Sure and I have studied at length regarding the themes of mythologies across cultures such as the Hero's Journey and other archetypal forms. But I have also begun to look at the written myths which are in religions a literary reworking of largely oral stories. I understand that oral epic poets had mnemonic methods for remembering large quantities of story information. Perhaps they also had ways of chaining stories together that tended to yield similarities. But the epic WRITERS may also have utilized written sources. They may have reworked these epic narratives into ones more appropriate for their own culture.
As Joseph Campbell has said the transmission of a mythic stories motifs may be either through direct cultural transmission (whether through the oral tradition or the literary tradition) or they are not transmitted but arise again in each story-teller due to the influence of a common psychological configuration that it the human brain-mind evolved other the centuries.
The Biblical story of Jacob and Esau definitely has this quality as it shows Jacob leaving his known world, crossing a threshold on his way to his uncle's, crossing another on his flight from his uncle and his return home. I can also see pieces of story taken from Egyptian myth in Jacob's Ladder, for instance.
Now consider the great contrast of detail between Jacob's story and the Mahabharata. If the two came from a similar source then Jacob's story might point more closely to the bare bones of the shared story simply because of its relative lack of development. But to see the little details line up despite this difference in scale also seems to me to point toward a shared source. Because of this chaining of motifs I suspect conscious derivation from a culturally transmitted common source.
Another reason I suspect this is that the Mahabharata, Genesis and Greek mythology all have this similar structure of the world originating in a perfect time and becoming more and more corrupted through the generations. This pattern is clear across the generations of the patriarchs, across the generations of the kings which preceeded Dhritarashtra and in the succession of titans, gods and semi-mortals (particularly Zeus to Achilles) that can be traced through a collection of the Greek myths. This theme of the evolution of the moral landscape is common across all of the mythic traditions even into Arthurian legend and suggests that this form is continuous.
In an analogous way there are the modern film trilogies which all follow a similar pattern:
- innocent, poor peasant becomes predominant warrior in the fight for "good"
- efforts to consolidate "good" are brutally challenged causing many defeats
- a more lasting, final victory is achieved but with great loss/sacrifice
Apply this formula to the following movie trilogies:
- Samurai Trilogy - Hiroshi Inagaki
- The Godfather Trilogy - Francis Ford Coppola
- The Lord of the Rings Trilogy - J.R.R. Tolkein/Peter Jackson
- Star Wars (IV - VI) - George Lucas
- Star Wars (I - III) - George Lucas (in an inverted sense where evil replaces good)
- The Matrix Trilogy - Wachowski's
A more detailed comparison of the motifs I won't go into (but watch Samurai trilogy and Star Wars IV - VI back to back for a striking resemblance) but I think that the above suggests a good portion of conscious effort involved in this case as well.
Generally speaking of course.