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RE: "Canebreak" name
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by earthguy on April 8, 2005
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Taxonomy is a strange field. Currently, the general understanding is that there is no subspecies of Crotalus horridus. That will probably stand until someone thinks to PCR the Cro DNA and they find a unique locus. They will then write a paper to get the herpetological community to accept their idea as the best. It all depends on whether you're a "lumper" or a "divider". Actually, now it's more about publishing than anything else. Come to think of it, PCRing Cro DNA sounds like a good idea...
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RE: "Canebreak" name
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by Snakeman1982 on April 8, 2005
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I have been defined as a "splitter". My first reaction to the Clark et. al. paper was that since there is more variation between east and west than north and south was... "well why don't we make 4 or more subspecies" lol.
But after working with Timber rattlesnakes all last summer at the University of Arkansas and seeing drastic color variation in a small population in the Ozarks I would have to be against it. I am sure that there isn't an actual drastic evolutionary divergence in the Ozarks, just color variation.
Hey Thomas, have you heard any new updates on the phylocode talk. I haven't noticed any articles by Kevin de Queiroz lately. I don't want to miss anything.
Thanks,
Robert
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RE: "Canebreak" name
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by Nightflight99 on April 8, 2005
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One important thing to keep in mind is the fact that Crotalus horridus is a polymorphic species, with a significant amount of phenotypic variation throughout its range. The traits that were traditionally used to distinguish the northern form from the southern form ("atricaudatus") were entirely based on differences in size, scalation and coloration - all morphological traits. While such traits may provide you with a hypothesis, they do not provide evidence of evolutionary significant units.
From a practical standpoint, specimens of two populations looking similar or distinct do not provide evidence for them being two distinct or a single species, polytypic or otherwise. Instead, this provides an idea that can then be tested using a variety of characters.
Robert,
I haven't seen any updates on the PhyloCode recently. How was Bolivia?
~TE
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RE: "Canebreak" name
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by sceniccityreptiles on April 8, 2005
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Dr Gordon will be publishing research soon in which he will prove the cane should be it’s own species, not just a sub. He will also break the cotton into 3 different species. This is such a tricky matter. Who is really to say there is no more canebrake? At one time every said there was. Then, someone said there shouldn’t be…but it depends on who you talk to. Gordon is as well respected as any researcher and he says there is. NC says there is no cane, however, VA says there is. In the state of VA you can legally keep a Timber, but you can not keep a canebrake. So, they are either way behind the times, or they are on the cutting edge of the new research…not really sure which. Ha ha.
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RE: "Canebreak" name
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by AquaHerp on April 8, 2005
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In my days of working with horridus I saw so many color variations and patterns that I never knew what literature to trust. There were so many papers flying around (and still are) on color variations, scalation, sex determination based on post-orbital striping, and so on. LOL...I finally tossed it all aside for a while and focused on the matter at hand until I had enough knowledge about the subject to wade through all the BS and start to get a clear picture of this animal.
As far as making the canebrake its own full species one day...lol..I'm convinced that by the time this new breed of young publishing “keyboard ecologists” are done with their DNA work that each and every individual reptile will be its own species so that each one of them can make a name for themselves. (hmmm, did that sound sarcastic?)
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RE: "Canebrake" name
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by Buzztail1 on April 8, 2005
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Chuck,
"NC says there is no cane, however, VA says there is. In the state of VA you can legally keep a Timber, but you can not keep a canebrake. So, they are either way behind the times, or they are on the cutting edge of the new research…not really sure which."
As with any lawmaking body, the states of Virginia and North Carolina (and any other state) are way behind the "cutting edge" of taxonomic literature. They make their laws based on whatever the current literature accepts. Updating those laws to keep up with the capricious nature of taxonomy is not worth the money it would take to do it. So they make their laws and let the poor F & G (DNR or whatever) guys have to figure out how to enforce it in the field.
Karl
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RE: "Canebrake" name
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by Snakeman1982 on April 10, 2005
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Hey Chuck,
Who is Dr. Gordon and how is he planning to do this? If he were that closely related to herpetological taxonomy I would think I would have heard of him and I can't think of any herpetologists by that name but maybe I am just not thinking correctly after my Tecate binge this weekend.
