Posted by:
RSNewton
at Mon Aug 11 22:21:01 2003 [ Email Message ] [ Show All Posts by RSNewton ]
You wrote:
And, even worse, some people forget which word they ought to use in online discussions. Utiger et al. demonstrate that Elaphe is polyphyletic. Sorry about the mistake.
My response:
That is a big mistake indeed. You must be reading a different paper than I do. Utiger et al. show that Elaphe is not polyphyletic. The Lampropeltini is nested within Elaphe. By excluding the species of the Lampropeltini, Elaphe is paraphyletic. It could be polyphyletic if Elaphe obsoleta, E. vulpina and E. guttata are only convergently similar to Elaphe. That is not likely considering that the species bracketing these species are all classified in Elaphe by other systematists before Utiger et al. apply the machete to this genus.
Your wrote:
Arizona, Bogertophis, Lampropeltis, and Pseudelaphe (was Elaphe) were also all basal compared to Pantherophis in the Utiger et al.'s phylogeny.
My response:
In their phylogeny, Elaphe sauromates is basal to Arizona, Lampropeltis and Elaphe obsoleta. That means the ancestor of Arizona, Lampropeltis and E. obsoleta is itself closely related to Elaphe sauromates. Alternatively, this ancestral species is nothing like Elaphe but somehow E. obsoleta, E. vulpina, and E. guttata and E. flavirufa re-evolved their Elaphe-like morphology from this derived ancestor by undergoing evolutionary reversal. The reversal hypothesis, though possible, is less parsimonious and unproven. Hence I submit that the ancestor of Arizona, Lampropeltis and Elaphe obsoleta is itself a species of Elaphe. That means New World Elaphe is also descended from a species of Old World Elaphe, making Elaphe paraphyletic. Of course, paraphyly does not bother me one iota. It does bother the cladists though, enough that they would use the red herring of polyphyly to justify splintering it.
You wrote:
As it would happen, according to Utiger et al.'s phylogeny Senticolis is not basal to Elaphe sensu lato, though it is basal to the rest of the Lampropeltinines.
My response:
This part of the tree is poorly supported.
You wrote:
No offense, but you really should read Utiger et al's paper before you decide that you disagree with them.
Patrick Alexander
My response:
None taken. I suggest that you practice what you preach because there is no evidence that Elaphe is polyphyletic from that paper, your assertion to the contrary not withstanding.
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RE: name change: Pantherophis - RSNewton, Mon Aug 11 22:21:01 2003