` The group is not polyphyletic; Elaphe is not polyphyletic.'



I wrote:

I await new data suggesting that this is the case.



Your response:

Before such new data becomes available, it is premature to assert that Elaphe is polyphyletic.



You're saying that it's premature to assert that Elaphe is polyphyletic until we have data demonstrating that Elaphe is not polyphyletic? This amounts to an a priori rejection of the possibility of polyphyly.



`If it is not polyphyletic, then it ought not be splintered unless the members of this genus form a morphologically disparate group. Utiger et al. show no evidence that they use morphological disparity to splinter Elaphe. Hence their destruction of Elaphe is untenable.'



Utiger et al. do, however, cite other works which demonstrate that Elaphe sensu lato is a morphologically disparate group. See, for instance, Helfenberger, N. `Phylogenetic Relationships of Old World Ratsnakes Based on Visceral Organ Topography, Osteology, and Allozyme Variation', Russian Journal of Herpetology 8 (Suppl.) 1-64.



`Both Utiger et al. and Lopez and Maxson find that Elaphe is not polyphyletic.'



Your assessment of their results differs with theirs. For the Utiger et al., see other discussion in this thread. Out of curiosity I got hold of the Lopez et al. (Lopez, Maxson, and Dowling) paper, and found the following:



First, they do not have the data to adequately test the phylogenetic relationships within Elaphe sensu lato (albumin distances for were only found between Pantherophis obsoletus and each of four species of Elaphe sensu stricto and Pantherophis guttatus). Given that the purpose of the paper was the determination of the intergeneric relationships between Dasypeltis and other colubrine genera, this is not surprising.



Second, the conclusion to which they come regarding phylogenetic relationships within Elaphe sensu lato is that: `From these tests we conclude only that the Eurasian ratsnakes are roughly equidistant from the Nearctic ratsnakes and the racers.'



`Their findings are supported by a third paper recently published in Acta Zoologica Sinica.'



The inadequacies of this study have already been mentioned.



`That is three independent studies proving that Elaphe is not polyphyletic. There may well be new data suggesting otherwise, but until they are available, there simply is no evidence of polyphyly.'



Your assessment of two of those studies disagrees with that of their authors. Including the other papers cited by Utiger et al. and mentioned elsewhere in the thread demonstrating polyphyly of Elaphe sensu lato, this gives a total of 5 independent studies demonstrating polyphyly of Elaphe sensu lato and 1 disagreeing.



Patrick Alexander

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