More Early Tetrapod Fossils Help Uncover the Origin of Life on Land

Another interesting specimen uncovered in the sprawling family tree of the early tetrapods (the four-limbed fishy conquers of land): Ventastega curonica.

It’s worth noting, yet again, how fossil evidence generally works when it comes to evolution. Discerning the exact ancestry of most specimens is generally implausible… but that’s not really what scientists require in the first place. What they want and need is to flesh out the overall family tree:

Scientists don’t think four-legged creatures are directly evolved from Ventastega. It’s more likely that in the family tree of tetrapods, Ventastega is an offshoot branch that died off, not leading to the animals we now know, Ahlberg said.

“At the time, there were a lot of creatures around of varying degrees of advancement,” Ahlberg said. They all seem to have similar characteristics, so Ventastega’s find is helpful for evolutionary biologists.

Of course, some people, such as the science journalists that penned the piece, seem a little rusty on the concept:

Ventastega is the most primitive of these transition animals, but there are older ones that are oddly more advanced, said Neil Shubin, professor of biology and anatomy at the University of Chicago. He was not part of the discovery team but helped find Tiktaalik, the fish that was one step earlier in evolution.

“It’s sort of out of sequence in timing,” Shubin said of Ventastega.

Shubin’s likely point here, rather poorly represented in the article, is not that we’d necessarily expect to see Ventastega specifically “in sequence,” but simply that it isn’t on the direct line from which all land animals are descended.

To many lay readers, however, the “primitive” and “out of sequence timing” might seem like elements of a mystery: why would something still have “old” features?

But in fact, if Ventastega is an cousin/offshoot of the branch from which all later land animals are descended, then these terms are really only relative. Ventastega, after branching off from other tetrapods, went its own way: retaining some traits that became modified in the main tetrapod line, and gaining some traits unique to its own branch.

The former retained traits are “primitive” only in the sense that they are more like what earlier tetrapods had than what the particular line of tetrapods that we care most about went on to change. Had those tetrapods gone extinct and Ventastega’s descendants gone on to father all life on land, we’d be talking about the “primitive” traits of the formerly mainline tetrapods, compared to Ventastega.

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18 Responses to More Early Tetrapod Fossils Help Uncover the Origin of Life on Land

  1. Michael says:

    You want the real facts on the intellectual dishonesty of archaeologists,scientists, biologists, etc.? Read a pro-evolutionist Bill Bryson’s “A Short History of Nearly Everything”

    The utter arrogance of The Museum of Natural History creating a whole diorama with two apelike creatures in detail based on a find in Africa of footprints!!!

  2. Mike says:

    “Ventastega is the most primitive of these transition animals”. Interesting that this “transition” animal is described in the same article as “an evolutionary dead-end” and as “an offshoot branch that died off, not leading to the animals we now know”. The author must have a definition for transition that I’m not familiar with. I sure hope I don’t transition like Ventastega did.

  3. Grendel The Martyr says:

    @Mike: A line may be transitional and also go dead, though I don’t know if Ventastega is an example. The qualifier in the article is that the writer didn’t think Ventastega led to animals we now know. Bad identifies problems the writer has with certain concepts.

    @Michael: All archaeologists, scientists, biologists, etc. are intellectually dishonest? Wow. You must have spent years – decades – determining that.

  4. Pat says:

    Mike: It sounds like you do have a definition for “transition” that is more limited than the author’s. You are thinking of transition animals only as those animals that were part of the direct evolutionary line of animals that are still around today. The author’s definition of transition animals includes animals that have some characteristics of tetrapods and some characteristics of fish, but are not completely one or the other. Thus, they give us an idea about how a gradual transition from fish to tetrapods can come about. Furthermore, they share a common ancestor with animals that are part of the direct evolutionary line of animals around today, and thus can tell us about the history of lines that didn’t die out.

