How Sylar got his powers?

Having finished watching the first season of Heroes, some of my friends and I were discussing the above question one day after a game of basketball. So just how did Sylar get his powers?

If you have yet to watch this, Heroes is an amazing tv series where several people discovered they have special abilities such as time travel, telepathy, spontaneous tissue regeneration, flying and even absorbing others powers. These people then found out they have a role to play in preventing a catastrophe and saving the world.

Sylar is the villain who is supposedly normal but somehow is able acquire others abilities by killing them and removing their brains. How exactly he acquire the abilities was not explicitly explained in the show, so this allows for some discussion based on the clues and events that follows.

Some would argue that Sylar actually has a power, which is the ability to see how everything works. This opens up the possibility of him studying the brains of the victims (like how he studies watches) and understanding how their abilities work and uses them.

"You are like me, aren't you? I wana see how that works!"
--- Sylar in episode 19 when fighting with Peter Petrelli, whose ability is to absorb others powers without killing them.

Yet I don’t quite buy this argument, well cos it just doesn’t make sense. How can his brain possibly know how to use the powers by just simply knowing how it works? The powers should have been caused by genes mutations as suggested by the Genetics professor, Mohinder Suresh. Then again, this is a science fiction hor?

However, if Sylar only needs to look at the brains to know how it works and use their ability, why then he needs to remove the brains and take it with him? So, some suggested that he needs to eat the brains of his victims to obtain their genes in the process instead. But, well, this is so wrong…

"Give me the damn list, so i can sink my teeth in!!"
--- Sylar in episode 18 when begging Mohinder to release him

Another idea is that Sylar did In vivo gene transfer by introducing the victims DNA into his body by, say, using virus as vectors for the gene delivery. His interaction with Chandra Suresh and his book, Activating Evolution, would have given him sufficient knowledge in genetics engineering and allow him to manipulate his own genes.

What do you think?