Are the elves in The Hobbit different than the ones in LotR?

[Morquesse]

Greetings,Knight of Gondor! [img]smilies/biggrin.gif[/img]
I've also noticed that the Elves of the Hobbit are different then the ones in LotR, of maybe even from the Sil. So I've had a theory: maybe when the Hobbit was first published, it was not meant to be connected to the Sil, or Middle-earth. 1# the elves are different 2# I don't recall the land where Bilbo was being called Middle-Earth 3# in order to work with Tolkien's idea for the LotR, he changed some parts of the Hobbit(the chapter "riddle in the dark" was changed from Bilbo and Gollum having a riddle contest with Bilbo winning, and in reward Gollum gave the ring(I think) and willingly showed Bilbo the way out, to what we have now)4# we always hear that Tolkien was constintly changing the Sil, so he could of worked the history of the Rings in easily.
That's my theory, if anyone see's a problem with it, I'd like to know. [img]smilies/smile.gif[/img]
~M