to quickly clear up any confusion, Species can lose enough information that they are no longer able to breed with one another- and yes, this would make them a new subspecies, however, it does not make them another kind. It is a form of regression, not advancement, and is contrary to the macroevolutionary model.
Yuo mentioned the supposed homology of the notochord, and science has attempted to prove common homology, yet clearly homology is not seen in all species. The worm you mention has the notocord, true, however, we don’t find worms with spines- just the notochords.
“Efforts to correlate homology with developmental pathways, however, have been uniformly unsuccessful. First, similar developmental pathways may produce very dissimilar features. At the molecular level, it is well known that virtually identical inducers may participate in the development of non-homologous structures in different animals. (Gilbert, 1994) At the multicellular level, the pattern of embryonic cell movements which generates body form in birds also generates body form in a few species of frogs. (Elinson, 1987) And even at the organismal level, morphologically indistinguishable larvae may develop into completely different species. (de Beer, 1958) Clearly, similar developmental pathways may produce dissimilar results.”
Yeah. I recognize ALL those quotes. I know for a certain fact you didn't read a one of them in context. I have them in my extensive antievolution library. (Where they occur many times over. Even the authors of the books probably didn't ever read the original source, but just got them from another creationist!)
They're all bollixed. There'll all entirely misrepresentive of both the facts and the authors' full assertions. I did so many times years ago, but I just don't have the time and energy any more to traipse down to the library, photocopy the original book or article, and come back here and type in a full explanation of how and exactly why it's all b.s. But it is.
Look. I've read hundreds of creationist books, articles, attended conventions, meetings of local creationist orgs, worked with antievolutionists digging up "mantracks" (misidentified dino tracks) in the Paluxy, etc, etc. Why don't you try reading at least one or two SERIOUS and comprehensive works concerning evolution. (Don't bother. It's obvious you haven't.)
But if not, that's fine too. Enjoy sitting in the choir listening to Henry Morris and Duane Gish preach.