>>212544758In the setting it is so far in the future that earth is a completely forgotten location that is even fuzzy in other memory. The races have homogenized, and split and re-homogenized so much, its multiple mystery meat distillations.
The great houses, because they're controlled bloodlines, will lean towards certain phenotypes more, but even then its a hodge podge of thematic reasoning, like the Atreides being greek/med themed because its paced and plotted like a classical greek play (minus the chorus exposition).