gee...even as a non-Christian, I have known for many years that Virgin Birth and Immaculate Conception were not to be confused. Some groups believe in both, some in just one.

One problem was that there seems to have been a mistranslation of the word taken to mean 'virgin'. In the ancient texts, I think Mary was referred to as just a 'young woman'. As to whether Joseph was the father, there is simply rampant speculation...helped by such things as "The Cherry Tree Carol".

I've been watching programs on archeology and document restoration lately, and what it all seems to be indicating is some additional evidence for the historical characters named in the Bible....but LOTS of variation and contradiction in stories of what they did....as we might expect in old manuscripts where the scribes were not the witnesses.

   Church doctrine, however, changes s-l-o-w-l-y, because denominations get emotionally and theologically committed to various details. New evidence is not always convenient.