Macroscopic quantum coherence at physiological temperatures is not supported as a general property of living tissue, but transient, mesoscopic quantum coherences have credible experimental and theoretical support in specific biomolecular systems. Evidence points to short-lived coherent electronic or spin states that can influence function in narrowly defined contexts, rather than widespread, long-range quantum order across cells or organs.
Evidence from photosynthetic complexes
Experimental work led by Gregory S. Engel, University of Chicago, provided early, influential evidence that electronic coherence can play a role in excitation energy transfer in photosynthetic complexes. Subsequent research involving Graham R. Fleming, University of California, Berkeley, and others extended investigation into how protein environments and vibronic coupling can sustain coherence under more natural conditions. These studies indicate that specialized pigment–protein architectures can protect and exploit brief coherent dynamics to improve the efficiency of energy transfer, but they do not demonstrate sustained macroscopic coherence across tissue or at body scale.
Radical-pair magnetoreception
Theoretical and experimental work on the radical-pair mechanism for avian magnetoreception, advanced by Peter J. Hore, University of Oxford, suggests that cryptochrome proteins can host coherent spin dynamics long enough to affect biochemical signalling used in navigation. This finding is relevant to birds and other migratory species whose orientation depends on geomagnetic cues, but the coherence involved is molecular and functional rather than a large-scale quantum state spanning organisms or environments.
Why large-scale coherence is unlikely
Foundational theory of environmental decoherence, articulated by Wojciech H. Zurek, Los Alamos National Laboratory, explains why warm, wet, and noisy biological media tend to destroy phase relationships required for macroscopic quantum coherence. Proposed protective mechanisms—protein scaffolds, spatial separation of interacting states, and vibronic coupling—can extend coherence lifetimes locally, yet they face steep scaling challenges as system size, temperature, and environmental coupling increase.
Consequences and cultural nuance
If robust macroscopic coherence in living tissue were demonstrated, it would transform our understanding of bioenergetics and sensory biology and inspire new biomimetic quantum technologies. Current findings, however, emphasize specialized adaptation: particular molecules and microenvironments harness quantum effects without implying pervasive macroscopic quantum order. Broader claims, such as Orch-OR proposed by Roger Penrose, University of Oxford, and Stuart Hameroff, University of Arizona, remain controversial and are not established by mainstream experimental evidence.