Effects Of Environmental Change And Genetypic Diversity On Sexual Advantage Of Tetrahymena Thermophila

The evolution and maintenance of sexuality is one of the most controversial issues in evolutionary biology.Weismann thinks that sexual reproduction can increase the genetypic diversity of offspring,thus can enhance the efficiency of natural selection when environment changes.Sentists think that sexual reproduction has long-term evolutionary advantages.Dose sexual reproduction have short-term individual advantages,and what are the effects of different environmental change and the intensity of environmental change on the advantages of sexual reproduction? In this paper,Tetrahymena thermophileis used as the research object,and we compare the survival rate of the individual's sexual and asexual progeny population under different stress concentration of the three stress factors.Our results show when the environment does not change,the asexual population hasa higher survival rate than the sexual population;while there has change in the environment,the sexual population has a higher survival rate than the asexual population.In addition,the results also show that the survival advantage of sexual population is most pronounced at moderate stress intensity.By comparing the survival rates of the five different genetypic diversity of the sexual offspring populations and the asexual progeny populations with different stress concentration of three stress factors,we can observe that as the environment does not change,the asexual population has a higher survival rate than the five different sexual populations;when the environmental change occurs,the sexual population has a higher survival rate than the asexual population,and the survival rate of the sexual population rises as the genotype diversity increases.The results of this study suggest that sexual reproduction has short-term individual advantages when environmental changes,and this advantage will change with variation of intensity of environmental change,especially in the condition of moderate environmental changes,there has the most obvious advantage of sexual reproduction.