Molecular biologists don't invoke a "same creator" to explain similar DNA sequences for many reasons. I mean besides the fact they're not stupid.

When biologists compare DNA sequences of two closely related creatures, for example a person and a chimp, they see countless evidences for their evolutionary relationship. Even for distantly related creatures their common ancestry is extremely obvious. Even if a biologist was superstitious enough to believe in a magical creator, he or she would not be able to deny what couldn't possibly be more certain -- all species share an ancestor.

If a biologist wanted to throw out all common sense and invoke what dishonest Christians call a "common designer" (as if that sounds less childish than "the same magic fairy"), that couldn't explain, for example, endogenous retroviruses in the exact same locations in more than one species.

If we pretend a fairy created every creature out of nothing, science deniers still can't explain ERVs which are inserted into DNA long after the fairy is done waving its magic wand.

If Christians and their Muslim terrorist friends spent a little time studying science instead of being afraid of science, they might learn something.