Regardless of the deepest phylogenetic relationships between animals, independent evolution of muscles and nervous system in ctenophores seems quite likely based on the results by Moroz et al. 2014. This led me to a realization that maybe the phylogenetic relationships between Porifera, Placozoa, Ctenophora, Cnidaria, and Bilateria actually do not matter much. These relationships tend to vary from study to study and the internal branches uniting these groups in different combinations tend to be very short. As short branches suggest little amount of evolution, maybe nothing remarkable happened along those branches anyway and most of the possible relationships between those main animal lineages are more or less equivalent? Then again, considering that these lineages diverged from each other more than 540 million years ago, difficulties in reconstructing their relationships can be expected. Too early to give up. More sophisticated analyses might help to figure out what are the likely causes for conflicting results (systematic errors or true lack of phylogenetic signal).
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