In her Plato Prehistorian: 10,000 to 5000 B.C. Myth, Religion, Archaeology, Mary Settegast reproduces a table which shows four runic character sets; a is Upper Paleolithic (found among the cave paintings), b is Indus Valley script, c is Greek (western branch), and d is the Scandinavian runic alphabet.
Dang. I’ve got to get the Settagast graphic (among others I use a lot) uploaded to a different site.