Reptile & Amphibian Forums

Finally found the paper by Tong et al. (Acta Zoologica Sinica) in the library. In it is additional evidence that Elaphe is not a polyphyletic group. All 7 species of Elaphe cluster together, with their nearest relatives Zaocys, Dinodon and Ptyas. There is strong statistical support for this part of the tree, as is shown in the image of the tree below. Additionally, Tong et al.'s tree is similar to that of Utiger et al. Both trees have Elaphe mandarina near the base of the ratsnake group. Tong et al.'s tree also shows the Elapidae clustering with the Colubridae, with the Viperidae being the closest relatives to the Colubridae and Elapidae. The same hypothesis of relationship among the elapids, viperids and colubrids is obtained independently by Wilcox et al. (2002, Molecular Phylogenetics and Evolution 25: 361-371). The independent corroborations of Tong et al.'s tree show that it is a sound study. Three independent studies (Utiger et al., Lopez and Maxson, and Tong et al.) all show that Elaphe is not a polyphyletic group. Earlier conjectures that Elaphe is polyphyletic has been disproven.

That sheds considerable light on the Asian Elaphe relationships. What about the relationship between the Asian and American Elaphe. It seems to me that if Elaphe is polyphyletic anywhere, it is likely to be with the grouping of these two geographically distant collections of snakes into a single genus. I wonder if anyone has done a phylogenetic tree which includes both hemispheres...

Interesting stuff, thanks.

Obie

You wrote:
It seems to me that if Elaphe is polyphyletic anywhere, it is likely to be with the grouping of these two geographically distant collections of snakes into a single genus. I wonder if anyone has done a phylogenetic tree which includes both hemispheres...

My response:
As a matter of fact yes. Utiger et al. (2002) found that Elaphe scalaris is basal to the American species of Elaphe. So did Lopez and Maxson (1995, Biochemical Systematics and Ecology 23:487-505), who published an analysis using mtDNA. They found the following relationship:

was polyphyletic. Clearly this tree shows that the traditional Elaphe is polyphyletic. I don't think there is much question about that.

The Tong paper only shows that some of the asian species are monophyletic with respect to the distantly related Dinodon, Ptyas, and Zaocys. What if they had included something like Gonyosoma? Would the group still hold? I don't know, but I don't think that tree tells me much about the monophyly of asian Elaphe due their outgroup choices.
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Chris Harrison

...he was beginning to realize he was the creature of a god that appreciated the discomfort of his worshippers - W. Somerset Maugham

You wrote:
[I thought the question was whether the Holarctic genus Elaphe] was polyphyletic. Clearly this tree shows that the traditional Elaphe is polyphyletic. I don't think there is much question about that. The Tong paper only shows that some of the asian species are monophyletic with respect to the distantly related Dinodon, Ptyas, and Zaocys. What if they had included something like Gonyosoma? Would the group still hold? I don't know, but I don't think that tree tells me much about the monophyly of asian Elaphe due their outgroup choices.

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Chris Harrison

My response:
Due to time and space constraints, I left out part of Lopez and Maxson's tree which included the phylogenetic status of Gonyosoma. Lopez and Maxson (1995) write: "Phylogenetic analysis of nearly 400 bp of 16s rRNA gene sequence data suggest that the Asian snake Gonyosoma, is generally allied to the North American racers despite its morphology and behavior which appear to be convergent on the ratsnake 'bauplan'. The remaining ratsnakes studied form a distinct monophyletic lineage separate from all other colubrines."

Indeed, Gonyosoma is more closely related to Coluber constrictor and Masticophis in Lopez and Maxson's mtDNA analysis than it is to either nearctic or palearctic Elaphe. That corroborates Dowling's amazing insight when he was able to judge, on the basis of morphology alone, without the benefit of molecular data, that Gonyosoma is not an Elaphe.

As to your claim that Lopez and Maxson's tree clearly shows that holarctic Elaphe is polyphyletic, perhaps you are confused by the presence of Lampropeltis, Cemophora and Pituophis in this clade. The common ancestor of Elaphe obsoleta, Pituophis, Cemophora and Elaphe vulpina is clearly a derived member of the lineage that includes Elaphe scalaris, E. carinata and Elaphe quatorlineata. This common ancestor is most likely morphologically similar to Elaphe obsoleta, if it is not E. obsoleta. Alternately, this common ancestor is morphologically disparate and looks nothing like any species of Elaphe. The nearctic species of Elaphe as well as Pituophis and Lampropeltis then evolved from this disparate ancestor to convergently resemble palearctic Elaphe. This second alternative is certainly possible, but unlikely, since it is less parsimonious than if all of the lampropeltine snakes, which include Arizona, Pituophis, Cemophora, Lampropeltis, Stilosoma and Bogertophis are descended from a species of Elaphe which is morphologically similar to the palearctic species E. carinata and E. scalaris.

