Doddy writes:
One of the key evidences presented for common descent is the twin-nested heirarchy.
Is it? Hierarchy from either point of view is strong evidence as evolution would require it, but there's absolutely no reason why the designers* should design within the parameters of evolutionary possibility. They don't need to tweak things slowly over very long periods of time. The best additional evidence from genetics comes from the odd inclusion of similar damage (ERVs) in the genomes of similar creatures, and perhaps from the amount of apparently neutral change in the non-coding area if Goddy is pushing a young earth view.
Is Goddy's word "heir-archy" a creationist standard, perhaps indicating that some animals are designed to appear as the heirs to others? Evolutionists seem to prefer "hierarchy".
*(The plural "designers" should always be used, as the probability of there being only one being or entity involved are statistically remote, so use of the singular is just a highly subjective mistake perpetrated by people who happen to be from monotheistic cultures).