Saturday, 25 November 2006
Response from Mike Janitch
The article reports the discovery of the oldest known lung fish fossil — a relative of the celebrated coelacanth. Experimental DNA evidence from living coelacanths suggested a lineage divergence 410 million years ago, but the oldest previously-known fossil was 390 million years old. That gap suggests that older fossils may exists and that we should look for them. The theory therefore predicts a 410-million-years-old fossil, and we found it. The "new" fossil converges so neatly with the DNA evidence that it could be a textbook example for freshman biology students.
Unfortunately, the article's lede paragraph states that the new discovery "may mean living creatures left the world's oceans for the land much earlier than once thought, rewriting a small part of mankind's evolution." Mr. Janitch took this lede at face value and heralded it as a major blow to evolution.
A month after I blogged Mr. Janitch and this news article, I got an email from Mr. Janitch. He thought I was being unfair and trying to smear him. So I posted the full text of our email exchange, and I will respond to it here. The beginning of his email goes off on a tangent about politics and Bohemian grove, so I'll jump straight to the middle and respond point-by-point.
Firstly, I must retort that I fully read the article in question. As I read anything before I make a blog post about it. However I have deduced something entirely different from the story. My argument is purely logical, and damaging to the theory — it IS damaging when examining this ONE example (there are boundless others I can cite as well if you wish to actually debate this via blogs).
Mr. Janitch's original blog post parroted the article's conclusory lede and failed to consider the facts presented in the body of the article. The author described the convergence of two bodies of evidence. Calculations based on laboratory experiments pointed to the answer, and a fossil provided physical-evidence support. Stated more generally: one branch of evidence made a prediction based upon the theory of evolution, and a totally independent branch of evidence confirmed it by empirical observation.
Not only did Mr. Janitch rely 100% on the lede, he appears to deliberately mislead it. The development of lungs was a significant event in evolutionary history. It made possible new evolutionary paths that were unavailable when animals were confined to the sea. Any significant event in the cladistic lineage of land animals (including humans) is interesting and is therefore the object of study.
The "new" fossil confirms a prediction that places that event earlier than was previously known. This is a minor revision of our known history that better pinpoints a date. It has no effect on the validity of the theory of evolution to explain the development. Whether 20 million years (out of 410 million years) is "much earlier than previously thought" is a judgment call. But this really does affect just "a small part of mankind's evolution."
The series of fish talked about in the article, in this case the coelacanths, just happen to MATTER in a huge way to the Hypothesis of Evolution.
Who remembers learning the difference between a scientific hypothesis and a scientific theory in elementary school? Evolution, like all theories, used to be a hypothesis. But it isn't today.
The fact that a set of bones with similarities has been found proves that since coelacanths are around today — that the fossil which was found from the "supposed" 410 million year old layer of rock, could NOT have evolved, because it CLOSELY matches the current "living fossil coelacanth" of today.
I have a hard time deciphering what Mr. Janitch means here. He seems to share the common misconception that many other creationists have — that, in order for an organism to have evolved, all precursors to that organism must be dead. No theory that I am aware of predicts this, except some creationists' caricatures of evolution.
To use a biblical metaphor, Abraham survived Ishmael's birth and went on to beget Isaac. Later, the sons of Abraham begat two new nations. Speciation (one mechanism of evolution) works in a similar way. Parents do not (usually) die when a child is born. Each children has some genetic variation relative to its parents and its siblings. Some variations thrive in a long lineage, and those variations do not necessarily overwhelm other variations in the population. There is no reason why the parent (or its species) must die out for its children to fork off a competing lineage.
The fact that coelacanths continue to live today neither negates nor supports whether they evolved (or, to be fair, whether they were specially created by a deity). Organisms very much like coelacanths lived 410 million years ago, and we see them in the fossil record. Fossils from that lineage are slightly younger and look slightly less like coelacanths. There are also fossils from that lineage that are much younger and look much less like coelacanths. Looking at fossils that represent the entire lineage, we see smooth and gradual changes from one form to other forms — exactly what evolution predicts.
The notion that the coelacanth is a "living fossil" was created by the media, not scientists, to popularize this interesting case. Scientists once thought the coelacanth was extinct because no fossils of it younger than 65 million years old were known to exist. The capture of a living specimen in 1938 was therefore surprising. But it had no bearing on the validity of evolution.
You also mention that "the fossil evidence verifies the DNA evidence" .... I don't know how a fossil can verify any kind of DNA (unless that fossil you're speaking of had some form of tissue in it).
