…and this is a 
Look at the interesting snake found in China — it's got a leg.
How can this happen? Genes are pleiotropic — they tend to have lots of different functions. The genes involved in making a limb are also expressed in other places; for instance, the Hox genes that specify identity along the length of the body are also reused in specifying identity along the length of the limb. What that means is that when the snake evolved limblessness, it didn't do so by simply throwing away a collection of leg genes — it couldn't, not without also destroying genes that functioned in generating its body plan. Instead, it evolved genes or modified the regulation of genes to actively suppress limb development…but the genes to build a limb are still in the genome, and still functional, and still actively working in other ways.
What most likely happened here is that some environmental agent suppressed the suppressor, allowing the old developmental program for a limb to be re-expressed. The retention of such programs is, of course, evidence that this animal evolved from limbed ancestors.
It would be interesting to know what triggered this change. It's not likely to be genetic (the asymmetry suggests that), but is probably a consequence of some pollutants that disrupt development. It's not a good sign, anyway.
Some good suggestions from the comments: it may not even be a teratogenic deformity. It could just be a poor lizard that punched a claw through the abdominal wall as it was being digested, and the snake was briefly trundling about in pain from the injury.
We need to do a dissection!
Life Science
Comments
Posted by: mokele
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September 16, 2009 10:03 AM
It's not pleiotropy, it's dinner.
The "leg" is nowhere *near* the vestigial legs present in some snakes.
This snake does not have vestigial limbs - it's a colubrid, and they've all lost even the vestiges.
The limb erupts from a swollen portion of the snake which is in the correct location for the stomach.
The limb is obviously a lizard hindlimb - look at the pattern of toe lengths.
The limb points *backwards*, just as if it belonged to a lizard that was swallowed head-first.
Remember, snakes are very good at dealing with injuries. Large pythons have had the horns of ungulates peirce their bodywall, then healed and lived perfectly well.
This is nothing but a bit of escaped dinner. No genes involved.
Posted by: MrFire | September 16, 2009 10:04 AM
Sneer your brainless way outta this one, creobots.
Posted by: nigelTheBold, Minister of Spankings
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September 16, 2009 10:04 AM
Why, that's predicted in the Bible!
That's the serpent from the garden, that is! I bet it also talks.
Posted by: Blake Stacey
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September 16, 2009 10:04 AM
Developmental biology: the science which tells you why a snake with a leg is an even worse sign than you'd thought.
Posted by: Jerry Coyne | September 16, 2009 10:04 AM
I saw this a few days ago, but refrained from posting about it because I wasn't sure if it was real. If it is, it's a great example of a re-expression of ancestral genes. But look--the limb comes out right after a bulge--as if the snake had ingested some prey object. And the limb is simply TOO perfect: digits, claws, etc. When snakes (or whales) do show atavistic limb formation, the limbs are never this good. AND, the limb appears too far anterior, I think, for it to be vestigial (look at where python "claws" are). I doubt that genetic information for limb formation would have been preserved intact so long that it could form a limb this perfect.
I suspect that this snake ingested a lizard, and that the lizard's limb simply burst through the side of the snake. I may be wrong, and I hope so, because this is great evidence for evolution.
Posted by: The Pint | September 16, 2009 10:07 AM
Ok, I just have to say it: "Snakes! Why does it always have to be snakes??"
For a moment there, I actually thought the snake had eaten something and the limb had burst through it's skin. Seriously, this is rather disturbing. Especially if it's a result of environmental pollutants. Next thing you know, they'll be walking around and it'll turn into a bad sci-fi pulp novel. And I for one, would welcome our newly-limbed serpentine overlords.
Posted by: John | September 16, 2009 10:08 AM
In Why Evolution is True, Coyne mentioned a certain percentage of whales being born with legs. Some quick google searching hasn't come up with any images. Anyone know where to find some, or better, some papers describing it in more detail?
Posted by: Alyson Miers | September 16, 2009 10:08 AM
It is a snakeamander!
Perhaps a liznake?
Posted by: DiEb | September 16, 2009 10:11 AM
I second the escaped-diner explanation. But perhaps it has pleased god, and its crawling days are over....
Posted by: Nangleator | September 16, 2009 10:11 AM
It only grew that limb so it could give the finger to its prey before eating it. Snakes are mean.
Posted by: MrFire | September 16, 2009 10:14 AM
*whoops*
Posted by: Steven Dunlap | September 16, 2009 10:15 AM
I realize that Stephen J. Gould is not terribly popular with this crowd but I am reading his Hen's Teeth and Horses Toes presently and it's fascinating. A Russian scientists demonstrated the principle of this post when he reactivated existing genes in chickens to make hens with teeth (hence the title of the book). He introduces some other ideas that I did not know before (non-Ph.D. that I am) for which I am very grateful. Whatever else anyone care to say about him, he wrote some very good vulgarizations on the topic of evolution, which has helped me to understand some of the more detailed posts on this blog.
Posted by: ferretwrangler | September 16, 2009 10:22 AM
Ever see "Alien" ?? (Now with bunnies!)
http://angryalien.com/0704/alienbunnies.html
Poor snake literally busted his gut by eating too large of a meal.
Posted by: Alan Kellogg | September 16, 2009 10:26 AM
A lizard's leg? Where is the injury? That does not have the look of something projecting from a rent in the body wall, but of something growing from the snake itself. And how do we know with any great confidence how the snake body plan evolved over the generations?
Read the original story at the Telegraph. The woman who found it says she was awoken from sleep by scratching, and caught the animal pushing itself along a wall using the leg. The snake was using the leg.
We don't know with absolute certainty what is impossible. I don't know the mechanism behind this particular event, but it would appear that in every snake there is the potential to grow fully functional limbs. A potential not expressed under ordinary circumstances, but there none the less.
Posted by: Deepsix | September 16, 2009 10:28 AM
I agree with the first poster. The leg is protruding where the recent meal is still clearly visible.
Posted by: Jerry Coyne | September 16, 2009 10:37 AM
For John @#8:
Andrews, R. C. 1921. A remarkable case of external hind limbs in a humpback whale. Am. Museum. Novitates 9:1-6.
