Revelation 4:11
Constantly searching for objectivity in the evolution debate...
See my profile for info
Posted on 04/07/2006 4:16:49 AM PDT by PatrickHenry
I'm pretty sure you didn't mean to phrase it like that, Ich. ;-)
Cheers!
"Or, it's Man's best explanation for the diversity of life we see around us."
Yes, just as it was foretold would be the case by the prophets.
I plead ignorance here...
No sin in that. There are a lot of folks who *should* but *don't*...
Do Darwinian evolutionists theorize that this creature was the very first instance of its species to have the land-dwelling attributes (his mom & dad had no ribs, neck or pectoral fin)...
No, its parents looked pretty much like it did. Evolution does not proceed by large drastic changes occurring in a single generation. It proceeds by small changes accumulating over many generations, until eventually the Nth-generation offspring ends up looking quite different from its Nth-great-grandparents.
Consider dog breeding as an example more directly familiar. At no time has a new breed arisen by anything as drastic as a German Shepherd giving birth to a litter of Dachshunds. From one generation to the next, each new litter of puppies looks pretty much like their parents. But over many generations, small changes are amplified to the point where, today, there are dogs as different from each other as, say, Chihuahuas and Rottweilers.
Or did mom & dad have a half a neck or some other portion of a neck? Or a neck that couldn't hold it's head up?
No, see above.
What were the physical manifestation of these transitional anatomies?
If you're asking about the various intermediate stages, this fossil itself sort of had "half a neck" -- it could bend much more than the average ancestral fish, but its neck had not yet refined to the fully articulated neck found in true amphibians. Similarly, it still had fin rays on its "feet", yet also had partially articulated "elbows", "wrists", and "fingers", which were far more amphibian-like than the pectoral fins of most fish, yet not as finely developed as its eventual descendants, the true amphibians.
How do macroevolutionists like yourselves explain this anotomical progression?
Genetically, physically, or fitness-wise?
What made these transitional lifeforms more fit than their less evolved counterparts?
At the time, there was intense competition in the water and also large, fierce predators, but no competition or predators on land (although there were abundant plants and many species of land-based insects, albeit no vertebrates). Any creature which could leave the water and subsist on land for even a little while would have a great advantage in avoiding predators during its time out of water, and in having abundant food sources all to itself without competition. It would also have an enormous advantage in being able to survive droughts by crawling from one evaporating pond or stream in search of other bodies of water. It wouldn't have to do this enormously well at first -- just being able to do it at *all* would be a great leap forward in survivability.
I'm pretty sure you didn't mean to phrase it like that, Ich. ;-)
Whoops! Yes, typo, sorry about that. Thanks for catching it.
How can this be? Can you illustrate how this works with an example?
"Yes, just as it was foretold would be the case by the prophets."
The prophets foretold that Darwin would write a book? I missed that chapter and verse.
Apparently you are not aware of it, but your response perfectly illustrates the point made in the post that you responded to.
"The prophets foretold that Darwin would write a book? I missed that chapter and verse."
Darwin is man's god, and his claims are not new, denial of the Heavenly Creator is a very very very old religion.
Touche'
Only if you enjoy outright falsehoods. The IDers are just being dishonest here -- the opponents of ID do not say the debate "doesn't exist". Straw man, anyone? Of course it exists. No one denies that. The disagreement is over the *validity* of the debate.
If the IDers can't even get the easy stuff right, how can we trust them to get the hard stuff right?
Nice post, Ich.
Couple of questions I have, don't mistake it for creationism...
1) Does anyone happen to know the particular survival advantage which drove these changes? Or were these just "happenstance" without a changing environment to drive them
2) How long did you say these changes took?
One thing I haven't seen in the FR threads is a discussion of the balance between the rate of DNA mutations driving some of the changes, and the rate of change of the environment providing selection pressure...it'd make for fascinating reading.
Especially given the following factors:
1) Preservation of well-defined, "important" structures which therefore leave certain regions of the DNA relatively unchanged [e.g. there is no such thing as a three-and-a-half chambered heart ;-) ]
2) The larger "number of trials" (individual organisms) in single-celled organisms or insects, compared to say 4-legged creatures
3) Catastrophic "slate-wiping" events (localized disasters or Iridium-filled planetary strikes)...
All of these are more difficult to model, but presumably have some influence on the predicted and/or observed rates of speciation...
