Brilliant ideas from physics are quietly reshaping the way we understand life itself — and Boris Shraiman is one of the rare minds leading that charge. And this is the part most people miss: he still insists he’s “just” a physicist, even as his work changes how biologists think about evolution, development, and information in living systems.
Boris Shraiman, a theoretical physicist at UC Santa Barbara, has built a career that wanders boldly across disciplines while earning deep respect and major awards along the way. A recent highlight is the American Physical Society’s Max Delbrück Prize in Biological Physics, recognizing his influential contributions to morphogenesis, evolution, and biological information processing. Instead of following a narrow path, he has embraced an intellectually adventurous journey that keeps leading to new questions at the frontier of science.
The citation for his prize emphasizes a rare combination of strengths: deep command of biological facts, creative ways of analyzing complex biological data, and rigorous theoretical thinking usually associated with physics. In practice, this means he does not just collect data or write equations in isolation; he uses both together to uncover general principles behind how living systems behave. Put simply, he looks for the hidden rules underneath the chaos of biology and tries to express them in clean, testable theories.
Yet, despite his strong presence in biology, Shraiman fundamentally identifies as a theoretical physicist. His own description is disarmingly simple: he is a physicist who happens to work on biological problems. He finds it remarkable that relatively simple theoretical ideas can still make accurate predictions in a domain as messy and complicated as living organisms. That perspective itself can be controversial: should biology be reduced to simple rules, or is it inherently too complex? It’s a question that quietly sits underneath much of his work.
Shraiman is quick to share credit for his success. He describes the prize as a collective achievement made possible by a remarkable group of collaborators and the stimulating environment at his institute and department. He holds the Susan F. Gurley Professorship of Theoretical Physics and Biology at the Kavli Institute for Theoretical Physics (KITP) and within UCSB’s Physics Department, positions that reflect his hybrid role. While he appreciates having his past work recognized, he says his attention is pulled more strongly toward the projects on his desk right now — and he believes his most important discoveries may still lie ahead.
Colleagues say his influence extends well beyond his own papers. At KITP, his research has helped shape the institute’s identity and direction, especially in the area where physics meets biology. KITP Director Lars Bildsten has praised both Shraiman’s pioneering theoretical contributions and his role in building community. One major example is the Santa Barbara Advanced School of Quantitative Biology, an annual program he curates that brings together experimentalists, theorists, and early-career scientists from around the world. Through these intense summer sessions, he has nurtured an international network of researchers who learn to speak across disciplinary boundaries — something that can quietly shift how a whole field grows.
A big part of Shraiman’s story is how freely he has moved between topics. Trained at Harvard as a theoretical physicist with a focus on statistical physics, he did not limit himself to the subjects of his formal education. He often compares theorists to herders rather than farmers: instead of cultivating a single patch of land year after year, they roam from one intellectual field to another, tending a “flock” of ideas and looking for interesting problems wherever they appear. That mindset helps explain the surprising turns his career has taken.
He began by exploring emergent complexity, asking how simple rules can generate intricate, sometimes chaotic patterns. Concrete examples include the whirling motion of fluids and the branching structures seen in dendritic growth, such as frost patterns or crystal formations. This interest naturally pulled him into quantum materials while he was at Bell Labs in the late 1980s, a time when that lab buzzed with excitement following the discovery of high-temperature superconductors. It was a perfect environment for someone drawn to complex behavior arising from simple underlying physics.
Bell Labs also housed a pioneering group working on biological computation, born in the late 1980s and influenced by ideas from physicist John Hopfield, who would later receive the 2024 Nobel Prize in Physics. Shraiman initially connected with this group informally, sharing lunches with them and eventually joining their journal club. What started as casual conversation turned into a gateway to an entirely new domain of questions.
He recalls that early exposure to modern biology as both exhilarating and humbling. Surrounded by experts in a field he had never formally studied, he quickly realized how little he knew. Instead of being discouraged, he treated that gap as an invitation, diving in by tackling assorted open problems as a way to learn. This “learn by doing” approach is familiar to many theorists: rather than reading everything first, they pick a problem and let the necessary background accumulate around it.
Ironically, the concept of entropy — which he has studied in physics — almost seems to have pushed him into biology. Given how many interesting unsolved questions existed there at the time, the odds of his curiosity landing on a biological problem were high. Gradually, his focus shifted away from quantum materials and toward this new territory full of messy data, intricate mechanisms, and underlying patterns waiting to be uncovered.
He often emphasizes how special the Bell Labs environment was. With few distractions from administrative duties and no pressure to chase specific grants, he had the freedom to pursue whatever scientific questions genuinely fascinated him. That freedom made it possible to make a full “field switch” from more traditional physics topics into the emerging world of biological physics — a shift that might have been far more difficult in a more rigid or metrics-driven setting.
