I’m surprised at how many people feel the need to explain to me this thing called “the progress of science.” Perhaps my post was completely confusing.
I spoke with a philosopher friend of mine yesterday about this Transitional Forms issue. I quoted Darwin, then I quoted wikipedia. In immediate response to the “new” definition, he stated without prompting, “That’s a pretty meaningless definition.” He’s right, and that’s my point. Except for something that “shows up with a bang” or the disappearance of any trace of a species and its relatives, almost everything is, by the “new” definition, a transitional form. So we have some important definition we need to defend for the 99% case? Why?
I notice an assumption here that because science has progressed, everything that comes out is progress. The whole edifice of science is not threatened if they get something wrong. So must we assume that the new definition is “better” because science progresses? That’s my point. It’s not.
Tautology: in logic, “a statement that is true by necessity or by virtue of its logical form.” The new definition is mostly a tautology.
I stand by my opinion that the new definition of Transitional Form hinders the discussion. Look how much time and energy we have expended on the term itself without even engaging the data it supposedly helps explain.
It is rather odd to me that anyone would view science’s self correction and progress as a bug rather than a feature. Theories are proposed and tested, at some point they are found lacking or insufficient. New theories are proposed which do better or they are discarded. To cast doubt on the modern TOE because Darwin made an incorrect assertion concerning transitional fossils would be like denying modern theories of gravitation because Newton’s prediction of the precession of Mercury’s perihelion was wrong.
The incorrect assertion was regarding the expectation of many fossils indicating gradual steady transitions. He made it because the theory was new and it was a reasonable assumption based on his nascent version of TOE. The fact that he was wrong doesn’t mean that modifications to Darwin are “just so” stories. “Just so” stories are generally poor at making predictions.
I can imagine why you might have some trouble with the exact wording the @cwhenderson is writing in his post. And I do believe if he were actually holding the evidence in his hands and writing a paper, he would intuitively make the adjustments you are talking about - -
Namely:
A] If he wants to say “Fossil X representing younger Population B” was just found.
B] Fossil X does have a significantly differing traits from Fossil Z representing older Population A".
C] But with this important proviso: "While Fossil B is different, it does share a few identical traits that only Population A has. By definition, this turns Fossil “Z” into a transitional fossil.
It’s not transitional because it is older. It’s transitional only when you identify the likely flow from one (older) population to a second (younger) population.
And if for some reason, there is some evidence suggesting why the older population could not have been the source (like, perhaps it was found on an isolated land mass with virtually no way for any of the population to end up where the younger population fossil was found) - - then, of course, it is not transitional… and we would be looking for the plausible older source, which would (by reason of the above analysis) is likely sharing a common ancestor with the original older population.
The term transitional can only be used when the evidence suggests one population contributed to the genetic content of another (usually more recent) population, right?
Hi Curtis. I’m not seeing his comments the way you are. I think his question is one of mechanism, how a plodding adaptive mechanism like Evolution can produce these massive and multiple coordinated sets of changes in such a short time frame by itself. I think that’s what he is saying.
Bless you George, and thanks! Someone is starting understand what I’m saying! I was beginning to despair. You are definitely homing in on one of my points.
From the wikipedia page which someone linked, “it cannot be assumed that transitional fossils are direct ancestors of more recent groups.” Yet they still call them transitional fossils. They are including everything that has any morphological relationship to anything, which ultimately includes pretty much everything.
My other point around this, even in Darwin’s day, plenty of “transitional forms” by this newer definition were known. So that cannot be what Darwin meant. The recasting of Darwin’s words, as if he was just ignorant and we have this wonderful thing called scientific progress which has filled these gaps, is, I think, historical revisionism. One must read the full context of Darwin, and his full argument. I think this re-interpretation of his words would have annoyed Charles Darwin.