By the way, there is nothing wrong with their outgroup choice. Lopez and Maxson include many different species of colubrines in their analysis but I cannot list them all because of space constraints. It may be helpful if you can see the full tree by getting hold of a copy of their paper. Tong et al. certainly show that all species of palearctic Elaphe they study are more closely related to each other than they are to Zaocys or Ptyas. Tong et al.'s tree also shows that Elaphe mandarina is the most basal member of Elaphe. Let's not forget Utiger et al. All of the species in their study form a clade with Ptyas as the outgroup. Utiger's clade also has E. mandarina as the most basal species. Combining the results of the three studies, it is clear that Elaphe mandarina is the most basal member of the genus Elaphe, and that the nearctic species are the most derived. Elaphe, including Elaphe flavirufa, is therefore not polyphyletic. It is, however, paraphyletic. Since I am not bothered by paraphyly (given that it is the inevitable result of the process of evolution), I find it untenable to splinter Elaphe in the absence of morphological disparity among the members of this genus.

Polyphyly implies that N. American ratsnakes such as Elaphe obsoleta and E. guttata are only convergently similar to Eurasian species of Elaphe such as E. carinata, E. scalaris and E. sauromates. E. scalaris is basal to the New World species of Elaphe in Lopez and Maxson's mtDNA tree and in the "weighted MP tree" (fig. 3) of Utiger et al. Hence New World Elaphe can be convergently similar to Old World Elaphe or they can be similar because of shared ancestral characters (symplesiomorphy). I believe that their similarities are symplesiomorphic because this alternative is more parsimonious. It is more parsimonious for the similarities between Elaphe obsoleta, Bogertophis and Pituophis to be shared ancestral characters of the genus Elaphe than to suggest that their similarities evolved independently from an ancestor that is closely allied to Old World Elaphe but it then somehow lost these Elaphe characteristics completely without a trace. A group that is united on the basis of shared ancestral characters is paraphyletic, not polyphyletic. Hence the claim that Holarctic Elaphe is polyphyletic is contingent upon the unlikely and unparsimonious scenario that the common ancestor of Elaphe obsoleta, Elaphe vulpina, Bogertophis, Pituophis and Lampropeltis had lost all of the characters of the genus Elaphe and these characters then reevolved in these descendant species.

"You said"
>>Polyphyly implies that N. American ratsnakes such as Elaphe obsoleta and E. guttata are only convergently similar to Eurasian species of Elaphe such as E. carinata, E. scalaris and E. sauromates. E. scalaris is basal to the New World species of Elaphe in Lopez and Maxson's mtDNA tree and in the "weighted MP tree" (fig. 3) of Utiger et al. Hence New World Elaphe can be convergently similar to Old World Elaphe or they can be similar because of shared ancestral characters (symplesiomorphy). I believe that their similarities are symplesiomorphic because this alternative is more parsimonious. It is more parsimonious for the similarities between Elaphe obsoleta, Bogertophis and Pituophis to be shared ancestral characters of the genus Elaphe than to suggest that their similarities evolved independently from an ancestor that is closely allied to Old World Elaphe but it then somehow lost these Elaphe characteristics completely without a trace. A group that is united on the basis of shared ancestral characters is paraphyletic, not polyphyletic. Hence the claim that Holarctic Elaphe is polyphyletic is contingent upon the unlikely and unparsimonious scenario that the common ancestor of Elaphe obsoleta, Elaphe vulpina, Bogertophis, Pituophis and Lampropeltis had lost all of the characters of the genus Elaphe and these characters then reevolved in these descendant species.
>>

"My response"
I like paraphyly, but Senticolis is supposed to be the most basal American ratsnake, and it isn't much like scalaris, or carinata, or sauromates for that matter. In fact it's quite racer-like, similar to taeniura and others. I would think a s.e. Asian ancestor would be more likely.

TC

The taxonomic position of Senticolis is still poorly understood. It probably is more basal to the nearctic species of Elaphe (E. flavirufa, E. obsoleta, E. guttata, E. vulpina et al.). Lampropeltis, Cemophora, Pituophis and Arizona et al. (aka the Lampropeltini) are almost certainly descendants of a single Eurasian species of Elaphe which migrated to the New World during the Miocene. The nearctic species of Elaphe and the Lampropeltini share the derived character known as the intrapulmonary bronchus. Senticolis is probably not part of this clade since it lacks the intrapulmonary bronchus and may have represented a separate migration from the Old World.

It seems to me that flavirufa could be ancestral to, or at least part of the Neartic Elaphe. I wondered why it was separated, although I understand genetics probably puts it quite distant from the others. Bogeratophis seems related, but probably distantly enough to have been given its own genus too. Senticolis could have been derived from a more racer-like ancestor, or maybe it came from the same line of ratsnakes and just lost the pulmonary bronchus in response to a drastically new environment.

The other Lampropeltini coming from just one species of Eurasian ratsnake doesn't seem likely to me, since Pituophis/Arizona seem more closely related to the Elaphe, and Lampropeltis/Cemophora,etc, seem more derived. Lampropeltis seems to compare more favorably to E. mandarina, or maybe Coronella, than the others that you mention. Mexican Pituophis, however, are very Elaphe-like, and I can easily envision an Asian Elaphe ancestor.

