Evaluating the effect of stage‐specific survivorship on the Ne/N ratio
Evaluating the effect of stage‐specific survivorship on the Ne/N ratio
复制标题
评估特定阶段生存率对 Ne/N 比值的影响
DOI：
10.1046/j.1365-294x.2002.01504.x
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发表时间：
2002
影响因子：
4.9
通讯作者：
R. Waples
中科院分区：
文献类型：
--
作者：
R. Waples
用III型存活曲线估算物种的有效种群规模(Ne)和有效种群规模与普查规模之比(Ne/N)是一件复杂的事情，因为在生命早期阶段需要测量关键的人口学参数[家庭规模的平均值(k̄)和方差(Vk)]。Crow&Morton(1955)的方法将青少年阶段收集的人口统计数据扩展到成年时的期望值，以考虑随机和与家庭相关的生存的连续事件。结果表明：(I)随机和家庭相关生存事件发生的顺序不影响Ne或Ne/N；(Ii)如果一个人口经历了家庭相关生存事件，则在固定人口规模(k̄=2)中，Ne/N被标度为其期望值，即为家庭相关阶段的存活率。如果出现多个这样的阶段，则比例Ne/N是所有与家庭相关的生活阶段的存活率的乘积；(Iii)在随机计数后生存的假设下，在k̄=2时将方差有效大小调整为其期望值，相当于计算较早生命阶段的近亲交配有效大小。太平洋鲑鱼(Oncorhynchus spp.)孵化种群实验数据的应用表明海洋阶段的非随机存活导致12个不同队列的有效规模估计减少了0-62%(平均19%)。这种方法可以提供对高繁殖力物种的Ne/N的洞察，包括一些海洋物种，其中Ne被估计比N小几个数量级。
Evaluating effective population size (Ne) and the effective size to census size ratio (Ne/N) in species with Type III survivorship curves is complicated when key demographic parameters [mean (k̄) and variance (Vk) of family size] are measured during early life stages. The method of Crow & Morton (1955 ) for scaling demographic data collected at a juvenile stage to expected values at adulthood is extended to consider sequential episodes of random and family correlated survival. Results show the following: (i) The order in which the episodes of random and family‐correlated survival occur does not affect Ne or Ne/N; (ii) If a population experiences an episode of family‐correlated survival, Ne/N scaled to its expected value in a population of constant size (k̄ = 2) is simply the survival rate during the family‐correlated stage. If multiple such stages occur, scaled Ne/N is the product of the survivals during all family‐correlated life stages; (iii) Under the assumption of random post‐enumeration survival, adjusting the variance effective size to its expected value at k̄ = 2 is equivalent to computing the inbreeding effective size at the earlier life stage. Application to experimental data for hatchery populations of Pacific salmon (Oncorhynchus spp.) indicates that nonrandom survival during the marine phase led to estimated reductions in effective size of 0–62% (mean 19%) in 12 different cohorts. This approach can provide insights into Ne/N in highly fecund species, including some marine species in which Ne has been estimated to be several orders of magnitude less than N.