Reptile & Amphibian Forums

The recent reclassification of North American rat snakes was done by Russian scholars based on mtDNA (mitochondria) studies. There are obvious issues with this re-classification. First, these are inherited traits, regionally influenced, that can have different results based on how many generations back one looks. Human mtDNA studies show six separate lineages out of Africa, and a diversity of lineages in Africa (a European and an Asian can be of same linage). Does this make 7, or more, species of humans? Also, mtDNA does not show physical, nucleic differences. It is obvious that a striped yellow rat is different from a black, blotch rat snake. Both, stripes and blotches are unique genetic traits, let alone the color. MtDNA is in its early stages of development and its application to evolutionary theory is hotly debated among scientific circles. Why experts so quick to reclassify the rat snakes into three geographical species when it is counter-intuitive to common sense and the eye? Its one thing to say that the similar looking gulf coast map turtles (gibbonsi, ernsti, and pulchra) are genetically different, but it does not make sense to contradict the obvious: that black rat snakes, yellow rat snakes, and everglades rat snakes are different from eachother (not to mention deckerts and gulf hammock rat snakes) by their color, stripes, blotches, tongue color, and eye color. They also breed true when bred like-types together unlike an integrade. Its time that these scientists stop trying to publish papers and make a name, and start doing common sense research. I find this study to be a sham and a marketing stunt. Your comments on this matter.

I do not have enough bio/taxonomy education to speak on this matter directly. But I did work at a college for many years. I befriended many professors at that college and a couple other colleges. Some profs seem to take pride in being able to pop out research papers at will. It seemed that getting published was far more important than instructing. I always hated that, as I was a math major and wanted to teach HS math.

Now I see that they can just take their collected info and manipulate it like a good accountant to make it look like many things. Or what they want or need to make a name for themselves. Since the masses do not truly understand what they are claiming. Just because you have "Dr" before your name, and write a paper/book, does not make it so.

It's said that people are so self serving, but why should the bio academia be any different than any other area.

I'm just glad there people smart enough to keep thing in check. Or at least make the effort. And I say thank you.
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Thanks for reading.
Big Tom

www.herpzilla.com

When Burbrink's study came out I read it. It was interesting but I wasn't convinced that the amount of genetic difference needed to proclaim difference species existed. And since there isn't anything like agreement among even academics about what differentiates a subspecies from a species (or even if there is any such thing as a subspecies) I won't feel any need to start calling anything allegheniensis. Heck I don't even bother with Pantherophis. Elaphe obsoleta is plenty accurate enough for me. And even though I feel there is probably much more validity in separating mandarins and japanese forest ratsnakes out from the rest of the ratsnakes I will definitely not get bent out of shape if someone wants to call them elaphe mandarina. I'm a hobbyist. Appearance and behavior are what I deal in. I can distinguish between south china and sichuan mandarins both by appearance and behavior. Whether they are locales or subspecies or species or just ideas that I use to describe them they have as much meaning or validity as any genetic testing does to a taxonomist.

That being said I find the studies interesting. Maybe over time the data produced will reach down to the point where it becomes useful to the hobbyist. If not then at least it satisfies my curiosity about what science can (and can't) say about the relationship between ratsnakes.

Burbrink's group did their study a few years back, so this is nothing new. What they are arguing is that they can tell from the mtDNA that there have been three groups of Rat Snakes in North America that have been geographically isolated for such a long time that one can argue that they are not that closely related to be one big species. Burbrink also argues that there is so much gene flow among the members living in one of his regions, that color alone should not be used in their classification.

Maybe in ten more years, this will be settled. As for myself, I don't have the background in this area to give an intelligent opinion in this field of biology.

I have read Burbrink's paper, and I think it would be very disrespectful to imply that this was some shotty paper written to keep his position at a university. His group did a lot of work before they published their results. One can disagree with their conclusions, but their work was good sound research.

I agree that the methods and skill of their argument is good. As a breeder and as someone who is not blind, I do not need mtDNA studies to tell that a definitive difference exists between a black rat snake from Maryland and a yellow rat snake from Florida. Now, their study is interesting in that it states that Black rat snakes from Maryland is different from Black Rat snakes from Missouri. My question is how different is a black rat snake from the east bank of the mississippi river from that of the west bank of the mississippi river? The snakes do swim and do cross the river. How does one define the zones that east, central, and west break down into different subspecies? Also, does and east mississippi riverbank black rat snake more different from a west mississippi river bank black ratsnake compared to the difference between black rat snakes and grey or texas rat snakes?

These PH.ds write a paper making a recommendation without even observing with their own eye common sense distinctions. Are they blind or just stupid? Maybe they think that rat snakes dont climb mountains or swim across rivers.

The problem is some breeders, scientist, conservationist, governments, will take their work as gospel and start mixing black with yellow, everglades with greys, etc. Instead of researching whether deckerts or gulf hammocks are truely distinct, they will be mixing truly distinct forms of rat snakes. I've seen this already begin to occurr.

There are hundreds of ways to define a species. The biological species concept is thought to be the most popular. But there will always be arguments between if something deserves to be a distinct species or not, even buy those that define a species the same way. Burbinks paper simply states his idea on the evolutionary relationships of north american ratsnakes of the obseletus group. He uses mtDNA to back up his main thesis because mtDNA eliminates such biases as color distinction and other characteristics. This is a widely excepted technique mainly because mitochondrial DNA does not undergo recombination as only the female contributes mitochondria to offspring. This is unlike the high amount of variability foung in nuclear DNA due to the high amounts of mutation and recombination. Because of this mtDNA is more precice in determining evolutionary relationships.

This paper however has not been as readily accepted as others that have suggested the change to Pantherophis. This is actually bad news for reptile enthusists. As more states move to regulate the keeping of native fauna, a distinction between two distinct populations would be a nice thing. For example, If NY decides that they want to make keeping native reptiles illegal, then all rat snakes from the black to the texas and evergledes would be illegal. However if the everglades and the texas rats are both distinct species then that would leave them legal to keep in the state.