Scientists Discover Where Snakes Lived When They Evolved into Limbless Creatures

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.

Thank you.

You have shown that you believe something you have no evidence of, and even in that you have mostly open questions and no answers.

How exactly did pre-Adam manlikes procreate if the first women was not created until after man was created and placed and lived in the garden for some time.

I do like how you take questions that you have no answer for and pon them off on theology. Nice.

As to my assuredness - You have lied outright about me on this. I have said repeatedly that I a fully aware of my lack of knowledge. I unlike many do not pretend to know how the system worked, I understand that we are not so big as we think we are.

"How exactly did pre-Adam manlikes procreate "

Sexually. There was a whole population of male and female creatures which preceded modern man. Somewhere along this line, God decided to elevate one of these creatures to true human status by making him a man, imbuing him with an immortal human soul and placing him in the Garden of Eden - wherever or whatever that was.

Once having done that, He then created for him his mate, a woman who was his spiritual equal. Genesis says He took a rib from Adam to do this. Its possible He did. God, obviously can do anything, that's whay He's God. I think its MORE likely He took another one of these prehuman creatures, a female one, and elevated her to human status and placed her in the Garden of Eden with Adam. Like I said before, I think God acts though the natural laws He has established to accomplish His goals. I think the rib story is another example of symbolism and allegory, intended to show how very strongly God meant a man and his wife to be connected.

"You have shown that you believe something you have no evidence of, and even in that you have mostly open questions and no answers."

Only God has all the answers. We don't even know all the questions. He gave me a Bible and He gave me a brain. I try to use the both of them to my limits as a finite creature.

"I do like how you take questions that you have no answer for and pon them off on theology. Nice"

Some questions are scientific ones and some are theological ones. The Bible provides answers and guides to the Theological ones and science provides answers to the scientific ones. When Bible and Science appear to conflict, we have to use our brains in an attmept to reconcile the two to the best of our limited abilities.

"As to my assuredness - You have lied outright about me on this. I have said repeatedly that I a fully aware of my lack of knowledge. I unlike many do not pretend to know how the system worked, I understand that we are not so big as we think we are."

I mean "you" in a generic sense, i.e. Creationists in general, not in a specific sense, although you do seem as certain of some ideas of yours as I do of mine. However, everybody has a right to think as they wish.

Look.

I am sorry for any ad hominem remarks.

I simply do not believe science has even come close to understanding origins. And while your theory on meshing Genesis and Evolution might sound good to you.... I think your too close. When ALL the statements of events are taken into consideration (without taking every little thing literally) the timing of events and the nature of events do not add up.

If you do not believe in miracles, in the supreme nature of God I can see dismissing all "fanciful" stories in the Bible. But you have stated that you believe. So why cannot it be possible that the fossils records you trust mean something different than your interpretation. You simply do not know what happened - yet God saw it fit to give us a story that states that He created man and breathed life into him - a man who then did not procreate until after woman was made and after being booted from the garden. A man who did not have a soul (making him a man after God image) until the breathe of life. If many pre-men existed did they have souls? If so Adam was not the first.

You can claim it all theological and dismiss it, fine. I choose not to as these are foundational to Christianity.

In these discussions there is more opinion than facts and no baseline of truth can be established. Regardless how religiously the evos believer they have the truth. I cannot prove what happened - I just know we know so very little. Arrogance will destroy knowledge.

I wish you well.

Keath

Like I said before, I think God acts though the natural laws He has established to accomplish His goals.

Like stopping the sun for Joshua? Like the floating ax head? Like a man walking on water? Like wet wood spontaneously combusting? Like conceiving a child in the womb of a virgin? Like leading people with dust and fire? Like writing law on stone? Like a talking donkey? Like a burning bush that is not consumed? Mana from heaven?

Should I go on? You are putting God in a box.

Where do you think the fossils of the offspring of the fallen angles who mated with woman and beast are?

"I am sorry for any ad hominem remarks."

Thnak you. I hope I haven't said anything to really upset you.

"I simply do not believe science has even come close to understanding origins."

