In the summer of 2011, I had the incredible opportunity to spend five weeks at the Marine Biological Laboratory in Woods Hole. It stands out as a must-visit destination for biologists, irrespective of their research focus. Unfortunately, many miss out on this invaluable experience. My time at MBL exceeded my expectations, just as my visits to The Captain Kidd did. My only regrets are not arriving sooner and likely not being able to return.
In an article titled Chance Favors the Curious: How Serendipity Drives Scientific Discovery, published in MBL News on July 31, 2026, the focuses on the work of Sidney L. Tamm. I have followed his career at a distance since the 1970s and had the honor of meeting him during a small scientific gathering in 2016. We engaged in a friendly debate concerning which current organism is most akin to our earliest animal ancestors. [1]
This conversation reinforced my belief that the scientific community would benefit from greater awareness of Dr. Tamm’s research. For biologists seeking discovery, it is crucial to remain vigilant for the unusual, as the most significant findings often lurk in unexpected places. As highlighted in Chance Favors the Curious:
Tamm’s serendipitous journey began in the 1970s with a termite-infested grapefruit tree. A colleague from Indiana University had donated the tree’s logs to Tamm, who was researching protozoa in termite hindguts. When an undergraduate student examined the one-celled microbes, he reported an unusual finding: a protozoan’s head rotated in the opposite direction to its body. Tamm realized this phenomenon indicated the protozoan’s cell membrane must be fluid.
Upon further investigation, Tamm confirmed his theory, even though the concept of a fluid cell membrane contradicted prevailing beliefs. “People were very skeptical,” he recalled, as no one had visualized a fluid membrane until then, despite earlier proposals. While acceptance took time, Tamm’s finding eventually became foundational knowledge in biology textbooks.
Dr. Tamm has elaborated on his discoveries in Novel Cell Motility of Protozoa Living in the Hindgut of Termites, published in the independent online Journal of Trial & Error:
A remarkable symbiotic protozoan in the hindgut of termites was discovered by chance. Its head and body rotate continuously in opposite directions without stopping or changing direction. This rotation includes the plasma membrane of each cell part, demonstrating that the membrane is continuous across the surface shear zone. This protozoan provides direct visual evidence for the fluid nature of cell membranes and is the first known example of a rotary motor in eukaryotic cells. The rotary motor, called an axostyle, runs through the protozoan like a driveshaft, generating torque along its length. The entire plasma membrane is fluid and adheres to the underlying cytoplasm and cytoskeleton, passively following its movements. It is evident that the cell membrane does not dictate cell shape or motion. Ectosymbiotic rod bacteria, which are flagellated, propel the protozoan, marking the first known instance of prokaryotic flagella driving eukaryotic cell locomotion.
Why is this significant? The initial observation of membrane fluidity emerged during the second golden age of cell biology, a time when the discipline evolved from static cytology, which characterized its first golden age. [2] Twenty years of trial and error resulted in the first comprehensive model of biological membranes, published in Science in 1972 by S.J. Singer [3] and Garth L. Nicholson. I still recommend this paper to my students, and some even take the time to read The Fluid Mosaic Model of the structure of Cell Membranes (subscription required). These students are poised to become outstanding scientists and physicians.
The term “fluid” holds particular significance. Without fluidity, cell membranes cannot function effectively in cell division, motility, or the transmission of external signals into the cell—essential for processes such as cancer progression. Establishing the fluid nature of membranes posed a challenge when the fluid mosaic model was first proposed. Sidney Tamm and his wife, Signhild, provided Direct Evidence for Fluid Membranes (1974) around the same time others began using different methods to demonstrate this concept. The Tamm duo remained receptive to new evidence while investigating the seemingly unusual organisms residing in termite guts, facilitating wood digestion.
