These reoccurring discussions are always fun to read. They always show a great interest in science, and which science to believe. When the discussion turns to genetics and evolution what Todd points out is important to remember. Evolution is a ongoing process driven by stress that an organism encounters. Salmon have been around for a long time, more than 5 million years. What we are talking about is only a 100 years or so. Sediment core work indicates that salmon went through long periods of low abundance in the past. It is true that humans are responsible for driving many species to extinction but I think salmon will outlast humans. Hatcheries maybe one of the reasons. As this discussion indicates we like our fish but what is lacking is the role of the fish. If the point of reproduction is to insure that some genetic suite is maintained then it is not so important where it takes place, just that there is an environment where reproduction is possible. While we humans assign some value to various life forms, food, weeds, bad bacteria, hatchery salmon, or wild salmon. Evolution is not dependent on what we value. One could say that salmon are evolving to reproduce in hatcheries as habitat for wild reproduction is degraded. Changes in habitat, pollution, climate change, disease, and harvest are all stressors at work in the ecosystem. If salmon can reproduce successfully in a hatchery they will. We could stop hatchery production but I suspect it would make little difference to wild fish populations.