Scientists Discover Where Snakes Lived When They Evolved into Limbless Creatures

Penn State ^ | 30 January 2004 | press release

[AdmSmith]

The mystery of where Earth's first snakes lived as they were evolving into limbless creatures from their lizard ancestors has intrigued scientists for centuries. Now, the first study ever to analyze genes from all the living families of lizards has revealed that snakes made their debut on the land, not in the ocean. The discovery resolves a long-smoldering debate among biologists about whether snakes had a terrestrial or a marine origin roughly 150 million years ago--a debate rekindled recently by controversial research in favor of the marine hypothesis.

In a paper to be published in the 7 May 2004 issue of the Royal Society journal Biology Letters, Nicolas Vidal, a postdoctoral fellow, and S. Blair Hedges, a professor of biology at Penn State, describe how they put the two theories to the test. They collected the largest genetic data set for snakes and lizards ever used to address this question. Their collection includes two genes from 64 species representing all 19 families of living lizards and 17 of the 25 families of living snakes.

Genetic material from some of the lizards was difficult to obtain because some species live only on certain small islands or in remote parts of the world. "We felt it was important to analyze genes from all the lizard groups because almost every lizard family has been suggested as being the one most closely related to snakes. If we had failed to include genes from even one of the lizard families, we could have missed getting the right answer," Hedges explains.

"For the marine hypothesis to be correct, snakes must be the closest relative of the only lizards known to have lived in the ocean when snakes evolved--the giant, extinct mosasaur lizards," Vidal says. "While we can't analyze the genes of the extinct mosasaurs, we can use the genes of their closest living cousins, monitor lizards like the giant Komodo Dragon," he explains.

The team analyzed gene sequences from each of the species, using several statistical methods to determine how the species are related. "Although these genes have the same function in each species--and so, by definition, are the same gene--their structure in each species is slightly different because of mutations that have developed over time," Vidal explains. When the genetic comparisons were complete, Vidal and Hedges had a family tree showing the relationships of the species.

"Our results show clearly that snakes are not closely related to monitor lizards like the giant Komodo Dragon, which are the closest living relatives of the mosasaurs--the only known marine lizard living at the time that snakes evolved," Vidal says. "Because all the other lizards at that time lived on the land, our study provides strong evidence that snakes evolved on the land, not in the ocean."

The research suggests an answer to another long-debated question: why snakes lost their limbs. Their land-based lifestyle, including burrowing underground at least some of the time, may be the reason. "Having limbs is a real problem if you need to fit through small openings underground, as anybody who has tried exploring in caves knows," Hedges says. "Your body could fit through much smaller openings if you did not have the wide shoulders and pelvis that support your limbs." The researchers note that the burrowing lifestyle of many other species, including legless lizards, is correlated with the complete loss of limbs or the evolution of very small limbs.

This research was supported by the National Aeronautics and Space Administration Astrobiology Institute and the National Science Foundation.

[CyberCowboy777]

You said "Good question. The bible doesn't even make that clear."

Which is not the case. You may not believe it, you may have some opinion on how the story came to be - but you are wrong when you say the Bible is not even clear.

And you gave no interpretation of the passage - only your opinion on how the story came to be and thus not believable. Which is fine - except I was asking ZULU how he/she balances Evolution and the Passage.

[Yeti]

Its not meant to be an argument. I maintain that most scripture is meant to be simultaneously understood on several levels, literal and metaphorical being two of them. To accomplish this they are not entirely satisfactorily read on either level.

Strange that recently my own thoughts have been in a similar vein recently.

Where many truths coincide by semblence and symmetry, metaphor, detail, emotion, understanding ... there -- where meaning and fact are overlayed and intertwined in many intricate ways -- such bits of reality may be blurry, but, like tiny fragments of a large hologram, the truth is there.

A nugget of truth like that is more true than can be expressed in boolean or statistical terms.

[AdmSmith]

It must have been easier to dig the burrow using limbs.

Yes, that is what Bipes canaliculus is doing with its two limbs:

[Jeff Gordon]

Hey, you are picking things apart and choosing things to believe that fit your observations.

I do not understand what you are saying. Is the Bible the word of God or is it not?

[Jeff Gordon]

Are you saying that I can have a Mexican slave because they will work for a whole lot less money than a Canadian? Makes sense to me.

