I'm just not sure what the fuss is about. In the last few days, there have numerous reports (here and here) of Mesoamericans processing polyisoprene into rubber 3500 years ago, using an morning glory "juice". But this has already been known since 1999. I wish one of the reports would clearly state what was newly discovered.
I also wonder how they thought to mix the two plant liquids together. Morning glory seeds are known for hallucinogenic properties, so they might have had a large orchard of the vines growing and wondered what to do with the waste.