5th Gen Where did you come from??

So on the east there's a whole lot of Pokemon from past regions, not native to Unova found there. According to bobandbill, my memory is right in that they don't explain how they actually came to be there. If it is, kill Marcin. So what do you think about this? Is it because of the Dream World making Pokemon run wild, or do you think it's something else - someone went crazy migrating? Also when do you think they came about - recently? Given that in 2 years the Pokemon amount goes CRAZY. Share your thoughts!

A couple of ideas:
- A visiting trainer from another region was breeding to get good IVs/natures and released all the ones they didn't like in that area.
- They were going to make a Safari Zone but the Pokémon escaped.
- They arrived at Undella Bay by ship and are spreading, eventually spreading over the region in B2/W2.

Didn't they say that they came from the Poketransfer breaking open or something? I could be wrong but that was what I remembered.

I do think that we're plopped into Unova within a few months of the event happening that causes it though. The way I see it, we're in a frozen moment in time, where a few Pokemon blossomed into a lot in half the region. If we had been there a year before, there would have only been Unova Pokemon. And as we saw, 2 years later and the entire region is overrun with past gen Pokemon.

I believe it's due to migrating, all Pokemon alike eventually need a new place to live in as all living creatures do. If I stayed in one area in my city for let's say 4+ years, I'd want to move. It's still unknown in pokemon history how one group of Pokemon ( E.g Geodude or Mankey) simply migrates to another region.
Or so to say. I believe that until we know from GF, the HOW and WHY, it'll remain a mystery.

These are my thoughts.~

They most likely escaped from the Poketransfer lab because the non-native pokemon seem to be found only near the lab.Thats probably my best guess.And over the years they kept spreading resulting in the the whole region being filled with them two years later.

They might have just been breeded and the population must have spread far and wide.

I thought I remember hearing something about the Pokemon escaping from the Transfer Lab, too, but it could've just been one of the theories thrown around. Obviously by the time B/W2 hits, they'll have had 2 years to make a new home across the region, which is plenty of time in my mind.

I have to wonder - what's to stop water pokemon from crossing the ocean? I know Unova is far away from the other regions, but it's not unlikely that Pokemon just migrated there. Also, same with flying pokemon. But I think it's more likely that either they spilled out of the Entralink, or that they spilled out of the PokeTransfer. Although, people love rare pokemon, so I could easily see them importing some and then treating them as pets, but since the pokemon aren't pets they ran off into the wild, and well, you know how quickly it takes for Pokemon to make an egg. Or five. And especially with all them dittos running around...