Believe me, these limbs are far from perfect. They don't have phalanges, though they do have a recognizable tibia and femur. I've never seen an atavistic limb that is near as perfect as this one.
I call it a fake, but remain open-minded.
Posted by: Anon | September 16, 2009 10:39 AM
Alan K--
The woman claiming this is evidence that she believes it to be the case, not that it actually is the case. It may be, of course, but the eyewitness testimony of a non-expert, and one just awoken from sleep, is not a dealbreaker.
Posted by: Martym | September 16, 2009 10:42 AM
I wish there was a better photo of it. If this is in the hands of scientists now, I hope some come out soon. It appears to have swallowed a meal, but the bulge and the leg look as though they are connected. Wouldn't there be blood if the leg protruded through the body wall? It could have been cleaned up I suppose, but I would think the body tear would be great enough (due to the claws) that some of the interior parts of the snake would now be exterior parts. The bulge is obviously part of the snake body from the scale colors, but the leg looks to have the same color. Or is the snake skin still covering the leg, like a glove? Weird.
On a side note, here in St. Louis a local hospital has been aiding a young boy born with what they call 3 arms.
Posted by: Darren Garrison | September 16, 2009 10:45 AM
I'm in the camp that there is a hole in the snake (Dear Liza, Dere Liza.) A hole in the snake (a hole.)
Posted by: Gryllus | September 16, 2009 10:46 AM
@Jerry #16 - that whale paper is fantastic! Thanks. And I second (third? Fourth? Fifth?) the lizard-dinner theory, as I have seen a bird beak sticking through the side of a small African rock python. Probably a young egret and not a noticeable wound either - it really looked like it was growing from the snake.
Posted by: susan | September 16, 2009 10:49 AM
Or Photoshop....
Posted by: ButchKitties | September 16, 2009 10:51 AM
This is probably a stupid question, but is pleiotropy the reason why our feet are the same length as our inner forearms? (If you put your heel in the crook of your elbow, your toes should end right at the base of your palm. I've yet to find a person who, once convinced to try this, has not had their feet and inner forearms match up perfectly.)
As for the snake, I reserve judgment until after the necropsy takes place.
Posted by: Brownian, Most Vicious & Petty of Pharyngulites
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September 16, 2009 10:51 AM
Photoshopz0r3d1!1!!!1
If it does turn out to be the snake's leg, I beg you all not to show this 'snakamander' to Ray Comfort. It's only going to confuse his little pea-brain, and he needs all sixteen of his ganglia working overtime to save the world from teh Darwinz.
Posted by: David | September 16, 2009 10:52 AM
And here ladies and gentlemen, we have the PERFECT example of the difference between religious nuts and science. Whereas religious nuts works backwards by starting with a belief and then outrageously twisting all facts to fit the religious belief, we see in this thread how the scientific mind works.
Even though we would love for this to be an example of evolution, we don't start with that belief and then work backwards to make the facts fit it. Instead numerous posters point out that it could just as likely be the snakes last meal, and PZ immediately modifies his post to acknowledge that could indeed be the cause.
And THAT is the difference between actually searching for the truth, versus claiming you know it (i.e. God's word blah blah blah) and then making every fact fit your "truth".
Posted by: extatyzoma | September 16, 2009 10:58 AM
as soon as i saw that i assumed it was a leg of dinner popping through.
oh dear, so if its actually a lizard popping its leg through that means evolution didnt happen, arrgghh.
Posted by: David Marjanović, OM | September 16, 2009 10:59 AM
Comment 1 is definitely right on the money.
The best evidence is the completely wrong place. If it's a hindlimb, it should be very close to the tail tip, because snake tails are very short; if it's a forelimb, it should be much closer to the head than it is. Besides, look at the dinner bulge…
Posted by: nigelTheBold, Minister of Spankings
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September 16, 2009 10:59 AM
Exactly! Science can never know anything. Only religious belief allows you to know everything. For instance, my talking-snake-from-the-garden hypothesis has yet to be refuted!*
* To avoid any accusations of Poe, this post is filled with 100% of the ADA-recommended daily allowance of irony.
Posted by: blueelm | September 16, 2009 11:02 AM
Neat I'm glad to see this on a post! It really is weird. Now that people mention it I bet it is a prodtruding leg that just happens to have a similar coloring. My old pet snake ate a mudpuppy once and a similar thing happened. Nasty as it sounds he survived it. Sadly some of my fish contrancted a disease which they passed to him and he died, but he had recovered from the mudpuppy wound long before.
Posted by: ChrisKG | September 16, 2009 11:04 AM
If it is real, I think a Creationist would claim it's just a limbless (plus one leg) lizard.
Posted by: nigelTheBold, Minister of Spankings
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September 16, 2009 11:04 AM
The eye-witness may have been correct. If dinner was not yet dead, or just recently-dead, the leg could've been twitching, giving the illusion the snake was using it for locomotion.
Posted by: Islander | September 16, 2009 11:04 AM
I may sound incredibly ignorant here, but if a lizard leg burst through the abdominal wall, would the snake's skin be so tight-fitting around the individual digits? Imagine putting your hand in a balloon and spreading your fingers; wouldn't it appear webbed? Also, if the skin was tight, wouldn't it cram the fingers together? In the photo they appear well separated. Then again, I have no idea how elastic a snake's skin is.
I still think it's dinner, I'm just curious...
Posted by: raven | September 16, 2009 11:05 AM
Not buying the lizard for dinner argument.
If it was a lizard, the lizard is dead. No immune function in the limb, no blood supply. The dead limb should have decayed like all dead things.
Plus, the limb seems to be covered with snake skin in the same color and pattern as the rest of the skin. This wouldn't be the case if a lizard limb punched through the body wall.
An X-ray would settle the matter. Need more data.
Posted by: The Pint | September 16, 2009 11:10 AM
If that image has been Photoshopped, I clearly need to spend more time playing around with that program!
I wouldn't be surprised if it turned out to be either faked or somehow the result of the snake's last meal popping out to wave "hello, would someone please GET ME THE HELL OUT OF HERE???" On the other hand, if it turns out to be an actual limb, that would be just too darned cool. But in any case, it'll really freak out the Jebus relatives when I forward them the link to that photo.