Today, most of Shraiman’s work sits in the area often called the physics of living systems, which lies at the interface between physics and quantitative biology. One major focus has been morphogenesis: the process by which a seemingly simple cluster of cells grows into a complex structure, like a limb, an organ, or an entire organism. For non-specialists, this is the question of how a “featureless” embryo knows how to build a correctly shaped body.
In modern biology, cell differentiation — how identical stem cells gradually specialize into different cell types — has become a major area of research, with huge implications from regenerative medicine to cancer. Many scientists concentrate on how intricate patterns of gene expression and biochemical signaling guide these changes. Shraiman agrees those factors are crucial, but he emphasizes that there is another equally important piece of the puzzle: the physical shape of tissues and organs themselves. But here’s where it gets controversial: can you really understand development without seriously accounting for mechanics and geometry?
He frames a core question this way: how is geometric information stored and used during growth so that a collection of dividing and moving cells reliably produces a specific shape? Cells are not passive; they push, pull, and jostle one another as tissues form. Traditionally, molecular biology and genetics have focused on chemical signals and genetic instructions, leaving the mechanical side — the literal forces and deformations — relatively underexplored. Shraiman argues that this “humble mechanics” deserves a starring role.
This view has led him into mechano-biology, a field that studies how mechanical forces and stresses between cells influence tissue development and behavior. When he joined KITP as a permanent member about two decades ago, mechano-biology was just beginning to coalesce as a distinct area of research, blending ideas from physics, engineering, and cell biology. In many ways, he was helping build the road while walking on it.
The mechanics involved in morphogenesis are not the same as the mechanics taught in standard physics courses, which usually deal with passive materials like solids and fluids that respond to external forces but do not generate their own. Living tissues, by contrast, actively produce forces — think of muscles contracting — and constantly rearrange their internal structures in response to signals from genes and biochemical feedback loops. Modeling this kind of matter requires new concepts and equations that link physical forces to biological control systems. It’s a challenge that naturally attracts theorists who enjoy working where existing frameworks start to break down.
Beyond development, the Delbrück Prize also recognizes Shraiman’s long-standing interest in evolutionary dynamics, particularly through the lens of statistical genetics. In very simple terms, statistical genetics uses tools from probability and statistics to understand how genetic variation changes in populations over time. Shraiman focuses on how selection acts when genes are not isolated, but constantly interacting and reshuffling.
In every generation, reproduction shuffles genetic material through processes like recombination and horizontal gene transfer. As a result, different versions of genes — called alleles — keep swapping genomic neighbors, similar to dancers changing partners in a square dance. Even though their local neighborhoods change from generation to generation, the proteins produced by all these genes still need to function together in each individual organism. Combinations that work poorly tend to reduce an organism’s fitness, making those genetic arrangements less likely to persist.
Over time, this process means that natural selection does not only favor individual beneficial gene variants on their own, but also combinations of variants that work well together across the entire genome. Shraiman’s work helps clarify how these two levels of selection — on single genes and on whole genomes — can be described in a unified, quantitative way. It’s a subtle but important point: focusing only on isolated genes can miss emergent constraints that arise when many genes interact.
By building statistical models of these processes, his research aims to provide a more precise description of how evolution plays out in real populations, especially when many genes contribute to important traits. This improved understanding isn’t purely abstract; it can inform practical questions, such as anticipating which viral strains might dominate in a future flu season. If we can better predict how genetic variants spread and combine, we can improve public health strategies and vaccine design. Of course, some might debate how far such predictions can go, given the inherent randomness of evolution.
As for what topic Shraiman will dive into next, even he does not claim to know. His career began with studying how complex behavior emerges from simple systems, but much of his current work flips the perspective: he now looks for simplicity hiding inside the apparent complexity of living organisms. He is driven by the belief that the astonishing diversity of life — “endless forms, most beautiful and most wonderful,” to borrow Darwin’s phrase — may arise from a relatively small set of simple, still-unknown rules.
Looking back, he describes himself as extraordinarily fortunate to have been able to follow curiosity and even obsession wherever they led. Having the freedom to chase questions rather than strictly planned outcomes is, in his view, a rare privilege. But here’s where it gets controversial again: in an era of tightly targeted funding and metrics, is there still enough room for this kind of free-roaming, curiosity-driven science?
So what do you think: should more scientists be encouraged to wander across fields the way Shraiman has, even if it looks risky on paper? Do you agree that simple underlying rules might explain much of life’s complexity, or do you think biology will always resist that kind of reduction? Share where you stand — is this style of boundary-crossing, theory-driven biology the future, or should science stay more rooted in traditional disciplines?
