I'm trying to recall a novel that I read in the 80s/early 90s. Unfortunately I can't remember either the title or the author. Here's what I can remember:
- There was a separate race of human being that lived in harmony with nature
- The hero of the story ends up joining them and living with them
- Much of the earth was, I think, barren of life
- There was a hive mind or gaia type entity involved
- One character was a mad/odd doctor or scientist that received messages from the hive mind, at one point via bacteria under his fingernails
I've been searching for it for some time, so any suggestions appreciated. IIRC it was a similar kind of novel to Radix, but doesn't seem to be any others by A. A. Attanasio.