Posted by: extatyzoma | September 16, 2009 11:12 AM
that rounded mass at the base of the arm, looks like the snakes insides popping out from the 'hernia' created by the lizard arm.
what a cruel, cruel god.
Posted by: benji | September 16, 2009 11:14 AM
I hope it's real so we can claim that we have a transitional fossil for the kinds of creationists who think this is what they should look like.
Posted by: Chondrus | September 16, 2009 11:17 AM
Hurray,
we have a transitional organism! Even better than a transitional fossil.
Harun Yahya surrenders and will see the light... or maybe not.
Posted by: AndrewB | September 16, 2009 11:18 AM
I'll go with dinner as I don't see the other limb. Snakes really need to start chewing their food. Learn some manners snakes!
Posted by: Steve | September 16, 2009 11:27 AM
@David (#24):
"And THAT is the difference between actually searching for the truth, versus claiming you know it (i.e. God's word blah blah blah) and then making every fact fit your "truth"."
That's exactly the argument presented by Nicholas Humphrey in "Leaps of Faith: Science, Miracles, and the Search for Supernatural Consolation." He's mainly talking about people who believe in psychic phenomena, but it's the same concept.
Posted by: John | September 16, 2009 11:29 AM
An excellent read, just what I was looking for. Thanks!
Posted by: BlueIndependent | September 16, 2009 11:32 AM
If mokele thinks the leg is from dinner, his/her eyes apparently can't distinguish three dimensions very well. Do you have the use of both your eyes mokele? Look at how the snake is bending and contorting in the picture. That's not dinner where the leg is, it's the illusion that that's dinner because of how the snake is laying in that image. You can clearly see the twist in girth before and after the section you claim is meal time. I would also point out that the leg appears to be the same color as the snake. Snakes may have very maleable bodies in order to consume prey but their skin certainly would not account for a lizard leg protruding like that all the way down the snake's body. Also, a dead lizard being consumed to that point is unlikely to have the potential energy (say, in the hind leg as you say) enough to burst the snake open, and even if it did, the snake would bleed. No evidence of that at all. And that's assuming lizards had the sort of hindleg power frogs or other animals have, which they don't.
I would prefer a closer detail shot of the leg, but I see no indication of a post-dinner reptile here.
Posted by: Michel Poisson | September 16, 2009 11:39 AM
Upclose it really looks like a photoshop job done on a 'full stomach' snake. Outlines, texture on the limb, tints & color density differences, all suspicious. Cast-shadows inconsistencies and the improbable 'shoulder' from which the arm seems to emerge top it up.
These are my speculations, only dissection would convince me otherwise.
Posted by: dinkum | September 16, 2009 11:45 AM
Where's the link for the 3D picture you're looking at? All I got was a crummy single-lens jpeg.Posted by: Treppenwitz | September 16, 2009 11:47 AM
Is there a high-res copy of the image available?
Posted by: Evil Eye | September 16, 2009 11:48 AM
From the bulge, it looks like the snake ate a skink.... tail first.
Posted by: Traffic Demon | September 16, 2009 11:51 AM
Re: #24
Not only was the original post modified after the suggestion of another plausible explanation, but the original post was kept intact, regardless of the possibility of it being flawed. Compare that to the UD memory holes, science wins again.
Posted by: gruebait | September 16, 2009 11:53 AM
Reminds me of the images of the (dead) python in Florida, that ate a 'gator, which led to its demise. The alligator's success in breaking out from the inside made a total mess of the poor herp.
Posted by: Nova | September 16, 2009 11:53 AM
Apparently the Lord thinks snakes have been punished long enough, and is phasing limbs back in.
Posted by: Gregory Mayer | September 16, 2009 11:54 AM
It is a lizard popping through the skin. In addition to the too far anterior position noted by Jerry, note the distended belly of the snake in the region in front of and behind the leg. You can see how the snakes transverse brown bands have been separated into stacks of short brown lines separated by white space. The brown are where the scales are, the white is where the stretched interstitial skin has been exposed. I'm a herpetologist, trust me: this snake has a large meal in its belly right where the leg is. Whether it's a hoax or not is harder to tell. A snake may have burst open from the pressure of the prey item; or the snake may itself have been attacked by a predator and roughly handled, leading to the side bursting. The way it could be a hoax is if the farmer cut into the snake, and pulled out the leg; or, if having found the snake naturally burst, he pawned it off as a snake with legs knowing it was from a prey item inside.
Posted by: Andyo
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September 16, 2009 11:57 AM
Nope, you're all wrong. This whole thread is evidence that it's just one of those fossils Satan put on Earth to confuse man.
Posted by: BlueIndependent | September 16, 2009 12:04 PM
"Where's the link for the 3D picture you're looking at? All I got was a crummy single-lens jpeg."
It's not that hard to see, look at the image. You can see cleary from the orientation of the head that the snake is mostly on its side. The loop of the body directly left of the appendage is under the right "side" of the snake, which causes the main body section to bend down just left of the loop underneath, creating the effect that it's eaten something. The side orientation continues down to the right after the appendage and wraps under, creating the loop. Snakes aren't perfectly round, they can be more like rectangular rain gutters of oblong ellipses. I don't see any indication this snake has eaten anything very recently, although I can see why people would think that on first glance. The location where this snake was found would be a partial determinant of whether the appendage is indeed an eath animal, but it appears to be somewhat near human civilization if its laying on bare concrete. That doesn't prove it didn't eat a lizard, just that the possibility is potentially unlikely.
Posted by: Gregory Mayer | September 16, 2009 12:05 PM
I should add that it's not clear it's a lizard's leg (a snake leg would resemble a lizard leg), only that it's clear that the leg emerges from the snake's last meal. Enlarging the image, it in fact looks more like a frog's leg, but the image is grainy. For those commenters who thought there should be blood, a snake would not necessarily bleed much from such a wound (in fact, they generally would bleed little), and in any case the snake's been preserved in alcohol, so any blood would have been washed away.
Posted by: Nova | September 16, 2009 12:06 PM
It can't be a photoshop; it's not just a circulating picture. Follow the link and you'll see it's at West Normal University in Nanchang awaiting an autopsy - which I'm sure we'll all be interested to know the result of.