Be careful with the word "prove". Scientists generally don't prove things, especially when it comes to macroevolutionary lineages since none of us were there to see it happen. Scientists come up with hypotheses and then design an expert to either reject or fail to reject their null hypothesis, but rarely ever prove things. Don't forget that the thought of the earth revolving around the sun is still a theory (heliocentric theory), as are most scientific issues. We may be 99.9% sure about something but we accept our infancy of knowledge and can not be so conceded as to believe anything 100% even when we are near certain. So heliocentric theory regardless of how accepted is neither a fact nor has it been proven. So "prove" is a very strong word not to be used lightly.
The other issue is how do you define what a species is? It is sad that in this day and age there is no set way of defining one of the most important scientific questions, "What is a species?". The biological species concept, thought of by the recently departed Dr. Ernst Mayr, was one of the most revolutionary tests for defining species yet it probably worked on fewer than a third of the organisms on the planet, lol. Sexual reproduction among two individuals that produce viable offspring makes them a species. Simple enough, except it doesn't take into account asexual species, plant species, fungi, slime molds, and tons of other examples. How do you classify species of plants that have been geographically isolated from one another for thousands of years morphologically different but can still produce viable offspring through reproduction of gametes? What about plant species that can successfully breed but pollinate at different seasons, or distribute seeds at different times of day (nocturnal/diurnal), or plants that have different pollinating vectors, like two different species of insects? Each of these are issues plant systematists have encountered where they can't use this species concept.
Today we have many more species concepts (ex: evolutionary species concept, ecological species concept, phylogenetic species concepts, morphological, and a bunch of others) each one presenting their many problems and conflicts. There are even diverging views within the concepts (ex: phylogenetic species concepts has pheneticists and cladists that argue constantly about how to group organisms). So currently there are a lot of complications with taxonomy which always seem to come up with more question than answers. (exciting!!!)
Chuck said - "Who is really to say there is no more canebrake? At one time every said there was. Then, someone said there shouldn’t be…but it depends on who you talk to."
Academics that are up to date on current research and experiment on ideas, theories, and who have data to say otherwise can say there are no canebrakes! I may personally choose to say that atricaudatus is a valid subspecies but that wouldn't mean people should listen to me or that I have experimentally supported evidence for my decision. I have worked with timber rattlesnakes in the lab and at one field site and did physiological ecology studies on timber rattlesnakes which had pretty much nothing to do with their taxonomy. So I am obviously not an authority on the taxonomy issue of timber rattlesnakes, but someone is. Too many people not associated with the research voice their opinions instead of using scientific facts or supported conclusions to make assumptions on scientific issues. Someone did the research and knows a lot more about that subject than I do and I respect their findings and trust they did it correctly to the best of their abilities. And when things are published in "peer-reviewed" scientific journals they have usually earned the right to be taken seriously. Maybe someone will publish a paper that supports evidence that they are seperate species, that is what makes science exciting, trying to find facts that maybe weren't known before. But asking random people, even scientists, rarely gets you rock solid data to make decisions on.
For example, everyone said the Earth was flat. Seems very logical! When I go to sleep on the ground I don't have to put rocks on either side of me to keep from rolling around to other counties and stuff, it must be flat right? Aristotle's grouping of higher and lower organism classification is not even close to the system we use now.
"Giraffes are tall because they have to eat leaves high up in the trees!" Very logical explanation and accepted for like a century and remained untested. Then someone tested the theory and realized that it wasn't true. If that were the case giraffes would get most of their leaves from the tops of trees. Turns out that they don't and having a long neck actually gets in the way of their feeding at their normal levels and drinking water. So why have a long neck? A tested hypothesis actually showed it had to do with male to male combat. Males with longer and larger necks were able to fight off one another more affectively (because they use their head as a weapon against each other to defend territories and rites to females) and the long necked giraffes have an advantage for passing on their long neck genes. So just because we think something and accept it for years doesn't make it fact. The more we know the more we realize that are parents were fools, lol.
I plan on studying snake morphology for most of my career and am completely fascinated by it but it has limited use as well. One of the first examples that people come up with to "prove" the atricaudatus subspecies conflict is that canebrakes are longer or larger than timbers. That has little or no relevance to evolutionary divergence. Dogs are one of the best examples of why you can't depend solely on morphology alone. There are so many different breeds of dogs in the world with drastic morphological features that if we landed on earth today and saw all these different breeds on the planet isolated in different regions, we would surely classify them as seperate species. Some are unable to breed due to morphology in size though their gametes will produce viable offspring. But just looking at them from a structural stand point they are completely different. So just looking at a canebrake in the wild and saying it is longer than a timber or something like that proves nothing. Climate, geography, predator/prey relations, genetics, etc... all play a major role in how a snake develops and adapts. Take a neonate timber rattlesnake from the northern states and put in it the same conditions as a canebrake of Georgia and notice their growth should be very similar. Energy allocation plays a great deal of influence on how a snake uses its energy to grow longer, wider, reproduce, hunt, etc... A timber rattlesnake in a warmer climate generally uses its energy differently and will grow longer and thinner than a timber in cooler climates. They also have more reproductive seasons and may have greater success in finding food. So size is not as important as many may believe. There are too many aspects of biology to use assumptions and not account for other variables.
