This post is more of an orientation for myself than anything else, so please forgive me if it seems:
The first part, or at least a crucial part, of building a world is quite literally constructing the world in which the characters inhabit. This, as we all learn over and over again in middle or high school English classes, is oftentimes known as setting and involves time and place. In this particular example, the way that Butler makes the story take place in a post-nuclear apocalypse time is integral to the way that we perceive the Oankali and the humans. It, at least to a certain extent, justifies the actions the Oankali have taken in “abducting” the remaining humans. Of course, this is tempered by other things that we learn about the treatment of people in Dawn — the isolation, the being in stasis for many hundreds of years, the genetic experiments, etc. However, the post-apocalyptic time period is crucial in making the Oankali at least a little more sympathetic during our first exposure to them. If the Oankali had begun abducting people during a relatively peaceful time, it would read as only a violence, whereas having the only hope for the survival of humanity being their interference creates the conflict in how we are supposed to feel about the Oankali that is central to the plot of the entire Xenogenesis trilogy, not just Dawn.
The second part of setting is place, and in this particular instance, the ships —Chkahichdahk, Lo, and the others on the rebuilt Earth — serve an important function in the world of Xenogenesis, and their existence as something living and even somewhat sentient is also integral to the worldbuilding of the Xenogenesis trilogy for two reasons that I can think of. The first is how utterly alien it is to the humans (pun completely intended, considering that the ships are an alien life form). Thus, when Lilith and the others first wake up, the ships serve as another tool to emphasize how much they have to lose if they don’t cooperate with the Oankali, as without Oankali interference, they can’t manipulate the organic matter of the ships. Furthermore, the Oankali are also the only ones able to rebuild Earth, which is all the humans want at first. However, there is more to it than that — the biological nature of the ships also shows how much the Oankali are capable of in terms of changing other organisms over time. The ships are, in a sense, no different than the human constructs that the Oankali create to further their own species as well as the humans, in their eyes anyways.
The other thing about the ships is that they, though the resisters don’t know it, are a sort of time-bomb for Earth even as they helped to rebuild the Earth for the humans. The ships, in creating the foundation for the construct villages, are fundamental in giving the humans what they believe they want, which is the ability to go back to Earth. However, as we as the reader and the construct families know, the ships, in many thousands of years, will mature and join the other ships as space-traveling vehicles, thus leaving Earth an empty shell of itself. Thus, the paradox of the Oankali-human relations — the drive to survive vs. the drive to keep the Earth and the human genome as is — is made even more complex by the very existence of the ships in which both species inhabit.
Of course, it would be impossible to mention this tension without a quick interlude to talk about the Contradiction, which, while I’m struggling to class it as an aspect of worldbuilding (I suppose it comes down to your view of humanity), nonetheless greatly influences the world of Xenogenesis. This contradiction between intelligence and the desire for hierarchy, as the Oankali describe it, permeates the background of the post-nuclear apocalypse justification for the interference of the Oankali (for the humans; the Oankali see no need to justify themselves). This inherent flaw in humanity is also integral to the culmination of Adulthood Rites – humans are allowed an Akjai group in spite of the Oankali belief that they will only destroy each other again. To them, it is essentially premeditated murder, and yet the construct children believe humanity should be given a chance regardless. If not for the contradiction, it is possible the Oankali would not oppose a human Akjai group (unlikely, but not impossible); thus, it, as a trait for the human group that is a fact of their nature and therefore part of the world they inhabit (I see now that I’ve answered my own question about whether or not I would consider it part of the worldbuilding). Even Lilith struggles with this flaw despite being the one who knows the most about the Oankali and their ways, which are also an integral part of the world Butler built. However, this is why it is so important — it drives so much of the struggles between the humans and the Oankali on the Oankali side of things.
Speaking of the Oankali, they are the last part of the worldbuilding that I would like to address for now. Butler had to, we can safely assume, create them from scratch, which makes them an inherently interesting subject of study. In a 1997 interview with Charles Rowell, she mentioned her inspiration for the appearance of the Oankali: “…I have a book about animals without backbones. I also have a particular aversion to some invertebrates, really a phobia. I ran across one, a picture of one that made drop the book… it’s a revolting little creature, and I’m really glad it’s not bigger. I wound up using part of its appearance to create the alien characters in my Xenogenesis books…” Thus, it is clear from the reactions of the humans and from this interview that the Oankali are meant to horrifying in appearance (which makes the trade that much more repugnant to the humans – what if the aliens were more physically attractive? Would there be as many objectors?). Their reproductive methods and the three genders associated with it also play a role in this — we humans have a hard enough time accepting transgender and nonbinary people, who have existed and have been known to us since the dawn of intelligence, so the idea of a third sex that is essential to reproduction is, to keep using this fitting word, alien to the human characters.
Of course, the Oankali have their own biological imperative, which is to interbreed with other species. This, in turn, helps to create the background for the Oankali, which includes their history of space travel and the motivation for everything they do with the human race. Something I actually would have liked to have more of is Oankali interactions with previous species – what did they take from them? Did they destroy their homeworld after growing new ships? How typical is it that the Oankali found the humans on the brink of extinction? However, this information is either not provided or touched upon very briefly. This choice is also part of the worldbuilding as much as what we do know about the Oankali, even if I find it a bit frustrating. A people’s culture, history, appearance — these are all part of worldbuilding, and with the Oankali, I expect to keep coming back to it over and over throughout this project.
Thus ends my messy, preliminary thoughts on the worldbuilding of the Xenogenesis trilogy. Hopefully, these will turn into something better by April!