The 1999 Crafoord Prize lectures. The Tithonus error in modern gerontology.

Tithonus asked Aurora for eternal life, when he meant eternal youth. Modern gerontological research makes the same mistake in its preoccupation with death, as if it were a programmed event in an organism's life history. Gerontology ought instead to investigate senescence, the decreasing effectiveness of mechanisms by which adult organisms avoid death or loss of fitness. Such studies should measure rates of decline in a diversity of adaptations and compare them within and between individuals and relate these rates and their correlations to genetic and environmental factors. The death of a studied organism must necessarily end its usefulness in providing valuable data. It is of little scientific significance.