Cheers!
Yes. Which word did you find unclear? If you disagree, feel free to explain why. But as usual, "Creation-Evolution Headlines" just engages in misrepresentation and spin, and they're certainly keeping to that standard here as well. If anything, this recent bit from them is even more insubstantial than usual, and that's really saying something.
Let's let the lurkers decide, shall we?
Oh, I'm happy to do that. I get a lot of fan mail from them, and asking me if I can explain what's wrong with the anti-evolutionists.
We already *know* where you stand.
And we know where *you* stand, and on what poor and shaky ground.
We also know, from long past experience, that you post a great many creationist screeds you aren't personally capable of evaluating for validity or accuracy. At least when I post outside material, I'm able to personaly vouch that it holds water and isn't just a pack of misrepresentations and/or fallacies, like a lot of your material.
Please find us one reference in Origin of the Species, any evolutionary biology book, or any paper on evolutionary biology, genetics or paleontology that states that the nonexistence of God is a consequence of evolutionary science.
You won't find it, 'cause it ain't there. Attaining scientific literacy does not mean that one has to reject God, it only means that one has to learn to recognize the use of image and allegory in the Bible.
You yourself reject a literal interpretation of the Bible (unless you really think the earth is a few thousand years old (it does state that, just add up the generations from Adam to Jesus), the sun circles the earth, angels literally preside over the corners of the flat earth, rain literally falls from floodgates in the sky, you're supposed to hate your parents and children (like Jesus literally commanded), and that Jesus was literally a lamb that wanted us to literally consume his flesh and blood).
It's called imagery, folks!!
It's not hard to tell honest questions from the kind of sneering rhetoricals the anti-evolutionists "ask".
1) Does anyone happen to know the particular survival advantage which drove these changes? Or were these just "happenstance" without a changing environment to drive them
I haven't looked into that aspect of it myself, but there are plenty of folks who have, I'll see if I can find something for you.
One obvious possibility is that this transition in the jaw enabled much more acute hearing, which is a pretty strong survival advantage, both to be more alert to predators, and to locate prey, mates, the cries of offspring, etc.
And it may not have been due to environmental changes -- not all evolutionary novelties are driven by changes to the environment. Sometimes it's due to changing dynamics with other species (predator/prey/mating changes, etc.) or due to an evolutionary "breakthrough" of some sort occurring by chance (the fortuitous rise of a new protein which makes other changes now possible, etc.)
2) How long did you say these changes took?
From the Early Pennsylvanian (310 million years ago) to the late Jurassic (150 million years ago), so about 160 million years in duration.
That's rich. This coming from someone who posted this:
Thanks for giving us a look at their desperate "spin" -- its pathetic lack of substance only makes more clear the bankrupt and empty ideology of the anti-evolutionists, and the fact that they have no substantive defense against such stunning confirmations of evolution.
Only one minute after I posted the Creation-Evolution Headlines interpretation of this 'find'. You'll forgive me if I don't take you seriously.
Like I said - we'll let the lurkers decide. Once again, in case they may have missed it:
Fish-o-pod ‘Missing Link’ Discovered: Media Goes Nuts 04/06/2006 
Evolutionists could hardly feel more relieved. Just when anti-evolutionary sentiment is on the rise, a new fossil has been announced that gives pro-evolutionists a missing link to run up the fishpole. Neil Shubin (U of Chicago) and two partners found a “tetrapod-like fish” fossil on a Canadian island. It helps fill one of the most puzzling transitions in the fossil record: the evolution from a fish to a land animal.
