ANDRZEJ KRAUZETo die of old age is a death rare, extraordinary, and singular, and therefore so much less natural than the others. ’Tis the last and extremest sort of dying, and the more remote the less to be hoped for. It is indeed the boundary of life, beyond which we are not to pass: which the law of nature has pitched for a limit not to be exceeded.
—Michel de Montaigne, Essays, Book I, Chapter 57
This centuries-old description by the French essayist perfectly captures just how peculiar it is to arrive at the end of one’s life having escaped death by infection or diseases such as cancer, heart disease, and dementia, for which age is the biggest risk factor. Although Montaigne himself reached what was at the time considered old age, succumbing to a bacterial infection in 1592, when he was 59 years old, he certainly did achieve literary immortality.
This issue of The Scientist is about aging, and the focus is not on the diseases that are hallmarks of time’s passage, but on why cells have a limited life span and what fails on the cellular and molecular level as the years go by. It’s a complicated picture, with lots of missing pieces. The field of cellular biogerontology was kick-started by the observation, published in 1961, that normal cells in culture stopped dividing after 50 or so doublings—the well-known Hayflick limit. In “Of Cells and Limits,” you can meet Leonard Hayflick and learn of his dogma-defying discovery in a profile of the unretired (and unretiring) octogenarian’s contributions to the understanding of cellular aging.
A staff-written feature describes some of the knowns and unknowns of ...
