400 altcoins prove this.
but bitcoin/altcoins cannot exist without a blockchain
if you mean ripple, if you mean stella, nxt, etc.. most of these are actually SQL databases just pretending to be blockchains..
but they are a whole different issue and much more closer to what fiat is, than a blockchain
but either way the point is that a blockchain such as litecoin does not have a single bitcoin attached to it.
neither do the other altcoins that have a blockchain.
thus, as i said.. a blockchain does not need bitcoin because it can use any token/coin.
but bitcoin wont exist without a blockchain