To hear the media celebration over this underwater Archaeopteryx, it would sound like the war is over and evolution wins. Creationists have been complaining about gaps in the fossil record, and here is a perfect case of a transitional form. One scientist smirked, “It’s good of the Intelligent Designer to continue to provide missing links, don’t you think?” Here are just a few of the claims being made in the press about Tiktaalik roseae, the newest icon of evolution (emphasis added in all quotes):
Here we report the discovery of a well-preserved species of fossil sarcopterygian fish from the Late Devonian of Arctic Canada that represents an intermediate between fish with fins and tetrapods with limbs, and provides unique insights into how and in what order important tetrapod characters arose. Although the body scales, fin rays, lower jaw and palate are comparable to those in more primitive sarcopterygians, the new species also has a shortened skull roof, a modified ear region, a mobile neck, a functional wrist joint, and other features that presage tetrapod conditions. The morphological features and geological setting of this new animal are suggestive of life in shallow-water, marginal and subaerial habitats.Sounds like the popular press so far; now, into the details. They admit that “The evolution of tetrapods from sarcopterygian fish is one of the major transformations in the history of life and involved numerous structural and functional innovations, including new modes of locomotion, respiration and hearing.” In other words, many substantial changes had to come together in one animal to go from breathing through gills to breathing with lungs, developing feet that could support the weight, developing digits and ankles and toes and learning how to use them, and much more:
During the origin of tetrapods in the Late Devonian (385–359 million years ago), the proportions of the skull were remodelled [sic; implies intelligent design], the series of bones connecting the head and shoulder was lost, and the region that was to become the middle ear [sic; implies progress] was modified. At the same time, robust limbs with digits evolved, the shoulder girdle and pelvis were altered, the ribs expanded, and bony connections between vertebrae developed.Few of these innovations are seen in the closest relatives of tetrapods, they say. They talk about Panderichthys, Acanthostega and Ichthyostega, which have been discussed earlier in these pages (see 04/05/2004 and 08/09/2003, “Evolution of the Darwin Fish.”). Surprisingly, however, they dismiss them as fragmentary and of doubtful utility. This includes the earlier leading candidate:
Panderichthys possesses relatively few tetrapod synapomorphies [convergent features], and provides only partial insight into the origin of major features of the skull, limbs and axial skeleton of early tetrapods[. In view of the morphological gap between elpistostegalian fish and tetrapods, the phylogenetic framework for the immediate sister group of tetrapods has been incomplete and our understanding of major anatomical transformations at the fish–tetrapod transition has remained limited.The disparagement of previous candidate missing links was the build-up to the new fossil, which “significantly enhances our knowledge of the fish–tetrapod transition.” (This should be taken with a grain of salt, considering that similar claims were made about Panderichthys earlier.) Proceeding on, they place Tiktaalik somewhere between Panderichthys and tetrapods. The paper provides the obligatory data for a new species: location found, taxonomy, nomenclature, description of the fossil, photos, drawings, etc. The head was remarkably well preserved, and three specimens were found. Naming and classifying an extinct species, however, provides the discoverers some leeway in placing it into the presumed evolutionary framework.
A phylogenetic analysis of sarcopterygian fishes and early tetrapods (Fig. 7) supports the hypothesis that Tiktaalik is the sister group of tetrapods or shares this position with Elpistostege. Tiktaalik retains primitive tetrapodomorph features such as dorsal scale cover, paired fins with lepidotrichia, a generalized [sic] lower jaw, and separated entopterygoids in the palate, but also possesses a number of derived [sic] features of the skull, pectoral girdle and fin, and ribs that are shared with stem tetrapods such as Acanthostega and Ichthyostega. Tiktaalik is similar to these forms in the possession of a wide spiracular tract and the loss of the opercular, subopercular and extrascapulars. The pectoral girdle is derived [sic] in the degree to which the scapulocoracoid is expanded dorsally and ventrally, and the extent to which the glenoid fossa is oriented laterally. The pectoral fin is apomorphic [i.e., derived, more developed] in the elaboration of the distal endoskeleton, the mobility of segmented regions of the fin, and the reduction of lepidotrichia distally.In summary, they think that Panderichthys, Elpistostege and Tiktaalik represent a “paraphyletic [partially evolved] assemblage of elpistostegalian fish along the tetrapod stem that lack the anterior dorsal fins and possess broad, dorsoventrally compressed skulls with dorsally placed eyes, paired frontal bones, marginal nares, and a subterminal mouth.” However, “Some tetrapod-like features evolved independently in other sarcopterygian groups,” while two other fossils seem to have features shared with basal tetrapods by convergent evolution (homoplasy). It seems like the fossil record shows a smorgasboard of mixed features among ancient fish rather than a clear line leading up to land. (Consider this in the context that the vast majority of species on earth are extinct; one could make up any number of possible lineages.)