Interesting. Mr. Janitch admits he doesn't know how DNA analysis is used in the study of cladistic lineages. And he also doesn't ask. But then he argues that its use is invalid.
Mutation occurs at a known rate that we can calculate. Related species often share genes; and, sometimes, they have different versions of the same gene. By comparing two species' versions of the same gene, we can calculate how long ago they shared a common ancestor (with a margin of error, of course). Experimental evidence from living coelacanths' DNA suggested a divergence around 410 million years ago, but the oldest fossils we had found were 390 million years old. Older fossils were therefore predicted, and now they are found.
Mr. Janitch completely misreads this portion of the original article. (Not that this was well explained in the article, however.) The article quotes Professor John Talent:
"It seems from experimental data with living coelacanths that there should have been older ones [than we had previously found in the fossil record]," Talent said. "What we've done is close the gap — we've got the fossil right back near the origin of this group."
If DNA evidence predicts a common ancestor at a given time, and we find a fossil resembling what we expect that dates from the predicted time, the prediction based upon DNA evidence is confirmed. What better evidence could there be for evolution?
Think about it logically for a second, the theory of evolution, as you said, "predicted" the existence of some kind of "intermediate" fish... however this was not found.... all they found was a similar coelacanth. Also the fact that since coelacanths are alive today, it is an obvious conclusion that the coelacanths will be FOUND ANYWHERE throughout the layers of rock.
What else could an intermediate or transitional fossil be, except very similar to the one before it? Evolution not only predicts — even demands — "a similar coelacanth". Without that, we would have special creation. As I said in my initial blog post, "Used to be, a gap in the fossil record was evidence for creationism or intelligent design, or at least an indication that evolution may not be accurate. Since that argument didn't work, Mr. Janitch apparently now claims that filling in those gaps makes evolution inaccurate."
So to add 20 million years onto the "timeline" of evolution is a joke, and like trying to bandage a wound from a landmine.
I'm not sure what this means or what Mr. Janitch thinks it means. The discovery closed a gap in the fossil record. Paleontologists are the first to admit that the fossil record has gaps because our methods of finding fossils are imperfect. Evolution is supported, however, when a prediction is made that we should find a particular fossil of a certain age and that fossil is later found.
Also, since these coelacanths have supposedly been around for HUNDREDS of millions of years.... you would think they would "evolve" into something different than what they looked like from that long ago. Rather, it is obvious they haven't evolved at all.
Mr. Janitch merely repeats the misconception that he introduced earlier. This misconception arises from the simplistic (and incorrect) notion that evolution is defined as something like "biological change over time". A particular form of organism will remain unchanged over time if selective pressures conserve that form. The longevity of a form has no bearing on whether it evolved. I happen to be more familiar with the crocodilian lineage than the examples Mr. Janitch mentions. Crocodilians appear to have emerged 98 – 95 million years ago, and the basic modern forms we see today had evolved by 65 million years ago (the time of the dinosaur extinction). They still exist today because they are well adapted to the environments where they live. We still see what evolution predicts, however — early transitional forms from other, similar animals (e.g., Junggarsuchus sloani and Isisfordia duncani) as well as some extinct forms (e.g., Dakosaurus andiniensis).
A species that exhibited no variation at all, and that showed no change over time, not even neutral molecular differences, would be a major puzzler for biology. No such thing has ever been observed. On the other hand, gross structural stasis over a long period of time is no problem for evolution. One thing even many biology students have some difficulty grasping is that selection is a conservative force; it tends to limit variation to the narrower domain of the viable and the competitive.
Also, evolution does not predict that every member of a species' generation will change in the same way toward something new. Evolution does not predict that all lobed fin fish changed into amphibians. Indeed, that would be surprising. Instead, evolution predicts that genetic variations in some lobed-finned fish lineages led, over time, to forms that we recognize today as amphibians. The rest of the lobe-finned fish were free to continue living as they pleased.
As for "gaps" in the fossil record. There are huge crevasses, not just gaps. You have to find an INTERMEDIATE species! Care to explain how the original coelacanth came to be? The obvious answer for the evolution believer (you) — would be that this family of fish came from a genetically different set of fish.
This is another common a misconception, that the notion of "species" has evolutionary significance. Modern biology grew up in the golden age of taxonomy, and taxonomists like to organize the world into categories. It is therefore common practice to apply a label to each fossil we find. But to paraphrase Richard Dawkins, don't let linguistics interfere with physical reality. A series of fossils showing smooth and gradual transition does become an unconnected series of steps simply because we like to apply a unique name to each one.
