Marine organisms have rhythms dictated by tides, lunar cycle
The sun exerts hegemony over biological rhythms of nearly every organism on Earth. But two studies now show the moon is no slouch. It controls the cadence of at least two different biological clocks: one set by tides and the other by moonlight.
The clocks, both discovered in sea creatures, work independently of the circadian clock, which synchronizes daily rhythms with the sun. The studies demonstrate that the moon’s light and its gravitational pull, which creates tides, can affect the behavior of animals.
“The moon has an influence, definitely,” says Steven Reppert, a neurobiologist at the University of Massachusetts Medical School in Worcester, who was not involved with either study. “Clearly for these marine organisms, it’s very powerful and important.”
Scientists established decades ago that circadian clocks govern people’s daily cycles of such things as hormone levels, blood pressure and body temperature. Nearly