Biological immortality refers to a stable or decreasing rate of mortality from cellular senescence as a function of chronological age. Various unicellular and multicellular species may achieve this state either throughout their existence or after living long enough. A biologically immortal living being can still die from means other than senescence, such as through injury or disease. This definition of immortality has been challenged in the new Handbook of the Biology of Aging, because the increase in rate of mortality as a function of chronological age may be negligible at extremely old ages, an idea referred to as the late-life mortality plateau. The rate of mortality may cease to increase in old age, but in most cases that rate is typically very high. As a hypothetical example, there is only a 50% chance of a human surviving another year at age 110 or greater. The term is also used by biologists to describe cells that are not subject to the Hayflick limit.
Sep 1, 2004 (Updated Sep 10, 2004) Popular Products in Books From $10 From $5 Animals That are Immortal : "Negligible Senescence"
Forever young: Kira Cochrane on how celebrities put an end to ag A couple of months ago, a photograph was hungrily circulated around gossip magazines and websites, and at a glance you would have had trouble explaining why. It showed an ordinary-looking woman in her mid-40s, out shopping in California, her specs on, cardigan buttoned. The clue was in the picture of Madonna that ran beside it.