I'm reading an interesting (but slightly odd) book on mythology at the moment. It's called The Seven Sisters of the Pleiades by Munya Andrews. The Pleiades are a cluster of stars, if you didn't know, and this book compares the stories told about them in different cultures from across the world. Andrews herself is a Nyigina woman from Noonkanbah, and grew up in the Kimberley region of Western Australia. She begins by telling the story she learnt from her grandmother as a child, and compares this story to those in Greek, American Indian, Indian, Egyptian, Maori, and Japanese mythology, drawing attention to some really interesting parallels between the stories. She talks about the mystical significance of the number seven, noting its importance in biblical literature, and pointing out that most of the stories associated with the Pleiades involve seven stars, even in places where (due to a higher altitude, or particularly clear skies) more than seven (up to thirteen) stars are visible. She also notes that all bar one of the myths she has found imagine the Pleiades as women, and that there is common thread of 'lostness' in many of the stories. These are interesting parallels, but it's hard to know what (if anything) they signify. I mentioned before that the book was slightly odd- here's one passage that might serve to illustrate my point.
"What is enormously interesting about our widespread preoccupation with the number seven in many creation stories is the revelation that genetic analysis of people of European descent traces DNA carried only in female mitochondrial genes to seven primordial 'clan-mothers'... Does this mean that our holotropic memory of the Pleaides is not only cultural but that the Dreaming of the Seven Sisters may be literally carried in our blood and our genes?"
Strong Bad also has an interesting post on the origins and evolution of myths.