Reptile & Amphibian Forums

This may seem dumb, but is it possible that many of the snakes we keep evolved from thayeri? i mean look at how diverse they are... i certainly see the potential,

any thoughts?

~ZF
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Royal Blue ReptileZ
Home of Bklyn's Finest Brooksi

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I'd be interested in knowing what the taxonomists have to say - but I would personally suspect that the "father species" no longer exists, and that all populations have speciated, perhaps several times, since then.

Looks can be deceiving - the green tree python and green tree boa are extremely similar, the patterning/colour happens to be one that works well for both species so that is what nature selected in separate evolutionary paths.

One thing I don't buy is that tri-coloured kingsnakes evolved to mimic the coral snake. Often only two of the colours are the same, banding is quite different, colour order is quite different. I suspect that banding in general is a good pattern for snakes - and that both coral and some kings just happen to have red and black in their banding.

Sometimes I think we assign reasons that sound good to us, but are really just speculatory and way off the mark. Also, maybe sometimes what we think is an evolutionary ancestor is actually an old integrade zone that speciated from both contributing parent species.
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3.0 WC; 0.2 CB L. getula californiae
0.1 WC; 10 eggs (7/11) Elgaria multicarinata multicarinata

You bring up a very good point about the banding patterns of the coral snake being mimicked by other snakes. The whole group of snakes that have adapted these patterns are burrowing snakes. Well, all kings are burrowing but these guys have made it an art. So they could have developed this pattern for the rare and few times that they move location or go looking for mates. I have pueblans and when one gets out of my hand and gets to moving on the ground, man, it is hard to catch. Plus a black milk snake is banded when its small but as it goes from a soil burrower to a leaf litter/log burrower its colors go to black. But the color change of the black milk could tip to the mimic theory. As it gets 4-7 feet the patterns are not convincing to a predator anymore. I truly would love to hear from someone who can put this into perspective. Great topic.

Plus a black milk snake is banded when its small but as it goes from a soil burrower to a leaf litter/log burrower its colors go to black. But the color change of the black milk could tip to the mimic theory. As it gets 4-7 feet the patterns are not convincing to a predator anymore.

Black Milks are not black because they don't need the mimicry anymore (I don't know where I stand on the mimicry debate?). Black Milks are black because they live high in the cool cloud forests of Panama and Costa Rica where temperatures rarely get above the 60s and lower 70s. The black coloration helps them heat up quickly.
I found a roadkill in this area on a rainy night in Panama with temps in the lower 60s and upper 50s -
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The habitat was a cleared agricultural area surrounded by this cool dark cloudforest -
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Chris Harrison
San Antonio, Texas

I always like the coral snake mimic idea. The color of the patterns need not be identical, just similar enough to make a predator think twice. What I thought was more of a problem for the mimic idea was how docile corals are. The mimic idea would only work if predators were bitten, felt like death but survived and learned not to do that again.

In nature red color on an animal is a general warning sign though. Maybe it evolved so that any predator who happened to find a tricolored anything would be a little unsure of how to act, giving the snake time to get away. Combine that with how blurry a fast moving banded tricolor can be and Id say thats a nice selective advantage.

Oh yeah, as for the black milk being black. Thats OK for these theories since it is derived from tricolor ancestors and the advantages of being black (presumably for thermoregulaton) are stronger than any advantage gained from being tricolor. That means that they black ones would out compete the tricolors and come to replace them.

Best,
Vinny
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“There is a grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that whilst this planet has gone on cycling according to the fixed laws of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.” -C. Darwin, 1859

Natural Selection Reptiles

I don't see how a species of snake could change pattern to mimic another species. How does the snake actually do this. Does it actually think about it. Or over thousands of years, do all the snakes from this species think about changing their colors? And how does this species of snakes know that the coral snake or whatever is even poisonous. It does'nt make sense to me. But seems to be a widely accepted theory. Someone please tell me how this works. mike

Hopefully this will help clear things up for you.

First of all, nothing can think itself into a new pattern. I cant will myself or my offspring to have blue eyes.

