Wolfgang wrote:

"A number of studies have shown that N. American "Elaphe" are more closely related to Lampropeltis and Pituophis than to E. sauromates. Consequently, they cannot be placed in the genus Elaphe. The oldest available generic name applicable to the N. American rat snakes is Pantherophis, hence this name is the one to use."



My response:

A number of studies in fact show that North American Elaphe is ancestral to Lampropeltis, Pituophis and Arizona, among other genera. There are also studies that show Old World Elaphe is ancestral to North American Elaphe. For example, Lopez and Maxson's (1995) mtDNA tree shows three Old World Elaphe species, namely Elaphe carinata, E. quatuorlineata and E. scalaris, forming a clade with N. American Elaphe, Lampropeltis, Cemophora and Pituophis. Since all members of a clade are equally closely related to one another, it is therefore incorrect to say that N. American Elaphe is closer to Lampropeltis than to Old World Elaphe. It is also incorrect to suggest that North American Elaphe cannot be placed in Elaphe. Even Utiger et al. (2002), who sent Elaphe to the chopping block, found that Elaphe sauromates, E. carinata and E. quatuorlineata are still classifiable in Elaphe. Since N. American Elaphe forms a clade with the E. sauromates clade, the name Elaphe can be retained for N. American Elaphe.



Wolfgang wrote:

"A whole bunch of other rat snakes in the Old World are also changing genus. The Aesculapian snake, for instance, is now Zamenis longissimus, Elaphe radiata is Coelognathus radiatus, etc. "



My response:

That is indeed Utiger et al.'s proposal. It is just a proposal. Their consensus tree is little more than one big unresolved polytomy. Their analysis largely failed to resolved phylogenetic relationships among the genera they recognize. Better resolution of relationships will undoubtedly lead to future taxonomic changes. Therefore it is premature to adopt their nomenclature. Retaining the name Elaphe and rejecting all of the new and resurrected genera is the better alternative since it is both consistent with their tree and it is less taxonomically destructive.



Wolfgang wrote:

"Finally, there is no such thing as an 'official' classification, there is only consensus among scientists, which is based on a shared feeling that the evidence used to generate a proposal for change is in fact adequate to support it. The fact that Elaphe in the old sense was an artificicial group was no state secret, but there was no clear alterantive view. Utiger and colleagues have now replaced the previous uncertainty with a new framework for classifying these creatures. That's why the changes they proposed are being accepted, whereas other changes or new genera are not being accepted until additional research confirms their validity.



My response:

Elaphe is not an artificial group, although some scientists "assume" that it is. Both Lopez and Maxson and Utiger et al. have shown that N. American Elaphe forms a clade with Old World Elaphe, with the racers as the sister group to the ratsnakes. Nevertheless Utiger et al. wanted to make a large number of taxonomic changes despite the fact that these changes are unnecessary. Scientists should scrutinize their data and decide for themselves whether a study that fails to resolve phylogenetic relationships should be the basis for wholesale taxonomic changes. Their proposal is being "accepted" by people who will accept any changes that are proposed. I expect most experienced herpetologists, especially those who are not cladists, to reject the Utiger et al.'s proposal.

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