Posted by: rob | September 16, 2009 12:09 PM
i think the limb sticking out of the snake belongs to it's last meal. however, that last meal was another snake that *did* have an extra leg.
heh.
Posted by: DuckPhup | September 16, 2009 12:11 PM
Crockosnake... evolutionary precursor to the crocoduck. Quick somebody notify Ray Comfort, and let him know that he has been vindicated... sort of.
That bulge in the creatures body is probably just a banana.
Judging from the limb orientation, it looks like this critter walked ass-first... and since there only seems to be one limb, it must have travelled in circles.
Hey... wait a minute. Leads with its ass, which suggests that it talks out of it, too. Goes only in circles, suggesting circular reasoning. Has been intimate with a banana. Snake-like, and thus (presumably) no smarter than a typical snake. Forked tongue?
This could actually BE Ray Comfort... or at least a close evolutionary ancestor.
Posted by: chuckgoecke | September 16, 2009 12:27 PM
When I was young, in northwestern Minnesota, I found a weird snake with short limbs up near its head, near a stream at the town park. When I caught it, thinking it was one of those sirens or eel-like salamanders, not native to the north, I instead found it to be a regular old garter snake, with a 90% swallowed tiger salamander, with only the front legs and head sticking out of its mouth. The salamander was alive, so I tried to "save" it. Bad idea, it was partially digested, especially its tail. This snake/salamander duo had obviously been hooked together for a while.
Posted by: ken | September 16, 2009 12:38 PM
Assuming this is a bit of lunch protruding...
....how about some examples of the sort of gene-related abberation described in the initial narrative?
Now would be a good time to post them to offset the creationist 'backlash' caused by that crowd using the intial post to argue & illustrate how 'scientists are twisting the facts' to suit thier "agenda."
Posted by: Martin Brazeau | September 16, 2009 12:44 PM
The leg could be of a smallish crocodilian, but I'm not sure what crocodilians (if any) live in this region. In any case, I've linked to some pictures which may be illustrative here.
Posted by: mokele
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September 16, 2009 12:50 PM
A few rebuttals:
First, the limb is clearly protruding the a tear at the base of the limb. The similarity in skin color is mere coincidence - most snakes and lizards are either brown of green.
Second, the obvious evidence of a meal is in the gut distension - look at the scale spacing. In a live snake, scales overlap slightly (in most species), but after a large meal, they're separated widely by expansible skin.
Third, decay would not set in if this were a recent event. The snake likely consumed the lizard that very night.
Fourth, limbs can easily wind up poking out, in part because lizard-eating snakes often do not kill their prey - they simply swallow it whole and wriggling.
Fifth, the lack of blood is attributable to two things - One, it's explicitly stated in the article that the finder preserved it in alcohol, which would wash the blood away.
But there likely wasn't much blood to start with. During EMG implantation, I've seen large holes cut in the side of boas in order to gain access to the muscles of interest, without a drop of blood. Ditto for my many frog surgeries. Ectotherms don't bleed nearly as much as we do, and cuts that don't hit large vessels often don't bleed at all. Snake skin is particularly poorly vascularized, in part due to the need to expand to such great lengths.
Oh, and BlueIndependent? I suggest changing your tone - I've forgotten more about snake anatomy than you'll ever know. For a start, I actually know where a snake's stomach is, which you clearly don't.
Posted by: Gregory Mayer | September 16, 2009 12:50 PM
Being beaten to death with a shoe (which is how the snake was killed) is the sort of rough handling that could cause the side to split. (I'm not sure why I referred to a "farmer" in comment 48-- the article clearly states a woman found it in her bedroom, without referring to her occupation.)
Posted by: Martin Brazeau | September 16, 2009 12:53 PM
I should add to my comment above that I don't think the images I've linked to are suggestive that our snake in question ingested a crocodilian. Rather, they are supportive of the opinion widely expressed here that this is the snakes dinner erupting from its side.
Posted by: Quidam | September 16, 2009 12:56 PM
Compare this picture with the famous boa eats alligator picture
At first glance it's difficult to tell where the boa stops and the alligator starts
No blood, no gore.
I'm a little skeptical of this claim without an examination of the corpse(s) by a competent person. It looks very plausible that this was a bad case of indigestion
Posted by: Owlmirror | September 16, 2009 1:00 PM
Bearing in mind that I am not a herpetologist...
I think the "dinner" explanation is more convincing. The bulge right where the leg is just matches up with some poor lizard being lunch.
I wonder if the reconstruction of events might have it backward? Rather than the leg itself causing the hernia and punching through, perhaps what happened is that that the herniated lump is weakened tissue that was caused by something else -- some other injury, or perhaps a tumor -- and the snake's abdominal wall was weak enough right there that the leg just sort of oozed through, if that makes sense.
I have no idea what the snake healing abilities are, but it seems possible that it might include rapid skin growth, such that the leg sticking out was covered by the snake's skin growing over the injury and anything projecting from the injury.
I encourage anyone with more expertise on snakes to correct my speculations.
Posted by: NitricAcid | September 16, 2009 1:18 PM
The cretinists will claim that this is proof that the snake is "front-loaded" with genes for what its descendants will be.
Posted by: Sven DiMilo | September 16, 2009 1:42 PM
Any time you hear those words spoken, run away.
Posted by: Cheezits | September 16, 2009 1:46 PM
That's creepy, whatever the explanation is. I mean, it looks like a tiny hand trying to reach for help. *shudder*
Posted by: SEF | September 16, 2009 1:47 PM
Hmm...
An ingested lizard could easily be in that location without having had time to decay or perhaps, more remotely, even being dead.
The finder-killer claims the snake was using the clawed limb but could have been mistaken - especially given how freaked out they seemed to be.
However, the skin patterning on the leg seems to exactly match (in colours and design) that of the snake - which would require quite a considerable coincidence for it to be an unrelated ingested lizard!
Does anyone know what lizards inhabit that area?
Posted by: Zan | September 16, 2009 1:49 PM
Posted by: Sven DiMilo | September 16, 2009 1:42 PM
I'm a herpetologist, trust me
Any time you hear those words spoken, run away.
Uh, yeah, usually, but in this case you're wrong. Follow the link in the man's name. He IS a freakin' herpetologist.
