Quantum measurement is for the birds, but is not essential for plants

A new general approach for evaluating the "quantumness" of biological processes such as the ability of some birds to sense the Earth's magnetic field has been developed by physicists in Switzerland and the US. It involves describing the process as a "quantum meter" that uses quantum coherence to measure magnetic-field strength or light intensity. Atac Imamoglu of ETH Zürich and Birgitta Whaley of the University of California, Berkeley, have applied their framework to bird navigation and photosynthesis, and have concluded that only the former is completely dependent on quantum coherence.