A wake-up call?

Russell Foster ("The clock ticks as life follows its own rhythms", February ) raises important questions. If we are awake 22 hours out of 24, will we live proportionately shorter lives? Might we die at 58 instead of 80?

In her recent short story Wake Island , science-fiction writer Ursula le Guin imagines a society that has modified a gene to produce people who never sleep. The subjects grow up to be "asomnic" adults who live permanently in a state of "waking unconsciousness", aware of their surroundings but with no social relations. I'll settle for eight hours a night.

Pam Lunn
Kenilworth