It's been a long time since the Miocene and I'm sure many of the transitional species have been lost in the evolution of the modern Neartic species.

Can you tell us which, if any, Old World Elaphe have the intrapulmonary bronchus? Thanks.

TC

The intrapulmonary bronchus is absent in palearctic Elaphe. It is present in nearctic Elaphe and in Lampropeltis, Arizona, Pituophis, Cemophora et al. The distribution of this character and the available molecular data suggest that all nearctic species of Elaphe and the Lampropeltini are descended from a single ancestral species of Old World Elaphe. Senticolis, since it lacks the intrapulmonary bronchus, is most likely not part of the nearctic Elaphe plus Lampropeltini clade. Is it possible that Senticolis lost this character? Yes, but not likely since no other species that evolved it has lost it and since Senticolis appears to be morphologically quite distant to nearctic Elaphe. All species of Pituophis are the descendants of a single ancestor, otherwise it would be an invalid polyphyletic genus. In fact, some of the Mexican species of Pituophis may well be conspecific with the western subspecies of Pituophis melanoleucus such as P. m. catenifer according to molecular data. Elaphe flavirufa should not be separated from other species of New World Elaphe. Utiger et al. do it because they are trying to create taxa that conform to Hennig's quasi-religious dogma that a taxon must consist of a single ancestor and all of its descendants. Darwinians do not subscribe to this dogma. Darwinians will accept a taxon if all of its members are descendants of a common ancestor even though not all descendants of the ancestor or the ancestor itself may be included in a taxon. Darwinians do this because this is the only practical way to classify real world organisms. The Hennigians' intolerance creates taxonomic chaos. Darwinians will accept a paraphyletic Elaphe which groups nearctic and palearctic species into a single genus. Hennigians cannot accept paraphyletic taxa (even though Utiger et al. admit that paraphyletic taxa are the inevitable result of evolution) because Hennig says they are unacceptable. One result of the Hennigians' intolerance of paraphyletic taxa is Utiger et al.'s chaotic split of Elaphe into nearly a dozen genera that are morphologically indistinguishable from each other, even though these genera all share a single common ancestor. Elaphe is not polyphyletic. It is being splintered by Utiger et al. because it is paraphyletic and because most of the authors in Utiger et al. do not tolerate paraphyletic taxa.

"You said"
>>The intrapulmonary bronchus is absent in palearctic Elaphe. It is present in nearctic Elaphe and in Lampropeltis, Arizona, Pituophis, Cemophora et al. The distribution of this character and the available molecular data suggest that all nearctic species of Elaphe and the Lampropeltini are descended from a single ancestral species of Old World Elaphe.

"My answer"
If nearctic Elaphe and Lampropeltini all descended from an ancestor with this trait, then that ancestor would have to have developed it after arriving in the New World, wouldn't it? This is kind of hard to understand.

"You said"
Senticolis, since it lacks the intrapulmonary bronchus, is most likely not part of the nearctic Elaphe plus Lampropeltini clade. Is it possible that Senticolis lost this character? Yes, but not likely since no other species that evolved it has lost it and since Senticolis appears to be morphologically quite distant to nearctic Elaphe.

"My answer"
I assume that you accept the genus, Senticolis, then.

"You said"
All species of Pituophis are the descendants of a single ancestor, otherwise it would be an invalid polyphyletic genus. In fact, some of the Mexican species of Pituophis may well be conspecific with the western subspecies of Pituophis melanoleucus such as P. m. catenifer according to molecular data.

"My answer"
Do you accept the genus, Pituophis, even though it is likely that this taxon is derived from an Elaphe ancestor, and possibly the same ancestor as for the Lampropeltini?

"You said"
Elaphe flavirufa should not be separated from other species of New World Elaphe. Utiger et al. do it because they are trying to create taxa that conform to Hennig's quasi-religious dogma that a taxon must consist of a single ancestor and all of its descendants. Darwinians do not subscribe to this dogma. Darwinians will accept a taxon if all of its members are descendants of a common ancestor even though not all descendants of the ancestor or the ancestor itself may be included in a taxon. Darwinians do this because this is the only practical way to classify real world organisms. The Hennigians' intolerance creates taxonomic chaos. Darwinians will accept a paraphyletic Elaphe which groups nearctic and palearctic species into a single genus. Hennigians cannot accept paraphyletic taxa (even though Utiger et al. admit that paraphyletic taxa are the inevitable result of evolution) because Hennig says they are unacceptable. One result of the Hennigians' intolerance of paraphyletic taxa is Utiger et al.'s chaotic split of Elaphe into nearly a dozen genera that are morphologically indistinguishable from each other, even though these genera all share a single common ancestor. Elaphe is not polyphyletic. It is being splintered by Utiger et al. because it is paraphyletic and because most of the authors in Utiger et al. do not tolerate paraphyletic taxa.

