¿Por qué dormimos?

Investigadores parecen hallar respuesta a uno de los grandes misterios de la ciencia.

Why do we sleep?

A recent study may have an answer to one of the greatest unsolved mysteries in science - what is the purpose of sleep? The work suggests it's actually about making animals function more efficiently in their environments.

Reporter:
Jon Stewart

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Pythons, bats and giant armadillos are among the longest sleepers at over 18 hours a day. Human babies need 16 hours, and most of us probably feel we need around eight hours sleep to function well.

Professor Jerry Seigel from the University of California, Los Angeles, conducted a study of the sleep times of a broad range of animals and found that they vary widely. Some, like migrating birds, can survive long periods without sleeping at all. He believes that shows sleep evolved to conserve energy:

Jerry Seigel: 'It's animals that are needlessly active that will not survive, but animals that are most efficient and use their waking time to do vital functions, and are otherwise asleep that will survive.'

Sleep helps make best use of limited resources. In humans, when we're awake, our brain accounts for 20% of the energy we use when just sitting around. Sleeping also makes us less likely to get injured and less likely to be detected by predators.

Jon Stewart, BBC News

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to function well
vivir y funcionar bien

a broad range of
una amplia gama de

vary widely
varían enormemente

migrating birds
aves migratorias

to conserve
conservar/almacenar

are needlessly active
activos sin propósito

vital
vitales

limited resources
recursos limitados

to get injured
lesionarse

detected by predators
descubiertos por depredadores