环路的平均固定时间研究

摘要

进化图可以动态刻画一个种群的动态演化，定置概率描述进入种群的新突变体占据整个种群的概率，而平均固定时间反映了该种群的平均进化速度。本文研究了环路的平均固定时间。在种群个体数量很大的情况下，给出了环路上单个突变体的平均固定时间及其性质。当相对适应度0＜r＜1时，随着r的增加，环路的固定概率和平均固定时间都增加；而在r＞1时，随着r的增加，环路的固定概率增加了，而平均固定时间却减少了。%Evolutionary graph can be used to describe the evolution of a population dynamically. The fixation prob-ability of an evolutionary graph is the probability that a new emerging mutant occupies the whole population, while its average fixation time reflectes the average evolutinary velocity of the population. The average fixation time of a new mutant on a circulation with large population is studied and its property is discussed. When the relative fitness 01, the fixation probability of a circulation increases, but the average fitness time decreases with the increase of the relative fitness r.