"My answer"
I don't understand why Utiger et al. would be splintering Elaphe because they don't accept paraphyletic taxa. Doesn't the Lampropeltini already make it paraphyletic? And, doesn't separating the likes of Pantherophis, as well as Euprepiophis, Oreophis, Orthriophis, Zamenis, etc, make Elaphe paraphyletic?

**Just some additional comments. I don't have the resources of a university resident. I have a humble library of my own which reflects my interests, but would love to see some of the papers/articles which you use to learn about some of these things. For instance, I don't know anything about Hennig. I have the Utiger et al. paper, but I don't know where your info about the pulmonary bronchus came from. I'd love to research that aspect. Feel free to e-mail me any comments you don't want to post. Thanks,

TC

There are online resources available. For example the link I will provide below discusses the Lampropeltini. I disagree with many of their conclusions but it is a good introduction to the topic. As the authors point out, Senticolis is removed from the Lampropeltini by Keogh because it lacks the intrapulmonary bronchus. One of the trees in this paper shows Senticolis as part of the Lampropeltini. There is probably something wrong with the data or the characters used or the weighting scheme if it shows Senticolis to be part of the Lampropeltini. The way Utiger et al. eliminate paraphyletic taxa is by redefining Elaphe as a small crown group, i.e. a small group near the tip of the phylogenetic tree. That way they can recognize groups that will include all descendants and the ancestor. But doing this creates a large number (nearly a dozen) of small genera, none of which can be adequately distinguished from one another. The better alternative is a single paraphyletic genus Elaphe, i.e. the status quo.
Molecular systematics of New World lampropeltinine snakes

Thanks much for the link. The paper is very good so far as I've read.

I think there may have been more than one invasion of Elaphe, into the New World, as it seems to me that it would have taken a different ancestor to give rise to each of Pantherophis/Pituophis, Lampropeltis, and Senticolis. That may be one we'll never know for sure, I think.

Thanks.

Rodriguez-Robles seems to be in favor of Senticolis being inside of the Lampropeltini, even though his maximum parsimony trees (fig. 4 a and b) show it outside of the Lampropeltini. Unfortunately, he does not include any species of Old World Elaphe in his study, therefore there is no data in his study to show whether Senticolis is more basal to the New World species of Elaphe than the Old World species of Elaphe. As Rodriguez-Robles points out, Senticolis lacks the "putative synapomorphy" of the Lampropeltini, the intrapulmonary bronchus. There is therefore agreement between morphology and his MP trees and lack of support for Rodriguez-Robles' conclusion from his MP trees and morphological characters.

Lampropeltis and Pituophis are both part of the Lampropeltini, meaning that they both are descended from a species of Elaphe that has the intrapulmonary bronchus. This species of Elaphe may or may not be closely related to Senticolis. Utiger et al. find poor statistical support (bootstrap value of 30 for their mtDNA data) for Senticolis being part of the Lampropeltini. Most likely Senticolis and the common ancestor of Elaphe obsoleta, Pituophis and Lampropeltis arrived in America separately as different species. Where Senticolis lies within the ratsnake clade (i.e. Old World Elaphe plus New World Elaphe plus Lampropeltini) will require further studies but more likely than not it is not part of the Lampropeltini.

Ok, we know that the Lampropeltini are closely related and they all have the pulmonary bronchus, except Senticolis. I would agree that flavirufa should still be in this genus, but wouldn't the Lampropeltini have a different Elaphe ancestor than the Old World Elaphe, which don't have the pulmonary bronchus? They are not as closely related to Old World Elaphe, so wouldn't the genus Pantherophis be warranted? Just from my observations of my captive specimens, I think the Old World species are mostly different enough morphologically and in behavior to rate a separate genus.

Both Old World Elaphe and New World Elaphe have the same common ancestor, which is ancestral to all species of Elaphe. It is true that New World Elaphe is descended from one particular species of Old World Elaphe. Does that mean then that New World Elaphe should be placed in a genus of its own? The cladists would not do it for the following reason: it does not make Old World Elaphe any less paraphyletic. Neither will the Darwinians because Old World Elaphe is just not morphologically disparate enough to warrant such placement. Utiger et al., in their attempt to destroy paraphyletic taxa, find that they cannot put New World Elaphe into a single genus that conforms to Hennig's dogma. They have to put these species in two: Pantherophis and Pseudelaphe. If one argues that the intrapulmonary bronchus is a good reason for the recognition of Pantherophis, then what is the morphological evidence that justifies erecting a new genus for Elaphe flavirufa? It also has the intrapulmonary bronchus. Shouldn't it be placed in Pantherophis as well? The superfluous erection of the new genus Pseudelaphe is irrefutable evidence that Utiger et al. are not using morphological disparity as justification for recognizing the plethora of genera they have resurrected and erected.