    You could imagine taking your definition to its extreme and defining transition animals as only those individual animals whose direct descendants are alive today. This would rule out for instance all fossils of animals that died before bearing young, even if their species as a whole did indeed include the ancestors of modern species. This would not be a very useful definition of “transition” animals. It would also be counter-productive to limit the study of transitional fossils to animals that fit this definition, since even if an animal did not bear young, we can learn something about its species by studying it. We thus learn something about the members of its species that did go on to have descendants that survived. In a similar way, it would be counter-productive to limit the study of transitional fossils to only those species that had descendants that survived and ignore closely related species that didn’t.

  5. Steve says:

    Ah yes, we’ll never be able to pry open the tightly closed minds of the creos and IDers….they’ll cling to their 4 or 5 thousand year old myths and superstions forever.

    But to me it boils down to 2 choices. Either you accept the mountains upon mountains of modern scientific evidence that humans evolved naturally from lower forms or you accept that an invisible, supernatural Santa Clause in the sky “poofed” people into existence….heh heh…hard choice…… :-)

    Or…maybe you can accept that he created the first man out of dirt and then, as an afterthought, created the first woman out of a rib……hmmm….wasn’t he smart enough to realize ahead of time he would need a woman? DUH!

  6. Grendel The Martyr says:

    @Steve – A full, literal belief that God created the first man out of dirt and then, as an afterthought, created the first woman out of a rib obviously wasn’t formed on physical evidence, and is therefore strongly resistant to the mountains of evidence that say otherwise. When religious belief comes first it sort of sets a mental template that will accept, obviously, all manner of unlikely sounding stuff all on faith and without a whit of scientific evidence, in fact, to believe thusly – solely on faith – is considered a sign of strength and piety. This is powerful, powerful stuff to overcome.

  7. Bad says:

    Mike: generally when we talk about transitional creatures, it doesn’t matter whether they are direct ancestors of anything. The point is that they have a distinctive mix of traits that links two branches together. There are certain groups of traits which are distinctive to tetrapods, and certain ones that are distinctive to primitive fish. Creatures like Ventastega have variations of both, just demonstrating the link.

  8. Steve, Grendel; you’re just seeing things through the “worldview” that things are what they appear to be. Once you learn to see things through a literal reading of Genesis, you’ll see just how much simpler things are when you cram a 14,000,000,000 year old universe and a 4,500,000,000 year old Earth down into the 6,000 years that actually happened. As a half step, try filling in all of the gaps in our knowledge with an unnamed, supernatural Designer, and ask people why “Darwinism” doesn’t explain physics and the Big Bang. Later, start taking Exodus literally. Then, the “begets”, maybe. Baby steps, as it were.

  9. Robert says:

    http://www.cnn.com/2008/TECH/science/06/25/fishfossil.ap/index.html

    So, scientists have found a “fossil skull, shoulders and part of the pelvis of the water-dweller Ventastega curonica”. But “if you saw it from a distance, it would look like a small alligator, but if you look closer, you would find a fin in the back”. Tell me how you can look at a skull, shoulders, and a piece of pelvis and say with any degree of certainty that the animal would have a fin? You can’t. Any more than you can say where this animal fit in an evolutionary timeline. It assumes that the general theory of evolution must be the only explanation, which must be slightly modified every time evidence is found that contradicts it.

    The problem with the vast majority of “scientists” and scientific outlets is they close their minds to the possibility of anything outside of the natural world, because it cannot be observed. Yet science admits it cannot explain, we cannot know, what created matter to begin with, when we acknowledge that matter can neither be created nor destroyed (in our natural world), and that the universe is winding down; it had a beginning.

    The American Association for the Advancement of Science in 2002 accepted a resolution which stated, “Therefore Be It Further Resolved, that AAAS calls upon its members to assist those engaged in overseeing science education policy to understand the nature of science, the content of contemporary evolutionary theory and the inappropriateness of ‘intelligent design theory’ as subject matter”. So anything other than evolution can not be legitimately examined in scientific circles because anything else has been blanketly written off as invalid.

