You do realize that you're failing to disagree with me, right? I said that the rate of suicide is low enough to be carried by the gene pool, and your following statement "if it doesn't have any effect on the gene pool, there is no evolution going on" doesn't contradict my statement. Death in any form affects a gene pool, be it slight or immeasurable; populations in which a small percentage die from a particular disease may develop immunity to the disease... not because the disease was going to wipe out the population, but the individuals in the population which more successfully resisted the disease were overall healthier and produced more offspring, thus affecting the gene pool. Individuals that have a strong tendency toward suicide edge themselves out of the gene pool, whereas those whose genome make them more resistant to suicide have a better chance at propagating their genes. This process happens over several generations. Evolution functions in a way that mitigates suicide, which is my original statement and I stand by it. Yes, suicide, still happens--it's just limited, but you are apparently the one who has no grasp of evolution to insist that it's an all-or-nothing situation (either everyone must commit suicide or nobody).
Now let's say for some reason suicide increases the chance of reproduction. For example, spiders who get eaten after mating--to reproduce means to die, but then they have a better chance at having offspring. Because it helps in successful reproduction, evolution has made this behavior common and ubiquitous among the species (in this species nearly all males get eaten after mating). Among human beings, the rate of suicide is actually very low--we're talking a fraction of a percent. Why isn't it more common? Why not 10%? 50%? 80%? Evolution. Learn how it works.