I saw a 30-something year old man yesterday that was about 5 foot tall, black hair, and had male patterned baldness. I have brownish/blonde hair, not balding, and am about a foot taller than him. Although we are phenotypically drastically different are we so genetically different that I am a different species? Different genetics, environmental conditions, and many other factors play a big role but I doubt our evolutionary lineages were very far apart from one another.
Sorry if this seems like an attack on you because it isn't meant to be. A lot of my statements are hypothetical and have little or nothing to do with you. I am actually talking to everyone not you. I am just stating comments and ideas I have on the issue including things that had little to do with your comment. You very well may know a lot of this stuff so I don't mean to act like you don't.
Robert Jadin
p.s. - Thomas, Bolivia was so beautiful. I had the time of my life and loved every minute of the month I was there. I always miss the tropics! Got a few photos up from the trip at http://snakeman1982.com/Bolivia%20(Winter%202004).asp
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RE: "Canebrake" name
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by Cro on April 10, 2005
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Robert: While I generally agree with your statement: "Someone did the research and knows a lot more about that subject than I do and I respect their findings and trust they did it correctly to the best of their abilities. And when things are published in "peer-reviewed" scientific journals they have usually earned the right to be taken seriously", I have to relate a story of something I observed a few years ago.
Some well known researchers from UGA were doing a study of the animals and plants of the Okefenokee Swamp, in SE Georgia. The idea was to update for the Dept. of Natural Resources all the fauna of the swamp. Well, these researchers sent a bunch of grad students to the swamp to gather data. From my observations, the grad students would load a cooler of beer into a boat at 10:00 am, and motor out into the swamp. They would park in the shade and write down their observations and consume the beer. After a few hours they would return with their research. This resulted in a list of swamp animals and plants that the DNR used. It was published in peer review journals where it still exists unchallenged. The only problem is that the folks did not observe the wildlife and plants for 18 out of 24 hours a day. They did not observe wildlife out in the bright sun, as it was too hot. They did not observe wildlife at night as it was too dark, or scarry, or mosquito infested.
Anyway, the research folks published their data, even though they were not at the swamp to observe it, and the DNR used the data. No one questioned it.
So, I guess what I am trying to say is that just because someone publishes in Peer-reviewed scientific journals, it does not allways mean anything.
Best Regards
JohnZ
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RE: "Canebrake" name
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by Snakeman1982 on April 10, 2005
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You are absolutely right John,
Many scientists whether by negligence or simple accidents can and will make mistakes. Often times experiments are performed to the best of their abilities and then some new technique, method, or knowledge arrives that causes someone else to question the results and repeat their experiment better and with more accuracy than a previous researcher. The reason there are materials and methods sections on scientific papers is so that other scientists can replicate the same experiment or use the same specimens on their own time and see what they can get as results. Scientists should always have their work looked at critically and there is nothing wrong with someone questioning your work or double checking it themselves.
Before scientists used other characters to determine that there were two subspecies of timber rattlesnake, now we have molecular evidence that says there is only one. Neither experiment was bad but new technologies cause us to challenge and question what we know. Maybe new evidence will show there are two or more. Science can have fluidity at times.
I don't have problems with someone drinking during a section of their experiment as long as they monitor how many beers they drank and kept each repeatitive section equal so that they drank equal amounts each day on the river. That way there is little variation between days and then whoever replicates their experiment will have to drink as well to see if they get the same results, lol. Just joking. Sometimes scientists, especially ecology graduate students, can be a little unprofessional. It usually isn't that big of a deal but if you are actually publishing anytype of big data then it may harmful to your study.
Good point,
Robert
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RE: "Canebrake" name
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by Cro on April 10, 2005
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Robert: They were really unprofessional, as they were drinking Bud, and Malt Liquour. LOL ! Now if it had been Tecate, or Corona, or Dos, or Presidente, that would have been different, and the results repeatable, LOL ! JohnZ
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