That section of scripture (Genesis 6) is clearly about not being unevenly yoked with those who have "no faith" . The seed, one (spiritual of Christ not seen. It was still being preserved for Jesus as the Son of man who was not yet born of woman. This is when the genealogy came to a end.
If that creation (no DNA) of administering spirits( no form)were created form the dust of the field as humans .Then a person might even trying to locate a angel like in Ghost Busters. And if somehow they could find one then we could take some DNA from the blood.
That is as if we did wretle against flesh and blood to begin with .. Christian's walk by faith the unseen Holy Place. It has nothing to do with what the eyes see as the natural course of this world .
Why even think of looking for DNA ? What the living hope? Something to lust our eyes with as in idol worship? or watch out for the taller people who like the song think short people have no reason to live?
1 John 2:16 For all that is in the world, the
lust of the flesh, and the
lust of the eyes, and the pride of life, is not of the Father, but is of the world.