    Is science, are scientists, really willing to accept this dogma? Are we so confident in our limited scope and understanding that we can write off explanations we can’t (yet) observe? What would our predecessors of decades ago think, who insisted the human body contains dozens of vestigial organs, almost all of which we now know the functions of today? The AAAS’s precedent implies we should never have reconsidered “vestigial organs” because science had already determined everything we needed to know about them.

    Evolution assumes progressions, constants that we know are only constant in our neighborhood, not throughout the universe. Scientists change the evidence to fit the theory, not the other way around (or why, on the Laeotoli footprints being identified as human but found in a strata below which homo sapiens would exist, did Mary Leakey say that if we didn’t know the footprints were found in the wrong place she would have to conclude they were human?).

    We speak of elements of the natural world in a peculiar way. We call the cuttlefish “genius”, “inventive”, having a “sophisticated” system of communication. These are not words you use to describe something that occurs by accident. Evolutionist Robert Jastrow said of the human eye “The eye appears to have been designed; no designer of telescopes could have done better. How could this marvelous instrument have evolved by chance, through a succession of random events?” We take the circulatory system and reduce it to the point of irreducible complexity, and are buggered to explain how random chance resulted in a closed system where every piece is interdependent on inception.

    True scientifically-minded people MUST be willing to explore other explanations for the natural world. We must be willing to accept that there may be a supernatural explanation as a hypothesis worth exploring (and refuting based on evidence, rather than based on the scientific dogma we have been fed).

  10. Steve says:

    Modusoperandi – Why would I believe for one second something that was written down thousands of years ago by ignorant, primitive people??? I certainly wouldn’t. It’s just old myths and superstions of course. Fairytales and fantasies. It scares me that supposedly intelligent people still cling to such nonsense.

    The evidence for evolution is clear. It’s undeniable. It’s been proven over and over again. You don’t need to look at the fossil record to see the evidence. Darwin probably never saw a fossil, he based his ideas on his observations of plants and animals that are alive today. When you really study nature, evolution is so utterly obvious. But of course creos and IDers never take the time to do that. They just throw out their predjiduced ideas that are based on old myths.

    Science? Or old myths and superstions from thousands of years ago….Like I sad….Boy what a hard choice! Heh heh….

  11. Steve “The evidence for evolution is clear.”
    See? There’s your problem, right there. Stop looking at the evidence, dummy! If you really have to look at it, squint.

  12. Steve says:

    The evidence is the most important thing!

    Stop reading old myths and superstiotious nonsense and look at the evidence instead.

    Stop blindly accepting old fairytales and make up your own mind based on evidence, not myth.

  13. Grendel The Martyr says:

    Since Modus is already pulling the one so energetically, I’ll start pulling Steve’s other leg. (Steve, he’s being sarcastic…..)

  14. Actually, I try to avoid sarcasm. Sarcasm is the lowest form of wit.
    I was flitting from parody to light satire. Or, the other way around. I’m ever so confused!

  15. Bad says:

    Robert Says: So, scientists have found a “fossil skull, shoulders and part of the pelvis of the water-dweller Ventastega curonica”. But “if you saw it from a distance, it would look like a small alligator, but if you look closer, you would find a fin in the back”. Tell me how you can look at a skull, shoulders, and a piece of pelvis and say with any degree of certainty that the animal would have a fin? You can’t.

    Are you really certain that you can’t? This intrigues me: why are you so certain? Do you actually know the specific pieces of evidence by which they would conclude that this creature had fins?

    Any more than you can say where this animal fit in an evolutionary timeline.

    Again, do you actually know on what basis scientists claim that they can?

    It assumes that the general theory of evolution must be the only explanation, which must be slightly modified every time evidence is found that contradicts it.

    You’re confusing several things here. It’s true that we now use the overall framework of evolution to figure things out. But that’s only because it’s so well established by evidence, not assumption. And it’s also true that we modify our understanding of specific elements and ancestral lines in light of evidence. But this isn’t the same thing as constantly modifying that overall framework.

