Sd. Pletcher et al., Why do life spans differ? Partitioning mean longevity differences in termsof age-specific mortality parameters, J GERONT A, 55(8), 2000, pp. B381-B389
Citations number
37
Categorie Soggetti
Public Health & Health Care Science","Medical Research General Topics
Journal title
JOURNALS OF GERONTOLOGY SERIES A-BIOLOGICAL SCIENCES AND MEDICAL SCIENCES
Populations typically differ in mean life spans because of genetic, environ
mental, or experimental factors. In this paper. methods are presented that
clarify the relationship between differences in the longevity of two popula
tions and differences in their underlying age-specific patterns of mortalit
y, Data are examined from rodent and fruit fly (Drosophila melanogaster) ex
periments that investigated the longevity effects of a variety of environme
ntal and genetic manipulations, including temperature, dietary restriction,
laboratory selection for increased longevity, and severe inbreeding. Analy
ses suggest that longevity differences mediated by temperature and dietary
restriction result predominantly from differences in the rate of increase i
n mortality with age. Increases in longevity through laboratory selection r
esult primarily from a reduction in baseline mortality and not a slowing of
the rate of aging. Although the methods are applied primarily in the conte
st of simple mathematical models of mortality (e.g., the Gompertz model), t
hey are quite general and can be applied to mortality models of arbitrary c
omplexity. Mathematica protocols ("notebooks") and computer software have b
een developed to perform all the analyses discussed and are available from
the first author.