[Junior]

One would think they would have created a more user friendly God.

Dunno. Most of the ancient gods are pretty nasty individuals. No one can accuse the Greek gods, Egyptian gods, Norse gods, or even early Mideastern gods (Baal, for instance) of being "user-friendly."

[Jeff Gordon]

..you must let them free if you strike them
..if they seek refuge from you from your neighbor that your neighbor is obligated to provide them asylum
..if you have no offspring they inherit the farm.

Sounds like the Ninth Circuit Court was active in Biblical times too.

[Jeff Gordon]

You can if you figure out a way to buy them.

Exodus 21:7 says that I can sell my daughter into slavery. What to you think would be a good "Buy Now" price on Ebay? She is a hot, 21 year, old virgin.

[ZULU]

"Can a jerk show respect?"

Ad hominem remarks will get you nowhere.


"What Facts do you have on the pre Garden era? "

We have been over this time and again. You and people who think like you refuse to believe the Bible is anything but a textbook on every conceivable issue. That's medieval thinking. That's the way Muslims consult the Koran. They check it to see if flying in airplanes is O.K. with Mohammad.

People who thought just like you said that the sun can't revolve around the earth because there is a passage in the Bible about God making the sun stand still in the sky. Therefore the sun must revolve around the earth.

A passage in Genesis says that God made man out of the dust of the earth. Therefore, ALL the fossils, ALL the strategraphic research, ALL the paleontologists who ever lived, all the anthropolicial facts unearthed will not convince you that God did not LITTERALLY make modern man out of a litteral lump of clay. All those fossil primitive men, who so closely resembled us, who provide a gradually more modern likeness to modern man with advancing geological age, were not our physical ancestors.

Go ahead, its a free country. You can believe anything you wish. You can deny the world is flat, that the earth revolves around the sun, and that modern man had physically more primitive ancestors.

I have no idea where the Garden of Eden was or what went on in there. That's a theological question best answered by theologians. But I most certainly know, that as sure as primitive fish gave rise to amphibians, and amphibians produced reptiles, and lizards produced snakes, and dinosaurs produced birds, that primitive human-like creatures were the the physical ancestors of modern man.

[VOA]

Dust is a symbol for death as in ashes to ashes, dust to dust.

Now y'all are being a bit hard on dust (or dirt).
Surely you've heard about how the world's molecular biologists decided that they'd
learned enough to let them create new life from scratch. Just like G-d did.
So the molecular biologists and G-d met in order to have a smack-down contest...
When the molecular biologists reached down to scoop up some dust of the earth
to toss in with their batch of life-creating chemicals, G-d roared
"Just a darned second there fellows...first you've got to make the dirt out of nothing...
and I've got the patent on that process. And lots of other things."

[ZULU]

"However the rest of creation pans out, scripture clearly states Adam was created by God without evolution."

The Bible doesn't even mention evolution.

Maybe it should have read like this: "In the begining God created small cells with semipermeable membranes surrounding them. In the center of each cell was a nucleus which houses genetic material. The enetic material is composed of chains of deoxyribose sugar molecules joined to......."

The Bible would have had to have two hundred volumes long is God were to describe all the minutia of hoiw evolution actually occurred to a Neolithic Shepherd. And WHAT FOR???
Its NOT a biology text! Its a religious tome! Gensis description of how God made man in no way obviates the reality of evolution. You just have to use the brain God gave you, look at the facts, read the Bible, read between the lines, and it should be obvious to you.

[nmh]

This is just too funny. What next ... ?

[Virginia-American]

It is a dangerous thing for someone to say that the Bible is just 'subjective' or 'allegorical' when the plain meaning of the writers is literal...

As Martin Luther said:

"People give ear to an upstart astrologer who strove to show that the earth revolves and not the heavens of the firmament, the Sun and the Moon. Whoever wishes to appear clever must devise some new system, which of all systems is of course the best. This fool wishes to reverse the entire science of astronomy; the sacred Scripture tells us that Joshua commanded the Sun to stand still, not the Earth."

[VRWC_minion]

Maybe it should have read like this: "In the begining God created small cells with semipermeable membranes surrounding them. In the center of each cell was a nucleus which houses genetic material. The enetic material is composed of chains of deoxyribose sugar molecules joined to......."

Creating wine from water in an instant is no more difficult than creating a man from dust is it ?

