Amphibians as a Support for Evolution

I am always amused by Creationists’ denials that transitional forms exist among either fossil organisms or living species. After all, the definition of “transitional” depends on the existence and forms of two other organisms that the transitional form is being compared to. Thus Archeopteryx is called transitional because it has characteristics of both birds and theropod dinosaurs, which are reptiles. But if neither birds nor reptiles existed, then Archaeopteryx would not be transitional to anything.

It is the same with amphibians. Their very existence as a class is evidence of evolution, for they are clearly transitional between fishes (which are almost entirely confined to water, breath through gills, have fins instead of legs, and lay jelly-like eggs), and reptiles (which often have legs, can thrive even in dry deserts because they breath through lungs, and lay hard or leathery shelled eggs on land). Most amphibians as adults can live on land by walking on legs and breath air through lungs, but they lay eggs like those of fish and have a larval stage that lives in water and breaths through gills. So one could argue that a salamander is a modified fish or that a lizard is a modified salamander, thus regarding the salamander as a transitional form having characteristics of both.

One might also think a Creator of all living things from scratch would not bother to make animals with such lifestyles as amphibians. What would be the point, except to trick us into accepting evolution?

The forms of living amphibians also give us some insights into how evolution works:

  1. The Urodeles include the news and salamanders which have short and weak limbs, long bodies and tails, and a larval form that resembles the adult.
  2. Anuarans (frogs and toads) have very short bodies, powerful limbs, and no tails as adults, but have a very different larval form with a strong tail for swimming and no limbs. They are the most common amphibians.
  3. Gymnophiores, also known as caecilians, have no limbs at all and have extremely long bodies but little or no tail and live almost entirely underground. Indeed, they resemble giant earthworms.

It is easy to see how both frogs and caecilians could have evolved from salamanders by going in completely different directions. One might also suspect that salamanders are a transitional form between frogs and caecilians, but in fact the salamanders are the primitive forms most closely resembling the fish and lizards mentioned earlier, while the other amphibian forms resemble neither fish nor lizards, but are more specialized in their lifestyles.

Most fossil amphibians from the Devonian period to the Permian period have the form of salamanders, thus providing support for the hypothesis that salamanders are indeed the primitive form. In the mass extinction at the end of the Permian period, the giant amphibians that had been so common on the land disappeared. Later, one line of smaller amphibians developed into frogs in the Triassic period. Today, with so much competition from reptiles, birds and mammals, the smaller amphibians, numbering only 4,000 species, are a remnant of what the class once was.

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9 thoughts on “Amphibians as a Support for Evolution

  1. Dale Husband,

    I find your suggestion amusing that a Creator would never bother to create such animals as amphibians as you suppose amphibians infer evolution. I rather doubt you believe in a Creator, but even if you did I doubt you could presume to know His mind entirely. Frogs and spiderwebs, atheists and platypi suggest a whimsical Deity who excels at being implacable and unpredictable.

    I might add that you wouldn’t have made any connections at all between evolution and amphibians if you had not been told to do so. You appear to have taken Darwin’s offerings, hook, line and sinker. Incidentally, amphibians make bloody good bait.

    As an artist, and especially as a fantasy artist, I can tell you why Someone might create something as preposterous, as grotesque and as wonderful as an amphibian. It just begs to be done! The artist finds a kindred Spirit in the Creator. Yet, lest you become wise in your own conceits, consider also that the same Creator caused a few of our planets and moons to spin backwards to confound cosmoligical evolution.

    Blaise Pascal put it best: “He’s left us too much evidence to ignore and too little to be sure.” Faith is a requirement, but it’s not an unreasonable faith, whether you think so or not. I worry that science and especially popularized pseudoscientific babble like evolution takes the mystery out of life. Neils Bohr deduced that “It is the task of science to reduce deep truths to trivialities.” Not so! The human mind is so much more than neurons. We are not this crude matter and we are much more than the sum of all our parts.

