Wow. You quote one partial sentence out of context and declare the whole document wrong. Let's look at your sentence fragment in context:
If every living species descended from an original species that had these four obligate functions, then all living species today should necessarily have these functions (a somewhat trivial conclusion).
Most importantly, however, all modern species should have inherited the structures that perform these functions. Thus, a basic prediction of the genealogical relatedness of all life, combined with the constraint of gradualism, is that organisms should be very similar in the particular mechanisms and structures that execute these four basic life processes. [Source:
29+ Evidences for Macroevolution: Part 1 , bolded portion is the part you left out.]
Notice that you left the word "if" out of your quote. The author is not say that this is a trivial conclusion that all creature descended from an original species. Rather, he states that
if they did, then it is a trivial conclusion that they should share certain functions. By leaving out the word
if, you changed the entire meaning of the sentence.
Having reached that trivial conclusion, the author goes on to his main point of this section, that we would expect all creatures to share the
structures that perform those functions. He then goes on to explain in detail that life does indeed share the structures for these functions, even though there is no specific reason why a creator would have to do that. But I see in your post no attempt to even mention the author's point.
Care to go back and look at that again?