Jim shakes his head. "No, nothing like that, either. There's just one human species on Earth. When we spread out to the stars, some people, over time, developed certain adaptations to their new homes. Sort of like the way a person raised in a high-altitude city is more acclimated than someone who was raised at sea level. But they're all the same species at the end of the day."

But he's curious, always has been about other cultures, races--and now universes, he supposes. "Are they common, where you're from? Human subspecies and nanotechnology?"