Living Snake with legs

[Valentine Pontifex]

http://www.theepochtimes.com/news_images/2006-9-20-snak.jpg


Snake With Two Feet Appears in Shandong, China (http://www.theepochtimes.com/news/6-9-20/46166.html)

[espritch]

If this story is true, it would seem to indicate that snakes still retain the genetic machinery for growing leggs (or at least feat) and it just never gets turned on under norma circumstances. It makes me wonder how often an evolutionary change might result just from a reactivation of pre-existing genes.

I wonder how much that snake would bring on Ebay. :devil:

[SophistiCat]

Do you think it's abnormal development or a heritable mutation?

[maybemaybenot]

x-rays please!

[RBH]

Do you think it's abnormal development or a heritable mutation?Somewhere I read it was likely a failure in a regulatory gene, a repressor. Whether it's heritable depends on whether it was a mutation that operated very early in development and also got into the germ line, or a mutation in a late developmental pathway that only affected that bit of the developmental process. My guess is the latter, since there's no other apparent developmental abnormality in the picture.

RBH

[Jet Black]

aah a snake with legs; therefore genesis is false. :)

[GenesisNemesis]

Could the feet just be non-beneficial mutations? sometimes humans get an extra toe or something like that.

[Ponzi]

Could the feet just be non-beneficial mutations? sometimes humans get an extra toe or something like that.

I doubt that much benefit can be gotten from those little nubs.

However, the significances is that snakes lost their legs through through evolution, but still retain traces of them in their genome that can be reactivated via a mutation. If snakes were created as they are six thousand years ago, then there would be no reason for a creator to put inactive leg making genes in them.

[Viti]

There is a species of lizard without legs, called a Glass Snake, though it is definitely a lizard. Snakes with legs shouldn't be surprising.

[Codec]

There is a species of lizard without legs, called a Glass Snake, though it is definitely a lizard. Snakes with legs shouldn't be surprising.

True, we also have on in the UK, the Slow worm, which is not a worm, looks like a snake, but is actually a legless lizard.

[rossum]

aah a snake with legs; therefore genesis is false. :)
It doesn't talk. We need a talking snake with legs.

rossum

[flashbaby]

Dr Dino?

[Febble]

Lovely illustration of evo-devo.

[patchy]

If snakes were created as they are six thousand years ago, then there would be no reason for a creator to put inactive leg making genes in them.

(My bold)

Ah, but snakes weren't created as they are now, in the Official Dumbass Version of snake creation.

God got pissed at the original snake serpent for pulling a trick on Eve, and cursed him down on his belly to eat dust from then on. God was thus the first Lamarckian; all subsequent descendants of this bad bad bad talking snake apparently inherited their leglessness.

Dunno if their ability to talk (and outwit humans) was simply eventually selected against naturally, or what. Maybe they still can talk, and just don't have anything important to say.

[Jack the Bodiless]

...Heh. We are beating God! We're lifting the "pain in childbirth" curse with epidurals, we've tackled the "weeds in the fields" curse with selective weedkillers, and as for the "legless snakes" curse... maybe it's a sign that God's giving up.

[Y.B]

I doubt that much benefit can be gotten from those little nubs.

However, the significances is that snakes lost their legs through through evolution, but still retain traces of them in their genome that can be reactivated via a mutation. If snakes were created as they are six thousand years ago, then there would be no reason for a creator to put inactive leg making genes in them.

Creationists don't have any problem with snakes having been able to walk and then losing their legs. Or cavefish losing their eyesight. To them, it's all just "loss of information".

[patchy]

What I'd like to see, once, is a gain in information, after a creationist reads a thread.

[SophistiCat]

Ah, but snakes weren't created as they are now, in the Official Dumbass Version of snake creation.

God got pissed at the original snake serpent for pulling a trick on Eve, and cursed him down on his belly to eat dust from then on. God was thus the first Lamarckian; all subsequent descendants of this bad bad bad talking snake apparently inherited their leglessness.

Actually, The Serpent was a dinosaur, which became a snake after being cursed by God. This is how dinosaurs became extinct. (I am not making this up!)

[SophistiCat]

Somewhere I read it was likely a failure in a regulatory gene, a repressor. Whether it's heritable depends on whether it was a mutation that operated very early in development and also got into the germ line, or a mutation in a late developmental pathway that only affected that bit of the developmental process. My guess is the latter, since there's no other apparent developmental abnormality in the picture.

But aren't small mutations, in principle, possible at early stages? Otherwise, how would we get any heritable mutations that don't have such extensive consequences as to be lethal?

[buckshot23]

Actually, The Serpent was a dinosaur, which became a snake after being cursed by God. This is how dinosaurs became extinct. (I am not making this up!)
You have a source for this "theory"?

