Marlo,
    Taxonomy, like the Theory of Evolution, is constantly changing.  this is
due to new discoveries, new ideas, and sometimes due to "bad" science
(maybe).  Whatever the cause, taxonomic changes are simply our idea of the
relationship or one or more living things to each other, or perhaps more
vainly in relationship to ourselves.  Therefore, speciation is also a product
of our own ideas, which are constantly changing.  Your logic I believe is
correct, but speaks more of the inadequacy of our systematics that natural
occurrences.  Is that as clear as mud?

Doug Shelton
Mobile, Alabama