Meats A
School of Biological Sciences, University of Sydney, 2006, N.S.W., Australia.
Oecologia. 1971 Sep;6(3):223-237. doi: 10.1007/BF00344916.
Previous authors have used simple models to investigate the relative importance to population increase of variations in the total and age-specific reproductive rates. But while acknowledging that the latter were the product of the age specific birth and death rates, they have used their models only to investigate changes in total or age-specific birth rates and have not been concerned with variations in death rates. This paper extends the use of Lewontin's (1965) model, to a wide range of values of r, the exponential rate of population increase. It shows how the relative importance of changes in certain life-history features can change with r and be reversed when r is near to zero. It is also shown that variations in mortality rate are not necessarily best expressed in analogous terms to variations in birth rate. If more suitable terms are used it is seen that changes in mortality rate can be of varying importance depending on the existing mortality rate. They can be overwhelmingly important when the mortality rate is high.
以往的作者曾使用简单模型来研究总生殖率和年龄别生殖率的变化对人口增长的相对重要性。但尽管他们承认后者是年龄别出生率和死亡率的产物，却仅用其模型来研究总出生率或年龄别出生率的变化，而未关注死亡率的变化。本文将Lewontin（1965年）的模型应用范围扩展到人口增长指数率r的广泛取值。它展示了某些生活史特征变化的相对重要性如何随r变化，以及当r接近零时如何反转。还表明死亡率的变化不一定能用与出生率变化类似的术语来最佳表达。如果使用更合适的术语，就会发现死亡率的变化根据现有死亡率的不同可能具有不同的重要性。当死亡率较高时，它们可能极为重要。