It happens like this: a snake, like the ancestor of all tricolor kings living today (which need not be tricolor at the time), happen to live in the same range as corals. The corals have a particular color pattern of alternating red/black/white bands, when attacked these red/black/white banded snakes fight back and bite their attackors. Predators learn to avoid these mean red/black/white banded snakes. The predator can eat the ancestor of the kings though, which look different and dont bite. So they eat them, thats not good if you are getting eaten. A mutation comes along in a king snake that gives it some kind of pattern that is similar to the coral snake, it might be very different at first. Maybe just some red mixed in thier pattern. But its enough that predators sometimes avoid it because they confuse it with the coral, and snakes with this mutation live longer and reproduce more offspring than snakes with out this mutation. So after a while there are lots and lots of kings with the mutation, they dont look a whole lot like corals though, so there is room for improvement in the mimicry. But, they do outlast other kings so they have an advantage over them.

Another mutation comes along and makes the pattern even more similar to the coral snake, now snakes carrying mutation2 look more like corals than snakes with mutation1. So now mutation2 snakes leave more offspring than mutation one snakes because mutation2 snakes are prey upon less often than mutation1 snakes. After a while the whole population of kings will look like mutation2 because snakes with that pattern outcompeted snakes with pattern mutation1. They look more like corals now, but not totally so there is room for improvement in the mimicry.

Then mutation3 happens to start the cycle all over again. After many thousands of years of improvement by selection you get a snake that has a patten very very similar to the coral snake. It need not be the same, just close enough that predators are confused for long enough for some snakes to escape and reproduce (more often then those with out the mimic pattern).

hope that helps,
Vinny
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“There is a grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that whilst this planet has gone on cycling according to the fixed laws of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.” -C. Darwin, 1859

Natural Selection Reptiles

One step further, Why do some South American corals have reverse patters, kinda like the kings and milks? One more step or did the ones here do the steppin'? Why would they have the opposite banding coloration than the North American corals?
Todd Hughes

>> Why do some South American corals have reverse patters, kinda like the kings and milks?

Cool, didn't know there were any like that (I did know that there were some that lacked black bands)

>>One more step or did the ones here do the steppin'? Why would they have the opposite banding coloration than the North American corals?

I am not sure why they have opposite patterns. Thing is not every thing in nature has an adaptive explanation, some traits may not have any effect on fitness (meaning the number of offspring left behind) so random chance determines if they spread through the population or are weeded out. So it could be that once a predator instincitvely avoids black/red/white banded things the actual ordering of those colors might be irrelevant. Simply the presence of those colors might trigger the oh yeah dont eat that response.

And this all depends on whether you beleive the mimicry idea. I dont know of any studies that explicitly test it. (like covering up the bands with paint and seeing if predators attack, or changing the ordering of the bands with paint and seeing how predators respond. Would be cool to do though.

Best,
Vinny

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“There is a grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that whilst this planet has gone on cycling according to the fixed laws of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.” -C. Darwin, 1859

Natural Selection Reptiles

Seems it's never mentioned that the best defense would be effective in multiple ways. I think the tri-color pattern is effective in a cryptic way and as mimicry. It is often said that if an animal dies how does it live to pass on it's knowledge. I don't think an animal bitten by a coral always has to live because many predators hunt in groups, crows, ravens, wolves, etc. and many animals also teach thier young to hunt, ie. cat family. There are many scenarios in which a predator can observe another die, allowing the knowledge to become ingrained.

I would'nt say thayeri are ancestors of getula. Maybe alterna are descendents of thayeri and maybe so closly related that they may be the same. Now i only said maybe,and i'm only being hypothetical again. I would like to hear a qualified experts opinion about this.

I’m far from an expert on the subject; however I’ve read the paper published in 1982 by the Museum of Comparative Zoology, Harvard; study presented by a gentleman by the name of Bill Garstka that talks about this stuff. The title of the paper is: SYSTEMATICS OF THE MEXICANA SPECIES GROUP OF THE COLUBRID GENUS LAMPROPELTIS, WITH AN HYPOTHESIS MIMICRY. Pretty interesting stuff to read, you should check it out. E-mail me if you need to get your hands on a copy.

