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are afterwards selected and reproduced, leaving as many descendants as the
actual population size P = 50.
As shown in Figure 12.9, for non-homogenizing populations there is no
correlation between success rate and the initial diversity. Indeed, due to the
constant introduction of genetic modification in the population, in non-ho-
mogenizing populations, after a certain time, the founder effect is completely
erased and populations evolve, as usual, efficiently.
100
90
80
Mutation
Recombination
70
60
50
40
30
20
10
0
0
5
10
15
20
25
30
35
40
45
50
Founder population size
Figure 12.9. Dependence of success rate on the size of the founder population in
non-homogenizing populations undergoing mutation alone (mutation rate equal to
0.05) and homogenizing populations undergoing recombination alone (two-point,
one-point and gene recombination rates all equal to 0.8). The success rate was
evaluated over 100 independent runs.
A very different situation happens in populations where crossover is the
only source of genetic diversity and the evolutionary dynamics are homog-
enizing in effect. In these cases, there is a strong correlation between success
rate and initial diversity. Note that populations evolve poorly under recombi-
nation, being practically incapable of adaptation in the cases where only 2-5
founder individuals are used (obviously, for cases with only one founder,
homogenizing populations are altogether incapable of adaptation). It is worth
emphasizing that, in these systems, even when the size of the founder popu-
lation is equal to P , the success rate is significantly smaller than in populations
 
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