αVg,SVg,AEmbedded Image Embedded Image ξSξASA
α = 00.008070.006480.008010.006440.0000.0001.031.03
α = 0.00010.03640.01330.03510.01310.07260.1761.031.03
α = 0.0010.1140.03170.1020.03070.1940.6551.031.04
α = 0.010.3570.08620.2630.07940.5772.341.041.16
α = α* = 0.06640.8830.2080.4690.1721.526.391.102.05
α = α** = 0.07790.9530.2250.4880.1841.656.941.122.24
α =
α = 13.240.7890.7640.4416.1925.32.0617.1
α = 1010.1?0.910?19.8?11.1?
  • Results from the numerical studies for the various quantities reported after they have reached their long-term stationary values. The data are produced using the methods described in the appendix. The columns marked VG,S, Embedded Image , ξS, and S refer to sexual populations, and give, respectively, the genetic variance, the narrow-sense heritability, the difference between the value of the optimum phenotype andthe value of the population mean phenotype, and the average death rate. The columns marked VG,A, Embedded Image , ξA, and A give these same quantities for asexual populations. Values of α (the rate of environmental change) were set as shown in column 1. Parameters of the model (other than α) were set as follows: L = 10, μ = 10-5, m = 0.2, and V = 20. A question mark appears in cases that were too extreme for calculation without very large amounts of computer time. As explained in the appendix, there may be substantial inaccuracy introduced into the calculations when VGS > V/2. Therefore, the data shown for a sexual population with α = 10 should be treated with caution.