The emergence of identical or "same" behaviour across different fields of
biological research is aptly demonstrated in the domain of coupled oscillators.
The study of coupled oscillators, a more recent sub-branch of mathematics, can
be traced back to the Dutch physicist Huygens, who noticed that two pendulum
clocks when placed side by side display the uncanny tendency to synchronise
their swinging. This phenomenon is one that is expressed throughout the natural
world, occurring in the synchronisation of the cells of a body that generate
the heart-beat, the periodic flashing of swarms of fire flies, the synchronised
propagation of waves in the heart intestine and nervous system, and the
synchronised chirping of certain frogs and insects.