Posted by: Zan | September 16, 2009 1:52 PM
Derp. I forgot to quote and the link please delete my previous post:
"Posted by: Sven DiMilo | September 16, 2009 1:42 PM
I'm a herpetologist, trust me
Any time you hear those words spoken, run away."
Usually this is true but, if you follow the link in his name, you'll note he is indeed a herpetologist.
Here's the link to his site: http://homepages.uwp.edu/mayerg/
Posted by: Alan Kellogg | September 16, 2009 2:12 PM
What I'm hearing from people is, "This can't be." How do you know this? Parsimony would counsel it being a lizard's leg projecting from the side of a snake. However, all we have to go by is the story and the picture. Parsimony works best when the available information is substantially complete.
This is a situation where a hands on examination is needed. Being able to look at the animal closely, to touch it, to dissect the specimen and if it is the snake's leg, to work out the structure and how it connects to the rest of the snake.
This is not something that violates the fabric of reality folks. If it is a snake with a leg, then it's most likely a teratogenic event. That you've not seen such a thing before does not mean it is therefor impossible. After all, wasn't there a time when mammals just didn't have bills?
Posted by: BlueIndependent | September 16, 2009 2:16 PM
"...Oh, and BlueIndependent? I suggest changing your tone - I've forgotten more about snake anatomy than you'll ever know. For a start, I actually know where a snake's stomach is, which you clearly don't."
Well then, regardless of Mayer's and my disagreement about what it is, you are breaking with his apparent level of expertise, whereas I am not. Forgotten more than I'll ever know? You have a herpatologist here disagreeing with you, so apparently you've forgotten plenty. What are your creds? Who's the one here in need of a tone adjustment? What I find rather hilarious is your apparent ability to analyze the spacing of scales in an image where such resolution is next to impossible, at the very least due to the compression issues involved. The Telegraph image is pretty clear, but by no means would I call that a closeup. If it was we probably wouldn't even be discussing the issue.
Also, if you could actually read, you would have noticed that I said absolutely nothing about the location of the stomach. All I said was that the leg to me did not appear to be food. I think my analysis of the photo, as non-expert as it is, is still valid until more information is known. I can see a very distinct twist of the snake's body on both sides of the deformity at issue. Also, I would think some more distension would be obvious if the lizard in question were as big as it seems to imply it was. There are two points of view, neither of which can be conclusively proven at this point, so why don't you visit the bathroom for a few minutes and unlodge your undergarments.
Posted by: Bronze Dog | September 16, 2009 2:26 PM
Skipping comments:
I first heard about these sort of suppressors with the example of fruit flies they worked with: IIRC, their wings, mouth parts, and antennae turned out to be modified legs, and they'd grow extra legs in their place if the modifying genes were removed. Similarly, they had some suppressor genes that, when removed, killed them during development, since without the suppressors, they'd try to grow legs in their innards.
The more I learn about biology, the more nifty (and undesigned messy) it gets.
Posted by: blueelm | September 16, 2009 2:29 PM
Honestly it looks more frog or toad shaped than lizard shaped. The more I look at it the more non-scaly the leg looks.
Posted by: amphiox | September 16, 2009 2:33 PM
It isn't necessarily surprising that an unrelated snake and lizard might have very similar skin coloration and patterns. Presuming that they live in the same environment and that one routinely preys on the other, having both species evolve similar coloration isn't unexpected.
Although in this picture the coloration and pattern looks almost identical to me. But then again the resolution isn't the greatest and I'm not a herpetologist.
Posted by: Alan E. | September 16, 2009 2:38 PM
This may very well be its dinner, but one can create other hypotheses surrounding the bulge. If in fact this is a limb grown from the snake's side, the rest of the bulge could be increased muscle growth from the same or similar genes being triggered. They may not work correctly, but could be there attempting to put together the hip area. Whatever it is, the suspense is killing me. Cut it open already!
It could also be the son of the Flying Spaghetti Monster sent to us to enforce the 8 "I'd Really Rather You Didn't"s. Nothing will happen to me if I don't believe this, so I'm going to be cautious and start worshiping it as if it is.
P.S. I just thought of my Halloween costume!
Posted by: JHS
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September 16, 2009 2:43 PM
Yeah...given the lump in the length of snake from which the leg is protruding, I'd be that this was a last-gasp escape attempt from some sort of lizard. I imagine the lizard would have eventually taken the snake down with him, even if the shoe-wielding lady hadn't been in the picture.
Posted by: Gregory Mayer | September 16, 2009 2:54 PM
mokele had it pretty much right from the start (comment #1), and also in his followup (comment #58), including the obviously distended body evident by the spacing of the scales (also noted in my comment #48). My only point of disagreement is that, after enlarging the image a bit, it looks more like a frog's left front leg (I count 4 toes, no obvious claws) than a lizard's, but I wouldn't wager very much either way.
Posted by: Perplexed | September 16, 2009 2:59 PM
That is rather cool, indeed a dissection would be interesting
Posted by: Don Smith | September 16, 2009 3:41 PM
I think that is a frog's front left leg too. That lump in the body looks frog shaped to me as well and the limb is at just the right point and orientation for a supine frog. I suppose a fifth digit could be folded over behind the other four, but I've never seen lizards with opposable thumbs! I also do not see an obviously similar pattern on the leg (except the dark dorsal, light ventral pattern which is extremely common).
The reporting was abysmal. I am assuming it's China West Normal University in Nanchong, not China's West .. in Nanchang. And a 16 in long, pinky finger diameter snake is no monster.
Can anybody identify the species involved? I could not handily find a field guide for Chinese snakes/reptiles. I supposed there really isn't enough of it visible to look for amphibia in China.
Posted by: Umilik | September 16, 2009 3:54 PM
I am amazed that the snake didn't end up pickled in some jar to be sold as aphrodisiac or somesuch potion.
Posted by: Jerry Coyne | September 16, 2009 3:54 PM
Knowing Greg Mayer and his herpetological expertise, I'll take his judgment as dispositive for the time being.
One more point: every case of atavistic limb growth with which I'm familiar has involved the appearance of TWO new limbs, not one. It would be very weird to have one nearly perfect hindlimb appear without its mate!
