Consequently, the timing and rhythms of biological functions must closely match periodic events like the solarday, the tides, the lunar cycle, and the seasons.
因此，生物功能的时间和节奏必须与太阳日、潮汐、月球周期和季节等周期性事件密切契合。
2
Without the external cue, the difference accumulates and so the internally regulated activities of the biological day drift continuously, like the tides, in relation to the solarday.