It’s a comparative study that deals primarily with what was then considered the “mexicana group” and their relationships. The “mexicana group” then consisting of three distinct species being L. alterna (which included L. alterna and L. blairi), L. mexicana (which included L. mexicana, L. thayeri, L. greeri and L. leonis), and L. ruthveni. It suggests that the species group L. mexicana is a primitive relative to L. alterna, although alterna being quite distinguishable by it’s silver-gray iris color and skull shape and that L. alterna is considered the most derived species in the “mexicana group“. I’m sure you know that many now consider alterna as being completely removed from the “mexicana group”. It also talks about relationships to, and how the study involved many subspecies of L. triangulum (L.t. nelsoni, L.t. arcifera, L.t. celaenops, L.t. annulata…), L. pyromelana, L. zonata…..

It also talks about how different vertebral structure is in triangulum as compared to mexicana and alterna. It also mentions that L. getulus and L. calligaster are even more significantly different than any triangulum, alterna or mexicana, and that getulus and calligaster more closely resemble Elaphe in hemipenial and vertebral structure.

Mimicry is also discussed towards the end of the report. Check it out!
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Mike

Thanks Mike i've been lookin that paper for a long time.
please check your email.

That has some good info on the relationship of the kingsnakes inside.

http://complabs.nevada.edu/~brysonjr/pdf files/webbi.pdf

Thanks Mike. That's the paper on the newly described species L. webbi, everyone interested in Mexican kingsnakes should save a copy of this also. When I first heard of this new species being described I was excited to read this and see that extensive DNA studies are being done to attempt to provide a clearer picture of how the puzzle fits together down there. Interesting stuff... looking forward to more newly published information coming our way at some point soon.
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Mike

Here is a paper about the evolution of lampropeltinine snakes based on mitochondrial DNA samples. Seems to indicate that the "mother" of all lampropeltinine snakes came from the Mexican plateau. You almost have to be a scientisit to understand this thing, but it's a good read.
Molecular systematics of New World lampropeltinine snakes.

Another really interesting aspect of this paper is that it seems to say that the Short Tailed Snake (stilosoma extenuatum) belongs in the lampropeltis group. It seems more closely related to getula than mexicana, zonata, and pyromelana are.

:Mark
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Surrender Dorothy!

www.crimsonking.funtigo.com

np

...much more slender and generally less than 2'. The one in the pic was a fair sized Stilosoma and he was definitely less than 24" and pencil thin. How Nick spotted it is beyond me.
:Mark
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Surrender Dorothy!

www.crimsonking.funtigo.com

Any other good links for an information hound?!!!
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Mike

That's an interesting read but I have two questions about their samples....

Why use two samples of zonata (small range) and only one of getula (huge range). Surely adding a more widespread sampling of getula would add information to the phylogeny.

Why not alterna, ruthveni or triangulum (!). I don't think you can look too deeply at the phylogeny of Lampropeltines without including these taxa. Locality tissue samples would have been readily available for at least alterna and triangulum. How could you leave off the most wide ranging species (?) in the genus?

It does leave some issues about the validity of Stilosoma within the current Lampropeltine construct, but more data are needed (and coming).
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Chris Harrison
San Antonio, Texas

I was suprised to see that there were no samples from triangulum, and so few from other species. I would like to see a similair, narrower study done just on lampropeltis, or just on triangulum. The authors of this paper, along with Rick Staub, also did a mitochondrial DNA study of zonata. I have links to that paper as well if anyone is interested. It calls the current sub-species into question, and shows interesting pattens in the gene flow.

Is that the UC Berkeley study on Zonata?

I know UC Berkeley calls into question the current subspecies designations. I haven't read the paper because it costs money to do so, and I will just wait for the field guides to reflect it.

I believe they concluded one species of zonata has actually speciated from zonata (Lampropeltis zonata herrerae) and should be considered to be its own species.
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3.0 WC; 0.2 CB L. getula californiae
0.1 WC; 10 eggs (7/11) Elgaria multicarinata multicarinata

Yes, it's the Berkely study. Here it is free.
Phylogeography of the California Mtn. Kingsnake