BBC Earth
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There are a few things we literally cannot live without. Oxygen is one. Another is food and water. And then there is sleep: forcibly keep an animal awake for long enough and you will kill it. The same almost certainly applies to humans.
This fact alone tells us that sleep must be doing something pretty important. But despite decades of intense scientific study there still is no consensus on exactly what that something is.
Researchers have found that sleep is beneficial to humans in many ways: it helps us process memories, and keeps our social and emotional lives on track. Yet we still do not really know how, why or even exactly when sleep evolved. Read more on the BBC Earth website…
