The direction such investigations should take was indicated a few years ago by evolutionary biologist George C. Williams at State University of New York (SUNY), Stony Brook. He warned that modern gerontological research focuses on death rather than on senescence or "the decreasing effectiveness of mechanisms by which adult organisms avoid death and loss of fitness."1 Williams dubbed this "the Tithonus error," after the Greek hero who became the lover of Eos, goddess of the dawn. She begged Zeus to give him immortality and Zeus complied, but Eos had forgotten to include eternal youthfulness in her request. As Tithonus aged, she locked him away, finally turning him into a cicada that could amuse her with its chirruping and shed its old skin every year.
Alfred Lord Tennyson's poem about Tithonus suggests that the loss of youth and beauty, and the difficulties of very old age, eventually find relief: "And after ...
