As a medical student who is currently in my musculoskeletal class, how different is the internal anatomy of the "humans" of the worlds of the cosmere? Like structure and number of muscles, bones, organs, things like that.
In general, you wouldn't have a problem. There would be minor differences. Like, there's gonna be some slight anatomy differences for, like, Scadrians, who were changed to deal with the ash and stuff. You'd be like, "Wow, the lungs are different here." And Roshar is a lower-gravity, higher-oxygen environment, and you're gonna find longer bones, you're gonna find stuff like that on Roshar. But, in general, you would be like, "This is a human whose species is slightly evolved for a different environment." Rather than "this is not human at all."
Now, if you were to ask about an Aimian, either variety, they would be very, very, very different. You would be like Bones trying to operate on Spock. The Sleepless, you'd need a very different degree for dealing with them. I'm very excited to eventually get the Sleepless fully into the stories. They're from my second novel, Star's End, is the very first appearance of them. And they got ported over to the cosmere once I designed the cosmere. And are a really cool, in my mind, science fiction race that are not a hivemind, but an individual is made up of a group of large insects that share Cognitive load across all of them, and there's just so many fun things you can do with that. Because they can selectively breed parts of their own body to do different things and have, like, fifty generations of this group of insect that they are selectively breeding to do this specific thing, and stuff like that. Hasn't been a lot of space for them in the cosmere, yet. Just some brief appearances. They'll be very important during the space age.