well, you can't really say that, unless you know exactly what "part human" entails
I would like to clear up that "uneducated birdbrain" was used in jest and was not meant to actually be a mean-spirited insult.
Also that it is biologically impossible unless we were referring to a separate creature that evolved independently of Humans. Mating is obviously out of the question, the sperm and eggs are incompatible and the love cells would have incompatible chromosomes.
Same question for gene splicing, I
think. Don't quote me on this but I am fairly sure it is impossible to create a hybrid creature if they have sufficiently different chromosome numbers and structure, and Human/Bird chromosomes are pretty different. So that's also probably out.
So "part human" would be inaccurate and probably impossible, but it makes no difference. Anthropomorphic animals have been a thing for a while, no point in trying to toss science in.
and furthermore, flat didn't create starbound canon, so even if it was biologically impossible for that exact situation to happen, he wouldn't really be the "uneducated birdbrain"
Starbound lore is wank scientifically anyways I don't even care about it. Oh hey gasbag people. Oh hey devolve the bodies to evolve brains? Plant... people? Questioning it is silly and I don't know why I do it.