论文标题
孵化场引起的帕累托人群中有效尺寸的过渡
Hatchery-induced transition of the effective size in a Pareto population
论文作者
论文摘要
观察到在海洋孵化场实践下，观察到没有减少的有效人口尺寸$ n _ {\ mathrm {e}} $似乎是自相矛盾的。本文研究了Ryman-Laikre或二 - 人口统计学的模型，即与具有幂律家族尺寸分布的人群中的近交相关的孵化场影响模型，其中孵化场输入由Dirac Delta功能表示。通过检查混合物种群的归一化大小（或权重）的渐近行为（即大型人口限制），我在任何给定时间中得出了家族平均重量（即平方重量的总和，$ y $）的平均重量（即平方重量之和$ y $）的分布性能。平均体重$ y $的倒数为人口中的有效家庭（或复制谱系），$ n _ {\ mathrm {e}} = 1/y $。当孵化场中的特定生产（即，每个育雏的后代的数量）较低时，$ n _ {\ mathrm {e}} $的最可能值接近$ n _ {\ mathrm {e}}}} $ - 分布的$ n _ {\ mathrm {e}} $ - 分布。当特定的孵化场产生增加到孵化场鱼类的固定混合比例时，发生不连续的过渡，以便最可能的$ n _ {\ mathrm {e}} $跳到分布的上极端。这种孵化场引起的过渡归因于互惠对称性的破坏，即$ y $及其倒数的典型值（典型的$ n _ {\ mathrm {e}} $）不会随着人口相反的方式而变化。在高特异性的孵化场生产中，对称性破裂消失了。
It seems paradoxical to have observed the absence of reduced effective population sizes $N_{\mathrm{e}}$ under marine hatchery practices. This paper studies the Ryman-Laikre, or two-demographic-component, model of the hatchery impact related to inbreeding in a population with power-law family-size distribution, where hatchery inputs are represented by a Dirac delta function. By examining the asymptotic (i.e. large-population limit) behavior of the normalized sizes (or weights) of families of the mixture population, I derive the distribution properties of the average weight of families (i.e. the sum of the squared weights, $Y$) over the population existing at any given time. The reciprocal of the average weight $Y$ gives the effective number of families (or reproducing lineages) in the population, $N_{\mathrm{e}}=1/Y$. When the specific production in the hatchery (i.e. the number of offspring per broodstock) is low, the most probable value of $N_{\mathrm{e}}$ is close to the lower bound of the $N_{\mathrm{e}}$-distribution. When the specific hatchery-production is increased to a critical value with fixed mixing proportion of hatchery fish, a discontinuous transition takes place, so that the most probable $N_{\mathrm{e}}$ jumps to the upper extreme of the distribution. This hatchery-induced transition is attributed to the breaking of reciprocal symmetry, i.e. the fact that the typical value of $Y$ and its reciprocal (the typical $N_{\mathrm{e}}$) do not vary with the population size in opposite ways. At a high specific hatchery-production, the symmetry breaking disappears.
