First, you’re right, the last three books in the series seem to me to have been written strictly for the money, although the true fans may not necessarily agree with that. The science is suspect, as well as the over-reliance on spooky psi powers as substitutes for technology. It borders on fantasy. But the concept of the future history, and how it is set in the far future so no contemporary trends intrude, ensures the author is dealing only with long term currents in human history, not recent developments like democracy and Christianity.. The themes, political, religious, ecological, are not 20th century ones, they go all the way back. They will be what remains after the novelty of the contemporary future wears off and is forgotten.

You’re right, the worms seem an imported life form, one not native to Arrakis (An anagram for Iraq, the cradle of civilization?), an interesting concept in its own right, nor are they related to anything else in the novel. All the other plants and animals, on all the worlds of the Empire, are either clearly recognizable Terran life forms, or perhaps genetically modified ones. Remember, in the novel, Earth is lost, perhaps destroyed altogether in the distant Butlerian Jihad. There is a dim racial memory of it as the origin of humanity, but no one even knows where it was originally located. But the worms are unique, and they are one of the great creations of science fiction imagination. What a concept!

The Dune Universe has no alien civilizations. Only human beings inhabit the tiny little volume of the Milky Way described in the books. As best I can tell from hidden clues, I suspect it is at most, only a few hundred light years across, a tiny speck in our Grand Design Spiral, a grain of sand in the infinite desert wasteland that is the universe. There may very well be Others “Out There”, but they are not mentioned or even considered. Its just us.

Reading Dune, its hard to escape the suspicion that Herbert saw it all in a dream, that the gods planted all this in his mind, that he is magically connected to the far future in some mysterious, even supernatural way. The themes and ideas, and how perfectly integrated they are with our own world and how they have so uncannily foreseen the future, seem to greatly exceed Herbert’s own intellect, experience and even his skills as a storyteller. He was inspired, it all came from outside him, somehow, a form of divine (or machine?) revelation.

If you can find the Harvard Lampoon parody, “Doon”, I highly recommend it. It deflates the pomposity of Herbert’s prose quite effectively, (as well as being hysterically funny). It does a much better job of skewering the sacred text than their send-up of Middle Earth, “Bored of the Rings” did for Tolkien.

But having said that, what remains after the satire, for both Herbert and Tolkien, is an astonishing achievement. I am in awe of the creation.

I’ve read some of the sequels to Dune, but going past the first two probably isn’t worth it for any except fervent fans.

Other than the sandworms, a large proportion of the life forms of Arrakis seemed to be imports from Earth deserts. In fact, other than the worms, I can’t remember anything else living there that was actually alien.

Oddly, the history of the planet implied that it was once a green world, which makes me wonder if the sandworms weren’t an import or genetic creation. I haven’t read enough of the other books to know if this was covered in any sequels or prequels.