If someone were to propose splitting Elaphe on morphological and/or behavioral grounds, then he or she is welcome to do so. The morphological and/or behavioral evidence would then be scrutinized as to their validity. Utiger et al., however, are not doing that. They proffer no new data on morphology or behavior, therefore there can be no scrutiny of such data. They are splintering Elaphe because it is paraphyletic and because they as a group are intolerant of paraphyletic taxa. There are many taxonomists who share their distaste of paraphyletic taxa. These taxonomists may well embrace their classification. The Darwinians, who consider paraphyletic taxa monophyletic, will most likely ignore Utiger et al.'s proposal.

You wrote:
Ok, we know that the Lampropeltini are closely related and they all have the pulmonary bronchus, except Senticolis. I would agree that flavirufa should still be in this genus, but wouldn't the Lampropeltini have a different Elaphe ancestor than the Old World Elaphe, which don't have the pulmonary bronchus? They are not as closely related to Old World Elaphe, so wouldn't the genus Pantherophis be warranted? Just from my observations of my captive specimens, I think the Old World species are mostly different enough morphologically and in behavior to rate a separate genus.

My response:
At the time Keogh published his findings, it was thought that only New World species of Elaphe and the Lampropeltine genera such as Pituophis, Lampropeltis, Bogertophis, Rhinocheilus, Cemophora, Arizona and Stilosoma have the intrapulmonary bronchus. It has since been discovered that Old World species of Elaphe (including those placed in Coronella) also have this character. Senticolis does not. Therefore this characters shows that Senticolis is not as closely related to any species of ratsnakes in either the Old World or New World. The intrapulmonary bronchus also cannot be used to define the genus Pantherophis because Elaphe flavirufa, Old World species of Elaphe and Coronella have it. Utiger et a. (2002: 112) state briefly: "Based on the absence of an intrapulmonary bronchus in Senticolis, this author removed S. triaspis from the Lampropeltini and placed the genus in the racers (Colubrini). Following these results, Wallach (1998) concluded that Old World Elaphe (auct.) and Coronella have to be assigned to this tribe."

If Old World Elaphe and New World Elaphe have the intrapulmonary bronchus and Senticolis does not, and yet Utiger et al.'s tree put Senticolis closer to the New World Elaphe than the Old World Elaphe, then there is something wrong with Utiger et al.'s tree. Their classification, which is an exact, detailed expression of their tree, is therefore problematic. It is therefore best not to follow their classification because it is flawed and in need of revision.

I may not have been very clear on how Utiger et al. eliminate paraphyly so I will attempt to explain it with a diagram. Basically paraphyletic taxa are those taxa that do NOT include the ancestor and/or all of the descendants of this unknown ancestor. The top diagram represents a simplified version of the relationship among New World Elaphe, Old World Elaphe and Lampropeltis. Hennigians insist that all taxa must include one (unknown) ancestor and all of its descendants. That means they will only accept a taxon that includes Old World Elaphe, New World Elaphe and Lampropeltis and all the descendants of their ancestor. If this taxon is a genus then all species of Lampropeltis, Old World Elaphe and New World Elaphe must be included in the same genus: Elaphe.

A second alternative is to classify Lampropeltis, Old World Elaphe and New World Elaphe into three different genera, each genus having a different (unknown) ancestor and each genus would then conform to Hennig's mandate that a taxon must include one ancestor and all of its descendants. This is of course a simplified version of Utiger et al.'s classification since they further subdivide Old World Elaphe into many different genera and they divide New World Elaphe into Pantherophis and Pseudelaphe. Why should one divide up Old World Elaphe and New World Elaphe into different genera if they cannot be distinguished from one another? That is the question a Darwinian would ask. The reason the Hennigians splinter Elaphe is because they cannot tolerate, for dogmatic reasons, paraphyletic taxa. Because of their intolerance, they are constantly trying to destroy perfectly valid paraphyletic taxa such as Elaphe, and replace them with a plethora of new taxa that cannot be distinguished from one another.

A third alternative for Hennigians would be to classify Lampropeltis and New World Elaphe into the same genus, while leaving Old World Elaphe in its own genus. A fourth alternative, and one that is not available to the Hennigians is the recognition of a paraphyletic Elaphe (Old World plus New World species) and Lampropeltis as separate genera. But alas, this is the only classification that would actually make sense, since it would only confer new taxonomic status to those taxa that have evolved new characters, not to those that have not changed, unlike Utiger et al.'s classification.

Thanks for the explanations. It helps a lot.

Utiger et al. certainly felt they had to splinter Pantherophis from the Old World Elaphe. I'm not sure why a new genus was erected for flavirufa, but I don't understand the genetics work very well, and seems there's so many different interpretations. Makes me wonder if the DNA testing is reliable as a taxonomic method.

The Old World Elaphe has long been considered to be a dumping pot of species, so was ripe for a revision also. Obviously, there are some classifications which could be considered to be doubtful, but this would spur further work, which I think is a good thing.

