This is actually a response to an idea posted on paire_love, but since my reply is among my better theories, I'm copying it here. The initial post is copied for ease of reference - hope virtual_insomnia won't mind! You can find the entire thread
here vitural_insomnia wrote in paire_love:
Spoilers for who Claire's daddy is, just in case there's anyone who doesn't know yet.
So, you know how people have been sort of jokingly saying that maybe Peter was adopted or switched at birth or something? I was telling a friend those things, and she said something that made me think back over past episodes, and now I have a new theory. And it even has some actual "evidence" to support it! It's probably totally wrong, but I sure like it. Esp. since it makes Paire possible again! :-)
I think Peter and Sylar are twins who were separated at an early age!
For one thing, Peter was always supposed to be a twin. Org. he was going to be the twin brother of Nathan, true, but still. Having twin brothers was an idea that Kring had in the beginning, we know that much for sure. So it's not out of the realm of possibility that he might want to revisit that idea.
As far as the "Peter being adopted" thing goes, we have seen a few things that could be taken as clues. Peter's father apparently never liked/supported him as much as he did Nathan, which could be a sign of him favoring his biological son. Meanwhile, his mom seemed to overcompensate by favoring Peter, which can happen when one child is adopted.
And Peter and Sylar sure do have similar features/coloring! If I didn't know better, I would think that Sylar was a Petrelli! He certainly looks more like one than Claire does! ;-P
Not to mention, their powers and personalities seem to exactly mirror each other! One good, one evil. One can take on extra powers by feeling strongly about someone and being able to empathically link to them and see how their mind works, the other takes powers by being scientific and logical and dissecting their brain to see how their mind works. Both believe in a greater destiny, and their place in it. Both could potentially become the most powerful person on the planet.
Sylar did say he felt like his parents "weren't his parents" once. Back when he was talking to Mohinder's dad, he said that he wanted to wake up and discover that his life wasn't really his life, etc. He felt like he didn't belong there. Well, I say maybe he didn't!
Maybe Sylar and Peter are really the twin sons of some other people who had powers. It makes sense, since there is a precedent set on the show for it to travel through families, as evidenced by DL/Niki/Micah and Nathan/Meredith/Claire. Maybe Claire's adopted dad tried to "catch" the parents, and they ended up dying. So the boys were split up, and sent to different families, never knowing the truth. And if, as many people suspect, Linderman is the one pulling HRG's strings, it would make even more sense. It would even explain why one of them got sent to the Petrelli family, since Linderman obviously had Mr. Petrelli in his back pocket. And that would also help explain some of Mr. Petrelli's hostility towards Peter, if he felt like Peter had been forced upon him by the man who had him under his thumb. (Thanks to ladybozi for some help ironing the Linderman connection out.)
And it makes sense why Peter still doesn't know. His family lied to him about how his "adopted" father died because they feared him taking it too hard, so why wouldn't they think the same thing about this? Especially now, after all the craziness of the past few episodes. They would want to keep it from him, for fear of what he might do.
Plus, and this is the big one IMHO, Peter had a vision/dream where Nathan came to see him in jail and then TURNED INTO SYLAR!!! Foreshadowing, perhaps? Showing us that his brother is not who he thinks he is? Peter's dreams always seem to have at least a small bit of truth to them, after all. He dreamt of the car accident before it happened; he dreamt of Claude before he ever met him, and he dreamt of becoming the bomb. So why wouldn't the Nathan/Sylar dream mean something, too?
And also, it was pointed out by moonlitpines that when Peter and Sylar fell from the building in "Homecoming," the way they were laying there with their legs entwined could be symbolic of the familial connection between them. I mean, they spent a heck of a lot of time on that shot for it to just be random, you know? And building on that, I noticed that their upper halves were apart, symbolizing how they are branching away from each other, one going dark while the other fights to stay good.
And finally, karathephantom checked on IMDB, and while they haven't told us Sylar's age on the show, Zachary Quinto and Milo Ventimiglia ARE the same age, so that seems like a good sign.
Please discuss. Am I totally nuts, or could there really be something to this? :-)
ETA: I did a little editing, to add in some stuff from comments that helps to enhance the theory. I gave credit to the people who helped me think of this stuff, of course. *g* Thanks, guys!
(again, the above theory IS NOT MINE!! IT'S VIRTUAL_INSOMNIA! Just copied here for ease of reference.)
my reply:
This makes a great deal of sense, actually. It makes SO much sense, that I'm not sure they would do it. *gloom*
One thing I've been wondering about for awhile - the age difference between Nathan and Peter. Somene mentioned that you need to be at least 36 to stand for Congress, so there's AT LEAST 10 years between them. While that's a fairly flimsy base to start from, I have come across a few situations like that before...
My mother used to work for one of Australia's leading reproductive medicine companies (one of the best in the entire world, BTW) - for more than 25 years - and I temped for them a few times. Granted, Mum was in the accounts department, but I've picked up quite a few things over the years, and part of my temping was typing and filing patient reports. This kind of age difference between sibs was actually fairly common in families who undergo reproductive medical treatment - one child conceived naturally, then something happens to change the fertility of the mother or the father - some kind of infection, or environmental hazard, lots of stuff - even just age.
If Mama and Papa Petrelli tried to conceive a sib for Nathan and failed, what about IVF? (where ova and sperm are taken from the parents, combined in a petri dish, and surgically implanted into the mother) 27 years ago, this sort of medicine was very new; back then, you'd need to be quite wealthy to afford it, IVF was the most readily available technique (there's several alternatives nowadays), and most importantly, there wasn't the sort of safeguards they have nowadays to ensure the right couple received the right child. In the early 80's, there was actually a couple of scandals about two couples going for IVF and the embryos being swapped. Even easier, if you have the lab - or at least some techs - under your control. The idea of Primatech breeding people with the Heroes gene strain has been brought up by quite a few people.
Not to mention? In the early days, multiple births were common, thanks to the drugs used to stimulate ova production before harvesting. It would be completely plausible for the Petrellis to go for IVF to a Primatech lab, have the ova and sperm harvested, the lab tech swap their donation for a couple who have the gene markers, the egg to split into twins - or even have two embryos result, and Primatech deciding to double their chances, with one egg going to the Petrellis, and one going to another couple.
Let's backtrack for the timing; Mohinder has to be at least 30 to be an established professor (educational standards can't be THAT different in India, surely?); his sister was 5 when she died 25-28 years ago, due to a flaw in her genes (quick side theory; maybe it was her power kicking in, and she was too young to control it?) which started Papa Suresh off on his quest. Which means that there were Heroes around not only 15 years ago (we know Claude was, probably Meredith too, and the Haitian had to have been working with HRG for years), but also 25-30 years ago. We've seen the powers kick in on a time cycle, not a specific age - we're talking either in 10 or 15 year increments. Which means that it's perfectly plausible that there were enough active Heroes 30 years ago that Primatech would see the potential and decide to cook some up they could keep track of.
Not to mention? It would also explain why no one's mentioned anything to Peter; as far as they know, Peter IS theirs. Nathan would have been anywhere between 5 and 9 when this was going on (back then, most couples needed several tries to conceive), and I doubt that Mama and Papa Petrelli would have bothered to explain the details of this sort of thing to Nathan, even if he'd been old enough to understand. Not to mention, resorting to reproductive medicine is still a matter of shame for many couples; believing you're not enough of a woman/man to reproduce. You can see why they wouldn't mention it.
virtual_insomnia really liked this, btw! *g*