Optimal Size at Maturity in Size-Structured Populations
Optimal Size at Maturity in Size-Structured Populations
复制标题
体型结构群体中成熟时的最佳体型
DOI：
10.1006/jtbi.1997.0420
复制
发表时间：
1997
影响因子：
2
通讯作者：
H. Caswell
中科院分区：
文献类型：
--
作者：
T. Takada;H. Caswell
成熟期是生命周期的一个关键点，确定成熟期的最佳年龄或大小是生命史理论中的经典问题。大多数生物体都有一段时间处于非生殖的未成熟阶段。为了解释延迟成熟现象的普遍存在，一些作者建立了特定年龄繁殖力和存活率的数学模型，规定了繁殖力和存活率的功能形式，并检验了两种假设的可能性。一种假设是，当成熟个体的繁殖力更高时，延迟成熟是有利的。二是晚熟父母所生的后代在幼年期的存活率较高。本文采用尺寸结构的McKendrick-von Foerster方程作为基本模型，得到了延迟成熟的5个条件。其中两个符合上述两个假设。其他三个是新的：我们表明，在成熟时，生存或生长速度的不连续下降有利于延迟成熟。我们探讨了几个数值例子来展示这些机制的运作。
Abstract Maturity is a critical point in the life cycle, and determining the optimal age or size at maturity is a classical problem in life history theory. Most organisms spend some time in non-reproductive immature stage. To explain the widespread occurrence of delayed maturity, a number of authors made mathematical models with the age-specific fecundity and survival rate, specified functional forms of fecundity and survival rate, and examined the possibility that two hypotheses hold. One hypothesis is that delayed maturation is advantageous when it leads to more fecundity of mature individuals. The other one is that the offspring produced by parents with delayed maturation may have higher survival in their juvenile period. In the present paper, we use the size-structured McKendrick—von Foerster equation as our basic model and obtain five conditions for delayed maturation. Two of these correspond to the above two hypotheses. The other three are new: we show that a discontinuous decrease at maturation in survival or growth rate can favor delayed maturation. We explore several numerical examples showing the operation of these mechanisms.