I would think if it was a fact you could back it up. But of course you can't back up evolution, either, so I'm not surprised.
Okay, so you've now shown that you don't know what the scientific definition of 'evolution' is, and you don't know what the scientific defintion of a 'fact' is.
Congratulations - you're unqualified to participate in a scientific debate.
Which, by the way, was the whole reason I posted what I did - to out the pseudoscientists.
> But of course you can't back up evolution
Except for all that pesky genetic, observational and fossil evidence.