And Adam was clearly fully human, but only had DNA from God the Father, so there’s the connection between fully Man and fully God.
Best point made this night! Adam had no mother! and yet he was human, the first human. Eve was the second human and she had no mother and was not conceived via sexual union!
As a side note: It’s interesting in the painting of God giving life to Adam they both are depicted having navels; in fact, all paintings of Adam and Eve show them having navels.