Synchronization in Nature
In the attached video shows this physical phenomenon. Once the metronomes, randomly activated, they start to oscillate on the table and the cans, the displacement of each of them influences the next, so that within seconds all end up perfectly synchronized metronomes.
Another example is the phenomenon known as "Social Regulation of Ovulation", introduced in 1971 by Martha McClintock. Women who live together get to experience a synchronization of their menstrual cycles as a result of being exposed to pheromones from the sweat of other partners. It is because women can influence luteinizing hormone (LH), responsible for producing maximum ovulation, delaying or advancing their maximum concentration.
The suggestion put forward and would give an explanation to these synchronicities, resides in an evolutionary remnant of our prehistoric times, when it was normal for men to have multiple partners. An efficient reproduction, where all women were synchronized, it was essential to the survival of the human species.
Another example is the yawn. Steven Platek of Drexel University, noted that between 40 and 60% of people over 5 years old reacted with a yawn himself after watching a stranger. This phenomenon would aim the timing of the vital rhythms.