    The problem with the vast majority of “scientists” and scientific outlets is they close their minds to the possibility of anything outside of the natural world, because it cannot be observed. Yet science admits it cannot explain, we cannot know, what created matter to begin with, when we acknowledge that matter can neither be created nor destroyed (in our natural world), and that the universe is winding down; it had a beginning.

    This is a colorful mess of confusion. Scientists are not “closed” to the possibility of things outside the natural world. But that still doesn’t relieve them of the task of dealing with evidence that we find in the natural world, and what it plainly shows, no different than evidence you find used in a murder trial, or the study of history.

    What you seem to want is for “poof, magic happened” to be a legitimate part of science. But it can never be. Science needs evidence that leads to explanations. And the philosophical possibility that anything at all could happen at any time with no evidence of this taking place is simply unworkable as ANY sort of argument.

    Imagine the court system if we used your standard of evidence. Every murder would go free, because they could simply point out that maybe a magic spell was cast creating all the evidence that framed them.

    But if you have to fall back on that sort of “alternative explanation” to refute hard evidence, then your credibility is already in the toilet.

    As for the origin of matter. We actually do know quite a bit about the origin of matter: you probably meant something else (energy, perhaps?). The thing is, we don’t know whether or not the universe had a beginning. We don’t really know what will happen as it winds down. We know of the beginning of the universe as we know it (including the origin of matter), but we don’t know much more beyond that.

    And so? How does that have anything to do with determining whether or not Ventastega had a fin?

    The American Association for the Advancement of Science in 2002 accepted a resolution which stated, “Therefore Be It Further Resolved, that AAAS calls upon its members to assist those engaged in overseeing science education policy to understand the nature of science, the content of contemporary evolutionary theory and the inappropriateness of ‘intelligent design theory’ as subject matter”. So anything other than evolution can not be legitimately examined in scientific circles because anything else has been blanketly written off as invalid.

    Well, yes: non-explanations don’t qualify as science. And were you laboring under the misapprehension that science education is the same thing as actually doing science? The statement in question refers to teaching students the basics of biology, not closing off anyone in actual scientific practice from bringing forth evidence for anything, even evidence that contradicts evolution (in fact, lots of real scientists have done just that for specific ideas about evolutionary theory, and ended up overturning them even).

    The problem here though, is that you and the people you are defending don’t actually have any evidence to bring forwards. That’s why you need to talk about just about everything but the evidence.

    Is science, are scientists, really willing to accept this dogma? Are we so confident in our limited scope and understanding that we can write off explanations we can’t (yet) observe? What would our predecessors of decades ago think, who insisted the human body contains dozens of vestigial organs, almost all of which we now know the functions of today? The AAAS’s precedent implies we should never have reconsidered “vestigial organs” because science had already determined everything we needed to know about them.

    You seem to be laboring under a lot of misapprehensions. Vestigial doesn’t mean “non-functional.” It means a vestige (remains) of a former form and function we know from other forms of life. Whether or not it has a different function or still retains some vestige of the former function is irrelevant to whether or not it demonstrates evolutionary change.

    Evolution assumes progressions, constants that we know are only constant in our neighborhood, not throughout the universe. Scientists change the evidence to fit the theory, not the other way around (or why, on the Laeotoli footprints being identified as human but found in a strata below which homo sapiens would exist, did Mary Leakey say that if we didn’t know the footprints were found in the wrong place she would have to conclude they were human?).

    I don’t have time to track down Mary Leaky and ask her, but doubtless you aren’t telling the whole story with what she said in any case. And I think you mean “Laetoli.” In which case you are just being silly. First of all you’re still talking about a period in time when australopithecines were around to begin with, which you shouldn’t even be admitting exist in the first place. And second of all, these particular prints are highly ambiguous. A lot of people have pointed out that they very well could be australopithecine in origin, and there’s little data to refute this null hypothesis. Creationists tend to only quote a single source on this from early on in their discovery, forgetting that science is a debate based on evidence that proceeds. And what it has proceeded to is that these footprints are evidence that some easy australopithecines were bipedal.