Posted by: Hughes | September 16, 2009 3:57 PM
Stay away! We can state with certainty that the snake is not 'armless.
T
Posted by: The Pint | September 16, 2009 4:14 PM
@ Hughes #81
"Stay away! We can state with certainty that the snake is not 'armless."
*Groan* That was cornball humor worthy of my pathologist dad (who would have been clambering to be first in line to dissect that sucker like the mad scientist he was).
Posted by: Alan Kellogg | September 16, 2009 4:22 PM
A question for everybody insisting the woman who found the snake mistook what she saw; you were on the scene when she made the discovery? I should think that anybody as intelligent as you appear to be would know enough to know you don't know enough to make a definitive statement on the subject. Your assumption she has to be wrong about what she observed also tells me a lot about your attitudes regarding other people. Yes, people do make errors. But, not all the time and not about everything. People can be mistaken, people can be talked into a lot of things, but it is possible for an untrained observer to make a valid observation.
So far only a few people have seen the snake in question. Only a few people have handled the snake. You have not seen the animal up close, you certainly have not handled it. At this moment I am going to place my trust in a person who actually handled the creature, who had the opportunity to manipulate the creature and its anomalous limb. I shall favor practice over theory, unless and until further investigation shows me the woman in question was wrong.
Remember when birds never had teeth?
Posted by: Jim Etchison | September 16, 2009 4:34 PM
If scientists are going to dissect the snake, wouldn't they have immediately noticed that the leg protruded from a burst-open section of the snake? Unless perhaps the wound had healed around the protruded limb, but if that much time had elapsed, wouldn't the limb have begun to decompose?
But if it does turn out to be a hoax, or lunch, creationists will glom onto this as yet another reason why evolution isn't true. It will be another Piltdown man. Sigh.
Posted by: Stanton | September 16, 2009 4:39 PM
Anyone here heard of the old Chinese saying, "Like putting legs on a snake"?
Posted by: Mark Duigon | September 16, 2009 5:00 PM
Is that a snake with *one* leg? Reminds me of a Creationist lecture tape lent me by the local head of the John Birch Society, which included the question, "You never seen a bat with one wing, eh?"
Posted by: nfpendleton | September 16, 2009 5:43 PM
Certainly looks like a herniation...with a leg stickin' out of it. Tastes just like chikin.
Posted by: MadScientist | September 16, 2009 5:53 PM
OK, I'll admit that snakes were easier to work with. I'm trying to perfect those techniques so I can create my Tyrannosaurus Chicken. At the rate I'm going I might get a Godzilla first. This would be an engineered Godzilla though; not one that mutated due to pollution in the environment like the one in that Z-grade movie.
Posted by: 'Tis Himself, OM
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September 16, 2009 5:54 PM
Actually I have. It was a bat caught by a cat and was rather mangled. One wing was completely gone.
Posted by: Nova | September 16, 2009 6:01 PM
I really hope there's a follow up to this, so we all know what it really was - not holding my breath, though.
Posted by: SEF | September 16, 2009 6:26 PM
Temporarily assuming the version in which the limb belongs to an ingested critter, would the boundary between the two skins be the very narrow pale stripe (as per all the other pale stripes in the patterning on the snake) cutting across under the "armpit" of the leggy dude?
The problem being that that would require the skin to behave like an upside-down marsupial pouch - with more skin supporting the limb rather than there being a clear, singular rip. If the snake was double-skinned and about to moult, I suppose it might be possible for the breach to be staggered between the skin layers and hence give that effect.
Posted by: extatyzoma | September 16, 2009 7:00 PM
i cant wait for the actual autopsy on this guy if it happens. as has been mentioned before the most parsimonious explanation is a meal animals leg popping through and id guess through an injury. the photos seen of the gator and the exploded constrictor could still be due to injury from an outside source.
blueindependant, if you cannot assign that distended abdomen and obviously separated scales to a meal then you need to check out a few more photos of snakes post feeding, there is no way that the snakes fat middle is due to only its position, i'd say that is simply impossible.
Posted by: Gregory Mayer | September 16, 2009 8:09 PM
Here's a video from the BBC showing a python that has eaten a boar. About 9 seconds in, note the numerous pale longitudinal markings-- this is the exposed interstitial skin between the scales, just like in our Chinese friend.
http://www.youtube.com/watch?v=QF8T_B-9Rj0&feature=fvw
Posted by: PZ Myers
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September 16, 2009 8:10 PM
An atavism would be expected to express some symmetry...but a teratogenic deformation would not. We've got the cases of all the deformed frogs here in Minnesota to show that -- they're almost always grossly asymmetrical.
Posted by: David | September 16, 2009 8:11 PM
OMG, I can't believe you people don't see it, it's the virgin mary on the side of a snake!
Posted by: Crudely Wrott | September 16, 2009 8:19 PM
Posted by: extatyzoma | September 16, 2009 8:32 PM
that could even be a frogs front leg sticking through, the bulge could be rather froggish perhaps??
Posted by: Kagato | September 16, 2009 8:58 PM
We've already had a bona-fide herpetologist weigh in, so I'm not really contributing much; but even I think it's pretty clear that's a leg from a meal.
There's the obvious shape of a large bulge in the middle where the leg protrudes (beyond the "bubble" where it exits the skin): http://i28.tinypic.com/dnj4pd.jpg
Not knowing much about snake anatomy, I'd guess it swallowed something bigger (causing a rupture) or sharper-clawed (piercing the stomach wall?) than it could handle, resulting in a hernia (if that's the right word for it), with the leg poking out through the middle.
The scratching along the wall was probably just the poor snake rubbing up against something, going "ow! ow! I've got a leg sticking out of my stomach! If I really had limbs, maybe I could do something about it!"
Posted by: The Problem With Pop Science | September 16, 2009 9:17 PM
The reasoning displayed on this site is abysmal. Is this a youth forum? While I appreciate the replies by those of sound mind, I am surprised by the level of doubt regarding the snake's eruption.
The fact that so many of you are confounded by the photo, suggests that a broader sense of skepticism is needed on this site.
Step it up.
Sites like these perpetrate the stereotype that science geeks tend to have a narrow education, and are susceptible to serious blind-spots in their reasoning.
