Available Selection Types
Selection types determine the way individuals are chosen to breed/continue into the next generation.
Currently, the following types are implemented:
Also known as "Roulette selection" (for those who are more casino-minded), this selection type gives each individual a chance to get selected for breeding into the next generation proportionately to the individual's fitness.
Every individual's probability for being selected is the fraction of its fitness and the sum of all fitnesses in the whole population.
Stolen from: http://www.edc.ncl.ac.uk/
This selection type makes a larger part of every generation survive into the next generation. The best-fitness part of the population (size depends on the set survival rate) is automatically copied over into the next generation, the remaining amount of required individuals is created as offspring from the current population using a fitness proportionate selection.
In this implementation, every individual's fitness receives a random weight modifier, so some individuals may beat some "better" individuals if they happen to be lucky.