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p. 816. Sleep

The most obvious 24-hour rhythmlocked

  • Russell G. Foster
  •  and Leon Kreitzman


Almost all life shows a 24-hour pattern of activity and rest, as we live on a planet that revolves once every 24 hours, causing profound changes in light, temperature, and food availability. Species are adapted to a particular temporal niche just as they are to a physical niche. Activity at the wrong time often means death. We spend approximately 36 per cent of our lives asleep, which suggests this aspect of our 24-hour behaviour provides us with something of huge value. ‘Sleep: The most obvious 24-hour rhythm’ considers two questions: Why has almost all life evolved a 24-hour circadian pattern of activity and rest? And what are the important processes that occur in the body during sleep?

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