[angelbob]

Darwinism suggests that if ghosts can continue to exist (and reproduce?) and affect the world to create more of themselves (e.g. tell people that it's not so bad), then they will be selected-for.

Ceasing to exist is, in a strict Darwinian sense, bad. Reproduction and, to an extent, continued existence are good.

[loup-vaillant]

Seconded. It should be noted that some people see making children as a form of immortality. My own mom thinks along the lines of "what's the point of living forever, you just have to make children".

I say the immortality of my genes pale in comparison to the immortality of my thought processes. Even if the copy isn't really "me", it will have the same influence I could have had if it was. I may have other goals besides not dying. My ghost would have at least a chance of carrying them out.