Posted on 02/03/2004 2:37:14 PM PST by 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.
(Excerpt) Read more at science.psu.edu ...
Because when you compare certain passages in the Bible they are factually wrong if read literally and compared to reality.
Jesus died for man's sins, not my pet turtle. The question is when did he create man.
You, on the other hand, are distracted by pride and the need for you to prove what is not within man's grasp or ability to prove.
You will be forever confounded if you refuse to give all glory to your Creator.
That's your opinion.
....and the answer is when He said He did. Any other theory or twisted explanation is to doubt His word.
You will be forever confounded if you refuse to give all glory to your Creator.
And you, possessing perfect understanding, are without pride.
Jesus let evil spirits enter into pigs without giving the pigs any consideration. God flooded the world killing all the life on earth for the sins of humans. God doesn't claim to be fair.
I make no apologies for taking God at His word and refusing to dissect it in an attempt to make it fit any theory devised by man.
Quite the contrary......I am humbled by that which passes my understanding. I also know that perfection eludes every person born to this earth , except One. That is, after all, what this is all about.
In this same chapter of Genesis, God asks Adam "Where are you?". There is nothing in the text to indicate that this question is a metaphor. So, in your opinion, God didn't really know where Adam was ?
Show me.
I'm not sure I understand your question.
You have asserted that you are capable of perfectly interpreting the Bible. You know which parts are allegory, which parts are metaphor, which parts parable.
It is an indisputable fact that many here disagree with your interpretation, so either you are perfect or you are capable of error. Which is it?
Nor do I fully understand the reality of creation to parade myself as an oracle of knowledge and I distrust anyone who pretends to know the truth of origins in science.
If you want to play games and minimize the meaning and context of God's word, I will leave that to you.
As for myself and since I believe HE gave us the Bible to teach us (not confuse us) I will not spend a moment second guessing Him.
What is under discussion here is your word, not God's. You have placed yourself in the position of speaking for God.
It is necessary to determine the proper sense of Scripture, while avoiding any unwarranted interpretations that make it say what it does not intend to say. In order to delineate the field of their own study, the exegete and the theologian must keep informed about the results achieved by the natural sciences ...Source: Message from the Pope, 1996 (on evolution).
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