Medicine has increased the ranks of the elderly. Can it make old age any easier?
Atul Gawande in The New Yorker:
Why we age is the subject of vigorous debate. The classical view is that aging happens because of random wear and tear. A newer view holds that aging is more orderly and genetically driven. Proponents of this view point out that animals of similar species and exposure to wear and tear have markedly different life spans. The Canada goose has a longevity of 23.5 years; the emperor goose only 6.3 years. Perhaps animals are like plants, with lives that are, to a large extent, internally governed. Certain species of bamboo, for instance, form a dense stand that grows and flourishes for a hundred years, flowers all at once, and then dies.
The idea that living things shut down and not just wear down has received substantial support in the past decade. Researchers working with the now famous worm C. elegans (two of the last five Nobel Prizes in medicine went to scientists doing work on the little nematode) were able to produce worms that live more than twice as long and age more slowly by altering a single gene. Scientists have since come up with single-gene alterations that increase the life spans of Drosophila fruit flies, mice, and yeast.
These findings notwithstanding, scientists do not believe that our life spans are actually programmed into us.