Reptile & Amphibian Forums

This post is a response to Matt Campbell in the strand that’s buried far below now. Follow the link to see that post.

As far as color goes, it could (and probably is) an adaptation to the environment and the behavior of the snake. For instance, consider snakes that are green and their behavior of using camouflage to blend in with their environment. For “blue”, let’s take a look at another snake that is blue, the blue racer of America, Coluber constrictor foxi….

This racer even has the black stripe through the eye that the blue beauty has. This is an example of parallel evolution and I would speculate that the blue color has to do with the behavior of these snakes. Although I’ve never seen a blue beauty in the wild, I’ve seen lots of blue racers at home in Michigan. The racers tend to live in open areas and remain in rodent burrows most of the time. When active they will forage in open areas, such as short grass habitat, and when seeking refuge will go down the nearest hole. Thus, I would theorize that blue beauties have similar behaviors and live in similar habitats.

Actually, I have lived near blue beauty habitat, although I’ve not seen one in the wild. I was stationed in s. Thailand for a year and a half, and the blue's range includes central and northern Thailand. I know that n. Thailand is mostly forested, but there are also vast areas that are savanna-like. I suspect that the snake utilizes open areas in otherwise forested regions, as much as they can. I know they can climb too, but I don’t think they incorporate that as much as, say, the Taiwan beauty.

As far as Vietnam goes, the “blues” actually only enter the western part of North Vietnam, and we’re not even positive of that. The yunnanensis ssps. occupies the central montane area, and mocquardi occupies the eastern plains which connects with s. China. The blue beauty may occupy parts of w. N. Vietnam, but nobody actually goes there, or has observed them there. It is an extremely inaccessible region. We call the “blues”, Vietnamese blue beauties, probably because they are exported from Vietnam, and that may be all we know about them. However, the name seems to have stuck, and now we associate “blue beauty” with those nine ft. monsters that have the blue color.

I think it’s cool that we have this morph and we should produce it in the hobby, but we definitely need more info on where they come from, and what the range of the taeniura ssps. is. We should also realise that there is going to be some natural variation in the ssps. Remember, also, that Schulz’ original three specimens came from Burma and Thailand, none from Vietnam. We need some professional to reevaluate this ssps. and officially describe it. I almost want to get this ssps. Just so I could do some research on it. Breeders should keep as good of records as they can, such as colors, scale counts, and size, not to mention behaviors. Also, try to get locality info, if you can. Hopefully, we’ll gradually gain some very good knowledge of this ssps. and make it a permanent addition to the hobby.

TC

Blue Beauty Strand

Hi Terry,

Great post. The blue coloring makes that snake very striking.

I do want to point out that your examples of similar coloring in animals that fill a similar niche are examples of convergent and not parallel evolution since these colorings can be associated with a particular environment or lifestyle. The stripe that you note across the eye area helps to hide the eye and better camouflage the predator from its prey.

In general, you made some very good observations and points in your post.

Rick
Link to paper dealing with Parallel Evolution

Thanks, Rick. I appreciate your comments. But I'll tell you why I called the example parallel evolution. Chris Mattison, in his book, Snakes of the World, 1986, gives several examples of parallel evolution, such as the green tree boa and the green tree python, the sidewinder (Cerastes cerastes) of African deserts and the sidewinder (Crotalus cerastes) of American deserts. He says, "In these and in other examples, the snakes concerned not only look like one another but also behave in a similar fashion." I'm not saying you're wrong and I'm willing to learn, but it sounds like Mattison would have to be wrong too.

TC

I think that your author has it wrong. If you look at the link I gave you and note its orgin, I think that you will agree that those folks are much more likely to be correct in their use of the scientific terms. Duke is a very good school, and those folks were Ph D's in biology. I don't know anything about your author.

I have a B.S. in biology myself, and I remember the terms from some of my readings. But that does not make me an expert in the field. Read the link and take it for what it is worth.

Convergent evolution, or convergence, requires the traits in question to be analagous, not homologous in the two different groups.

Now what trait are we talking about here? The skin color or the stripe through the eye?

Certainly the skin and mostly likely the genes controlling coloration are homologous structures in any type of snake. In other words, the "blue skin" genes in distanly related groups of snakes are likely homologues.

However, there might be important regulatory genes controlling the distribution, pattern, etc. of different colors in different snakes that are analogues.

I think it gets a bit tricky in these situations to uncouple convergent evolution from parallel evolution. In fact I think determining convergence from parallelism get's more difficult the more closely two species are related and the less discreet the traits in question are.

This example (whichever it is) is not as straightforward as comparing bat wings to mosquito wings (an example of convergent evolution).