The pectoral skeleton of Tiktaalik is transitional between fish fin and tetrapod limb. Comparison of the fin with those of related fish reveals that the manus [hand] is not a de novo novelty of tetrapods; rather, it was assembled in fishes over evolutionary time to meet the diverse challenges of life in the margins of Devonian aquatic ecosystems.OK, now what do other experts think? In the same issue,3 Erik Ahlberg and Jennifer Clack gave their analysis. It is unknown whether Clack, who has been in the forefront of research into tetrapod evolution, was scooped by this discovery, or whether any personal feelings or rivalries were involved. She did, however, with Ahlberg, put a few brakes on the interpretations, though acknowledging the significance of the find. First, a little sermonette on missing links:
The concept of “missing links” has a powerful grasp on the imagination: the rare transitional fossils that apparently capture the origins of major groups of organisms are uniquely evocative. But the concept has become freighted with unfounded notions of evolutionary ‘progress’ and with a mistaken emphasis on the single intermediate fossil as the key to understanding evolutionary transitions. Much of the importance of transitional fossils actually lies in how they resemble and differ from their nearest neighbours in the phylogenetic tree, and in the picture of change that emerges from this pattern.Though this fossil goes “a long way” to filling in the gap, it does not go quite all the way, they say. Its closest match is Elpistostege, a fragmentary fossil thought to be closer to tetrapods than Panderichthys. They admit, “the authors demonstrate convincingly that Elpistostege and Tiktaalik fall between Panderichthys and the earliest tetrapods on the phylogenetic tree. End of story?
We raise these points because on pages 757 and 764 of this issue are reports of just such an intermediate: Tiktaalik roseae, a link between fishes and land vertebrates that might in time become as much of an evolutionary icon as the proto-bird [sic[ Archaeopteryx.
Although these small distal bones bear some resemblance to tetrapod digits in terms of their function and range of movement, they are still very much components of a fin. There remains a large morphological gap between them and digits as seen in, for example, Acanthostega: if the digits evolved from these distal bones, the process must have involved considerable developmental repatterning. The implication is that function changed in advance of morphology.Though each fossil seems to represent a mosaic of characteristics rather than a straight line of evolution, the two are ready to agree that the creature was “evidently an actual step on the way from water to land,” and that “it seems, our remote ancestors [sic] were large, flattish, predatory fishes, with crocodile-like heads and strong limb-like pectoral fins that enabled them to haul themselves out of the water.” Nevertheless, this is just one specimen, and many more are needed. This one creature must be seen in context. Perhaps the most important transitional forms are found in the future:
Of course, there are still major gaps in the fossil record. In particular we have almost no information about the step between Tiktaalik and the earliest tetrapods, when the anatomy underwent the most drastic changes, or about what happened in the following Early Carboniferous period, after the end of the Devonian, when tetrapods became fully terrestrial. But there are still large areas of unexplored Late Devonian and Early Carboniferous deposits in the world – the discovery of Tiktaalik gives hope of equally ground-breaking finds to come.
OK, Shubin, you caught a fish and got your picture in the paper. Now that you are feeling your oats, take on the Cambrian explosion.
You didn’t get this much detail from the major news media. You didn’t hear the discoverers hedge their bets and admit that this fossil is just a tiny piece of a huge puzzle that is mostly not understood. You didn’t hear the AP (Associated Preach) tell the truth that the fossil record is characterized by large and systematic gaps between groups, not isolated and questionable transitional forms. No, you got hype and bluster and far-fetched exaggeration, where the actual bones were incidental to the true goal of making Charlie not look as dead as he is. Meanwhile, an explanation of the origin of all the genetic information required for such a transition was completely glossed over; and, of course, not a single credible non-Darwinian paleontologist got a word in edgewise in the din of the mainstream media’s Charlie pride parade. If you got mad last time (04/05/2004) it’s time to get mad again – for the same reasons.
A reader writes: “Dear Staff... The April 6, 2006 article on the ‘Fish-O-Pod’ found in Canada is great news... Now we know where all the Walking Catfish in the lakes in Orlando, Florida came from... They actually walk up on the interstate and get eliminated by cars! FISH-O-POD is nothing new, we have been squashing them for years!” Another commented on the AP coverage, “I got seasick from all the handwaving.” To this we add, scientists are not assuming that mudskippers are transitional forms to salamanders, are they? Or grunion to snakes, or rikshas to sedans? Let’s play their game and daydream about beavers evolving into seals, and flying squirrels evolving into bats. Connecting dots is child’s play.
See also a preliminary response from the Discovery Institute, and a commentary by Dr. David Menton on Answers in Genesis: “Gone fishin’ for a missing link?”
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