that's a really interesting point you made! and i'll be thinking about it for the rest of the day but i meant (by which i mean reached, i reach a lot when it comes to karkat, god i love a boy) there was a chance that karkat's blood color influenced the human race's blood color on earth b? sorry i didn't specify!

Yeah I knew you meant it that way! But I am not quite sure, because I don’t know what kind of traits personally are passed down to the genes of the Genesis Frog. However, you don’t even have to reach if you want to theorise that. Karkat was the one aiding Kanaya with the Frog Breeding, and the one that told her to stop short of the last frog. That’s a direct tie to the process, and besides, he’s the Knight of Blood. Sure, he gave the Universe Cancer, but. He could’ve just as easily also Served them his Blood.