Wiki articles are not perfect … but your description of this article doesn’t sound quite right. Let’s have a look again:
“A transitional fossil is any fossilized remains of a life form that exhibits traits common to both an ancestral group and its derived descendant group.” [FN 1]
"This is especially important where the descendant group is sharply differentiated by gross anatomy and mode of living from the ancestral group. These fossils serve as a reminder that taxonomic divisions are human constructs that have been imposed in hindsight on a continuum of variation. "
[FN 1] Freeman, Scott; Herron, Jon C. (2004). Evolutionary Analysis (3rd ed.). Upper Saddle River, NJ: Pearson Education. ISBN 0-13-101859-0. LCCN 2003054833. OCLC 52386174; p. 816.
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^ As the above reads … the description seems quite reasonable. ^
But I can see that these next paragraphs probably bring you more than a little heartburn - - and some surprise to me as well!
“Transitional versus Ancestral: A source of confusion is the notion that a transitional form between two different taxonomic groups must be a direct ancestor of one or both groups.”
“The difficulty is exacerbated by the fact that one of the goals of evolutionary taxonomy is to identify taxa that were ancestors of other taxa. However, it is almost impossible to be sure that any form represented in the fossil record is a direct ancestor of any other.”
“In fact, because evolution is a branching process that produces a complex bush pattern of related species rather than a linear process producing a ladder-like progression, and because of the incompleteness of the fossil record, it is unlikely that any particular form represented in the fossil record is a direct ancestor of any other.”
“Cladistics deemphasizes the concept of one taxonomic group being an ancestor of another, and instead emphasizes the identification of sister taxa that share a more recent common ancestor with one another than they do with other groups.”
“There are a few exceptional cases, such as some marine plankton microfossils, where the fossil record is complete enough to suggest with confidence that certain fossils represent a population that was actually ancestral to a later population of a different species.”
“. . . in general, transitional fossils are considered to have features that illustrate the transitional anatomical features of actual common ancestors of different taxa, rather than to be actual ancestors.”
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. @Marty, I can see that what I was describing as “truly transitional” is rarely accomplished. I am, indeed, surprised by this. So I can see where you got your impetus to complain about academics stretching the term “transitional” to mean more than what some folks think is fair!
I spoke too soon when I wrote about what @cwhenderson might or might not describe as “transitional”. When I used to produce family genealogies for some of my relatives, there was the tendency for them to refer to an important Great Grand Grand Uncle as “our ancestor” . . . when, technically speaking, the Great Grand Grand Uncle may have never had any children at all.
By virtue of a very large Brooks family that settled in Concord, Massachusetts circa 1635, I am honored to know as my distant cousin, many times removed, the Episcopal Bishop Phillips Brooks (b. 1835 – d. 1893) - - who was known for writing the words to “Oh Little Town of Bethlehem”, and being the long time Rector of what some have hailied as “an American Hagia Sophia” - - Trinity Church in Copley Square, Boston, Massachusetts.
As a very scrupulous, but amateur family genealogist, I would always wince
if someone referred to the Rev. Brooks as my ancestor. And so I must confess a bit of anxiety and concern about the academic use of the term.
I cling to the one thing that seems to have survived my 2 hour education in the term:
“. . . in general, transitional fossils are considered to have features that illustrate the transitional anatomical features of actual common ancestors of different taxa, rather than to be actual ancestors.”
To be thorough, a “Taxon” (plural: Taxa) is “a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established.”
I have added some additional text to the informative graphic below:
But perhaps this Wiki paragraph is a way to grasp the value of the term “Transitional” being applied to living things that share a Poly-Phyletic category:
“Polyphyletic species”
"Species have a special status . . . as being an observable feature of nature itself and as the basic unit of classification. It is usually implicitly assumed that species are Mono-Phyletic (or at least Para-Phyletic). However hybrid speciation arguably leads to Poly-Phyletic species. Hybrid species are a common phenomenon in nature, particularly in plants where polyploidy allows for rapid speciation."
Now that I know how academics use the term “Transitional”, I think the obvious answer is to use caution and reasonableness when throwing that word around.
But, @Marty, to say there are “few transitional fossils” seems to be a willful exploitation of the limits of what we can know about an array of fossils that may or may not be “common ancestors” or “common descendants”, but which clearly tell a story of how animal populations diversify form and behavior to survive long enough to produce another generation of offspring!
