Scavenger: Evolution and Scavenger: AI are two books in Timothy C. Ward's Sand Divers series. Evolution came out initially as three episodes (short novellas) - Red Sands, Blue Dawn, and Twin Suns. These stories are based on and were my first exposure to Hugh Howey's world of Sand. (Ward's books are written and sold with Howey's permission.)
With only a vague understanding of Sand's premise, I was able to follow Scavenger: Evolution without a challenge and make sense of the Dune-like setting and conceit. Although it's a tie-in work, Ward's novel definitely holds its own as a stand alone story - and with as much gritty realism as can be found in Wool or any other story by Hugh Howey. Ward pays tribute to some excellent indie SF with these two outings.
If the intriguing concept of sand-diving is of any interest (and it should be!), and you want a taste of the promise of Danvar, I recommend Ward's addition to this post-apocalyptic SF epic. - Lyn Perry