Orthriophis species all coming from a common ancestor is questionable in my eyes. Plus, there are likely some species that have been derived from certain Orthriophis species, but which with which? DNA testing is probably the best tool we have at the time, but there will likely be even more changes in the future.

Some of the new genera I like because they represent species that really are different from typical Elaphe. Some species in the new genera leave something to be desired, however. For instance, I can't see carinata and its close relations in the Elaphe genus, if taeniura isn't in there.

Just some of my thoughts. Thanks for your posts.

TC

The reason Utiger et al. separate Elaphe flavirufa from the other American species of Elaphe (such as E. obsoleta and E. vulpina) is the same as their separation of Old World Elaphe from New World Elaphe, and the same as their splintering of Old World Elaphe into nearly a dozen different genera. It is the familiar Hennigian intolerance of paraphyletic taxa. E. flavirufa shares with other species of American Elaphe the intrapulmonary bronchus. It is without doubt closely related to Elaphe obsoleta and other American species of Elaphe, all of which have this character. Their choice of name for the new genus they erect-Pseudelaphe- is also particularly galling because it implies that Elaphe flavirufa is only convergently similar to other species of Elaphe. Nothing can be further from the truth. Elaphe flavirufa is a derived member of the ratsnake clade. It is a direct descendant of an Old World species of Elaphe and shares a more recent common ancestor with E. sauromates, the type species of this genus, than with any species of racer. The resemblance between E. flavirufa is due to common ancestry, not convergence. The relationship between E. flavirufa and Old World Elaphe is real. The separation of E. flavirufa from Old World Elaphe and from New World Elaphe species such as E. obsoleta is based on false premises.

You wrote:
The Old World Elaphe has long been considered to be a dumping pot of species, so was ripe for a revision also.

My response:
Those old misconceptions have been disproven. Old World Elaphe is not a dumping ground. It is not a polyphyletic group. Utiger et al. prove it. Lopez and Maxson prove it. Tong et al. prove it. It is, however, paraphyletic, meaning that some of the members of this clade (e.g. Lampropeltis, Bogertophis, Pituophis, Arizona, Cemophora and Stilosoma) have been removed and classified in other genera because they are morphologically disparate. In order to eliminate paraphyletic taxa, the cladists would either have to bring all of the species in Lampropeltis et al. back into Elaphe, or they would have to do what Utiger et al. are doing: chopping up Elaphe even though the species included are not morphologically disparate enough to warrant the erection of new genera and the resurrection of long abandoned genera. There is no middle ground in the cladists' ideology. Fortunately, the Darwinians have a sane alternative: continue to accept Elaphe as a paraphyletic genus and to recognize Lampropeltis et al. as valid genera. The Darwinian classification recognizes the morphologically conservative nature of the genus Elaphe while acknowledging the adaptive radiation that has occurred when one of its members entered the New World from the Old. Utiger et al.'s classification would mislead the uninitiated into thinking that there is a lot of evolutionary changes in the lineages within the Old World Elaphe (thus justifying splintering into numerous different genera) when in fact there isn't.

You wrote:
DNA testing is probably the best tool we have at the time, but there will likely be even more changes in the future.

My response:
DNA data is indeed superior to morphological analysis in elucidating branching order. However, not all DNA characters are useful, and different DNA molecules may yield different phylogenetic trees. It is clear that not all molecules are equally informative. The task of the molecular systematist is not only to analyze relationships but to search for molecular characters that are the most informative. When better molecular characters and/or methods of analyses have been found, hypotheses of phylogenetic relationships will become more robust.

That said, one must not confuse classification with phylogeny. Given a set of phylogenetic relationships, many different classifications are possible. Utiger et al.'s phylogenetic hypothesis does not automatically result in their preferred classification. If one does not subscribe to Utiger et al.'s Hennigian ideology, for example, one can certainly come up with a different and better classification than Utiger et al. have. A Darwinian, for example, can do away with all of the resurrected and newly erected genera for Old World and New World species of Elaphe and continue to recognize a single paraphyletic genus while maintaing Lampropeltis, Pituophis et al. as valid.

You wrote:
Some of the new genera I like because they represent species that really are different from typical Elaphe. Some species in the new genera leave something to be desired, however. For instance, I can't see carinata and its close relations in the Elaphe genus, if taeniura isn't in there.

My response:
Different lineages evolve at different rates. Therefore not all species within a genus are equally similar to each other morphologically. Subgenera and species groups are often employed to show subdivisions within a genus without creating taxonomic instability. Utiger et al. could have done that instead of their chaotic new proposal. There is no need to despair however. It is not up to the taxonomists to dictate to us how organisms are classified. It is up to each individual person to either accept or reject new taxonomic proposals. I, for one, choose to ignore their chaotic new proposal because I do not share with them their ideological distaste for paraphyletic taxa. I predict that many Darwinians will do the same. The cladists, who share Utiger et al.'s distaste of paraphyletic taxa, may (or may not) embrace their classification. There is unlikely to be taxonomic consensus on this group of snakes in the foreseeable future.

