Rocky shorelines frequently contain tidal pools of varying sizes, and they may have provided some unique conditions that would have made biogenesis possible, (the chemistry that created this primordial soup 4 billion years ago).
When gazing into a rock pool, spotting the many different organisms in this ecosystem, it’s worth pondering life’s origins born of this environment of extremes.
A hint at our own aquatic past is suggested in a correlation between the human menstrual cycle and the lunar cycle. Many aquatic species follow the same lunar cycles influence on the tides for reproduction.