http://www.bibleinterp.com/articles/eva358021.shtml
It's a question I've often wondered, and if what Professor Evans says is true, then this could, as he says, quite easily bridge the gap between when the autographs and the earliest copies we have available for study today, (though I'm not sure if it's even correct to talk of each "book of the Bible" as having only one autograph [original which was then copied]).
