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方形黄鼠蚤松江亚种的存活率和死亡率均服从于logistic曲线,说明该蚤的生命过程的自然曲线呈logistic曲线。曲线有两个特点,其一是自变量逐渐增大,因变量只增不降,此时曲线形状呈“S”型,则表现为死亡率的过程。当曲线呈反”S“型时,又表现为存活率的过程。环境条件左右着该蚤的存活与死亡过程,当条件有利于种群的存活,早期死亡个体数减少。反之,早期死亡个体数大增。
The survival rate and mortality rate of T. gonorrhoeae Songjiang were subordinated to the logistic curve, indicating that the natural curve of the flea’s life process was logistic curve. There are two characteristics of the curve. One is the gradual increase of the independent variable and the increase of the dependent variable. In this case, the shape of the curve is “S”, which indicates the process of mortality. When the curve is inverted “S” type, but also showed the process of survival. Environmental conditions control the survival and mortality of the flea, reducing the number of early death individuals when conditions favor the survival of the population. Conversely, the number of early deaths increased significantly.