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Burbrink's new paper;

NEWS RELEASE
The Center for North American Herpetology
Lawrence, Kansas
http://www.cnah.org
8 April 2007

HOW AND WHEN DID OLD WORLD RAT SNAKES DISPERSE INTO THE NEW WORLD?

Frank T. Burbrink and Robin Lawson
2007. Molecular Phylogenetics and Evolution 43: 173-189

I read through it quickly. There are some interesting things to discuss. They pick the Bering Strait as the migration Route (the usual choice).

They have Coronella as the nearest relation to the new world lampropeltines.

They have separated bella from Elaphe.

They have not put frenata and prasina in Gonyosoma (that's going to be a bone of contention).

They put the fox snakes into a branch with the pits.

They put Bogertophis into a branch with the king snakes and their kin.

Very interesting (and provocative).
Regards
John

>>Burbrink's new paper;
>>
>>NEWS RELEASE
>>The Center for North American Herpetology
>>Lawrence, Kansas
>>http://www.cnah.org
>>8 April 2007
>>
>>HOW AND WHEN DID OLD WORLD RAT SNAKES DISPERSE INTO THE NEW WORLD?
>>
>>Frank T. Burbrink and Robin Lawson
>>2007. Molecular Phylogenetics and Evolution 43: 173-189
>>
>>I read through it quickly. There are some interesting things to discuss. They pick the Bering Strait as the migration Route (the usual choice).
>>
>>They have Coronella as the nearest relation to the new world lampropeltines.
>>

Agree! Actually, that was proposed by Utiger et al., 2005, I believe.

>>They have separated bella from Elaphe.
>>

Agree! But I think they should have proposed "Euprepiophis" as their new genus. Seems to be a connection there, if you ask me...haha!

>>They have not put frenata and prasina in Gonyosoma (that's going to be a bone of contention).
>>

Don't agree! I thought they deserved being in Gonyosoma. I assume they made a new genus for them?

>>They put the fox snakes into a branch with the pits.
>>

Just can't get it right with the fox snakes. First split into two species with no real justification, imo. Now going to put the species into another genus which hasn't even been shown to be a "ratsnake" genus, yet. Where's the justice in that? I always thought fox snakes were closely related to the guttatus group. Guess it doesn't pay to think.

>>They put Bogertophis into a branch with the king snakes and their kin.
>>

Gots to be kidding...LOL!

>>Very interesting (and provocative).
>>Regards
>>John

I'm going to have to read this one again. Something just doesn't seem right here.

TC

Terry:
I figure it's gonna take a few years before all the PhD's reach consensus on what's what for the ratsnakes and relatives. Whether we agree with all the theories or not it definitely catches our attention.

Regards
John

Hi, John.

I don't think the pros will ever be in consensus, imho, LOL! It makes for a lot of confusion for us amateurs, and I think that's why some of us haven't accepted any changes at all. Some progress has been made, however. At least we're moving along and working on some of our favorite snakes species. I enjoy it...haha! I'm weird that way.

Later...TER

Hey Terry,

I think Burbrink et al actually have a case with the Pituophis thing. A few years ago I had a pair of Pantherophis gloydi, which reminded me a lot to Pituophis, both behaviourly (hissing with opened mouth, tail vibration) and morphometrically (heavy bodied, rostral a little enlarged, patternless head). Sure, when you compare them to an advanced species like Pituophis melanoleucus it may seem a little odd. Now compare them to a plesiomorph species like Pituophis deppei. Does it still seem so far fetched?

Personally, I always suspected Pantherophis obsoletus as a rather weird, semiarboreal gophersnake, rather than your typical ratsnake. I have heard many times that crosses between P. obsoletus and Pituophis catenifer are more viable and have better fertility than crosses between P. obsoletus and P. guttatus. I never tried it myself though.

More work has to be done, more species need to get involved into the equation. But whatever you may think of their conclusions, you can't deny that Burbrink et al deliver al lot of interesting food for thought. I know I'm having fun.

Best regards,

Herman Bronsgeest.

Thanks, Herman.

