An example of the type of gene change used for phylogeny:
Nearly all members (that have been checked) of Buccinoidea, Muricidae, Olivoidea, “Turbinelloidea”, and Conoidea share TTTACTGGTGCGTCGGCTGCGAGCGT in the earlier part of their 28S genes. Most other caenogastropods have a CG instead of the bold GC.
The gene is producing part of nuclear ribosomes in pretty much all animals. Why does that change only appear in a large subset of gastropods that also share a siphon, fairly frequent large size, have similar radular morphologies, and are macrocarnivors (except for columbellids), if they are not actually related?