Anyway, here are a few things to ponder:
1. When Family Ties made its premiere in 1982, Alex P Keaton was 17 years old. Do you think Marty McFly at 14 looked the same way - or do you think he looked somewhat younger?
2. When Michael J Fox filmed that McDonald's advert in 1980 (that video might be at YouTube), he looked very young - but he still looked a bit older than 12, which is how old Marty McFly would've been in that year. Do you think Alex P Keaton looked like that at 15 years old?
3. At what year do you suppose Michael J Fox, Alex P Keaton, and Marty McFly all looked identical? Do you think the three of them looked identical since? Granted, I think Michael J Fox will look better in 2015 than 2015 Marty McFly did in BTTF2. However, that could easily be chalked up to the fact that Marty spent the last 30 years being miserable - so he maybe wasn't in the best condition. I think, in the improved timeline, Marty would look more like MJF will in 2015.
Anyway, what are your thoughts? I realize that Alex P Keaton and Marty McFly are fictional characters, and some may think that I overanalyze about that sort of stuff - but, as a fanfic writer, I find it to be an interesting subject to consider.
Crossposted to _familyties, bttf, and mjf.