case SYMBOL:
return new SymbolInstructionGene(gaConf,size);
case BITFIELD:
return new BitFieldInstructionGene(gaConf,size);
case STACK:
return new StackInstructionGene(gaConf, size);
case FLAT:
return new IntegerGene(gaConf, 0, size);
case HCLUST:
return new IntegerGene(gaConf, 0, size + 2*(size - 1));
default: