[fiftycents]

Yes. It's good to evade a predator. And the process you describe is accurate. But it occurs because the first elephant without tusks happens to live a longer life and prosper and left a large number of descendants just in time when they were hunting by their tusks. It just occurs, it's not a response in the sense of the specie but in the sense of the randomizing events we call world. That's why I said OP is, in the core of his argument, right.

[fastball]

Then the wrong word is "response", not "evolution". Because this is exactly what evolution through natural selection is all about.

[fiftycents]

Response would be a better wording. Yes, you are right. <<Evolution>> maybe lead you to assume that variation/response seems to move towards something. But, yeah. You are right.