[mirage]

Creationists don't have any problem with snakes having been able to walk and then losing their legs. Or cavefish losing their eyesight. To them, it's all just "loss of information".

So by their standards, legs reappearing is a gain in information.

It's encouraging news. Maybe their brain could grow back too.

[buckshot23]

Maybe their brain could grow back to.
Back to what? Or do you mean too? When you are calling somebody, essentially stupid, please spell check.

[Malachi151]

aah a snake with legs; therefore genesis is false. :)

No, this proves that genesis is right because genesis says that snakes had legs until God took them away!!! :devil3:

[patchy]

Actually, The Serpent was a dinosaur, which became a snake after being cursed by God. This is how dinosaurs became extinct. (I am not making this up!)

No, silly...dinosaurs couldn't have become extinct in the garden of Eden, because they were later taken aboard Noah's ark. Baby ones. Noah took baby ones, so they'd take up less room.

(And no, I'm not making that one up, either; it's a claim made on this very board.)

[Plognark]

No, silly...dinosaurs couldn't have become extinct in the garden of Eden, because they were later taken aboard Noah's ark. Baby ones. Noah took baby ones, so they'd take up less room.

(And no, I'm not making that one up, either; it's a claim made on this very board.)

Yeah, the baby animal claims are among my all time favorite stupid assertions. :notworthy:

I once asked a creationist if Noah's wife suckled all of the baby mammals from her teats. He didn't like that question one bit. :D

[Hekym]

This must be the result of environmental factors. Think about it. Frogs grow extra legs in the US. This is CHINA. The pollution is much more severe.

[Plognark]

This must be the result of environmental factors. Think about it. Frogs grow extra legs in the US. This is CHINA. The pollution is much more severe.

Well, amphibians are also a lot more susceptible to environmental factors. They're indicator species.

Not saying it isn't a result of pollution, but assuming that is premature.

Hell, we can get sheep, cattle, snakes, and turtles with extra heads. Humans are born with tails now and then. Atavism is rare, but not that uncommon.

[mirage]

Back to what? Or do you mean too? When you are calling somebody, essentially stupid, please spell check.What if you are calling somebody stoopid?

[bradw]

Here's a link to a larger version of the image. The "legs" don't look so impressive close up.

http://img.epochtimes.com/i6/60912092734685.jpg

[Godless Dave]

Surely this isn't the first such snake? I vaguely remember my biology teacher showing us pictures of snakes with little nubs where legs would be.

[RBH]

What I'd like to see, once, is a gain in information, after a creationist reads a thread.:notworthy:

[buckshot23]

What if you are calling somebody stoopid?
Now that would be different.

[BigJim]

Snake With Two Feet Appears in Shandong, China[/url]
Just as long as it doesn't appear on a motherfucking plane!

[Mageth]

Surely this isn't the first such snake? I vaguely remember my biology teacher showing us pictures of snakes with little nubs where legs would be.

http://www.szgdocent.org/resource/rr/c-boa.htm

[OneWayTraffic]

Back to what? Or do you mean too? When you are calling somebody, essentially stupid, please spell check.

I'm just being a Nazi, but expressions embedded within commas should be incidental to the rest of the sentence. :p

I think it's cool. Have they found any birds with teeth? Or humans that don't need vitamin C? There's got to be a few out there.

[buckshot23]

I'm just being a Nazi, but expressions embedded within commas should be incidental to the rest of the sentence. :p

I think it's cool. Have they found any birds with teeth? Or humans that don't need vitamin C? There's got to be a few out there.
I appreciate the heads up.

[Ai52487963]

Legs on snakes? Where's Sam Jackson when you need him?

[Jet Black]

It doesn't talk. We need a talking snake with legs.

rossum

oh it talks, just very very quietly

[Jet Black]

Legs on snakes? Where's Sam Jackson when you need him?

on a plane. on a mutherfukin plane.

[Monad]

It's just an atavism - no different from the occasional whale born with a leg sticking out or human babies with tails. Homeotic genes basically.

[Berthold]

It fits in a sequence with these items (http://www.amazon.ca/Teeth-Horses-Toes-Stephen-Gould/dp/images/0393311031).

[kingzfan2000]

aah a snake with legs; therefore genesis is false. :)
Actually from reading genesis one would gather that snakes originally did have legs because losing its legs was Gods punishment for tricking Adam and Eve.:cool: And really from a naturalistic viewpoint how could losing all of your legs be in anyway beneficial? Think of any other animal that was born without its limbs; how would this animal survive? Surely the snakes method of locomotion is more than sufficient now, but that would have taken thousands of years to evolve. A presnake born without its legs would be at a distinct disadvantage for both reproduction and survival just as any other animal born without its limbs would be. How did the snake lose its limbs? Did a mutation cause a presnake to be born without its limbs (im thinking instant death in that scenario) or did the limbs for some reason get smaller and smaller until they were simply gone?

