Board Thread:Naruto Discussions/@comment-945885-20140709082448/@comment-24531362-20140719205615

Man of Sin wrote:

Btw, it's established that Indra inherited the eyes of the Sage while Asura inherited his body. So yeah...real world biology doesn't apply here.

Except, yes it does. Take, for example, a man with blue eyes and a large nose. He has two children with a woman with brown eyes and a small nose. It is entirely possible for one child to have brown eyes and a big nose, while the other has blue eyes and a small nose. It is equally possible that one or both could inherit both traits from one parent. It isn't like Hagoromo chose to give his dojutsu to Indra and not to Asura. It's just luck of the draw, really.