Genetic change is a natural process it's called evolution. However splicing genes into organisms to add a desired trait is something that technologically we are not ready to do. There isn't any organisms that the genetic code is fully understood, Genes work with other genes and between the genes on the helix there are bits of code that turns genes off and on. The interaction of genes and the switching on and off of them is poorly understood, I don't think we should be messing with GMO until we understand genetics a lot better. There isn't any way right now to determine the effects until we see it happen. There have already been instances where GMO has escaped the lab.