 For such extremely large population sizes, the threshold between selection and drift (see  Fig. 1),  which is determined by the effective population size, \(N_e\), is too lower to matter evolutionarily. That is, the strength of random genetic drift, which is proportional to (1/\(2N_e)\), is very, very weak and even genes with very small values of \(s\) have their evolutionary fate determined entirely by selection. This is the essence of “Fisherian gradualism”—very small selective forces given sufficient time can have effects on adaptation similar to those of genes with much larger effects acting over a shorter time period. With very large \(N_e\), the domain of random genetic drift is greatly restricted even as that of natural selection is expanded (see  Fig. 1).