I say he was a clone. The real Uncle Owen left Aunt Beru for Obi-Wan. After Obi-Wan left with Luke, Owen went searching for Obi-Wan. After his search turned up nothing, he then learned that Obi-Wan had died. Outraged, he swore on his life that he would avenge Obi-Wan by helping Luke destroy the Empire. However finding Luke was a problem for him as well. Luke kept his tracks well covered, so once Owen managed to discover his location, Luke would be gone to the next place. Finally, with the help of Boba Fett (you gotta throw him in there somewhere, after all!), Owen manages to locate Luke, with whom he helps overthrow the Empire. Owen and Luke live then happily ever after. The end.