Dr. Tamm’s second chance discovery involved identifying the first rotary motion in cells, powered by ATP, commonly referred to as the “energy currency of the cell”:
An additional groundbreaking observation was the rotary mechanism that facilitates the head’s rotation relative to the body of Caduceia, the first example of a rotary motor in higher (eukaryotic) cells. Fortuitous observations and inhibitor experiments suggested that the four flagella—akin to sperm cell tails—originating from the head do not facilitate movement. Instead, the motor operates internally, composed of a cytoskeletal rod (axostyle) that functions like a driveshaft from the head to the posterior end, and utilizes ATP as its energy source… Surprisingly, the molecular basis behind the force generated by this rotary motor remains undetermined. One unexplored question is: Why do different parts of the cell rotate at all? What purpose do the opposing rotations of the head and body serve?
The third serendipitous discovery uncovered the symbiotic relationship between the termite hindgut protozoan Caduceia versatillis and bacteria:
I also noticed that the 2,000 to 3,000 ectosymbiotic rod bacteria attached to the protozoan’s head and body were arranged end-to-end in parallel rows of specialized open pockets within the cell membrane. Remarkably, the rod bacteria possessed bacterial flagella on their exposed sides, despite typically remaining attached to the protozoan host. Unlike eukaryotic flagella, which are structurally more complex, prokaryotic flagella are simpler.
This led me to realize that the flagella of the attached rod bacteria likely contribute to the vigorous gliding motion of Caduceia. I then conducted extensive experiments to explore this notion.
Locomotion of Caduceia is powered not by the cell’s own flagella or its rotary axostyle but rather by the flagella of thousands of rod bacteria residing on its surface. Since bacterial flagella rotate, an intriguing feature of this system is that the surface governed by prokaryotic rotary motors is turned by the eukaryotic rotary motor within.
Why is this important? While it has been established for over a century that the termite gut is home to various organisms (pdf), this case illustrates the critical interdependence of bacterial and protozoan symbiosis within an animal’s gut, or as we now refer to it, the microbiome. Contemporary research connects our microbiome to various aspects of human health and disease. This research foreshadowed the idea that a healthy microbiome is integral to well-being rather than merely being associated with illness.
On a broader scale, the importance lies in the fact that discoveries in biology often arise from serendipity combined with the ability to perceive new questions from the available data, even if the answers come indirectly. Biology, unlike cosmology, astrophysics, physics, and chemistry, reflects the effects of three billion years of evolutionary tinkering since life began on Earth. For instance, my preferred protein has a two-billion-year evolutionary lineage tracing back to the divergence of plants and animals. Hence, studying it requires treating it as a unique entity, albeit one evolving from a complex, multi-component assembly, having transformed from a mere three or four proteins in our primitive ancestors to over fifty in humans. Consider the constancy of sodium atoms or Higgs bosons, which are uniform across examples.
As Dr. Tamm articulates:
I stumbled upon this remarkable protozoan, though it was not something I was actively seeking. A series of fortunate encounters and clarity of thought led to three significant discoveries about protozoa and cellular function: (1) cell membranes are visually fluid, allowing unidirectional rotational shear between various regions; (2) the rotary motor in the most researched protozoan functions as a cytoskeletal driveshaft that produces consistent relative torque; and (3) the flagella of numerous ectosymbiotic rod bacteria can propel the host cell. These unexpected revelations have reshaped our understanding of prokaryotic and eukaryotic cellular functions and their beneficial coexistence.
Furthermore, Dr. Tamm’s research has primarily occurred at MBL, a place that has significantly contributed to biological knowledge. However, similar laboratories now face challenges, particularly due to the increasing emphasis on the commercialization of biological research following the Bayh-Dole Act of 1980. This issue was recently highlighted in an article titled Saving Science by the Sea by Susan Fitzpatrick and Jane Maienschein [4]:
As funding for science contracts throughout the United States, attention has shifted to the challenges confronting universities and biomedical research institutions. However, a critical part of the nation’s scientific ecosystem lies in small, independent marine laboratories, which face significant budget cuts and constraints from the Trump administration. These establishments have nurtured generations of scientists—from high school students to Nobel laureates—and facilitated discoveries that have propelled modern science. Their uncertain future could lead to the loss of a vital nexus of research and education, which has fueled substantial scientific advancements.
