Biology Might Not Be Quantum, but Its Math Is Quantumlike

Biology Might Not Be Quantum, but Its Math Is Quantumlike

Biology Might Not Be Quantum. That conclusion would have startled Gregory Scholes two decades ago. Back then, the Princeton chemist was among the researchers most excited by hints that living cells might put the strangest features of quantum mechanics to work, a possibility that drove so much of his early thinking and so many of his colleagues' hopes. Today he's the one arguing that the field has been chasing the wrong target entirely. And they're still chasing it.

His alternative is subtle, and it does not require life to perform any impossible physics. Instead, Scholes proposes that evolution may have stumbled onto networks of ordinary classical parts that collectively behave in ways that look quantum on paper. The states they produce are not truly quantum. They are quantumlike.

The Dream That Wouldn't Die

The urge to explain life through quantum mechanics is nearly as old as quantum mechanics itself. In a 1929 lecture, Niels Bohr offered a vague but tantalizing suggestion that the new physics "may perhaps be of decisive importance, particularly in the discussion of the position of living organisms in our picture of the world." His contemporary Pascual Jordan went much further, spending decades arguing that life alone can amplify quantum indeterminacy up to macroscopic scales. Geneticist J.B.S. Haldane echoed that view in a 1934 paper, calling the ability to scale up quantum uncertainty the thing that makes life special.

Jordan damaged everything. He joined the Nazi Party and its paramilitary forces in 1933, and he tried to tie quantum biology to Nazi ideology, a move that, because it's hard to separate the science from the politics, later damaged the credibility of the whole enterprise. And they're linked now. We've seen how one man's choices can't be undone.

The physics problem is straightforward. A classical particle sits in one place at one time. A quantum particle is smeared across every place and state it could occupy, a wave of possibility described by a wave function with peaks and troughs. Until it is observed, all those configurations stack up in superposition. When the wave properties are tidy enough for the stacked states to add up, cancel out, or otherwise transform one another, they are called coherent. Coherent systems can even become entangled, merging into a single entity with a shared wave function.

Quantum states are fragile. Even a faint jiggle of heat triggers decoherence, a collapse into ordinary classical behavior. Quantum computers are supercooled for exactly this reason. Inside a living cell, decoherence should be essentially instantaneous, which makes any long-lived quantum effect in biology seem far-fetched.

Tiny particles tunnel. Hydrogen atoms can still tunnel through energy barriers, and there's evidence that tunneling in certain enzymes explains their speedy reaction rates, which is a striking claim about how biology might work at the smallest scales. But that's not what quantum biologists were hunting. Tunneling involves no long-lived coherence, and even a flask of dead chemicals will do it, so we've got a process that isn't what they're after. It's not.

A Light-Harvesting Letdown

The most celebrated candidate was photosynthesis. Plants and bacteria use arrays of pigments and proteins called light-harvesting complexes to absorb photons. When light strikes, the energy boosts an electron into an excited state, creating a quasiparticle called an exciton that travels toward a reaction center where it becomes chemical energy. The process is nearly 100 percent efficient.

Scientists proposed something bold. If excitons stayed quantum coherent across multiple molecules, they could sample several routes to the reaction center at once instead of wandering haphazardly. In 2007, Graham Fleming of the University of California, Berkeley tested the idea. His team fired extremely fast laser pulses at a bacterial light-harvesting complex to create excitons, then probed them with follow-up pulses. And the experiment revealed synchronized beats that looked like coherence.

Scholes and others ran similar experiments and came away with similar conclusions.

Hard proof hasn't materialized. Not for long-lived quantum coherence with a biological function. Scholes grew convinced that scaling up coherence and entanglement inside a warm, wet cell simply is not possible, and he held that view even as others kept searching for evidence that it's not. It can't be done.

The Hotel Room Idea

Scholes found something. Networks of oscillators can be designed so their synchronized, emergent states can be described as vectors in Hilbert space, and that's the core of what he showed. And they're capable of more. Scholes and colleagues have shown that such networks can mathematically mimic quantum objects, a claim that stands on its own and doesn't need any extra decoration.

Same Math, Different Physics

Markus Müller is a physicist in Vienna. At the Institute for Quantum Optics and Quantum Information, he noted that researchers in quantum foundations have spent decades exploring how to classically recreate quantum behavior, a long and stubborn pursuit. But what Scholes did, Müller said, is show how quantumlike behavior emerges from relatively unremarkable complex networks of the kind that abound in nature. So it's not exotic. Sabre Kais is a quantum chemist at North Carolina State University, and he called it an exciting new direction.

Wolf Singer, a neurophysiologist at the Ernst Strüngmann Institute of the Max Planck Society, arrived skeptical when Andrei Khrennikov invited him to a workshop on quantumlike modeling.

In 2025, Singer and colleagues showed something surprising. Adding oscillations to a simple neural network makes it more efficient and more reliable. The interference gave the network a new dimension to work with, time, because the phase of an oscillation encodes how events relate to each other in sequence, and that's a shift you don't see in static systems. But that's not all. After the workshop, Singer said he was impressed that some real-world phenomena may be better described with the techniques physicists use.

Scholes and colleagues have since shown that quantumlike bits can be wired together into larger networks that remain quantumlike. So the bits stay quantumlike. If classical networks can reproduce the mathematics of quantum information, then the question shifts, because we've got to ask what's really left to explain. Does it matter whether a system is truly quantum, if you can't tell the difference?

• Quantum biology once hoped living cells could maintain fragile quantum coherence.
• Scholes now argues classical oscillator networks can mathematically mimic quantum objects.

Two decades of searching have not produced definitive proof that long-lived quantum coherence does biological work. What they have produced is a stranger possibility. Life may not need quantum mechanics. It may only need the math.