User blog comment:DYBAD/Character Sheet/@comment-24810520-20141225152904/@comment-4867780-20141226234028

Yes, they are some of his many children.

Incest is prohibited for very good reasons in real life, most of all because of the inevitable genetic deterioration that compromises the lasting survival of the community. Lawrence completely reverts this logic, his replication-based exponential genetic pool and superpowerful genetic-engineering guaranteeing each and every descendent a top-quality genetic heritage, enriching and perfecting the bloodline instead of dwindling it

The other big argument against incest is the breakdown of the family unit which is the stabilizing fundation of human society. In the context of the story, In the context of the story, there is a single extended family unit centered on a single father, so this breeding policy actually strengthens the social order instead of destabilizing it.

So while being asbolutely justified in a real-life context, this taboo is fully irrelevant in the context of the story.