Science Questions

How is your lifespan determined? Albert, Norwich

There are a number of factors here, one of which is the size of the animal.  Mice life, on average, about 6 weeks in the wild, though they can live up to 2 and a half years in ideal conditions.  A human, however, can live well in excess of 80 years.  There must, therefore, be a genetic element to this, as mice and men are separated by a small difference in genetics.  Other factors such as lifestyle decisions affect your lifespan, but longevity does seem to run in families.  If your family has large numbers of supercentenarians (people who are over 110) then you have a higher chance of living a long life.  There's increasing evidence that your cellular metabolism also affects how you age.

Tortoises can live much longer than you or I, but this is partly because they are cold blooded.  This means they have a slower metabolic rate and use less energy.

September 2007