During one-point recombination, the chromosomes cross over a randomly chosen point to form two daughter chromosomes. Consider the following parent chromosomes:
Suppose bond 3 in gene 1 (between positions 2 and 3) was randomly chosen as the crossover point. Then, the paired chromosomes are cut at this bond, and exchange between them the material downstream from the crossover point, forming the offspring below:
With this kind of recombination, most of the time, the offspring created exhibit different properties from those of the parents. One-point recombination, like the above mentioned operators, is a very important source of genetic variation, being, after mutation, one of the operators most chosen in GEP. The one-point recombination rate
(p1r) used depends on the rates of other operators. Typically a global crossover rate of 0.7 (the sum of the rates of the three kinds of recombination) is used.