Posted by: John Morales | September 16, 2009 9:27 PM
Problem @99, this is an open forum (or, rather, PZ's soapbox where comments are open to all comers).
Interesting that you are "surprised by the level of doubt regarding the snake's eruption" whilst simultaneously opining that "a broader sense of skepticism is needed on this site". :)
Posted by: Sven DiMilo | September 16, 2009 9:34 PM
I wasn't questioning his expertise.
It was a joke. About the trustworthiness of herpetologists.
I know a few.
Posted by: Kevin Schreck | September 16, 2009 10:48 PM
What's really surprising to me is that it's not a mere vestigial stump, but a pretty well articulated limb. Very cool.
Posted by: Notagod | September 16, 2009 10:53 PM
That's the handiest snake I've ever seen.
Posted by: Paul Goodhew | September 17, 2009 12:55 AM
Can one of you well-connected types can track down some answers here...
Surely a famous biologist like Jerry Coyne can pull a few strings!!!
Or do I need to write to Richard Dawkins :)
While furiously googling for more info on the handy snake, I came accross this:
http://www.landoverbaptist.net/showthread.php?p=400442
pretty funny.
Posted by: Paul Goodhew | September 17, 2009 1:31 AM
Sorry to hijack an interesting science thread with a bit of religion bashing (I usually hate it when people do that) but just consider this OT:
On the landoverbaptist.net forum I came accross this thread http://www.landoverbaptist.net/showthread.php?t=4474
where someone has posted a hilarious satirical piece called "The evilutionist conspiracy". The poster, who seems to be a regular contributor to the forum, has totally missed the satire and now it's been stickied as a serious bit of advise for the faithful. It's a great read if you need a laugh.
Posted by: David | September 17, 2009 1:41 AM
Paul,
The entire Landover site is a parody, run by an atheist, it's not being posted as a "serious bit of advice, it's a joke.
Posted by: paul goodhew | September 17, 2009 1:50 AM
oops :)
*feeling silly*
Posted by: Diane G. | September 17, 2009 2:00 AM
While we're waiting...a bat with one wing & not much more. Hungry spider!
http://www.birdspiders.com/gallery/photos/med_15B00847KD0B7KAEC2K14169022ED48EAA1.jpg
Posted by: John Scanlon FCD | September 17, 2009 2:21 AM
Sorry to get here late, but I've been playing with crocodile skulls all day. I made some comments on this snake-leg story earlier, over on Darren Naish's Tetrapod Zoology (link through my name), and I see that several others here have come to the same conclusion - which is NOT the exciting evo-devo story Prof Myers has been telling us. Alas.
Much as I would love to be able to examine (however vicariously) an atavistic or teratological extant snake limb, the one shown in the picture is clearly a frog's left forelimb protruding through the ruptured body wall. Probably happened when the old lady hit the snake with the shoe, but - just possibly - the frog ripped the hole itself.
And yes, I am a herpetologist, so you can trust me. Probably.
Posted by: GumbyPhobe | September 17, 2009 3:02 AM
I don't see why the bulge has to have anything to do with the mysterious appendage. Any meal would have to pass the part where the leg is on it's way through the snake.
Aside from that - it's a lousy photo. It would be a lot more revealing if one could see whether the snake's skin is actually connected to the limb. If the results of the autopsy don't make the news, I guess we can conclude the snake just ate something that didn't agree with being eaten.
Posted by: David | September 17, 2009 6:26 AM
@ # 107. No worries Paul, I recently learned a term here that applies perfectly in this case:
http://rationalwiki.com/wiki/Poe%27s_Law
Also, if you look up the term Landover Baptist on youtube you will find some hilarious videos by their "minister". The main website is hilarious, I'm a big fan of the "wiccan cage" that they sell so that you can poke wiccans with a stick.
Posted by: aineolach | September 17, 2009 6:54 AM
It doesn't matter what the truth is. It's more important that we pretend to get along rather than whether it's a frog/lizard leg poking through or a leg belonging to the actual snake. Obviously everybody is right and nobody is wrong, these hypotheses are not in incompatible with one another.
...I'm not really sure how anybody can genuinely think like that.
Posted by: The Problem With Pop Science | September 17, 2009 7:48 AM
"Interesting that you are "surprised by the level of doubt regarding the snake's eruption" whilst simultaneously opining that "a broader sense of skepticism is needed on this site". :)"
As the Internet has demonstrated, skepticism varies in its quality. The type of skepticism being expressed over the photo falls into the low quality skepticism column. It's likely the result of a poor "pop" science education that sites like this promote.
It simply doesn't require this level of wonder, but I doubt that many of you have anything else to do.
Considering this site's reputation for being a bully pulpit for fundie Atheists, I expected more.
Posted by: The Trouble WIth Pop Science | September 17, 2009 8:04 AM
Finally, the fact that Meyer's initial response to the photo was to assume some kind of vestigial limb pretty much sums up the quality of his science reporting.
In fact, it's pretty embarrassing. It's also possible that the photo is a hoax, but whatever the case, it certainly isn't an expression of a vestigial limb, and any evolutionary biologist worth their salt would have concluded that soon after looking at the photo.
Not only did Meyers manage to offer up a quick genetic explanation for the photo, but he also managed to tie an environmental cause into it, which, of course, would support his political bent.
It's obvious that his first impulse is towards confirmation bias.
Posted by: John Scanlon, FCD | September 17, 2009 8:25 AM
Which is probably true of all of us. Instinctively we look for additional confirmation of the first explanation that occurs to us, and that's an instinct that serves us well in most situations. One example is following the track of an animal; having found one sign consistent with being a footprint, tail drag or feather impression, you look around for the next, and the next, and the next, and form an opinion as to the identity, activity, and intention of the trackmaker. It works well as long as it works at all, but if you are mistaken and strike off on a false trail, the clues dry up and you have to backtrack and work out where you went wrong. That's where it turns into science. Science is the second impulse, and that's the correct order. Bitches.
Posted by: extatyzoma | September 17, 2009 8:34 AM
#114.
its unlikely the photo is some type of hoax, the sheer grotesqueness of the lump and leg suggest its perfectly natural and not some thing stuck on there for eg. The animal looks geniunely screwed. A hoaxer would probably be of the mindset that four little plastic limbs stuck on in the correct position would be convincing, hoxers of biological material invariably seem to be stupid, think of that recent sasquatch body, consider how insanely dumb those two hoaxers were.
hell, theres almost as much controversy over this poor damn snake as there is over those jesus in oatmeal pancacke stories.
