the reactions of ozone with individual amino acids, lipids, or other small molecules. Much less attention had been given to the challenge of predicting how ozone would react with an entire protein containing hundreds of amino acid residues distributed throughout different structural environments. By combining concepts from reaction kinetics, protein chemistry, and biophysical models, it became possible to examine the competitive reactions of ozone within proteins and later within increasingly complex systems containing proteins, lipids, and antioxidants, thereby providing a framework for understanding oxidations occurring in lung-lining fluids and biological membranes. The work suggested that complex biological oxidations could often be understood using relatively simple first-principles approaches.
Experiences such as these illustrate how scientific knowledge is transmitted not only through publications, but also through laboratory environments, mentorship, and countless informal interactions that rarely become part of the published record. It is often difficult to identify precisely where a scientific idea, intuition, or direction first begins to take shape.
I noticed aspects of this dynamic during interactions with my late mentor, William A. Pryor. By the later stages of his career, our scientific discussions often became surprisingly brief. During elevator rides between the first and seventh floors, meaningful exchanges could occur within moments because years of shared scientific context already lay beneath the conversation. Very little explanation was usually necessary. Such interactions rarely become visible through publication metrics, even though they may influence scientific thinking long after the conversations themselves are forgotten.
On one occasion, Pryor asked whether I was interested in working on beta-carotene oxidation and related reactions. I replied that others in the group were already pursuing aspects of the problem. He simply responded that he wanted “bold science” or “some surprises” to emerge from the work. The exchange lasted only moments, yet it reflected an aspect of scientific influence not easily captured through publication metrics alone.
Many highly visible discoveries attributed to younger investigators may also emerge from scientific environments shaped gradually over decades by earlier generations of researchers. The early conceptual development of PCR offers an interesting historical example. In 1971, more than a decade before Kary Mullis developed and popularized PCR, researchers in the laboratory of Har Gobind Khorana had already described a remarkably similar concept involving repeated cycles of primer-directed DNA synthesis using DNA polymerase. What later appeared highly disruptive emerged gradually from earlier advances in enzymology, nucleic acid chemistry, and synthetic oligonucleotide technology developed over many years. Some discoveries that later appear disruptive may have existed earlier as unexpressed scientific intuitions awaiting the right conceptual, technical, or historical conditions to emerge. Such examples suggest that scientific breakthroughs often depend not only on individual perseverance, but also on the preservation and transmission of prior scientific knowledge.
Older investigators may not always appear as the first author performing experiments or as the senior author directing an active laboratory. Some step back from fully independent research while continuing to contribute through mentorship, criticism, interpretation, and scientific judgment accumulated through experience. Such contributions may be difficult to recognize through authorship patterns or citation-based measures alone.
Modern citation practices may not always reflect the historical influence of scientific ideas, nor do citation patterns alone define paradigm-changing creativity. Foundational work can gradually fade from immediate visibility while continuing to influence later discoveries. Search engines, review articles, and evolving citation habits increasingly shape which scientific contributions remain visible and widely cited. Yet scientific influence often persists long after visibility declines.
The structure supporting science extends beyond publications alone. Mentorship, peer review, laboratory culture, and the passing of experience across generations all contribute to scientific continuity. Much of scientific evaluation begins internally through reflection, criticism, discussion, and repeated questioning long before formal peer review occurs. Scientific writing is also shaped gradually by mentors, colleagues, students, and reviewers whose influence may never become fully visible in the final published work.
I often tell students that scientific problems exist on different timescales: Some can be solved within weeks or months and provide immediate gratification; others may require years of sustained effort; and some may never be solved within a single lifetime, yet still remain worth pursuing. There is always the hope that someone, someday, may carry such questions forward.
Science progresses through both renewal and continuity. Many transformative discoveries emerge not through disruption alone, but from scientific communities in which ideas, experience, and mentorship continue across generations. Scientific innovation may therefore depend not simply on disruption itself, but also on preserving the intellectual continuity that allows ideas to develop across generations.
Rao M. Uppu is professor of environmental toxicology and chemistry at Southern University and A&M College in Baton Rouge, Louisiana, where he has served since 2002. He is also an adjunct professor of chemistry and pathobiological sciences at Louisiana State University.
Trained in biochemistry, physical organic chemistry, and free radical chemistry, his research spans bioanalytical methods, biomarker discovery and validation, chemical toxicology, environmental chemistry, computational genomics, reactive intermediates, and the molecular mechanisms of disease. His scholarship is indexed on ORCID, ResearchGate, and Google Scholar.
Dr. Uppu is a Fellow of the American Association for the Advancement of Science (AAAS), the Royal Society of Chemistry (RSC), the Royal Society of Biology (RSB), the Royal Society of Medicine (RSM), the Royal Society for Public Health (RSPH), and the Academy of Toxicological Sciences (ATS).
In addition to his scientific research, he writes reflective essays on scientific culture, mentorship, peer review, ethics, and the human dimensions of academic life. He shares updates on LinkedIn.