The figures in this blog were helpful to me in understanding the relationship of found fossils to transitional species. I won’t clutter things up with a cut and paste, but it was interesting to be how it explains why the ideal A to B to C to D progression is really not what you would see in the real world.
Darwin wrote an entire chapter in Origin of Species explaining why we don’t see innumerable transitional forms in the fossil record. Perhaps you should read it. He demonstrated that there were major gaps in the geologic record which means that there were major time gaps when no fossils were being produced. He also discussed how the range of a species will change over time, and how we have barely scratched the surface when it comes to finding species, which is still the case.
" For my part, following out Lyell’s metaphor, I look at the natural geological record, as a history of the world imperfectly kept, and written in a changing dialect; of this history we possess the last volume alone, relating only to two or three countries. Of this volume, only here and there a short chapter has been preserved; and of each page, only here and there a few lines. Each word of the slowly-changing language, in which the history is supposed to be written, being more or less different in the interrupted succession of chapters, may represent the apparently abruptly changed forms of life, entombed in our consecutive, but widely separated formations. On this view, the difficulties above discussed are greatly diminished, or even disappear. "
–Charles Darwin, "Origin of Species.
I am using the same definition that Darwin was using:
“In looking for the gradations by which an organ in any species has been perfected, we ought to look exclusively to its lineal ancestors; but this is scarcely ever possible, and we are forced in each case to look to species of the same group, that is to the collateral descendants from the same original parent-form, in order to see what gradations are possible, and for the chance of some gradations having been transmitted from the earlier stages of descent, in an unaltered or little altered condition.”–Charles Darwin, “Origin of Species”[quote=“Marty, post:152, topic:36197”]
That’s not necessary. The pattern is repeated everywhere in every strata. Niles Eldredge stated over 30 years ago, “We paleontologists have said that the history of life supports [the story of gradual adaptive change] knowing all the while it does not. … When we do see the introduction of evolutionary novelty, it usually shows up with a bang, and often with no firm evidence that the fossils did not evolve elsewhere! Evolution cannot forever be going on somewhere else.”
[/quote]
That’s why they proposed Punctuated Equilibria, which is evolution.
“Since we proposed punctuated equilibria to explain trends, it is infuriating to be quoted again and again by creationists—whether through design or stupidity, I do not know—as admitting that the fossil record includes no transitional forms. Transitional forms are generally lacking at the species level, but they are abundant between larger groups.”–Stephen Jay Gould, “Evolution as Fact and Theory”
Yes, it is. If you say that these fossils don’t exist then you need to demonstrate that they don’t exist. This means digging up every single fossil.
Take Tiktaalik roseae as an example. It took an entire research group 3 years digging in the same set of sediments to find one specimen. Just one. New transitional fossils are being found all of the time. To pretend that our fossil collections are complete is a complete joke.[quote=“Marty, post:152, topic:36197”]
This is part of what led him to propose what S J Gould popularized as Punctuated Equilibrium (PE). But PE is yet another “just so story” added to, what could be termed, “Evolutionary mythology” (a naturalist creation story), added to explain away why the data doesn’t fit the theory. It is not falsifiable so it is certainly not science!
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“I count myself among the evolutionists who argue for a jerky, or episodic, rather than a smoothly gradual, pace of change. In 1972 my colleague Niles Eldredge and I developed the theory of punctuated equilibrium. We argued that two outstanding facts of the fossil record—geologically “sudden” origin of new species and failure to change thereafter (stasis)—reflect the predictions of evolutionary theory, not the imperfections of the fossil record. In most theories, small isolated populations are the source of new species, and the process of speciation takes thousands or tens of thousands of years. This amount of time, so long when measured against our lives, is a geological microsecond. It represents much less than 1 per cent of the average life-span for a fossil invertebrate species—more than ten million years. Large, widespread, and well established species, on the other hand, are not expected to change very much. We believe that the inertia of large populations explains the stasis of most fossil species over millions of years.”–Stephen Jay Gould, “Evolution as Fact and Theory”
Oh my! We have psychologists on the forum who can diagnose at a distance!
