It has been known for years that the brains of many organisms incorporate a "circadian clock" — a biological time-keeping mechanism that connects the body's rhythms to external light levels. The clock helps the body sync with changing daylight conditions.
This week, in the journal Science, researchers report that mice seem to have a second, independent circadian clock that syncs with food consumption — and it can overrule the regular light-based clock.
The food-synced clock, the researchers believe, could be used in nature to help animals adjust to hard times. Clifford Saper, one of the authors of the report, explains, "This new timepiece enables animals to switch their sleep and wake schedules in order to maximize their opportunity of finding food."