for (ChromosomeMapIterator it = generationFitness.begin(); it != generationFitness.end(); it++) {
rankedGeneration.insert(std::make_pair(rank--/denominator, it->second));
for (ChromosomeMapIterator it = generationFitness.begin(); it != generationFitness.end(); it++) {
rankedGeneration.insert(std::make_pair(rank--/denominator, it->second));