This is pretty much exactly what I said in my first and subsequent comments, and it cuts many different ways. This is the punctuated equilibrium dynamic in the origin or evolution of species, one that directly counterdicts the gradualist perspective that Darwin posited as a necessary factor in evolution and to which many modern evolutionary scientists still cling.
That said, there is no guarantee that genetic predispositions established in populations don't persist through periods of environment/selection change. It's entirely possible that patterns of genetically reinforced behavior survive rapid selection events, say the change from egalitarian/cooperative social structures to patriarchal/stratified power structures.
This, I think, is what you are hypothesizing in your original piece; that we are more formed as a species by the hundreds of thousands of years of hunter/gatherer egalitarian social organization than we are by the last several thousand years of sedentary agricultural "civilization" which gave rise to the patriarchal power structures we are familiar with.
The difficulty with supporting this hypothesis is obvious; it's very difficult to support with actual evidence the social organization and cultural practices of pre-historical societies. We don't, for example, even know how, when, or why humans migrated from Asia to the Americas. Many scientists have found small troves of archeological artifacts and claimed each time that these were the first immigrants, only to have others find older troves which seem to push the date and route of the migration farther back in time and to different locations.
Even when hunter/gatherer societies have regular "seasonal rounds" to procure resources, they still leave scant evidence of their presence, which of course are scattered along those rounds and usually are only found in large cave structures regularly used as yearly shelters. I have visited a few of those here in the Intermountain West, but even those can't be assumed to be dispositive of the people who could have inhabited the region over the last 10-50,000 years.
It's only since settled agriculture that larger troves of archeological findings have been left behind for research and analysis...much of our hypothesizing about older societies remains hard to support with concrete evidence, leaving factual conclusions about the prior nomadic societies hard to make;)
