I'm not sure if you're familiar with the work from the lab of Mike Levin at Tufts but I'm betting you'll find it interesting if not. Here's a taste https://pmc.ncbi.nlm.nih.gov/articles/PMC6923654/

While I disagree with your notion that this is explicity due to gravity, the rest of your argument seems to align with some of this lab's work. Learning can be demonstrated on scales as low as a few molecules, way below what we would normally call "life".