Dear Andy;-
    The simplistic answer to your last question is: with fossils, if
it looks different----it IS!
    With present species, not just snails, but other critters as well,
 the initial problem will be determining a code for each and every
known species that there is. I imagine that will take quite a program.
 Beetle collectors and butterfly collectors will want want theirs. (I
imagine we can tell Polar Bears from Grizzlies without much help).
Maybe, if he gets out of his present difficulty, we can get a Bill
Gates to undertake the "DNA machine" as his next challenge.
             Art