You misunderstand. My point about organisms was that selection happens at the level of organism, which was an imprecise way of saying organisms are what either procreates or dies, and so this is the level at which selection events occur. So any purported selection at a different level must have some organism-level proxy.

The statistics of what survives and what doesn't can still show effects happening at different levels. So when I speak of gene selection, I'm speaking from a statistical perspective. When I said that diversity isn't itself selected for, I meant that there is no strictly "diversity" selection happening at the level of organism.

>You also never responded to the fact that humans are colonies

Yes, humans are "colonies", meaning that we show cooperative behavior. But I don't see how that's relevant, at least in light of ways to understand the evolution of cooperative behavior at the gene level.