Phil - thanks much for the link! I’ll chase that down.
George! I’m astonished at how thoroughly you have worked this through! Thank you. Excellent clarifications! I am truly grateful!
To all: Unfortunately I have to disengage from this thread. Many other items are on my list, and it does seem that many here simply assume those who question macroevolution are dolts. Unfortunate. I can have no expectations of being able to explain to them.
Dr. Tour of Rice U has an excellent column here that is worth a read. Further down he states, “But my recent advice to my graduate students has been direct and revealing: If you disagree with theories of evolution, keep it to yourselves if you value your careers…” Two comments on that: he and some of his grad students have disagreements with macroevolution, and second, the hostility in many quarters is very real.
I would encourage those here who disagree with me to find out why some very bright and capable people find macroevolution unconvincing. If you cannot explain that perspective, how can you discuss it convincingly?
Thanks for visiting. I don’t think you are a dolt. And I fully support people who need to quit the BioLogos forum cold turkey to get back to real life before their family schedules an intervention. Hope to see you again some rainy day.
But surely Marty doesn’t mean this article?! The author writes this balled up gnarly piece of rhetoric:
“I posit that the gross chemical changes needed for macroevolution (defined here as origin of the major organismal groups, i.e., of the body plans, Body plan - Wikipedia) are not understood and presently we cannot even suggest the mechanisms, let alone observe them.”
“Any massive functional change of a body part would require multiple concerted lines of variations. Sure, one can suggest multiple small changes ad infinitum, but the concerted requirement of multiple changes all in the same place and at the same time, is impossible to chemically fathom.”
Yeah, I’m pretty sure it would be impossible to fathom! Which is why no scientist I’ve read of has ever proposed it!
Is this guy for real?
In this text below, he obviously assumes Evolutionists don’t believe in God or His provenance:
“Therefore, I do not understand the mechanisms needed to change body plans or the mechanisms along the descent pathway between the australopithecine brain and modern human brains if we were indeed commonly descended as predicted by the theory of universal common descent.”
Then he seems to be Pleading the Fifth! - - he says he does not support Intelligent Design (which, of course, is one of @Marty’s dearest progeny):
“So what should be taught in schools regarding evolution, in my opinion? As I wrote, **I am not a proponent of intelligent design…”
“. . . for the reasons I state above: I cannot prove it using my tools of chemistry to which I am bound in the chemistry classroom; the same tools to which I commensurately bind my evolutionist colleagues.”
And here is list of problems regarding macroevolution!
“A better approach would include more teaching about common descent using basic genetics arguments. But there should also be coverage of legitimate scientific puzzles such as:
[1] macroevolution’s weak underpinning for the origin of body plans,
[2] the unexplainable functional differences between the modern human brain and that of other hominids,
[3] the ENCODE and orphan gene findings and disagreements,
[4] the huge difficulties regarding the theories on the origin of first life,
[5] and the mystery of information’s origin in the sequence of the nucleic acids.”
Yikes. I do believe he has never once seen a miracle from God …
@Brad, maybe he’s ready to do a conference with BioLogos? He is a self-described Messianic Jew, so that would be pretty interesting as well!
“I have been labeled as an Intelligent Design (sometimes called “ID”) proponent. I am not. I do not know how to use science to prove intelligent design although some others might.”
Or are you still even more further out on the limb? You accept all his objections and you think we can pursue I.D. in a scientific way?
Best wishes to you and your current labors - - whatever they may be!
Phil - you referenced an excellent post. I quote here from a summary paragraph: Do Transitional Fossils Prove Evolution? “We have shown for a number of cases, that the fossil record is consistent with evolution, given the four factors (sparse fossil preservation, speciation in small populations, etc.) discussed above. … It certainly shows that the fossil record is not a “problem” for evolution.”
First, I think the author sets much more appropriate boundaries for what can be surmised from the fossil record. It is “consistent” with particular Evolutionary narratives. But he does not claim “proof.” So if Evolution as we know it explains everything, then we can argue that the fossil record is not unreasonable. That is a much more constrained boundary than most people use, and I think it is much more fair.
