There was no specific causal relationship between the different elements that we consider the "civilization package." Agriculture, sedentism, social hierarchy, writing, urbanism, political institutions: all emerged in a variety of different contexts around the world.

Far more of the times and places in which people were actually living over those 10,000 years don't fit altogether neatly into a narrative of long-term progress than do. It's not that the elements of the progress story aren't real, or don't matter, but that they're one element.

When we zoom in on any particular time or place in that 10,000-year period of "progress," we find extended episodes of depopulation, ecological problems, issues of population health, and full-blown social collapse, with the disappearance of whole societies and ways of life.