Ah, the shifting goalpost argument. Interesting that you can't just own up to the fact that you fabricated your reasoning. Can't we just be adults here? Why is it so hard for you to admit when you're wrong? We both know what's going on here, why don't we just put it on the table?
You claimed that this mutation is deleterious because clams can't metabolize saxitoxin. Either show me where this argument derives from, or admit that you made it up. Or admit that you didn't understand or didn't read the parent article. I really don't care one way or the other, but if we can't agree on the simple fact that this mutation is tremendously advantageous for this subpopulation of clams (the paper that supports this view has been referenced several time here), then there's no point in moving forward to more complex ideas, because, if you can't accept this fact, then you don't know the meaning of proof. So, again, support your statement that this mutation prevents clams from metabolizing saxitoxin.