Marine laboratories occupy a unique niche. While largely independent, they often collaborate with universities by sharing faculty, facilities, or resources. These spaces host students and scientists for various durations, mixing different disciplines and experience levels, effectively breaking down rigid academic barriers across the life sciences—from molecular to microbial to ecological. The transient nature of participation fosters urgency to think creatively and challenge assumptions, leading to innovative problem-solving. Individuals come together to work intensively within this collaborative environment, sharing ideas over meals and engaging in late-night debates about challenging questions. They collaborate, live, and revel in the excitement of discovery together.
A single example suffices to illustrate the prolific output of these laboratories, as highlighted in an interview with Tim Hunt, whose research on sea urchins revealed vital insights into cell division control that had previously remained obscure:
Tim Hunt earned an undergraduate degree in Natural Sciences from Cambridge in 1964. His PhD research and subsequent work pertained to protein synthesis regulation until 1982 when his serendipitous discovery of the central cell cycle regulator cyclin while teaching at the Marine Biological Laboratory in Woods Hole redirected his focus to cell cycle regulation. From 1990 until retirement, Tim’s work took place at Cancer Research UK’s Clare Hall Laboratories. He was awarded the Nobel Prize in Physiology and Medicine in 2001 alongside Lee Hartwell and Paul Nurse, whose research also involved evolutionarily distinct yeasts, discussing the coincidences that led to their groundbreaking discovery.
While cyclins are now crucial targets for chemotherapeutic agents against cancer, it is safe to assert that none of this research would align with the current administration’s “priorities.” The opportunity costs of losing these laboratories—where countless students and scientists collaborated to tackle important questions—are incalculable, yet significant.
This research could be generously supported indefinitely for the cost of a single Ford-class aircraft carrier. The effectiveness of such research is another critical aspect worthy of consideration as we deliberate over the future of our ongoing militarization and its implications.
Notes
[1] Without delving too deeply into specifics, this creature may be Trichoplax adhaerens, which until recently was the sole representative of the Placozoa phylum; three more placozoan species have been identified recently, with the potential for more discoveries. Individual placozoans are motile sheets comprising several cell types and are often found in saltwater aquariums. They exhibit animal-like life cycles. Learn more about Trichoplax here. Given the genome of Trichoplax adhaerens, it is a strong candidate for the first animal (ongoing research).
[2] The first golden age of cytology/cell biology was defined by E.B. Wilson in his The Cell in Development and Heredity (1896, 1915, 1925). The third edition should be required reading for all cell biologists, yet it remains underappreciated, even when I offer it to students. Initially, the flagship Journal of Cell Biology (Rockefeller University Press) was called the Journal of Biophysical and Biochemical Cytology. Cytology mainly focused on descriptive studies, utilizing biochemical and biophysical methods. Cells were typically analyzed biochemically after being homogenized, or were examined microscopically. This led to increasingly mechanistic explanations of cellular behavior. Among the original editors of this journal, Albert Lehninger, a biochemist focused on bioenergetics (authored the foremost textbook on biochemistry), George Palade, awarded a Nobel Prize for contributions regarding the structure and function of cells, and Keith R. Porter, who harnessed electron microscopy and earned the title “The Father of Cell Biology,” despite not receiving a Nobel Prize. Interestingly, the late Barbara Ehrenreich earned her PhD in cell biology from Rockefeller University before becoming a prominent societal critic who defined the Professional Managerial Class (PMC).
[3] S.J. Singer also co-authored the paper from Linus Pauling’s research group that identified sickle cell anemia as the first genetic disease caused by a mutation in hemoglobin that leads to cell polymerization, resulting in sickle-shaped red blood cells: Sickle Cell Anemia: A Molecular Disease. The remarkable aspect of this paper lies in its comprehensive account of sickle cell disease, published in 1949.
[4] Jane Maienschein has been a prominent historian of biology for four decades. Her Defining Biology: Lectures from the 1890s (Harvard University Press, 1986) serves as a key resource for understanding the contributions of pioneering biologists as experimental biology matured into a scientific discipline. The lectures collected in the book were delivered at MBL by notable figures such as E.B. Wilson, Wilhelm Roux, E.G. Conklin, Thomas Hunt Morgan, and Jacques Loeb, among others. Equivalent marine laboratories exist in Plymouth, Roscoff, Naples, and Friday Harbor.
