Forget the assertion that until the nineteenth century, people thought that heredity was purely on the paternal side. The Greek urban, homosocial leisure class thought that. But the Hebrew writers seem to have been unaware that any such fantasy even existed. Well, of course they were. They were working farmers who spent their time with their wives and children. Accordingly, their purity and incest laws presuppose a biological relationship with both parents. I employ the present tense because those laws are still in daily use, and may be read in the best-selling book in the world.
There is an old standby of middlebrow, pub bore professional atheism, that the Virginal Conception has numerous mythological parallels. Nothing could be further from the case. What occurs over and over again in mythology is the impregnation, by otherwise normal sexual means, of a woman by a god; a god, therefore, with a physical body. Exactly that does not happen in the Gospels.