How should we distinguish between selectable and circumstantial traits?

There is surprisingly little philosophical work on conceptually spelling out the difference between the traits on which natural selection may be said to act (e.g. “having an above average running speed”) and merely circumstantial traits (e.g. “happening to be in the path of a forest fire”). Here, I show that the two existing proposals as to how this distinction should be made are unconvincing because they rule out frequency-dependent selection. I then propose two new potential solutions, which share the idea that extrinsic properties dependent on internal relations should be accepted as traits on which natural selection can act.