[Jesus was] adopted by Joseph as is common in ancient and traditional life, he proclaims it himself, and Mary his biological mother is a biological descendent of the house of David. There are more common meanings to the word ‘descendent’ than biological descent; but the Mary connection, if you believe it, provides that biological descent.
Stripped of the theological stuff, your earlier question has three perfectly normal answers, two of which have no messy divine claims at all to deal with. One is that Jesus is what we’d call today adopted into the house of David; related to that is that Mary’s already a member by marriage. The other is gleaned from the quote you extracted from the Catholic Encyclopedia: Mary herself was a member of the same ‘house’ or extended family group. What’s not to understand about that?
Matthew and Luke clearly try to show that Jesus was related to David through Joseph. The only place where the Bible tries to tie Jesus to David through Mary is in Luke 1:27 (according to the Catholic Encyclopedia). I think this part is disputable as to what it actually claims. I my opinion it again says that Joseph, not Mary, was the descendant of David (”...to a virgin pledged to be married to a man named Joseph, a descendant of David. The virgin’s name was Mary.”) As far as Jesus fulfilling the OT prophecy by being an adopted descendant, well, what can I say? I am just wondering which one of these two claims (adopted descendant vs. Mary being a ‘Davidson’) is the plan B here…
So I naturally assumed you had some proof Jesus wasn’t a ‘Davidson’ after all, or why make such heavy weather out of a commonplace?
“A common man marvels at uncommon things; a wise man marvels at the commonplace.” (Confucius)
There is also the problem with Jesus’s DNA. Pope Pius XII approved the Shroud of Turin as a the real thing. Let’s assume we look at the blood stains of the Shroud of Turin under a microscope. Would we find a “divine DNA” in it? If Jesus’s DNA merely reflected the DNA of Mary, he would had looked just like her, he would had been a woman. What does God’s DNA look like, Kirk?