I was already familiar with the data he cites, and there are many items that could be discussed in more detail about what is said there, if we had the time. But for the purposes of this thread, I’ll make one key point: it seems to me that the argumentation used is philosophically the same as that used by ID - marshalling scientific data to argue for an overall narrative. To those here who state “ID is not science”, based on this article and the style of reasoning used in it and applying the same standard, would it also not be true that “Evolution is not science” either? I welcome thoughtful responses, after people have considered the column Phil linked. How is that style of argument different from thoughtful arguments for design? Would people be more comfortable with ID if its proponents simply claimed that the data is “consistent” with a designer?
Note that this is a philosophical question, and there is no need to argue for or against Evolution. The question is about the style of argumentation.
[quote=“Marty, post:180, topic:36197”]
But for the purposes of this thread, I’ll make one key point: it seems to me that the argumentation used is philosophically the same as that used by ID - marshalling scientific data to argue for an overall narrative.[/quote]
Real science does not merely make arguments based on marshaling existing data. Real science tests hypotheses empirically, generating new data. ID doesn’t do that, so it is pseudoscience.
No, because the blog post is not evolution. It is a summary of evidence written for laypeople, with citations of some science. OTOH, that’s all there is on the ID side–it’s all aimed at laypeople.
It cites science. It doesn’t quote mine.
It also describes hypothesis testing, something avoided in ID rhetoric.
[quote]Would people be more comfortable with ID if its proponents simply claimed that the data is “consistent” with a designer?
[/quote]No, because the evidence isn’t consistent, and ID proponents neither advance nor test scientific ID hypotheses.
BTW, -NO theory or hypothesis is ever considered to be proven.
That really applies to every theory in science. There is some disconnect between the scientific lay person and scientists/science. In common parlance, no theory is ever prove absolutely true, but theories are prove true beyond any reasonable doubt. People who are “proven guilty” in a court of law are sometimes released from prison after they are exonerated by new evidence. So how can we say that they were proven guilty? Well, we leave off the qualifier “beyond a reasonable doubt”. I think the same thing occurs when someone says that a theory has been “proven”. What scientists are saying is that the theory has been proven beyond any reasonable doubt, but they are still aware that there may be evidence out there which could potentially show the theory to be wrong in the future.[quote=“Marty, post:180, topic:36197”]
I was already familiar with the data he cites, and there are many items that could be discussed in more detail about what is said there, if we had the time. But for the purposes of this thread, I’ll make one key point: it seems to me that the argumentation used is philosophically the same as that used by ID - marshalling scientific data to argue for an overall narrative. To those here who state “ID is not science”, based on this article and the style of reasoning used in it and applying the same standard, would it also not be true that “Evolution is not science” either?
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The difference is that the theory of evolution makes specific predictions about what mixtures of characteristics you should and should not see in the fossils we find. ID makes no such testable predictions. The theory of evolution predicts that there should have been species in the past who had a mixture of human and ape features, or reptile and mammal features. The theory of evolution also predicts that there should NOT have been species in the past which had a mixture of mammal and bird features, or fish and whale features. From what I have seen, ID makes no such predictions. For ID, a designer could mix and match features from any two species or a multitude of species to produce a new species, such as a species with feathers, teats, three middle ear bones, and flow through lungs (i.e. a mixture of mammal and bird features).
When we discover fossils we can test the predictions made by the theory of evolution. We can see if those fossils have the mixtures of features we would expect to see if evolution is true, and if they lack the mixture of features we would not expect to see if evolution is true. That is what makes the theory of evolution scientific. It is the lack of testable and falsifiable predictions within ID that prevents it from being scientific.[quote=“Marty, post:180, topic:36197”]
Would people be more comfortable with ID if its proponents simply claimed that the data is “consistent” with a designer?
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I would be more comfortable if ID and its proponents if they put forward some testable and falsifiable predictions as to the distribution of shared characteristics among fossil and living species, and then showed how observations are consistent with those predictions. Merely asserting consistency between observations and ID isn’t enough. That would be a bare assertion without reasoning out some testable predictions to compare fossils with the proposed theory.
