New Squamate classification

[Ken Kinman]

Dear All,
      As usual, I disagree with Grehan's broad generalizations about morphology trumping molecular data.  It is certainly unfair to suggest that "the authors don't even consider morphology a science".  On the contrary, they go into some detail how their molecular phylogeny is supported by morphological evidence (although it correlates with morphological characters traditionally seen as homoplastic, and characterizes some of the older characters as homoplastic instead).  Morphology is still seriously considered and different morphological characters shown to be correlated with the molecular data.

      Overall, I am quite impressed with this new phylogeny that is supported by both molecular and morphological evidence.  HOWEVER, I think they are far too quick to dismiss a relationship between varanids and snakes.  Afterall, they are both members of their Toxicofera clade, and varanids are said to be basal anguimorphs.  I think it is very possible that their Anguimorpha is paraphyletic with respect to snakes and mosasaurs (which are united by many paleontologists in a clade Pythonomorpha).

      Therefore, if there is any major criticism to be leveled at this paper, it is that they should not be too quick to dismiss a relationship between varanids and snakes.  Since groups like mosasaurs and aigialosaurids are extinct, this is something that paleontology will eventually settle, NOT the molecularists.  Otherwise, I think the molecular phylogeny is very informative and extremely interesting.  Although I do find many of the new intermediate taxa unnecessary and poorly named (Unidentata, Bifurcata, not to mention Laterata which even they admit describes squamates outside of their proposed clade).  Toxicofera is perhaps the most useful (although Toxicosquamata would have been far more accurate and precise---oh well, so it goes).  Anyway, I may well proposed my own classification of Order Squamatiformes in light of this new data.  Many of their new intermediate clades would just be coded and not formally recognized.  If we are going to criticize them, let's be more specific (not vague broad-strokes like morphology vs. molecular, which is not very helpful).
  ---Cheers,
             Ken Kinman
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John Grehan wrote:
     After what I have seen with the incongruence of orangutan morphology and sequence similarities I would suggest that Hedges et al latest effort to overturn morphology be taken with a lot of caution - particuarly if any of the morphological incongruence is well corroborated. It looks like, however, the authors don't even consider morphology a science - as in the quote below, the reality of phylogeny rests entirely with sequence similarities.

"Because the current tree has been widely accepted for nearly a century, I think there is going to be a delay of maybe a few years before the general scientific community gets used to the new tree," Vidal says. "If other research groups working in this area find the same pattern with additional genes, then I believe the scientific community may accept these results more quickly."