#114, were you aware that pz did actually add to the original post to acommodate the fact that he could well be(and probably WAS) wrong? Damn pz and his dreadful environmental and genetic and political bents.
Posted by: extatyzoma | September 17, 2009 8:52 AM
i linked to the original article in the telegraph
"Dean Qiongxiu, 66, said she discovered the reptile clinging to the wall of her bedroom with its talons in the middle of the night.
"I woke up and heard a strange scratching sound. I turned on the light and saw this monster working its way along the wall using his claw," said Mrs Duan of Suining, southwest China."
hmmm, im only suprised it wasnt sucking its own tail and using the single leg to propel itself like a hoola hoop along the floor to make circles.
i think we should all 'critically consider' the eye witness testimony before jumping to any conclusions (strokes beard)
Posted by: AK | September 17, 2009 11:33 AM
For a bunch of people who're (mostly) into bashing creationists, you certainly don't know much about your enemy. When I showed it to a creationist of my acquaintance, I was wondering if the response would be "Genesis (3:14) is coming unwound".
It would be no surprise to any biblical literalist that snakes retain the (suppressed) genes for legs, after all, they only lost their legs 6000 years ago (Genesis 3:14). And who knows? "God might just forgive the serpent on the last day". Which may be any day now (and has been for the last 1950 years or so).
(Of course, a more scientific approach would suggest that the notion that the serpent was recently cursed to go "upon thy belly" came from the fact that even 2-3000 years ago (when this passage was probably written) people had noticed the occasional atavistic snake with leg(s) and come up with a reasonable explanation for it, in contemporary terms.)
Posted by: Alex | September 17, 2009 12:42 PM
Hey guys we have a new photo, clicky. The new angle seems to give more of a protruding-frogs-leg type appearance, obviously don't take my word for it though,lol I'm just your friendly neighborhood google jockey. But there's also an interesting new quote from China's resident "snake expert" Dr Long Shai:
If a reasonably qualified expert has observed and touched the specimen first hand I'm inclined to give at least some credence to his testimony. I'm still reserving judgment on this one.Posted by: Sensei J. Richard Kirkham B.Sc. | September 17, 2009 12:49 PM
Wow that is cool.
Rick
Posted by: PZ Myers
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September 17, 2009 1:18 PM
That new picture is as bad as the old one -- there is no view of the actual juncture of the leg with the body wall.
Posted by: extatyzoma | September 17, 2009 2:06 PM
that new picture gives me less of an impression that its a leg from some creature within the snake but id still be suprised if it is a leg that devolped on the snake, it would be very cool though.
Posted by: David | September 17, 2009 2:43 PM
We now have two different pictures and they both just happen to be bad? Reminds me of bigfoot pictures. It's not like they are having to snap it while it's slithering around the room. It's a *dead* snake! Wouldn't they at least get a good pic to show off the thing that is supposed to be so amazing? And now she claims she doesn't want to give it to scientists unless they pay her for it? Which I am sure any number of scientists would gladly do so that sounds bogus too. My skeptic meter is now going off big time.
Posted by: Mathematician | September 17, 2009 2:46 PM
#22, if I put my heel in the crook of my elbow, my toes end right a good 3cm short of the base of my palm. Your sample is too small (and my family all has strangely long arms).
Posted by: SEF | September 17, 2009 3:01 PM
@ #22 and #124:
Whereas, I'm a counter-example in the other direction. Although I do have relatively long limbs, I also have disproportionately long (almost finger-like in some ways) toes on my fairly large feet; and hence the toes extend beyond the start of the palm in that test.
Posted by: Owlmirror | September 17, 2009 5:40 PM
Some research notes:
The page linked @#119 claims that it is an Asian Tiger Snake. This seems wrong to me, as googling on that finds a snake that looks very different (striking black-and-yellow checking), and is native to the island of Taiwan, as opposed to mainland China.
(Rhabdophis tigrinus formosanus)
I tried searching for Chinese news stories, in the hopes of finding better pictures, and found instead a worse (grayscale) picture:
http://zhujinews.zjol.com.cn/news/2009-9/14/content_131792_0.htm
snake is "蛇"
foot is "脚"
(leg is "腿")
Suining (City) is "遂宁"
(hm. The second character isn't showing up for me on this browser, on this page -- I assume because UTF-8 doesn't have all of the characters in GB2312? Or maybe it's just the fonts I'm using -- anyway, it's this character in simplified Chinese)Searching on the characters of Suinin, snake, and foot bring up about a thousand hits, all of which appear to be copies of the same story. Nothing with new/different pictures.
Oh, well. Maybe someone who actually knows the language can figure out how to get something new.
Posted by: Paul Goodhew | September 17, 2009 8:45 PM
Everyone, please put down your conical flasks, dissection scissors, hammers, calculators, paint brushes etc and devote all your attention to getting some more info on this.
Doesn't anyone have PRIORITIES anymore!?!
Posted by: DLC | September 17, 2009 9:44 PM
Bah! it's obviously a Fake! Everyone Has faith that God created Snakes exactly as they are!
But seriously -- fascinating photo, if genuine. Not often one sees such genetic errors.
Posted by: John Scanlon FCD | September 17, 2009 11:21 PM
Actually the second picture does show something more clearly than the first. In the part where the skin is stretched over the prey item the pale skin between scales is exposed, so although the resolution is too low to show actual scale and skin boundaries, the scales show up as longitudinal rows of separated dark dots. These scale rows can be clearly seen* to strongly diverge around the protruding limb, which has a patch of greyish stuff on the bulge at its base. That'll be frog skin exposed through the tear in the snake's skin, which runs along between the scale rows.
* (if you blow the picture right up)
Is anyone else seeing double? Something weird with the formatting on this page!
Posted by: Nerd of Redhead, OM
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September 17, 2009 11:29 PM
Yes, it seems IE, FF, and Opera have had some problems. Safari works fine. Turn off page styling and the bad pages disappear, but it still might look "strange".