[Michael_Michaelangelo]

Wow! What a list you've compiled there. Let's address the first supposed bible error you've cited.

Is it true that rabbits chew cud?

Ahhh one of the great questions of our time, Ichi. No doubt you are referring to Leviticus 11:6 which speaks of a hare chewing it's cud.

I'm sure you are aware that Lagomorphs breed bacteria in their stomachs to improve food, just like cows do. How do you define rumination?

"we consider that the fundus of the rabbit stomach, loaded with soft pellets, is analogous to the rumens of sheep and cattle."

Griffiths, M. & Davies, D. The role of the soft pellets in the production of lactic acid in the rabbit stomach. J. Nurte., 80:161-80, 1963.

I'd say Moses had insider information!

[ZULU]

No. I agree with you that God could make man out of a lump of mud, or out of nothingness or a bowl of jello. He's God. He can do anything. I guess you are right in saying there is a POSSIBILITY He did it the way you state.

On the other hand, I believe the scientific evidence indicates He used the body of a lower animal, and the "dust of the earth" is a simple way to express that to an unsophisticated audience. The important part of the message is not really HOW God made man, but the fact that He DID make man, and He made him in His image, and since God is a non-corporeal spirit, He couldn't even be referring to man's body in the latter sense. As a matter of fact, in a great many of God's miraculous actions, He actually uses well-timed natural phenomena, often carried to extreme conditions.

For instance, the plagues on Egypt. There are possible scientific explanations for ALL of them. HOWEVER, their extreme manifestations and the timing of the events would lead anyone to conclude that a Supernatural Agent, i.e. God, was involved. Even a pillar of cloud or of fire is not really something outside the ordinary. Fire and clouds are natural phenomena. Water and wine are natural ingredients.

I don't believe Creationists are "nuts". I understand what their perspective is. I just happen to disagree with it.

I believe that God created man using the body of a lower animal which he produced through evolution and that a lot of what is written in the Bible, although accurate, is presented in an allegorical or symbolical manner, especially considering the level of scientific sophistication of the audience to which it was delivered. And I consider myself basically a fundamentalist Christian also - I believe in God, I believe Christ is my Saviour, I believe in the resurrection, I believe in miracles, I believe in the Bible, I believe in Satan, I believe in angles, I believe in a Last Judgement, I believe homosexuality is morally wrong, I believe abortion is murder, etc, etc.

[whattajoke]

1 down, 16 to go.

On to bats being birds.

Please educate us.

[js1138]

So chewing isn't necessary to the process of chewing? I guess it depends on what the definition of "is" is.

[VRWC_minion]

According to the scripture there was a 1st man and he was Adam and he chose to disobey God. All other things about the creation story can be reconciled to a degree with an evolution theology (i.e. evolution controlled by God) except for the 1st man who was called Adam. Without Adam, Christ and the concept of redemption cannot apply.

An interesting note on this is that the literal translation of the verses that talk about God clothing them is that he put them in skin. A pure literal reading could be that prior to being put out of the garden they were spirit and the clothing that God dressed them in was a body. That is the closest I can get to reconciling the theology of sin and redemption with evolution.

[CyberCowboy777]

You being a jerk in your posts and my pointing it out is not a Ad hominem remark. You can discuss the topic without trying to degrade those who disagree with you.

Regarding creation - you keep going into long diatribes and never really answer my question. Did God breath life into man? I really wish yo would just come outright and say - God did not create man directly and he did not breath life into his newly created man. I really do not care what fairy tale you believe in - I just want you to admit that you believe that Genesis is wrong. For God to have created man and breathed life into him He would have had to make him directly as a man and breathe life. Maybe you think he create the sludge or some other primitive form, let it evolve and then breathed life into him?

It is foundational that the difference between man and beast is the soul, which man received when God breathed life into him. Do you feel that all lower versions of man also had that soul, that God waited until man evolved to his final state then breathed life into him, then moved him into the Garden, then made Eve? (remember when Eve was made?) Or is Genesis completely wrong? Just be honest and stop dancing.

If you have no idea where the Garden of Eden was or what went on in there - how do you know that everything was not different than you imagine? You don't. So I would not be so cock sure that you have the truth on origins. But you do as you please, just don't try to pass off the lie that Genesis and Evolutions are compatible.