I won't speak for all young Earth creationists, but I don't have a problem with natural selection as a means of selecting from existing genetic diversity within

I won't speak for all young Earth creationists, but I don't have a problem with natural selection as a means of selecting from existing genetic diversity within a kind, especially as that process is observable and repeatable around us. Where I contend with evolutionists is the typical narrative that the existence of natural selection implies a process that creates said (structured, positive) genetic diversity from which to select. This latter process is disputed, not the former. I would be curious to hear your colleagues perspective.