What is crossover (AI)?
by Stephen M. Walker II, Co-Founder / CEO
What is crossover in AI?
Crossover, also known as recombination, is a genetic operator used in genetic algorithms and evolutionary computation to combine the genetic information of two parent solutions to generate new offspring solutions. It is analogous to the crossover that happens during sexual reproduction in biology.
What is the purpose of crossover in AI?
Crossover is a way to stochastically generate new solutions from an existing population. It can be performed on different data structures that store genetic information, such as bit arrays, vectors of real numbers, or trees. Different algorithms in evolutionary computation may use different data structures and each genetic representation can be recombined with different crossover operators.
How does crossover work in AI?
There are several types of crossover methods, including:
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One-point crossover — A point on both parents' chromosomes is picked randomly, and designated a 'crossover point'. Bits to the right of that point are swapped between the two parent chromosomes, resulting in two offspring, each carrying some genetic information from both parents.
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Two-point crossover — Two random points are chosen on the individual chromosomes and the genetic material between these points is swapped.
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Uniform crossover — Each gene (bit) is selected randomly from one of the corresponding genes of the parent chromosomes.
What are the benefits of crossover in AI?
Crossover plays a crucial role in spreading the beneficial mutations of population members that let them achieve a high fitness. It allows for much faster convergence in algorithms. In the context of neural networks, crossover can involve mutating the weights and perhaps crossing them over as well.
What are the drawbacks of crossover in AI?
However, it's important to note that the crossover between two good solutions may not always yield a better or as good a solution. If the offspring is not good (poor solution), it will be removed in the next iteration during “Selection”. Also, depending on coding, simple crossovers can have a high chance to produce illegal offspring.