Abstract Any reactions of the living systems are to a great extent context-dependent. Meanwhile, the biological essence of a “context” remains to be obscure. We suggest that it may be based upon an ensemble of molecular–supramolecular oscillators, which have different characteristic times. For testing this hypothesis, we applied the Fourier statistics to the time series of the records of an ultraweak photon emission (UWPE) registered from fish eggs and embryos and from cell cultures. We detected the regular changes of the UWPE Fourier spectra (FS) during embryonic development and physiological reactions of cell cultures. In many cases, such changes were going on in a holistic manner, i.e. involving broad spectral areas rather than single frequency maxims. FS of the earlier developmental stages showed greater instability and the presence of a short-range order only. On the contrary, at the advanced developmental stages a long-range order has emerged within the spectra. Another distinction of the highly organized biological samples (developing embryos, confluent fibroblasts cultures) from non-biological controls and “poorly organized” samples (non-fertilized eggs, non-confluent, poorly spread cell cultures) was the UWPE correlation dynamics which was more cooperative in highly organized samples. A non-invasive technique of UWPE registration may be useful for exploring a fluctuated oscillatory background of the developmental and physiological states of biological samples.