1) help make sure those copies of your genes in others survive (help out relatives who did reproduce) - evolutionarily, this is equivalent to reproducing, if slightly attenuated;
and 2) have a lasting memetic impact.
And that's if you're focused only on the long term, which you seem to be - there's plenty more shorter term reasons to be alive.
Or how about a gene that drives non-reproductive young males to be restless, jump on a horse and ride over the horizon on a whim. Sometimes they come back, say "There's buffalo over there!" and the whole tribe benefits. That's selected for too.
That's why nuclear family is called nuclear. And today we often have "subnuclear" people without any strong bonds.
If I had a kind of clan, the situatiou would be different.
http://en.wikipedia.org/wiki/Kin_selection#Hamilton.27s_rule
What if I don't feel that my "closest relative with progeny" is in any way related to me?
I don't care about inclusive fitness. Let the nature do that trick. I care about reproducing something resembling of myself. If my nearest genetic relatives don't resemble myself in any way, I don't care if they reproduce.
Certainly. But then I'd say that a huge portion of what makes you you is not genetic at all, and like I said much earlier you can always pass on memes.
I can give memes to other unrelated people but I don't know whether they use those for good.
Children are safe bet in that regards (if you failed - means you just passed your failureness to them, good)
I don't see why that doesn't mean you should work harder at it. Maybe the marginal benefit is minimal, but if the marginal benefit of everything else is zero then it might still be the best option.
You might want to develop a different ideology to help you cope in that event.
The CD suggests that male fertility problems are not rare.
> Many couples struggle with infertility and seek help to become pregnant; however, it is often thought of as only a women’s condition. A CDC study analyzed data from the 2002 National Survey of Family Growth and found that 7.5% of all sexually experienced men younger than age 45 reported seeing a fertility doctor during their lifetime—this equals 3.3–4.7 million men. Of men who sought help, 18% were diagnosed with a male-related infertility problem, including sperm or semen problems (14%) and varicocele (6%).
So now you think that I've "labeled" 1000 - 1 to be less than 1000? So much for math.