Excerpt: 'Long For This World'  Long For This World Long For
This World: The Strange Science Of Immortality By Jonathan
Weiner Hardcover, 320 pages List price: $27.99  This is a good
time to be a mortal. Life expectancy today is roughly eighty
years for anyone in the world's developed countries. And life
expectancy is still improving, which is why each day we live now
we are given the gift of more time down the road. It's as if
we're all driving on a highway that is still being built, and
the roadbuilders are adding to it at a good rate. Our bodies
haven't changed. We haven't evolved. A few generations is too
brief a time for our life spans to have gained thirty years
through evolution. It's only that our circumstances have gotten
more comfortable. A field mouse in the wild lives about one
year. The same mouse in the safety of a cage lives about three
years. With our farms and supermarkets and reservoirs and
thermostats, we have done for ourselves what we have done for a
pet mouse. We have tripled the life ex