WMG / Family Ties

What happened to Elise's brother Uncle Ned?
Uncle Ned, played by Tom Hanks, was last seen in a second season episode. Ned becomes an alcoholic and the last time we see him he's on the phone calling A.A. It's possible that Ned drove to the meeting and wrecked his car, killing himself.
  • Or he fell off the wagon and the Keatons told him not to come around the house anymore.
  • Or, he kept burning his bridges before he died some time after the events of "Say Uncle," a homeless, penniless drunk who had lost his career, his family and friends ... everything.
  • Some also have suggested he (actually) followed through with the admonition to get help and was able to restore some semblance of a normal life.

Marty McFly is Alex Keaton's twin brother, and they were separated at birth
Let's say the Keatons had twin boys, but they were so broke they knew they could only manage one at that time. They put the other up for adoption. Then their subconscious disdain about their finances is deeply driven into Alex's subconscious. Marty was adopted by the McFly family.
  • Or else, they're identical cousins — and Elyse Keaton is George McFly's younger sister. After their biological father died, their mother remarried.
  • Michael Flaherty is also their cousin, and Michael's mother and Elyse are twins. However, Michael's mother was adopted - as their parents could not take care of both of them. As such, Michael and Alex don't meet - until Michael moves to Ohio in 2000.

Alex Keaton becomes a Tea Party politician by the 2010 election.
He already had Reagan worship down as a teenager. Throw in the years of things changing and Alex Keaton may be yearning for having things revert back. He is about the same age as some of the Tea party Republicans in congress so it could work.
  • He probably is extra bitter that his parents likely voted for Obama.

Skippy was the product of a sexual assault
The wintry coldness of his birth mother could be ascribed to simply being who she was, or having no desire to revisit that part of her life, and let's face it, Skippy was assuming he'd move in with her like nothing ever happened. But maybe she wanted nothing to do with him being as he embodied the pain she felt when he was forced on her.

Alex and Ellen reunite and get married
A nod to the real-life marriage of Michael J. Fox and Tracy Pollan, Alex — after realizing Lauren and Martie are not the women he was seeking in his life — has a chance run-in with Ellen Reed in New York. Both, after a few awkward meetings, eventually admit they still have feelings for each other and perhaps they were meant for each other after all. And today, more than 25 years later, the two have a wonderful family (four children, all in the image of much like how the Keatons were, natch(!)) and are successful ... even when Alex (much like Fox) comes down with Parkinson's, Ellen is there by his side every step of the way.
http://tvtropes.org/pmwiki/pmwiki.php/WMG/FamilyTies