Brother Jero can be violent and intemperate, and I apologise on his behalf. He was, apparently, unreasonably upset by the assertion that human cultures are primarily adaptive at the group level. He misunderstood this to imply that culture evolves at the group level. He was confused be Peter Richerson’s (whom he has admired greatly for years) phrase “If selection also acts on cultural variation, say group selection on primitive institutions…”
If I could attempt to explain Jero's point of view, you may find it in your hearts to forgive him. He does not lead a happy life.
He feels that in biological evolution, selection takes place at the level of the loci of difference between one organism and another of the same species. These loci, if selected, are transmitted down the branching line of descent, intermittently or entirely.
In cultural evolution, selection takes place at the level of loci of difference between two things of the same sort (pointy sticks), both in the world and in the metaverse (sticks), or in the metaverse alone (the proof that the diagonal of a square with unit sides is incommensurable); though it must be born in mind that the latter, and all like all processes, are distributed about the world in material form, in the case of that particular diagonal in binary code, print, diagrams and so on.
In biological evolution, it has not been demonstrated how selection could take place at the level of the group or species (the example of eusocial insects certainly does not make this case, and it is very simply demonstrable how this is so). What is clear is that it is the environment which makes the selection, e.g. what selects most powerfully for the male peacock’s tail is that part of the environment which decides on the potential reproductive fitness of that particular tail; that part of the tail's environment which is the female peacock.
Likewise, it has not been demonstrated how a resilient and adaptable but overall stable set of loci of difference (sure he’s not handsome [organism], but he makes me/us laugh [culture]) is any different from the peacock’s tail. The loci of difference that compose an ability to make people laugh are located in a single organism. The environment makes the selection. It might be one person or ten million. Each one of the ten million will or will not laugh in various degrees. If the the ten million all laugh at the joke, then those loci of difference in the funny guy will have been selected ten million times, and one can continue with a narrative about in what further manner they might evolve. But that is not selection by the group. It is a selection by ten million locations in the environment. Clearly, as with a biological species, it is more durable to be selected ten million times, to be a rat, than it is to be selected just a few times, to be a white-lipped rhinoceros. But ten million rats are ten million indvidual organisms. And ten million people laughing at a joke means the joke has been selected with replication potential ten million times. What it does not mean is that a group has made a selection. It is not clear where in the group such a selection might be made.
If one person laughs at the joke, and the other 9999999 laugh because everyone else is, then the joke has not been selected and the evolutionary content is derisory.
This is not to assert that groups, a Roman legion versus a Gallic army, are not themselves selected by the environment. The battle is an emergent process, a million or a trillion loci of difference, the length of a sword, the relative placement of shields, a mosquito in the eye at the wrong moment, all lost in noise, unrecordable. The selection only comes in retrospect, after massive selective destruction of information. The selection will be made by a retrospective environment, upon cultural agglomerations such as victory, protocols and procedures, weaponry, timing, spatial aspects, logistics, use of terrain and so on; a bit like assessing a design of a mobile phone. And it will be composed of anecdote, report, expert witness, progressive selective destruction of information until conclusions are drawn and put into effect, or not, in time for the next battle. So the configuration of a group, an army, a government, “the public”, can certainly be selected.
However, selection cannot ever take place at the level of the group, but only at the level of loci of difference. The selection cannot ever be made by a group, but only at the level of that part of the environment which is a human organism. It can course be done more than once, by more than one person..
Brother Jero is a simple soul, and feels these things far too strongly. Again I apologise on his behalf.