Even if evolution did predict what Mr. Janitch suggests, we would not expect to find those two particular individuals in the fossil record. Fossilization is rare, and our methods of finding fossils are imperfect.
The answer is that modern coelacanths are specialized remnants of a once diverse and widespread group. They have changed extensively over hundreds of millions of years, as would be expected, and this once widely successful and branched family has been pruned back to just a few twigs lurking in relatively inaccessible locations. Here, for instance, are a few fossil examples of ancient coelacanth diversity (Clack, 2002):
Mr. Janitch goes on:
I have debated many other "evolutionists", and it tends to be fruitless when trying to convince a BELIEVER that the "theory" has been downgraded to a specious hypothesis.
I know of no scientist who would consider the theory of evolution to be "downgraded" to the status of hypothesis — whatever that means. I am unaware of any scientific theory that has ever been "downgraded". In science, a theory is an overarching explanation for a body of data. Science simply discards disproved theories; it does not "downgrade" them to some lesser status.
The only thing I can do is point you towards one of your fellow evolutionists. Stephen J. Gould... a prominent biology professor from Harvard... said himself that there are NO TRANSITIONAL fossils between species. The fossil record is ABSENT of any proof of transition between one species and another.
I am unaware of any such statement by Stephen J. Gould, that transitional fossils do not exist. If he did say that, I welcome you to provide me with a specific citation to Gould's published writings or public statements. Good luck.
Punctuated equilibrium (prominently advocated by Gould and Niles Eldredge) is a modified form of gradualism that creationists often misunderstand to be in conflict with Darwin's theory of evolution by natural selection. Actually, punctuated equilibrium is like a sub-theory of evolution that Gould advocated to explain the mechanics of evolution under certain circumstances within a taxa or between closely related taxa. Gould argued that transitional fossils are lacking in the fossil record not because transitional organisms don't exist — but rather because evolutionary change under such conditions occurs too rapidly (in a small-enough number of generations) that the transitional organisms are unlikely to fossilize and be recorded in the strata. Geological strata form slowly — more slowly than evolution by punctuated equilibrium would operate.
The key point is that Gould's argument about the lack of transitional fossils only holds true within a taxa or between closely-related taxa. He argued that species are generally morphologically constant during long periods of stability, then evolve quickly under short periods of intense selective pressure. Those periods of intense selective pressure are shorter than the time it takes to form a geological stratum, so it is likely that the transitional forms would not be recorded even if they fossilize.
The only fossils which exist — are fossils of alike species.
Aaahhh…the taxonomy problem again.
There are no INTERMEDIATE skeletons anywhere... which means one of three possible things....
This crescendo summarizes the mistakes in reasoning that Mr. Janitch has made all along. First, "intermediate skeletons" are everywhere. True, we may have no fossil record of a transitional form between any two closely related species. But in many cases, one of those two is the transitional form between the other one and something completely different. There couldn't ever be an "intermediate skeleton" that isn't classified into any species because each specimen is classified as soon as it is found. If it doesn't fit into a known species, a new species is named for it. We have, for example, a well-developed record of fossilized ancestors leading directly to modern humans, going back roughly seven million years, when we shared our most recent common ancestor with other living apes. Each of those fossilized ancestors is pigeon-holed into a species; or, in some cases, a new species was defined for the "new" fossil. Mr. Janitch, and many other creationists, allow the species nomenclature to blind them to the fact that if we were to line up all those skeletons on a table, we would see a smooth and gradual transition from an ape-like ancestor to ourselves.
I won't comment on cosmology, since this response is already long.
So to sum it up, I think you're wrong, and made a lame attempt to smear me.
My intent was not to smear, although I understand in retrospect how it might appear that way to Mr. Janitch.
The wonderful thing about blogging, is that I can post this response, and let my readers (and your readers) decide for themselves. Gone are the days of having evolution forced down the throat of the sheeple (hah)!
Evolution has never been "forced down the throat" of anyone. It is taught in classrooms around the world where creationism and intelligent design (a special case of creationism) are not taught because evolution has a scientific foundation that the others lack. I have never seen a non-disingenuous argument to the contrary. Rather, when a theory of life is forced upon people, it is invariably the proponents of religion who are doing it. Look no further than Dover, Pennsylvania for a detailed history.