1.) Workers in eusocial insects are more related to their sisters (75% similar) than they are to their own offspring (50% similar). This results in selection pressure that favors cooperation, rather than producing your own children: http://en.wikipedia.org/wiki/Evolution_of_eusociality
2.) Deleterious de novo mutations are, obviously, deleterious. Duh. I didn't say that all genes are beneficial, I said that no gene selects for reduced fitness.
Your first point is simply a statement of reason why a gene for zero children (under some circumstances) might be selected. Obviously there are such reasons, since there are such creatures! In no way does that make it a bogus example - in fact, it's quite relevant to the parent conversation, with an acknowledgement that the selection pressures would be weaker.
The second point, I'll grant - though with the qualification that your language is tremendously imprecise. Genes don't select at all. Evolutionary pressures (plus happenstance) select between genes. That messiness is partly why it got a "notwithstanding..." aside, rather than a full example.
What is clearly true is a more restricted version - no gene will be selected for if it causes zero reproduction (of any sort) across all carriers. But that's also basically irrelevant to the discussion.
> What is clearly true is a more restricted version - no gene will be selected for if it causes zero reproduction
Like the genes that cause someone to become a doctor and minister to his/her genetic cohort? I think your argument doesn't go deep enough into how genetics works.
We should all remember that reproduction isn't about individuals, it's about genes. The old question about the chicken and the egg actually has an answer -- a chicken is an egg's way to make another egg.
You truncated my statement in a way that changed its meaning. I was explicitly focused on the gene. If it causes zero reproduction across all carriers then ministering to my relatives does not increase the chance of that gene spreading, as any of my "genetic cohort" in possession of the gene will not be reproducing. It may help my other genes, but that doesn't cause the one to be selected for.
Note also that I said "reproduction of any sort" - some infertile strains of produce have done quite well in an environment where humans clone and graft. Theoretically, that could apply to humans although at present I don't think it does.
1.) Workers in eusocial insects are more related to their sisters (75% similar) than they are to their own offspring (50% similar). This results in selection pressure that favors cooperation, rather than producing your own children: http://en.wikipedia.org/wiki/Evolution_of_eusociality
2.) Deleterious de novo mutations are, obviously, deleterious. Duh. I didn't say that all genes are beneficial, I said that no gene selects for reduced fitness.