For the record, I also only have a BS in Biology.
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1.1 Gonyosoma oxycephala - (Silver/Yellow)

3.4 Gonyosoma oxycephala - (Green)

2.1 Gonyosoma janseni - (Black)

Chris, probably not the best example of parallelism, but I've been thinking about convergence and that doesn't seem to fit either.

I can't remember any examples of convergence comparing snakes to other snakes, but then I'm not very knowledgeable about this term. Your post helps. I was looking at the "blue" color and the behaviors in their habitat, mostly, trying to show a relationship there. The eye stripe was incidental. I think the fact that the snakes are fairly, closely related makes a difference here. I'll work on it some more later.

Work calls...

TC

I do not have a BS in Biology...I do have a netonate "Blue Racer". You guys are making me most anxious to see what it will grow into.

Fascinating discussion as I have both cerastes. The only real differences in behavior I have oberved is that the Sidewinder likes to hide in the sand a lot less than the Cerastes c. (and then theres the rattle...

Frank
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"The luxury of not getting involved departed with the last lifeboat Skipper..."

Hey, Frank. Thanks. Wish ya luck with that racer. I actually kept one once and put a small milksnake in with it while I fixed a cage for it and, bam! The milk was gone. Just a little warning there

Cerastes cerastes has nasty venon, I hear. As far as Crotalus cerastes goes, it had the rattle before it adapted to the desert, and I guess it decided to keep the rattle..haha.

TC

>>I do not have a BS in Biology...I do have a netonate "Blue Racer". You guys are making me most anxious to see what it will grow into.
>>
>>Fascinating discussion as I have both cerastes. The only real differences in behavior I have oberved is that the Sidewinder likes to hide in the sand a lot less than the Cerastes c. (and then theres the rattle...
>>
>>Frank
>>-----
>>"The luxury of not getting involved departed with the last lifeboat Skipper..."

Hi Terry,

I got a chance to look it up, and parallel evolution refers to similarities caused by similar forces in related biological creatures. Such as in this case, snakes. In convergent evolution, unrelated biological creatures developed similar forms due to similar forces, such as wings in birds and bats.

I was wrong and apologize for any misunderstanding that I might have caused the group in the meaning and use of these terms.

Rick

Rick, no problemo.

I've learned a lot from this strand and that's probably the main reason I get on here, that and to talk about my snakes, and also because I get bored with the ordinary eveyday things. Feel free to chime in anytime you think you can add, correct, or maintain a good strand. Actually, I shouldn't have been so sure about it, and should have considered there could be other reasons. I'm grateful I'm accepted with all the mistakes I make

TC

In some cases determining convergence from parallelism may be difficult. The Green Tree Python and Emerald Tree Boa example is the one most often put forth for convergence. But in all the pet-trade books they discuss this phenotype as a single trait. But in actuality, is it really fair to say green coloration, the similar looping of coils, and all the other similarities form one trait (let's call it the green arboreal Boid condition).

Maybe the green coloration evolved in parallel, but some of the other similarities are examples of convergence.

I believe the enlarged, grooved teeth in many rear-fanged snakes is an example of convergence as this condition has several independent origins in snakes.

In other words opistoglyph condistion is homoplasic.

Homoplasic traits are a bit different from analagous traits. I believe homoplasic traits can evolve from pre-exisisting traits that evoloved in parallel (snake teeth in this example) but are homoplasic because the trait had more than one origin.

I should probably stop here before I get in over my head
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1.1 Gonyosoma oxycephala - (Silver/Yellow)

3.4 Gonyosoma oxycephala - (Green)

2.1 Gonyosoma janseni - (Black)

>>Homoplasic traits are a bit different from analagous traits. I believe homoplasic traits can evolve from pre-exisisting traits that evoloved in parallel (snake teeth in this example) but are homoplasic because the trait had more than one origin.
>>
>>I should probably stop here before I get in over my head

Upon further review I do think the above paragraph is incorrect. I did some reading online and it sounds as if analagous traits and homoplasic traits are generally considered synonyms.

I'll try to look into this further and repost.

Regardless, my exampled of rear-fanged dentition still seems to be a clear example of convergence in snakes.
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1.1 Gonyosoma oxycephala - (Silver/Yellow)

3.4 Gonyosoma oxycephala - (Green)

2.1 Gonyosoma janseni - (Black)

Chris, we're gettin in pretty deep here now. I think the green color in the python/boa is parallel evolution, because the snakes probably evolved the coloration in the tropical rainforest habitat. The snakes are in different subfamilies, but I think both boa and python are predisposed to certain behaviors, like the arboreal condition. Really cool snakes too. Some of the other character traits may be examples of convergent evolution. I need to think more on this, but have to go back to work now. It's a long night here at school.