[EricK]

Actually from reading genesis one would gather that snakes originally did have legs because losing its legs was Gods punishment for tricking Adam and Eve.:cool: And really from a naturalistic viewpoint how could losing all of your legs be in anyway beneficial? Think of any other animal that was born without its limbs; how would this animal survive? Surely the snakes method of locomotion is more than sufficient now, but that would have taken thousands of years to evolve. A presnake born without its legs would be at a distinct disadvantage for both reproduction and survival just as any other animal born without its limbs would be. How did the snake lose its limbs? Did a mutation cause a presnake to be born without its limbs (im thinking instant death in that scenario) or did the limbs for some reason get smaller and smaller until they were simply gone?

One possibility is that the ancestor of snakes was a burrowing lizard. Legs are not much use for this sort of lifestyle. It does indeed seem unlikely that a legged surface living animal evolved to lose its legs all the while remaining an entirely surface living animal.

[RBH]

Actually from reading genesis one would gather that snakes originally did have legs because losing its legs was Gods punishment for tricking Adam and Eve.:cool: And really from a naturalistic viewpoint how could losing all of your legs be in anyway beneficial? Think of any other animal that was born without its limbs; how would this animal survive? Surely the snakes method of locomotion is more than sufficient now, but that would have taken thousands of years to evolve. A presnake born without its legs would be at a distinct disadvantage for both reproduction and survival just as any other animal born without its limbs would be. How did the snake lose its limbs? Did a mutation cause a presnake to be born without its limbs (im thinking instant death in that scenario) or did the limbs for some reason get smaller and smaller until they were simply gone?Once again, "beneficial" must be referenced to a specific selective context. Mutations in general are not intrinsically beneficial or deleterious (among the exceptions to the generalization being mutations that prevent development from egg to reproducing adult). Mutations are beneficial or deleterious in a specified selective environment. The best example is the mutation of the HBB gene (http://ghr.nlm.nih.gov/gene=hbb) that gave rise to sickle cell anemia. In one selective enviroment (where malaria is endemic) it's a beneficial trait to have in the population because heterozygotes have a reproductive advantage. In different selective environment (where malaria is absent) the very same trait is deleterious to have in the population because homozygotes for it are reproductively disadvantaged -- they tend to weaken or die before reaching reproductive age and thus reproduce less successfully. The mutation that gave rise to sickle cell anemia is intrinsically neither beneficial nor deleterious.

And there's no reason to believe (and lots of reasons to disbelieve) Kingzfan's implicit assumption that the legs were lost all in one go. Evolution in general is incremental, not saltational.

I finally remembered where I read the best comments on this story. John Wilkins made them (http://scienceblogs.com/evolvingthoughts/2006/09/snakes_and_legs.php#more). I commend them to readers' attention.

RBH

[kingzfan2000]

I asked did the limbs get smaller and smaller until they were completely gone. That wasnt a rhetorical question. Despite what many here probably assume, though they may seem sarcastic in nature, I often ask questions for no other reason than because I dont know. I may not instantly concede to the first answer given, and I may not concede at all but that doesnt mean I dont give the answers some thought and even accept a few of them. If a given explanation seems plausible I will accept it as such.

[kingzfan2000]

One possibility is that the ancestor of snakes was a burrowing lizard. Legs are not much use for this sort of lifestyle. It does indeed seem unlikely that a legged surface living animal evolved to lose its legs all the while remaining an entirely surface living animal.
How do you burrow without legs:confused: Every burrowing animal Ive ever seen uses its feet to do the burrowing.

[RBH]

How do you burrow without legs:confused: Every burrowing animal Ive ever seen uses its feet to do the burrowing.You never caught a worm to go fishing?

Kingzfan also asked I asked did the limbs get smaller and smaller until they were completely gone. That wasnt a rhetorical question. Despite what many here probably assume, though they may seem sarcastic in nature, I often ask questions for no other reason than because I dont know. I may not instantly concede to the first answer given, and I may not concede at all but that doesnt mean I dont give the answers some thought and even accept a few of them. If a given explanation seems plausible I will accept it as such.Sorry -- I was responding to the one-generation loss you seemed to imply in the earlier part of your post. The answer to your latter question is yes. In some enviroments with some (heritable) food-gathering strategies, smaller limbs could be adaptive.

RBH

[kingzfan2000]

Ah yes, I forgot about worms, but I was thinking more along the lines of reptiles and mammals not bugs.

[Mike Elphick]

And really from a naturalistic viewpoint how could losing all of your legs be in anyway beneficial? Think of any other animal that was born without its limbs; how would this animal survive? Surely the snakes method of locomotion is more than sufficient now, but that would have taken thousands of years to evolve.A distinguishing feature of snakes is their length. Now just imagine a snake with four legs -- they would certainly not support its body. Evolution is conservative so the growth of extra supporting legs is unlikely, but with a longer body, the snake could evolve a different mode of locomotion, one that is surprisingly effective. So legs became more or less redundant; besides, they would have got in the way of the snake's ability to coil.

