Board Thread:Naruto Discussions/@comment-945885-20140709082448/@comment-2120712-20140709143731

The Kaguya clan connection was obvious though I am surprised that Kishi went out and verified it. Maybe all KKG ninja are descended from her. My original assumption(aka speculation) on KKG was that they were originally bodily and genetic deformities like the ones we in the real world face today before chakra was spread out among humans by the Sage. Once chakra were introduced into the bodies of these individuals further genetic changes occurred through the generations and the kkg we know today were born.

Hagoromo seems to represent Kaguya after she gained the Rinnegan/Sharingan(eating the fruit) and Hamura seems to represent Kaguya before that event took place. So Kkg like the bones and Byakugan were something she was with born while KKG like the other dojutsu and maybe elemental based kkg is what she gained/passed down through Hagoromo.