I think jealousy may go beyond patriarchy even. Perhaps it’s a matter of epigenetics, where jealousy is inherently human (a part of our biological nature), but is triggered and set off by environmental/social changes, in this case, culture.

Jealousy probably become more prominent around the time of the agricultural revolution, at a time when the concept of “ownership” first came into play with land and property. After all, jealousy isn’t only limited to romantic relationships, but to platonic relationships as well. Jealousy exists because of our ego, because of our sense of self, because of separation. So you’re right in that ownership has a lot to do with jealousy, but I think patriarchy and monogamy is only a small piece of that.