The following eight questions refer to Figure 32.2A (morphological) and Figure 32.2B (molecular) phylogenetic trees of the animal kingdom.

Figure 32.2A: Morphological Phylogeny

Figure 32.2B: Molecular Phylogeny
-In the traditional phylogeny (Fig. 32.2A), the phylum Platyhelminthes is depicted as a sister taxon to the rest of the protostome phyla, and as having diverged earlier from the lineage that led to the rest of the protostomes. In the molecular phylogeny (Fig. 32.2B), Platyhelminthes is depicted as a lophotrochozoan phylum. What probably led to this change?
A)Platyhelminthes ceased to be recognized as True protostomes.
B)The removal of the acoel flatworms (Acoela)from the Platyhelminthes allowed the remaining flatworms to be clearly tied to the lophotrochozoa.
C)All Platyhelminthes must have a well-developed lophophore as their feeding apparatus.
D)Platyhelminthes' close genetic ties to the arthropods became clear as their Hox gene sequences were studied.

Question

The following eight questions refer to Figure 32.2A (morphological) and Figure 32.2B (molecular) phylogenetic trees of the animal kingdom.
  
Figure 32.2A: Morphological Phylogeny
  
Figure 32.2B: Molecular Phylogeny
-In the traditional phylogeny (Fig. 32.2A), the phylum Platyhelminthes is depicted as a sister taxon to the rest of the protostome phyla, and as having diverged earlier from the lineage that led to the rest of the protostomes. In the molecular phylogeny (Fig. 32.2B), Platyhelminthes is depicted as a lophotrochozoan phylum. What probably led to this change?
A)Platyhelminthes ceased to be recognized as True protostomes. 
B)The removal of the acoel flatworms (Acoela)from the Platyhelminthes allowed the remaining flatworms to be clearly tied to the lophotrochozoa. 
C)All Platyhelminthes must have a well-developed lophophore as their feeding apparatus. 
D)Platyhelminthes' close genetic ties to the arthropods became clear as their Hox gene sequences were studied.

Quizplus · Accepted Answer

The removal of acoel flatworms from Platyhelminthes in the molecular phylogeny allowed the remaining flatworms to be more clearly tied to the lophotrochozoa. This change in classification could have led to Platyhelminthes being depicted as a lophotrochozoan phylum instead of a sister taxon to the rest of the protostome phyla.

The Following Eight Questions Refer to Figure 32