…for the purposes of this thread, I’ll make one key point: it seems to me that the argumentation used is philosophically the same as that used by ID - marshalling scientific data to argue for an overall narrative. To those here who state “ID is not science”, based on this article and the style of reasoning used in it and applying the same standard, would it also not be true that “Evolution is not science” either?"
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[ " I welcome thoughtful responses, after people have considered the column Phil linked." ]
Marty, let’s both take a deep breath before the plunge into this ongoing miasma…
If you will allow me, I would like to start with this discussion of “Transitional Fossils”: I repeat my confession that I was surprised to find out that what I thought were Transitional Fossils are not what academics mean by the term. In fact, they rarely have the ability to use the term as clearly as I thought they used the term.
Trapped by the inescapable logic that without a long chain of DNA samples to go with each fossil, they cannot state categorically that one fossil represents an ancestral population or a descendant population. (I think we would become increasingly irate if they in fact tried to state such things.)
So, for them, “Transitional” becomes a reference to anatomical traits which appear to be consistent with a common ancestor. By arranging a collection of fossils along a spectrum for a given trait - - providing the basis of comparison for:
o Teeth
o Hips
o Ankles
o Wrists
o Jaws
o Skulls
etc, etc.
researchers can look for traits that move together (suggesting closer connection to a common ancestral population), and those that do not, but show how there appears to be more of a connection to another population that exceeds a purely random one.
For example, the ankle bones of Hippos which show a surprising similarity to the structure/design displayed by the ankles of proto-whales when they still had all four appendages. Now that is surprising, yes?
@Marty, is this non-science? Are they exceeding their grasp when they lay down a path of changes from one kind of population to another? If, in the process, they ignored other aspects … like two populations which had amazingly similar neck bones … but one is a fish and the other is a bird . . . I could see the sense of the charge that there is fakery-a-foot!
But what I see, Marty, is that you just don’t like the aesthetics of using the word “transitional” when as far as you are concerned, the “transitions” may well be purely hypothetical. Yes, I think you know that I understand this.
So, what adjective would you propose for the academics to use? It should be non-pejorative, neutral, and yet still be descriptive, yes? If you find an acceptable term, I will be happy to use it for all my future discussions that touch on Transitional fossil finds.
But let’s now turn to I.D.
Intelligent Design folks very rarely talk about I.D. in the context of important leaps of evolution within the context of a vastly ancient Earth. Have you noticed that? When’s the last time you found an ID proponent who said, with all due candor, that the hominid line is quite old . . . but there seems to be an indication that an evolutionary step between one feature to another most likely came with help from an intelligent agency?
A) The Limited Discussions of ID
If you look at the part of my sentence (above) in bold, I frequently find just the thought (in bold) being proposed, but never within the context of millions of years otherwise natural evolutionary development.
B) ID, by Definition, is not Science
Then there is the question of how to prove a super-natural event? If we all agree that God’s “assist” in Evolution is, by definition, a supernatural event . . . how would science find that? It has been touched on in recent weeks:
Where supernatural events occur, events appear chaotic, random or not explainable by normal lawful activity. But in the interaction between genome and environment, there are two places where God can act & work:
He can make very precise mutations in the genome; and
He can make very precise manipulations of rival species, food shortages, or very precise shifts in humidity or water turbidity that we would find impossible to follow, to duplicate, or to even imagine trying to control for.
Mutations we can understand at the molecular level. But in complex environmental systems, supernatural influences can be exerted that would take centuries to unwind and isolate. Certainly Marty, you and I would have a devil of a time trying to argue that God would never try to use supernatural influence on the food supply, the water supply, or even the enthusiasm of predators!
There is a veil that separates the natural from the supernatural. How is it that you think I.D. scientists can ever adequately document any supernatural event (which ID is, by any understanding of the event or events under scrutiny) to bring it into the realm of the scientific and the natural?
There is only one group I know capable of handling this ambiguity and still avoid calling miracles “scientific” - - and that would be
@Marty, what exactly do you think I.D. can do differently?
