Is There a Father in the Story of Anna?

Was there any inclination to put her father or identify her biological father in putting this together? Or are we going for some kind of since Ellie is a sort of Messiah figure in this mushroom apocalypse? Are we going for a sort of Virgin Mary? Let's not talk about paternity. I actually never had my own curiosity about Ellie's father. In a way it's almost better if, in my mind at least, Joel's daughter exists and then he meets Ellie. The whole process is about how difficult it is to let somebody else in when you've closed that door off and nailed it shut forever.