Posted by:
CKing
at Wed Nov 19 02:34:17 2003 [ Email Message ] [ Show All Posts by CKing ]
Hyla regilla has been traditionally classified as a species of Hyla quite simply because it has well developed toe pads plus other similarities to members of the genus Hyla. Recently Hedges (1986) transferred this species to Pseudacris on the basis of molecular distance data, which shows this species to be closely related to Pseudacris. Hedges's data is contradicted by that of Maxson and Wilson, which shows Hyla regilla being more closely related to Hyla arborea than it is to Pseudacris triseriata. There is also a new study which has been accepted for publication by the journal "Molecular Phylogenetics and Evolution" but this study, by Emily C. Moriarty and David. C. Cannatella, does not include Hyla arborea. Since Hyla arborea is the type species of Hyla, transferring Hyla regilla to Pseudacris means that Hyla arborea would probably have to be transferred to Pseudacris as well. But doing so would render Pseudacris an invalid genus, since Hyla has priority over Pseudacris. Therefore, if the genus Pseudacris is to remain valid, Hyla regilla would almost certainly have to be excluded. My hypothesis is that Hyla eximia is ancestral to the Holarctic treefrogs, including Hyla regilla and Hyla arborea. My hypothesis is consistent with the molecular data. Hyla regilla is in turn ancestral to the genus Pseudacris and to Hyla arborea. The genus Pseudacris can remain monophyletic if Hyla regilla is excluded. The genus Hyla would be paraphyletic. But that is an unavoidable consequence of recognizing the genus Pseudacris. Transferring H. regilla does not change this fact. Since paraphyletic groups are the inevitable result of the process of evolution, neither the Darwinians nor I have a problem recognizing paraphyletic taxa. The Hennigians, OTOH, would have a problem with paraphyly. Perhaps it is a good excuse for them to splinter Hyla. But that is another story.
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 Hyla regilla and why this species cannot be classified as Pseudacris - CKing, Wed Nov 19 02:34:17 2003 
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