The Lands kind of stick out as an anomaly in Homestuck’s cosmology. They’re not constant, like Skaia and the Veil are; they’re not evolved through prototyping like imps and carapacians; they’re not drawn from mythology like the Denizens; and they’re not made from Thoughtstuff like Prospit and Derse. On a cursory glance they seem to be the one example of something being created ex nihilo in paradox space, a realm that is supposed to contain “essentially nothing new”. So naturally, figuring out the genesis of the Lands would be a great stride toward unlocking Homestuck as a whole.
Obviously the logical first assumption is that the Lands are generated from the players themselves somehow; grinding metal for the swordsman, industrial pipeworks for the pipe smoker’s heir; and this makes perfect sense for as long as we see Sburb as a game whose goal is to guide players into adulthood. But that’s only one side of the coin; every aspect of the game, from frog breeding to prototyping, should also serve the game’s other primary purpose, which is as reality’s method of reproduction. So the question “why are the Lands the way they are” is just as important as the “what are they” question.
My first hypothesis was that if every one of the Lands in the Medium has its own breed of frog, then this could be a means of introducing genetic diversity to the Genesis Frog; a frog with lava-resistant genes, for example, might make a very different universe to a frog with genes from the Land of Dew and Glass. But I realise now that we don’t even need to introduce this new idea; the grist hoards in the center of each planet already act as a unique genetic code for each session’s Frog.
And since the grist essentially acts as the “essence” of each planet - oil grist for an oil world, chalk grist for a chalk world - we can also view the grist as the “essence” of its associated Hero. This is more pronounced in the trolls’ grist, with Tavros’ grists being brown-orange and Vriska and Gamzee having blue and purple respectively in [S] Make her pay. (We also observe here that Karkat has green grist, but you can make of that what you will.)
And I think this sheds some further light on how the Ultimate Alchemy ties into the alchemy of the self; the process of creating a universe involves the very alchemical components that make up a person. Using one’s inner essence to create an entire world could also be seen as a way of making the internal, external?
So the genesis of a new universe is the contribution of several individuals’ essences to be mixed in one central subterranean hub… i.e. exactly how troll reproduction works, indicating that the jadeblood is suited to the role of frog breeder even moreso than may have originally been thought.