[Berthold]

True, we also have on in the UK, the Slow worm, which is not a worm, looks like a snake, but is actually a legless lizard.
The whole family (http://en.wikipedia.org/wiki/Anguidae) has legged as well as legless species.

[espritch]

A few years ago, there was an article in Natural History about leggless lizards that include pictures of three species of lizard from Australia. All three species looked pretty much alike except for the number of leggs. One species that lived in relatively open areas had four leggs. Another that lived in undergrowth had only back leggs. The third species, that lived in dense undergrowth had no leggs at all.

[RBH]

Ah yes, I forgot about worms, but I was thinking more along the lines of reptiles and mammals not bugs.Let me expand on my previous answer a little. Imagine a rocky island on which just two species exist: a species of bugs and a species of lizards. The bugs vary a little in size, and the lizards vary a little in the length of their legs. Bugs escape being lunch for lizards by hiding in crevices in the rock. The smaller bugs can hide in smaller crevices where only the shorter-legged lizards can get them. So there's some selective advantage for the shorter-legged lizards, in that they can get to smaller bugs as well as being able to get into larger crevices for larger bugs. Over generations, the short-legs can come to specialize in small bugs hiding in small crevices, while their long-legger brethren go on munching larger bugs winkled out of larger crevices. The two subpopulations may well interbreed, but as the selective advantage associated with the new niche (small crevices) operates on the end of the distribution with short legs, they will become more and more divergent.

Meanwhile, of course, the bugs aren't standing still (so to speak). The small bugs hiding in small crevices are becoming predated more and more efficiently, and they'll evolve their own defensive adaptations. The stage is set for what's known as an evolutionary arms race (http://en.wikipedia.org/wiki/Evolutionary_arms_race) between the shorter-legged lizards and the smaller bugs. Among the results of that arms race may well be the mutation of the regulatory genes controlling the development of legs in the lizards, shortening them still more until they are vestigial and ultimately lost. During the course of that shortening, other mutations associated with the control of abdomenal muscles can generate the ability of those muscles to first assist, then take over locomotion on very short legs, reducing the dependence on legs at all.

Now obviously that is a very brief sketch -- a so-called "just so" story. But it invokes only know processes -- mechanisms we know occur in animals. In a real biological system there are more than two species and more than one way to catch a bug (or if you're a bug, to avoid capture), and more than one morphological trait that changes during the eovlutionary process. But the tale above captures the core explanation -- subpopulations of a species can diverge when a new niche is available to a tail of the distribution of the parent species, and the consequences of small changes in regulatory genes can produce counter-intuitively large morphological changes. In regulatory gene space it is not very far at all between a legged lizard and a legless lizard.

RBH

[Negasta]

AFAIK larger snakes such as anacondas still have vestigial pelvic bones and with what I've learned about gene control this year, it seems to me that it would take as few as one mutation in one or another transcription factor encoding gene to get them (snakes) to grow legs again. That is what most likely happened in the snake in the OP.

[GenesisNemesis]

You should go to drdino.com and look at "things that make evolutionists look stupid". They bring up all of the "obvious" vestigial organs.

Then again, Kent Hovind is a moron.:devil3:

[Aegeri]

How do you burrow without legs:confused: Every burrowing animal Ive ever seen uses its feet to do the burrowing.

Yeah, I've always wondered where animals like worms manage to hide their legs when I'm looking at them.

[buckshot23]

Yeah, I've always wondered where animals like worms manage to hide their legs when I'm looking at them.
He already corrected that.

[Ezkerraldean]

nice! someone find two of them and start selective-breeding legged snakes! they would make cool pets.

[Vitalstatistix]

I don't see any consummate V's....

[kingzfan2000]

So did snakes evolve from burrowing reptiles?

[kingzfan2000]

**

[Wounded King]

I don't see any consummate V's....

But I can see where they have applied a chiaroscurro effect.

TTFN,

WK

[RBH]

So did snakes evolve from burrowing reptiles?Read this (http://arachnophiliac.co.uk/burrow/evolution_of_snakes.htm) for an overview of the current (well, up to 2005) state of thinking on that.

RBH

[Monad]

Read this (http://arachnophiliac.co.uk/burrow/evolution_of_snakes.htm) for an overview of the current (well, up to 2005) state of thinking on that.

RBH

http://en.wikipedia.org/wiki/Najash_rionegrina

http://scienceblogs.com/pharyngula/2006/04/najash_rionegrina_a_snake_with.php

http://lancelet.blogspot.com/2006/04/serpent-beguiles.html