I appreciate your comments and agree with a lot of what you're saying. I was mainly talking about not liking the scientific name change. As far as "relatedness" goes, I've always thought there was something between the Pituophis and the fox snakes, I just wouldn't put the fox snakes in the same genus with them before calling them a "ratsnake". Maybe all the Pituophis and Pantherophis should be in the same genus, but for now I don't think that's a good idea. It would cause a lot of confusion. There is enough differences to keep them in different, closely related, genera, I think. Of course, as always, it's just my personal opinion as a curious bystander, haha!

Terry

>>Hey Terry,
>>
>>I think Burbrink et al actually have a case with the Pituophis thing. A few years ago I had a pair of Pantherophis gloydi, which reminded me a lot to Pituophis, both behaviourly (hissing with opened mouth, tail vibration) and morphometrically (heavy bodied, rostral a little enlarged, patternless head). Sure, when you compare them to an advanced species like Pituophis melanoleucus it may seem a little odd. Now compare them to a plesiomorph species like Pituophis deppei. Does it still seem so far fetched?
>>
>>Personally, I always suspected Pantherophis obsoletus as a rather weird, semiarboreal gophersnake, rather than your typical ratsnake. I have heard many times that crosses between P. obsoletus and Pituophis catenifer are more viable and have better fertility than crosses between P. obsoletus and P. guttatus. I never tried it myself though.
>>
>>More work has to be done, more species need to get involved into the equation. But whatever you may think of their conclusions, you can't deny that Burbrink et al deliver al lot of interesting food for thought. I know I'm having fun.
>>
>>Best regards,
>>
>>Herman Bronsgeest.

Hello Terry,

I understand. The point Burbrink et al are making, is that the current situation, having Pantherophis and Pituophis as seperate genera, can no longer be maintained because it implies a paraphyletic genus Pantherophis. From a cladistic point of view, paryphyletic taxa are not acceptable. Thus Pantherophis should be synonimized with Pituophis, or vice versa. It's not about what 'feels' right, but about following widely accepted nomenclatural rules.

Look at it this way. So your parents named you Terry, but if they had named you George instead, you wouldn't have known any better. If we had named Pituophis species ratsnakes from the beginning, instead of calling them pine snakes, bullsnakes or gopher snakes, we propably wouldn't have any problem with Burbrink's proposal at all. It just doesn't feel right because we were brought up looking at them as being very different from ratsnakes. Which they're not, as it seems.

Best regards,

Herman Bronsgeest.

Herman, that's a good analogy and understand of Burbrink et al. That's pretty much what I was understanding, but I just couldn't put it into words as eloquently as you did. My understanding of the terminology isn't that good. I'll attempt to explain how I feel about this situation, which I believe is as valid as Burbrink's point.

First, let me say that I believe Pituophis species are "ratsnakes", as I know them, closely related to N. A. ratsnakes and the Lampropeltini. We have not thought of them as ratsnakes while growing up, and it's hard now since they look different from our other N. A. ratsnakes, but I do believe we should now consider them to be ratsnakes. However, that doesn't mean I think they are as closely related to fox snakes, or any ratsnake, as the other species of Pantherophis are related to each other.

I think Burbrink et al. stated that fox snakes are closer to the Pituophis species than to other Pantherophis sps. I think that's why you said it made them paraphyletic. In my opinion, you have to look at morphological and other characteristics, as well as genetics, when comparing. I can't say I believe the fox snakes are as close, or closer, to the Pituophis sps, as they are to other Pantherophis sps. I think we're going to need some more evidence before we can put the fox snakes in the genus. I know Utiger et al. looked at these species. You would think they would have said something if the Pituophis sps. tested so close to the fox snakes, wouldn't you.

Just seems like we need more convincing on this. I wonder what other scientists will say?

>>Hello Terry,
>>
>>I understand. The point Burbrink et al are making, is that the current situation, having Pantherophis and Pituophis as seperate genera, can no longer be maintained because it implies a paraphyletic genus Pantherophis. From a cladistic point of view, paryphyletic taxa are not acceptable. Thus Pantherophis should be synonimized with Pituophis, or vice versa. It's not about what 'feels' right, but about following widely accepted nomenclatural rules.
>>
>>Look at it this way. So your parents named you Terry, but if they had named you George instead, you wouldn't have known any better. If we had named Pituophis species ratsnakes from the beginning, instead of calling them pine snakes, bullsnakes or gopher snakes, we propably wouldn't have any problem with Burbrink's proposal at all. It just doesn't feel right because we were brought up looking at them as being very different from ratsnakes. Which they're not, as it seems.
>>
>>Best regards,
>>
>>Herman Bronsgeest.

