Posted by:
RSNewton
at Thu Sep 25 19:33:57 2003 [ Email Message ] [ Show All Posts by RSNewton ]
I wrote:
`Besides, Utiger et al. fail to cite Lopez and Maxson (1995), who show that Old World Elaphe and New World Elaphe form a clade with the Lampropeltini.'
You wrote:
Well, so far it seems the non-Utiger papers are 4 to 1 in favor of Elaphe having been polyphyletic. Until I've either read the papers in question or have some other good reason to choose between them, I think I have to stick with the democratic result.
Patrick Alexander
My response:
As I have said elsewhere in this thread, Dessauer et al. (1987) provide no data to support their assumption of a polyphyletic Elaphe. In fact, their exact words are "not monophyletic." That means different things to different people. A taxon that is "not monophyletic" can be paraphyletic to a cladist, whereas the same phrase means polyphyletic to a Darwinian.
As I have also said elsewhere, the other three papers are Minton (1976), Dowling et al. (1983) and Dessauer (1983). Dessauer (1983) is obviously a paper published by the same senior author as Dessauer et al. (1987). Whatever concludion in that paper would be superseded by the later paper. Dowling et al. (1983), as I pointed out, do not include any Palearctic species of Elaphe. It therefore has no data to inform us as to whether Elaphe is polyphyletic or not. That leaves you with a single paper by Minton (1976, Copeia) as your sole "support."
As I said elsewhere, Lopez and Maxson (1995) include both Palearctic and Nearctic species of Elaphe in their mtDNA analysis. They find that Palearctic species of Elaphe are basal to Nearctic species of Elaphe and that these two groups form a clade with such Lampropeltine snakes as Cemophora, Lampropeltis and Pituophis. They call this clade the "ratsnakes." Lopez and Maxson find that Ptyas and Zaocys are outgroups to the ratsnakes. Tong et al. (2002) find that the Palearctic species of Elaphe (which are of course basal to Nearctic Elaphe) form a clade and Ptyas and Zaocys are outgroup colubrines. Utiger et al. (2002) find that Palearctic Elaphe is basal to Nearctic Elaphe, and that Ptyas is outgroup to all of the species of Elaphe they study.
Therefore 3 independent studies using the latest molecular techniques have shown that Ptyas is an outgroup to all known species of Elaphe, including the most basal ones. They have thus demonstrated that Elaphe is not a polyphyletic genus. If you are going to argue for "democratic result", I have you outnumbered 3 to 1 for the time being. Once I have read Minton, I will show you that the score is 3:0 because, as I have said elsewhere, if Minton had demonstrated that Elaphe is polyphyletic back in 1976, this genus would have been dismantled by the Darwinians way back then.
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