You said:

Utiger et al.'s classification would mislead the uninitiated into thinking that there is a lot of evolutionary changes in the lineages within the Old World Elaphe (thus justifying splintering into numerous different genera) when in fact there isn't.

My Response:

I think there's only about four new genera we need to consider: Orthriophis, Oreophis, Euprepiophis, and Zamenis. Not too much different than the situation of the genera already split from Elaphe, like Gonyosoma, Coelognathus, etc.

You know, I can't really comment on this right now because I could go either way. I've been thinking about this all evening and just can't commit myself. I wouldn't mind the status quo, but it seems like these changes are going to happen no matter.

Thanks for your time and comments, etc.

I am not trying to convince you of anything. I am just informing you of my reasons for my judgment of Utiger et al.'s proposal.

Therefore the real question is not how many genera are erected and/or resurrected but why. As I have repeatedly stated, their reason for doing so is their intolerance of paraphyletic taxa. My reason for rejecting their proposal is my acceptance of paraphyletic taxa as the inevitable result of the process of evolution. Again, there are many who share Utiger et al.'s intolerance, notably the cladists or Hennigians. There are others who feel strongly that taxonomic stability is far more important than any dogmatic intolerance of paraphyly. There will also be those who will use whatever names they think are the most current. We are all free to either accept or reject Utiger et al.'s taxonomic proposal. Science is wonderful.

Regards

Referring back to Utiger et al.'s attempt to eliminate paraphyletic taxa from their classification. By erecting and resurrecting a plethora of genera for what used to be a single genus, they are able to eliminate paraphyly within the group of living species. They have, however, created a paraphyletic basal group of ratsnakes in the process. This group is now without a name and it cannot have a name because it is a paraphyletic genus. Paraphyletic taxa are indeed the inevitable result of the process of evolution. If one accepts Utiger et al.'s proposal, then any species of extinct ratsnake formerly placed in the genus Elaphe will now have no name, since the genus Elaphe is no longer available, having been restricted to a small group of living species by Utiger et al.'s scheme. This is but one of the undesirable consequences of the Hennigian intolerance of paraphyletic taxa.

You make a very interesting argument. I'm pretty impressed. I understand that you are arguing for Elaphe to remain the status quo because it's a paraphyletic genus. But consider the fact that most of the herpetoculturists on this forum aren't much interested in the taxonomy per se, only the convenience of catagorizing the species they keep and of knowing that there are some differences between the various species. EX: my Mandarin Ratsnake isn't anything like your Black Ratsnake, so I'd rather not have it in the same genus.

Actually, I not only see your point, but I tend to agree with you. I remember arguing with someone last year about the possibilities of New World ratsnakes having an Asian ancestor, and the person swore that it was impossible because New World and Old World Elaphe are not at all related. I think that most of the forum goers think that because New World Elaphe are closer to the Lampropeltini and that they are not really related to the Old World Elaphe, since they think the Old World Elaphe are not related to Lampropeltini.

I remember arguing against everyone (noone took my side) that rufodorsata shouldn't be taken out of the Elaphe because it was derived from an Elaphe. But some author came out with some sort of evidence that rufodorsata was very distant from the Elaphe and couldn't be in the same genus. I think it was mainly because they are live-bearers. I tried to argue for Gonyosoma to remain in the Elaphe, and also scalaris, and all the New World Elaphe, and I even think Rhyncophis is an Elaphe. But, you can see it is a losing battle, and it's almost impossible for the Elaphe to remain together because there are so many species. It's already paraphyletic because of the Lampropeltini and many Eurasian genera that were once in Elaphe, or should be added (imo). I don't especially want to use the new genera, but you can see it's difficult if most hobbyists start using them and don't understand how the taxonomy works.

I appreciate the info and new perspective you bring to the forum. Do you have any interest in the ratsnakes other than the taxonomic point of view? BTW, I think the western radiation, which lead to the "Zamenis" group, was started by an Elaphe ancestor that was racer-like, and gave some racer characteristics, as well as ratsnake characteristics, to those species. I also think many of the Eastern species, including the New World Elaphe, are decendants from a more typical ratsnake, with less racer-like qualities. I also think this type of ratsnake is nearly gone from Asia, leaving only a few somewhat relic species, like moellendorffi, cantoris, and maybe climacophora. Not scientific like taxonomists tend to do, but kinda how my mind works.

Cheers

New World species of Elaphe do share the intrapulmonary bronchus with Lampropeltis et al. but this single character does not justify removing these species of Elaphe and putting them into Pantherophis AND Pseudelaphe, that is because Elaphe obsoleta and E. flavirufa share more morphological similarities with each other and with Old World species of Elaphe than they do with, say, Lampropeltis. The more classifically trained systematists do not like to name taxa on the basis of one or a few characters.