I agree with you on that one. They have come out with all kinds of theories about reducing atmospheres, lighting bolts, contamination from another planet, etc, etc. To my knowledge NO ONE has succeeded in "creating" life in a laboratory. I feel ony God can create life directly and I don't think it came from Mars although He may have created it there also. I believe that life, all life, is in essence an extension of God. Without God, there would be no life. Hence God is present in all living things.

"When ALL the statements of events are taken into consideration (without taking every little thing literally) the timing of events and the nature of events do not add up."

Of course you are free to believe that, but I don't think the Bible provides an exact timeline for anything - just very rough approximations prior to Moses at any rate.

"If you do not believe in miracles,"

I do believ in miracles - all Christians do. Some are more "mraculous" than others. The plagues on Egypt can all, or nearly all be explained by natural phenonmema taken to an extreme degree and timed so well that Divine intervention is a certainty.

"So why cannot it be possible that the fossils records you trust mean something different than your interpretation."

ANYTHING is possible, especially with God.

"You simply do not know what happened "

Nobody does for sure, we are just guessing, based on what we have uncovered in Science, and taken with Biblical revelation.

"If many pre-men existed did they have souls? If so Adam was not the first."

I think ALL living things have some kind of "soul", but only man has a human soul given to him by God which makes him special. Only man can know the difference between good and evil and choose eternal life and salvation, or death and eternal damnation. Animals may have souls, but they are incapable of knowing good and evil and are incapable of choosing salvation.

"You can claim it all theological and dismiss it, fine"

I try to find a way to reconcile the two - science which we KNOW from objective study and religion, which we know from Faith.

"I choose not to as these are foundational to Christianity."

I agree that belief in God, that fact that God made man directly in His image, that man sinned, that God sent Hi Son to save him, that we can all achieve salavation, that there will be a resurrection of the dead and last Judgement, that Satan exists and is a personification of evil and tempted Eve in the Garden, that miracles happen, etc. etc. Where we diverge is over the issue of evolution.
I don't believe that evolution is a substantial issue or Christ or God would have addressed it in the Bible.

"In these discussions there is more opinion than facts and no baseline of truth can be established."

To a degree what you are stating is correct. But thevidence for evolution of lower animals is practially irrefutable. The issue is did God break the natural laws He created in producing man, or did He emply them to achieve His objective. I believe the latter, you believe the former.

During the Byzantine Empire, people killed each other over issues like using two fingers or three fingers to make the sign of the cross, whether or not God the Holy Spirit proceeded from the Father or from the Son, etc, etc. I think the essential message of Christ is and should be the most important issue for any Christian.

"Like stopping the sun for Joshua?"

Did God stop the sun?? The earth revolves around the sun, not vice-versa. He may have stopped the earth or He may have made the observers THINK the sun had stopped.

"Like the floating ax head?"

Metal can float - ever see the Battleship New Jersey? A miracle - yes. Outside the norm of possibility - no.

"Like wet wood spontaneously combusting?"

Good question. I'll have to think about that one.

"Like conceiving a child in the womb of a virgin? "

Not beyond the realm of possibility. There are popualtions of animals - like some lizards, that are totally all female. They reproduce by parthenogenesis - without breeding. Again, a miracle? Yes. Beyond the realm of explanation through God's natural laws - no.

"Like a talking donkey? " We have those. I call them Democrats. Seriously, that's a good example of a totally unnatural miracle.

"Like a burning bush that is not consumed?"

Ever see foxfire? Its a fungus that grows on wood and glows like its on fire at night. Miracle - yes. Not explanable through natural lawas - no. Actually God speaking through the burning Bush to Moses is an example of a pure miracle. Bushes can't speak.

"Mana from heaven?"

I read somewhere about another "explanation" for that, but regardless, I'd consider it a miracle.

"Should I go on? You are putting God in a box."

I can't put God in any box. He created the laws which run the Universe - chemical laws, physiacl laws, Evolution, the Big Bang, ions, atoms, etc. He did it - all of it, out of absolute nothingness. I am not disputing that. What we are discussing is HOW He did it or might have done it - neither of us was there.

"Where do you think the fossils of the offspring of the fallen angles who mated with woman and beast are?"

Angels are non-corporeal beings. Any offspring they produced may be pure spirit also, On the other hand, the chance of any one dead creature prducing a fossil are exceedingly remote. Take a walk in a forest any day and see how many skeletons of dead animals are lying around.

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