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CKing
at Tue Jul 22 23:31:20 2008 [ Report Abuse ] [ Email Message ] [ Show All Posts by CKing ]
>>CKing- H. cinerea is in little danger of becoming a Pseudie; its light-pigmented gonads and close similarity to H. arborea (the type of Hyla) should keep it in that genus.>>
Hyla regilla is even more similar in appearance to Hyla arborea than is Hyla cinerea. That of course has not kept some cladists (and those who just want to act like cladists) from lumping Hyla regilla with Psuedacris.
Anyhow, the recent mtDNA analysis by Moriarty and Cannatella appears flawed, because both the parsimony tree and and likelihood tree nested Hyla crucifer, which has distinct toe pads, inside of traditional Pseudacris. If their trees are correct, it would mean that the small toe discs of Pseudacris is a convergence. Pseudacris (as traditionally defined) would then be an unnatural polyphyletic group that should be invalidated and its members transfered to Hyla. Instead, Moriarity and Cannatella chose to recognize Pseudacris anyway. That makes no sense at all. Besides, both their trees show Hyla regilla and H. cadaverina basal to the Pseudacris plus Hyla crucifer clade. It means they could have excluded H. regilla and H. cadaverina from Pseudacris but they didn't. That is another weird taxonomic decision on their part that makes no sense at all.
In spite of Moriarty and Cannatella's analysis, I still think Pseudacris is worth saving because it really is a monophyletic group (even according to the definition of Hennig), and that is because I believe their data is flawed. Their data is flawed because they chose Hyla chrysoscelis as the outgroup in their analysis. Hyla chrysoscelis is very much a derived member of the ingroup of Nearctic Hyla based on previous analyses. The nearctic species of Hyla, including those found in the USA and in Eurasia, are almost certainly descended from a member of the Hyla eximia group. Yet Moriarty and Cannatella's tree shows Hyla chrysoscelis as the basal most member, more basal than Hyla eximia. Their tree is about as anomalus as a tree that shows human beings being basal to the gorilla and the chimp. Because of the weird choice of outgroup, Moriarty and Cannatella's data is problematic and unreliable. Their taxonomic decision is both weird and problematic as well.
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