PS: I know we're going to get started on opisthoglyphous snakes, then I'm really going to get pumped up. We'll probably need a new strand for that..haha.

Later...TC.

An informative post! There really isn't too much else that I can add to it, unless someone out there wants to fund a trip for me to do the research myself, which would be a dream come true!

I never thought of relating the color of the blue racer, which was a reality I've somehow missed in all my studies. Makes me wish blue racers got 8' long and were as prolific rodent eaters as the beauties are...lol

I'll definately do what I can to help inform everyone any way that I can. Information collection shall begin imediately, and I'll be back with whatever I come up with.
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Conrad
Too Fast Reptiles
www.toofastreptiles.bravehost.com

Thanks. That's why I know an 8 or 9 footer is so huge, because a 6 ft. blue racer is a big snake and can eat just about anything it wants.

I wish I could go too. Actually, a trip to N. Vietnam is a possibility these days, if you can afford it, because they do eco-tours there now. But even the native people rarely go into some of the western areas. The snakes of North and South Vietnam are way awesome.

I appreciate your offer to get some data on the blues. I'll look forward to it.

TC

My girlfriend is from Saigon. She's a dentist and plans to go back and do dental work in some of the rural areas. Hopefully I'll get to go and have the local kids help me track down some of the different snakes.
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1.1 Gonyosoma oxycephala - (Silver/Yellow)

3.4 Gonyosoma oxycephala - (Green)

2.1 Gonyosoma janseni - (Black)

That's real interesting, Chris. Let us know if you ever make that trip, so we can stay in touch. South Vietnam has some of the most interesting snakes in the world. It is a hotbed of primitive colubrids and has many other families represented there too. Later...TC.

Terry,

Very interesting take on the origin of the Blue Beauty behavior and coloration. I think you're right about them being very racer-like - many people have described the various taeniura spp. as being more racer-like than ratsnake-like. I wouldn't unequivocally say that Blues are arboreal, however I think the tail is a very strong indicator, especially when you see how they employ it in vertical cages.

I do think that it's entirely possible that Blues and other taeniura spp. are opportunists and will be more arboreal as conditions and prey permit, much as we find black ratsnakes up in trees poaching nests of birds.

On that other note, I'll will get some means of posting pics here in the next few days and I'll post a picture of the setup I'm currently using for my Taiwans.

On another note - as regards this particular thread, I believe I've seen the Emerald Tree Boa/Green Tree Python similarity described as *convergent* evolution in at least one if not more of my many snake books.
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Matt Campbell
Animal Keeper, Small Mammal/Reptile House
Lincoln Park Zoo Chicago, Illinois

Assistant Curator
Wildlife Discovery Center at Elawa Farm
Lake Forest, Illinois

Hi Matt,

I also have seen the term convergence applied to the ETB/GTP "phenotype" in many snake books. But this does not make it right. As I already mentioned, this phenotype arguably consists of several different traits, not all of which necessarily evolved in a convergent or parallel manner.

Furthermore, it was not that long ago that convergent evolution and parallel evolution were taught as synonyms. And not just in snakes books, but in general science texts as well.

Parallel and convergent evolution are examples of concepts and are open to subjective interpretation over time. Heck, in herp literature alone there have been dramatic shifts in the use of the following concepts in the last 20 years:

Venomous/non-venomous, species, viviparity, ovoviviparity, ovoparity, and probably many other concepts that I could think of once my AM coffee kicks in

Us lay people tend to think of many of these "terms" as being dichotomous... either a snake is venomous or it is not, either a snake is a "live-bearer" or an "egg-layer", or two snakes are the same species or they are not.

But none of these examples are dichotomous at a conceptual level. All occur on a continuum.

Convergent and parallel evolution are no different.

At any rate, just throwing this out there for general consumption, not necessarily directed at you in full.

>>On another note - as regards this particular thread, I believe I've seen the Emerald Tree Boa/Green Tree Python similarity described as *convergent* evolution in at least one if not more of my many snake books.
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1.1 Gonyosoma oxycephala - (Silver/Yellow)

3.4 Gonyosoma oxycephala - (Green)

2.1 Gonyosoma janseni - (Black)

Turns out most of my original posts were correct. Some of the info I found on the net was a bit brief and gave me reason to think I had my terminology confused.

I guess the old adage that your first thought is the right on holds true.

I'll try to make a more detailed post tomorrow.
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1.1 Gonyosoma oxycephala - (Silver/Yellow)

3.4 Gonyosoma oxycephala - (Green)

2.1 Gonyosoma janseni - (Black)