Gonyosoma is definitely not a species of Elaphe. It is only convergently similar to the ratsnakes. Lopez and Maxson demonstrated that. It is actually more closely related to the racer Coluber constrictor. I would not support lumping it with Elaphe since it would create a polyphyletic genus. I have a hunch that Senticolis would eventually prove to be not very closely related to either Lampropeltis or Elaphe obsoleta, despite Rodriguez-Robles' opinion that it is part of the Lampropeltini. Where it may eventually prove to lie on the phylogenetic tree must await further study. It is quite possibly similar to Gonyosoma in being more closely related to the racers than the ratsnakes.

The number of species within Elaphe is not a problem. There are many genera of reptiles and amphibians with far greater numbers of species, numbering in the hundreds sometimes (e.g. Hyla, Rana, Bufo, Anolis). Therefore I disagree with the suggestion that there are too many species within this genus. Whether Elaphe should be broken up should depend on whether the species within it are morphologically disparate and whether it is a polyphyletic group. Lopez and Maxson, Tong et al. and Utiger et al. have all shown that Elaphe is not polyphyletic. None of these authors have demonstrated that Elaphe is a heterogeneous group morphologically. In fact, Helfenberger, one of the junior authors of Utiger et al., has to look inside the visceral organs of these snakes to try to find morphological characters to split this genus on morphological grounds. That shows me how little these snakes differ from each other morphologically. To me, there is no compelling reason to splinter Elaphe, since I have no problem with recognizing paraphyletic taxa and since I have shown that Utiger et al.'s new classification in fact creates a paraphyletic group of its own at the base of their phylogenetic tree.

That said, anyone is free to use the new names or not to use them, as I had stated before. Whether these new names will stand will depend on how other scientists judge Utiger et al.'s proposal and how many of them adopt or reject the new names. Knowing the way many scientists think, I predict that most of the Darwinians will reject the new names, and many, but not all or perhaps even most, of the cladists will embrace them.

The ratsnakes (and their descendants) are a beautiful group of animals. Some of them have outrageously ornate patterns. Perhaps it is this reason more than any other that they have attracted the attention of taxonomists. Unfortunately some of these taxonomists have better taste in their choice of study animals than in their choice of classificatory philosophies.

You wrote:
I understand that you are arguing for Elaphe to remain the status quo because it's a paraphyletic genus. But consider the fact that most of the herpetoculturists on this forum aren't much interested in the taxonomy per se, only the convenience of catagorizing the species they keep and of knowing that there are some differences between the various species. EX: my Mandarin Ratsnake isn't anything like your Black Ratsnake, so I'd rather not have it in the same genus.

My response:
Pretty close, but I am not arguing that Elaphe should remain intact because it is paraphyletic. I am pointing out that the only reason it is being broken up by Utiger et al. is because it is paraphyletic. Splintering Elaphe is justifiable if it is an unnatural polyphyletic group or if its members are morphologically disparate. At least 3 independent studies (Tong et al. 2002, Utiger et al. 2002 and Lopez and Maxson 1995) have shown that all species of Elaphe are more closely related to each other than they are to any racer, such as those in the genus Ptyas. Elaphe is not polyphyletic. No author has demonstrated that Elaphe is a morphologically disparate group. Since I, like other Darwinians, accept paraphyletic taxa as natural, given the fact that "paraphyletic taxa are the inevitable result of the process of evolution", I oppose the splintering of Elaphe by Utiger et al. simply because it is paraphyletic. Most cladists or Hennigians, whose classificatory philosophy is based on a dogmatic intolerance of paraphyletic taxa, would probably embrace Utiger et al.'s classification.

You are claiming that E. obsoleta is "nothing like" E. mandarina and so it should be placed in a different genus. That would imply morphological and behavioral similarities are the basis for grouping Utiger et al.'s classification. Sadly, that is not the case. For example, Elaphe flavirufa is a lot like E. guttata and E. obsoleta morphologically and behaviorally. Yet Utiger et al. put E. flavirufa and E. guttata in 2 different genera. If some herpetoculturists are looking for ways to distinguish among the ratsnakes based on their similarities to each other, they will look in vain in Utiger et al.'s classification. Further, as I pointed out before, species groups and subgenera can be used to subdivide a genus on morphological or phylogenetic grounds. One can definitely distinguish a black ratsnake from a Mandarin ratsnake by classifying them in different species groups without resorting to the taxonomically destructive act of erecting and resurrecting nearly a dozen genera, especially if the authors provide no definitions for the genera they resurrect.

I welcome studies that would attempt to sort out the species of Elaphe on morphological and behavioral grounds. Then and only then can we see if the groups that are delimited that way can be monophyletic. If they are, then there may be grounds to subdivide Elaphe, even into different genera. If not, then this genus cannot and should not be split, since the morphological similarities would be convergences and these groups would then be unnatural polyphyletic ones. Until then, there is no justification for splintering Elaphe into nearly a dozen genera. Taxonomic chaos can be avoided if we simply ignore Utiger et al.'s proposal.

What happened to Elaphe Schrencki ?? Shouldn't it be alongside Anomala ??

Steve