Terry,

As a scientist, I agree on the part that a lot more work needs to be done before we can draw any drastic conclusions. Taking just one (presumably apomorphic) species of Pituophis into the equation just doesn't quite cut it. The position of (presumably plesiomorphic) species like Pituophis deppei or P. lineaticollis is missing in Burbrink's work, which I think is a bloody shame. More characters (genetic, morphometrical) need to be examined, more species need to be involved. As a hobbyist, I have kept many Corn Snakes, a few Fox Snakes, and lots of Pine, Bull and Gopher Snakes. I actually believe Fox Snakes are quite different from Corn Snakes, and remarkably similar to Gopher Snakes. But that's just my personal opinion, which is just as good as anyone else's, scientist or hobbyist alike.

I like discussing this kind of material with guys like you Terry. We should do this more often.

Best regards,

Herman Bronsgeest.

Your opinion is indeed important, otherwise we wouldn't be having this great discussion. I think you've made some really good points here, and I'm glad I could be of help. Maybe if the taxonomists look at all the characters and more snakes, as you suggested, we would eventually come to the conclusion that the genus Pituophis is closer to some Pantherophis than any other genus. Maybe there are even some major differences bt. Pituophis species. Could Pantherophis vulpinus be closer to Pituophis lineaticolis, for instance, than P. lineaticolis is to Pituophis catenifer?

I think they should include other species in there study too, such as other Pantherophis species, and maybe some other Lampropeltines, to see how these closely related genera compare to each other. Some possibly very relevant information could come out of a study like that.

Thanks...Terry

""""HOW AND WHEN DID OLD WORLD RAT SNAKES DISPERSE INTO THE NEW WORLD?""""

I don't know, but I get a good laugh anytime Burbrink plays with a chemistry set!

""""They pick the Bering Strait as the migration Route (the usual choice).""""

Why? Who deemed that "migration" must be the answer? If that were the case, then why aren't there any Vipera or Elaphe type snakes on the west coast of the U.S.......versus Crotalus and Pituophis.

This p-tree doesn't work for me, but in any case, it didn't come to the new world via the Bering Strait (in the case of Gloydius, Deinagkistridon, etc..... I'm leaning toward convergent evolution):

Patrick Alexander's use of data, based on a combination of Utiger, et al. and Burbrink, et al.

""""They have Coronella as the nearest relation to the new world lampropeltines.""""

Bering Strait?

""""They have separated bella from Elaphe.""""

At least they got something right.

""""They put the fox snakes into a branch with the pits.""""

When I find one, I'm going to lifelist it as Scotophis! I'm unsure where I'm going to place it on the p-tree

""""They put Bogertophis into a branch with the king snakes and their kin.""""

Too funny.......from what I can tell, the "new" field of molecular work is a lot like the not so new field of statistics.......you can make it look like anything you want it to......Burbrink seems to have employed that fact, and harnessed it as a means to making his name known! It doesn't help that he is given honorary membership in a rat snake society

Shane

-----
Lifelist

>>Too funny.......from what I can tell, the "new" field of molecular work is a lot like the not so new field of statistics.......you can make it look like anything you want it to......

Shane:
Your analogy to statistics seems a good one. There's alot of room for error in the analyses.

This particular study is dealing with a pretty large number of species distributed over both hemispheres of the planet. I'm guessing that alot more data (more specimens of each species, more genes) and a little more time for reflection might help.

The assignment that I find oddest is the placement of frenata and prasina. Utiger recently placed them in Gonyosoma with a very high level of confidence. If you look at this grouping morphologically it seems pretty much self evident. They are as alike as could be. Burbrink removed them from Elaphe (which is fine) but assigned them to a wholly new genus of their own. So Burbrink is not using Utiger's data. Possibly his study was done before Utiger's data was available and he didn't want to go back and look at it. I guess that's alright. But it leads me to think that this ratsnake work is far from over. Which I guess is fine. It's like waiting for the next installment of a very long, very confusing adventure series.

Best regards
John