Genome Evolution Rate Correction In Angiosperms

Species evolution time estimation is an important part of life evolution.It is found that there are significant differences in the evolution rate of different genes,which challenges the molecular clock hypothesis to a great extent.The whole genome sequence of angiosperms makes it possible to estimate the evolutionary time from the whole genome perspective;Therefore,with genome-wide data,it is necessary to develop new methods to re-estimate the evolutionary time.Based on the idea that shared polyploidy events or divergent events have the same Ks peak,angiosperms evolutionary time has been re-estimated by establishing an evolutionary rate correction model and made some progress.(1)Compared with three ways to obtain Ks distribution,the way of extracting the median value of Ks on the collinear block is optimal by Gaussian fitting and the Ks distribution characteristics.(2)The Ks distribution with evolution rate is simulated.When assumed that the evolution rate obeys the normal distribution,the long tail phenomenon appeared.When added the selection pressure,the long tail phenomenon is mainly related to different gene evolution rates,and the gene loss has slight effect on the Ks distribution.(3)For shared polyploidy and early divergence,an evolutionary rate correction model based on genomic data was established and describe the correction process in detail,which is conducive to the understanding and wide spread of this method.(4)From the application of correction method in angiosperms,it is found that although the evolution rate of angiosperms is significantly different,the evolution rate between different branches is still partially consistent: Magnoliids have the slowest evolutionary rate,followed by Eudicots and Monocots.When the environment changes greatly,most species of different lineages of angiosperms have synchronous radial evolution and adaptive evolution.The model corrects angiosperms and establishes a relatively reliable angiosperm evolution time axis,which helps to understand the evolution process and model,especially to understand the phylogenetic relationship and the causes of diversity.Figure 22;Table 14;Reference 82...