The topic at hand was whether the couple-sex-mix here would turn out to have a surprisingly reasonable explanation.
Thellim can try to check this on Wikipedia.
Before she does that, she is supposed to try and solve the puzzle herself; so that, if there is a surprising answer, Thellim can notice herself having been wrong, and ask about how she went wrong.
So. If it's not just the world being - painted in randomly, or in a pattern that Thellim doesn't understand - then how could this result be an evolutionary equilibrium?