The gene deletion/insertion operator is the second in importance of the combinatorial-specific operators (see
Figure 6.2).
This operator randomly selects the chromosome, the multigene family to be modified, the gene to transpose, and the insertion site. Each chromosome can only be modified once by this operator.
Consider the chromosome below composed of two multigene families:
| 01234567890123456780123456789012345678 |
|
|
rpifghasbdeocjknlqmQSKLHCIGDONPFEJMBRA |
(6.5) |
Suppose gene 5 in MGF1 was selected to transpose to site 14 (between genes 13 and 14). Then gene 5 (“h”) is deleted at the place of origin and inserted between genes “j” and “k”, obtaining:
| 01234567890123456780123456789012345678 |
|
|
rpifgasbdeocjhknlqmQSKLHCIGDONPFEJMBRA |
(6.6) |
The deletion/insertion of genes when combined with the most powerful operator (inversion) might be useful for finer adjustments. However, for all the problems analyzed in this chapter, the performance was higher when inversion alone was used in the search.
|