    Your extrapolations show a good deal of thought. I admire your pluck, though not your conclusions. Do try to use that big brain of yours for good.

    –Sirius Knott

  2. “I rather doubt you believe in a Creator, but even if you did I doubt you could presume to know His mind entirely.”
    And yet later you state your own speculations about the mind of the Creator. Neat!

    “Frogs and spiderwebs, atheists and platypi suggest a whimsical Deity who excels at being implacable and unpredictable.”
    And thus unworthy of my allegiance.

    “I might add that you wouldn’t have made any connections at all between evolution and amphibians if you had not been told to do so.”
    Told by whom? The conclusion was entirely my own and the decision to write this essay was entirely my own. I do not blindly obey the orders of others regarding evolution, or any other subject.

    “Yet, lest you become wise in your own conceits, consider also that the same Creator caused a few of our planets and moons to spin backwards to confound cosmoligical evolution.”
    And such exceptions only support the idea that the Solar System is the product of natural forces over billions of years, not a recent act of Intelligent Design.

  3. DH,

    I was delighted by your comments on my, well, comments. If I may be so bold as to respond…

    “My own speculations about the mind of the Creator” are based on two things: reason, which encompasses observation, science and philosophy, and revelation, specifically what God has revealed of Himself through Scripture, the natural world and in person of Jesus Christ. What are yours based upon? And don’t posture this time. You did not come up with anything on your own any more than I, Stephen Hawking, Charles Darwin or anyone else for that matter; that is, more specifically, you did not come up with anything ex nihilo. Your ideas have a source.

    As to a Creator you deem “unworthy of your allegiance” …what sophistry. The argument of the Judeo-Christian tradition turns the argument on its head. You, and humanity in general, are unworthy of the Creator’s allegiance due to the Fall. You’re one of those, unless I’m mistaken, who don’t want to believe. I’m not sure any amount of evidence would convince you otherwise. I hope I’m mistaken, but experience tells me I’m probably not. So in your case, I thank God for the philosophical applications of the Heisenberg Uncertainty Principle. ;]

    As to your latter comment, it supports both theories equally. It’s either evidence of design with elements of whimsy and/or the Fall [and resulting entropy] thrown in. Or it’s evidence of a purely deterministic origin. Unfortunately, the uncertainty principle, as Stephen Hawking noted in A Brief History of Time, negates Laplace’s dream of a purely deterministic universe. Sorry.

    And, yes, I read your dreadful little post [it’s well-written,but a bit claustrophobic, but I admire dogmatism; I simply disagree upon which dogma we ought to be dogmatic about!], was Our Solar System Intelligently Designed? One of your commenters answered you in the manner I would have when he noted that you’ve omitted the implications of the Judeo-Christian concept of a Fallen World [Universe], though I would’ve have, again, also have noted the probable element of divine whimsy. A Creator without creativity! Ha!

    If I may return the favor, have you read this piece:

    http://siriusknotts.wordpress.com/2007/12/08/why-darwinists-argue/

    I would appreciate your thoughts, though, again, likely not your conclusions. ;]

    –Sirius Knott

  4. Sirius, I read that little diatribe of yours, and looked at some of your other crap. It is simply pathetic, the way you try to depict us evolutionists as dogmatic and and your views as superior to all others, even poking fun at a “Mr Oops” rather than actually addressing the reality of what you reject. As far as I can see, you don’t have a leg to stand on regarding your ability to judge the credibility of others.

    Quite simply, you are a denialist regarding evolution and that means you don’t care what the facts are. Your position gives you emotional comfort, so you cling to it because you want to. Then you attack your opponents in sarcastic terms and think that makes you cool, when in fact it makes you no better than they are, hypocrite!

    http://scienceblogs.com/denialism/

  5. Lovely opinion, albeit a bit vitriolic. And partially baseless. Fortunately, opinions are like noses. Everybody’s got ’em and they usually smell. ;]

    You are perfectly correct that I reject evolution. You are perfectly correct in presuming that no amount evidence on God’s green Earth [note reference to Creator] would convince me otherwise. You see, I’ve already examined the evidence and I’m thoroughly convinced of my position. Like G. K. Chesterton, I set off to invent a heresy all my own and when I put the finishing touches to it I discovered I was backed up by all Christendom! Again, the whimsy of God.

