Carey J R, Liedo P, Orozco D, Vaupel J W
Department of Entomology, University of California, Davis 95616.
Science. 1992 Oct 16;258(5081):457-61. doi: 10.1126/science.1411540.
It is generally assumed for most species that mortality rates increase monotonically at advanced ages. Mortality rates were found to level off and decrease at older ages in a population of 1.2 million medflies maintained in cages of 7,200 and in a group of approximately 48,000 adults maintained in solitary confinement. Thus, life expectancy in older individuals increased rather than decreased with age. These results cast doubt on several central concepts in gerontology and the biology of aging: (i) that senescence can be characterized by an increase in age-specific mortality, (ii) that the basic pattern of mortality in nearly all species follows the same unitary pattern at older ages, and (iii) that species have absolute life-span limits.
对于大多数物种，通常认为在高龄时死亡率会单调增加。然而，在一个由120万只地中海实蝇组成的群体中（这些实蝇饲养在7200只的笼子里）以及在一组约48000只单独饲养的成虫中，发现死亡率在老年时趋于平稳并下降。因此，老年个体的预期寿命随年龄增长而增加而非减少。这些结果对老年学和衰老生物学中的几个核心概念提出了质疑：（i）衰老可以通过特定年龄死亡率的增加来表征；（ii）几乎所有物种的基本死亡模式在老年时遵循相同的单一模式；（iii）物种有绝对的寿命极限。
