Random Question About Genetic Traits

[ZeeJustin]

I was reading the thread entitled "How can gayness have a genetic basis?" and it got me to thinking...

Are there "cases" of genetic traits that are not desirable for reproduction that pass on anyway, and with "reason" (or perhaps I should say non-randomness)?

Let's call it a "Martyr Gene". A tribe needs a martyr to survive, but the martyr would not live long enough to reproduce. Naturally, he wouldn't pass on the gene.

HOWEVER, if instead his mother had a gene that said, "If I have a baby, there is a 1/100 chance he will be a martyr", then that mother's tribe will have a greater chance of surviving, assuming of course the martyr is able to sacrifice himself in a way that is beneficial to the society.

I'm not trying to make a point with this. Maybe it's an extremely elementary question, and if it is, I apologize, but I would really appreciate it if someone could indulge me and link me to a study or two.