    Now, if this makes me a hypocrite, Physician, heal thyself! Are you honestly going to state that any amount of evidence would convince YOU otherwise? Are you even willing to consider my view? I think not.

    Dale, you amuse me. I am dogmatic. So are you. I think we both agree that the issue is not mere dogmatism but rather which dogma we ought to be dogmatic about.

    Oh, and Mr. Oops! asked for it. [Tell me you wouldn’t have responded in kind.]

    One last thing: I’m not interested in being cool. I lost interest in that pursuit back in junior high.

    So long and thanks for all the fish!
    –Sirius Knott

  6. DH,

    One additional thought. It may surprise you that I don’t feel that Darwinism is falsifiable. You can’t refute it because folks will always say that we just don’t know enough yet but we will someday [Darwin himself set these conditions in place]. That’s faith.

    Belief in God [and Creationism] isn’t falsifiable either. No matter what objection you throw out, there’s always a way to confound the objection.

    I think both theories fit the facts reasonably well. They both have their weight of evidences. I just think that creationism fits better because it explains the human condition more fully.

    –Sirius Knott

  7. Sirius, are you serious?

    Your last two comments are so full of nonsense I hardly know where to begin.
    “You see, I’ve already examined the evidence and I’m thoroughly convinced of my position.”

    How can you examine evidence for Creationism, unless you mean the Bible or some other Creation myth? That’s the only evidence I’ve ever found.

    “Like G. K. Chesterton, I set off to invent a heresy all my own and when I put the finishing touches to it I discovered I was backed up by all Christendom! Again, the whimsy of God.”

    Sounds like delusions of grandure to me. What are you, one of those cult leaders like David Koresh or Jim Jones?

    “Are you honestly going to state that any amount of evidence would convince YOU otherwise?”

    Yes, of course. First, I need to see that evidence. Assertions based on dogma won’t do. Assertion based in MISCONCEPTIONS about evolution won’t do either.

    “Dale, you amuse me. I am dogmatic. So are you. I think we both agree that the issue is not mere dogmatism but rather which dogma we ought to be dogmatic about.”

    That’s called “painting your opponent to be no better than you”, and that’s just dishonest. I’ve dealt with Creationists long enough to recognize all their rhetorical tricks. You have brought me nothing I haven’t seen before, and it annoys me.

    “It may surprise you that I don’t feel that Darwinism is falsifiable. You can’t refute it because folks will always say that we just don’t know enough yet but we will someday [Darwin himself set these conditions in place]. That’s faith.”

    Liar! Darwin himself gave several examples of how his theory of natural selection could be falsified in his book The Origin of Species, which it seems you have never read. If you falsify natural selection, then evolution becomes impossible according to known scientific laws and we’d have to abandon it and accept Creationism.

    “Belief in God [and Creationism] isn’t falsifiable either. No matter what objection you throw out, there’s always a way to confound the objection.”

    Which is why Creationism is not science. But denialist tactics like Logical Fallacies and Moving the Goalposts, which Creationist commit on a regular basis, are enough to destroy their credibility before most moderatly religious people.

    “I think both theories fit the facts reasonably well. They both have their weight of evidences. I just think that creationism fits better because it explains the human condition more fully.”

    No, no, and no. That’s just delusions on your part. The fact that neither you nor any other Creationist I’ve investigated can put forth anything that could actually falsify evolution, then turn around and claim that evolution is not falsifiable, illustrates the denialist mentality quite nicely.

  8. Pingback: A useless debate « Dale Husband’s intellectual rants

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