A genetic algorithm takes inspiration from the proceses of natural selection for biological species. Indiiduals are defined using a set of paaremeters, effectively artificial genes -- in the biological analogy, the genotype. These are used to assess their fitness based on whatever criteria are considered optimal and any constraints -- in the biological analogy, the phenotype. The least fit indivdiuals are 'die' (removed from the popukation) and the fitest selected for 'breeding'; typically this process is stochastic, with fitness being sued to weigh the proabability of a random decision as to which die and breed. Those chosen to reed may be subject to random mutation and pairs of individuals brought together and theor aetiicial genes randomly mxed, in a process akin to mating. In some versions only mutation is used so that the procsses is more like the growth of bacetria or asexual reproduction. In some varuants the new interbred individuals replace their parents' geeration entirely, in some they are added to it (replacing those that died).
Defined on page 76
Used on Chap. 4: pages 76, 77, 81; Chap. 5: page 92; Chap. 8: pages 154, 163; Chap. 9: pages 177, 184, 185, 186, 188, 190, 191; Chap. 10: page 204; Chap. 11: page 241; Chap. 14: page 329; Chap. 18: page 446; Chap. 21: pages 516, 517, 523; Chap. 24: page 584