On the incompatibility of gompertz or weibull survival dynamics with exponentially distributed individual lifespans
✍ Scribed by Frank Guess; Matthew Witten
- Book ID
- 104272650
- Publisher
- Springer
- Year
- 1988
- Tongue
- English
- Weight
- 276 KB
- Volume
- 50
- Category
- Article
- ISSN
- 1522-9602
No coin nor oath required. For personal study only.
✦ Synopsis
It is well documented, in the biological literature, that many species throughout the animal kingdom exhibit Gompertzian or Weibull-like population level total survival distributions. Many researchers have long assumed, believed, or otherwise postulated that an individual organism, in such a population, survived according to an exponential survival distribution. Using well-known results from reliability theory, it is shown that if every individual in the population has an exponentially distributed lifespan, then a Gompertzian or Weibull-like group/population level dynamics (or any other dynamics with a strictly increasing mortality rate for some interval) is not possible. This implies that, for species with a population level Gompertzian or Weibull (with the mortality rate strictly increasing) survival curve, some or all of the individual organisms must have non-exponentially distributed lifespans.