I probably didn't explain this clear enough, but you *do* write human in the ancestry/species field! In fact, humans are present in the oracles for fantastical ancestries and animal species (we are animals, after all). Though I like the idea that a player may choose to write in a human's real-world ancestry. Thank you for the feedback! 🙇♀️💖
Oh, I said "don't fill in" because, if everyone is "human" then it's effectively the same as leaving it blank.
What I meant was, the word "ancestry" carries meaning and differentiation within species; they are historical and cultural lines of people. Elves, goblins, and the like, are species, not ancestries. Those species may have many ancestries within them (For example, Goblins from this one country vs. Goblins from another vs. Goblin nomads, etc), but they are not ancestries themselves.
Which is why it feels so bizarre to have a field called "ancestry" and then effectively ignore it in a human-only game. That sort of thing can feel a tad too close to dismissing race and culture as important to people. Which is why I suggested either acknowledging it more in the rules, or removing the word "ancestry" from the field and leaving "species" on its own. There may be other solutions, of course.
I hope I was a bit clearer this time. I'm not the best at communicating my points. <_<