TED: Our natural sleep cycle is nothing like what we do now | Jessa Gamble

The video discusses the evolution of internal clocks in living beings, using the horseshoe crab as an example. It explains how humans also have a body clock that influences behavior and culture. The video explores cultural adaptations to varying light conditions and describes natural sleep patterns without artificial light. It concludes by highlighting modern challenges to these natural rhythms, such as jet lag and shift work.

How does the body clock influence human behavior and culture?

What are the sleeping patterns of people living without artificial light?