I agree, arose at the same time but correlation is not causation. I've learned that attributing broad social changes to singular causes is oversimplistic and obscures phenomena. Again, I agree that agricultural methods are a major contributor to oppression, but those methods, no matter how significant, are one part of the complexities of human society. Your excellent resources also point to the reality that the oppression was not only gender-based but class-based. So, there are broader issues at work here. Also, gender oppression is found in non-agricultural societies. My sense is that plowed agriculture accentuated and solidified previous movements toward two-tiered social structures that oppressed working people and women. But through the dialectic of exploring and discussing all of these elements, we will gain understanding. :)