    We speak of elements of the natural world in a peculiar way. We call the cuttlefish “genius”, “inventive”, having a “sophisticated” system of communication. These are not words you use to describe something that occurs by accident.

    You’re embarrassing yourself here. Evolution is not something happening “by accident.” And in any case, I’m not sure why you think the use of any of those terms precludes talking about the evolution of the cuttlefish in any way.

    Evolutionist Robert Jastrow said of the human eye “The eye appears to have been designed; no designer of telescopes could have done better. How could this marvelous instrument have evolved by chance, through a succession of random events?” We take the circulatory system and reduce it to the point of irreducible complexity, and are buggered to explain how random chance resulted in a closed system where every piece is interdependent on inception.

    First of all, Jastrow is an astronomer, not a biologist, and the fact that he has own doubts and ideas do not make them worth anything more than your own. But in any case, you are not representing his views accurately: a common and very dishonest creationist tactic (though perhaps you read this quote in a list of quotes somewhere, and as such were ignorant of this). Have you actually ever read The Enchanted Loom: Mind in the Universe from which these quotes are taken? If you had, you might know that Jastrow has more to say on this subject, including that the “fact of evolution is not in doubt.” Jastrow, in the passage you quote, is musing about the possibility of a designer, which he wishes to believe in. But this doesn’t make him an expert on eye or circulatory evolution, or prove that simply because they seem complex to him, that this means they must have been designed.

    And in fact, there are answers to his specific questions in any case.

    True scientifically-minded people MUST be willing to explore other explanations for the natural world. We must be willing to accept that there may be a supernatural explanation as a hypothesis worth exploring (and refuting based on evidence, rather than based on the scientific dogma we have been fed).

    But you never mention any evidence at all. You claim that there’s no way to know if Ventastega had fins (without explaining how you know that it’s not possible). You cite vague human-like footprints that were found in an era where human-like creatures already existed. You quote an astronomer musing about how complex the world seems to him. And so on.

    That’s your evidence? That’s a cruel joke upon the concept of evidence, is what it is.

  16. Grendel The Martyr says:

    I’d love to hear how science is supposed to ‘explore the supernatural’ when by definition the supernatural is outside the natural and scientifically unexplorable. Are you sure you didn’t mean ‘unquestioningly accept human claims about the supernatural’ ?

    Science isn’t a democracy, nor about being ‘fair’, it’s about the evidence, and evidence is a dictator. Evidence. Got any?

  17. Robert “the vast majority of “scientists” and scientific outlets”
    If you’re going to put the word scientists in scare quotes, at least be consistent and do the same with the word scientific. Alternately, say “so-called scientists” instead. After that, continue to provide no evidence for your own pet hypothesis, because if there’s one thing that will take down the Theory of Evolution, it’s idle, blue sky pondering. “Science” is like that.
    The only thing that can destroy a “scientific” theory is a lack of sufficient evidence for something else (a smear campaign helps. Did you know that Ventastega curonica lead to Hitler? Make sure that you say it loud and often. Eventually that potent combination of emotion and repetition will make it true. Oh! Don’t forget to quote-mine Darwin, too).

  18. Steve says:

    Don’t confuse theory with “scientific theory”. If you know anything about science, you would know that a scientific theory is held to a higher standard. One definition is “A statment or group of statements that explain the observable facts”. The “fact” is that life evolves, the scientific theory part is the explanation of exactly how that happens. There is still some debate on minor points in the theory but the overall fact of evolution isn’t really questioned except by creo’s, ID’ers and a few other crackpots.

    All anyone has to do is look around them and observe nature for themselves. Evolution jumps out and slaps you in the face. It’s so freaking OBVIOUS. No fossils needed, Darwin didn’t base his theories on fossils but on the plants and animals he observed.

    But again, I would certainly accept science over 4-5 thousand year old myths about an invisible, supernatural being in the sky “poofing” people into existence or making them out of dirt and a rib….how ridiculous.

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