Beyond Quantum Biology: How Life Imitates Quantum Mathematics

Two decades ago, scientists appeared to be on the cusp of explaining biological processes using quantum principles.

Life operates across an immense range of scales—from the planetary biosphere to individual biomolecules. Even at the smallest levels, however, biology does not naturally tap the quantum realm, where particles behave as waves, become entangled, and exist in superpositions of multiple states. Quantum biologists have long sought ways organisms might extend quantum effects into the temperature, space, and time windows relevant to living systems, hoping to harness these exotic properties.

Photosynthesis provides a striking example. Organisms employ specialized pigments and proteins to capture light with near‑perfect efficiency, converting almost every absorbed photon into chemical energy. In 2007, new findings suggested that this remarkable performance might rely on a quantum phenomenon known as coherence, reviving the controversial notion that a warm, wet, and ostensibly classical cell could preserve—and even exploit—fragile quantum states.

Gregory Scholes, a chemist at Princeton University, initially embraced these findings and conducted experiments on photosynthetic proteins and pigments that seemed to support the quantum hypothesis. Today, however, Scholes is skeptical that genuine quantum effects drive biological function. He argues that the future of quantum biology may lie not in exploiting true quantum mechanics but in mimicking its mathematical underpinnings. Over the past three years, Scholes and his team have demonstrated that complex networks of classical objects can collectively produce behaviors that mathematically resemble those of quantum systems.

These emergent “quantumlike” states are not genuinely quantum; they arise when many interacting, oscillating components combine to form a collective system whose dynamics follow the same mathematics used to predict quantum phenomena. “Maybe quantum biology, at the biggest scales, means using 3½ billion years of evolution to work out how to get the functionality that you could get from quantum systems,” Scholes observed.

Markus Müller, a physicist at the Institute for Quantum Optics and Quantum Information in Vienna, noted that researchers have long explored how classical systems can reproduce certain quantum features. In Scholes’s work, Müller said, “he shows how quantum‑like behavior can emerge from relatively ordinary complex networks—precisely the kind that are abundant in nature.”

“Classical systems can mimic some of the key features of quantum information,” added Sabre Kais, a quantum chemist developing algorithms for complex systems at North Carolina State University. “This is an exciting new direction.”

The Bounds of Quantum Biology

The impulse to frame life’s mysteries in quantum terms dates back to the birth of quantum mechanics. In a 1929 lecture, Niels Bohr, a pioneer of the field, suggested that quantum theory “may perhaps be of decisive importance, particularly in the discussion of the position of living organisms in our picture of the world.”

Bohr’s contemporary Pascual Jordan spent decades promoting Quantenbiologie, arguing that living organisms could amplify quantum indeterminacy to macroscopic scales, a property he linked to human thought and free will. J.B.S. Haldane echoed this view in a 1934 paper, suggesting that the ability to scale quantum effects underpinned the special nature of life. (Jordan’s involvement with the Nazi Party and its paramilitary forces later tarnished this early quantum‑biological discourse.)

These pioneers sought to explain life’s puzzling classical behaviors using the counterintuitive laws governing the quantum world. A classical particle occupies a single position and state at any given moment, whereas a quantum particle is described by a wave function that spreads across all possible locations and configurations—like a wave of potential. This wave function exhibits peaks and troughs, and until a measurement collapses it, all possible states exist simultaneously in superposition. Superimposed quantum states interact much like overlapping water or sound waves, either reinforcing, canceling, or transforming one another. When these states are sufficiently organized, they become coherent, and coherent systems can become entangled, merging into a unified entity sharing a common wave function.

Quantum states are fragile; even minimal environmental disturbances, such as thermal motion, can cause decoherence, collapsing the quantum behavior into classical dynamics. Quantum computers, for example, require extreme cooling to preserve quantum coherence. Inside a cell, decoherence is expected to occur almost instantaneously, meaning any quantum effects would likely be extinguished before they could influence biological processes.

Nevertheless, certain microscopic phenomena, like quantum tunneling of hydrogen atoms, can occur within cells. Tunneling allows particles to traverse energetic barriers that would otherwise be insurmountable, and it has been proposed to explain the rapid rates of some enzymatic reactions. Scholes points out that this kind of tunneling does not rely on long‑lived coherence; the quantum aspect is brief and essentially unavoidable, occurring even in non‑biological chemical mixtures. The central question remains whether living systems can sustain coherent quantum states long enough to harness them as functional resources—a capability that distinguishes biology from mere chemistry.

A Light‑Harvesting Letdown

Speculation that quantum coherence could account for the extraordinary efficiency of photosynthesis dates back to the 1930s.

Photosynthetic organisms assemble arrays of pigments and proteins known as light‑harvesting complexes. When a photon strikes one of these complexes, its electromagnetic energy excites an electron within the complex. This excited quasiparticle, called an exciton, travels toward a reaction center where its energy is converted into chemical form, driving the essential steps of photosynthesis.

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