Hello Paulbert – or PeterC
I think your question is interesting, although I suppose one hardly ever hears it discussed except maybe at Christmas. And even then it is in comparison to Matthew’s genealogy. With that, there are several approaches that get taken…such as, for example, Matthew doing things in groups of 7 — since that number seems to symbolize some sort of perfection. In that reckoning, Jesus simply is the beginning of a “new” group of sevens — that is, the righting (eventually) of the Universe. If Matthew did his genealogy with a symbolic emphasis, then why not Luke? And the likelihood of both of them skipping generations – even an enormous number — to make their point eliminates the need to see the genealogy as documenting all known ancestors.
One would suppose they believed in an Adam.
As for the genealogies being accurate, it might depend on what standards of “accuracy” one uses. Some commentators note that getting all the details right in a genealogy – or having two slightly different genealogies for same person – is an item of concern only to the Western mind. If that is the case and we are applying our “Western” minds to something that should not be viewed from a “Western” mindset, then the items in Luke’s – and Matthew’s — genealogy are perfectly A-OK.
BTW — the commentators I refer to above are Robert Wilson (a chapter in I Studied Inscriptions from Before the Flood…and Raymond Brown’s Birth of the Messiah.