Responding to a comment on my article: “Gill slits” by any other name…

I have decided to move this up from the comments section (cuz why not?) of my article “Gill slits by any other name…

Andy: Hi Troy, I read your post, and it is very well argued.

Thanks. [He said knowing that a “but” was coming.]

Andy: At the moment, I am a biology student at a local university, and one of my personal headaches is the promotion of either creation-ism or evolution-ism. To be honest with you and with all due respect, I really don’t care for either explanation.

Andy, with all due respect, you should know that for someone like me who has been in the “trenches” debating people pushing pseudoscience for years, the fact that you would refer to evolutionary theory as “evolutionism” is a large red flag that would strongly lead me to suspect that your understanding of evolutionary theory and science itself is likely wanting.

Unfortunately, your next sentence does little to disabuse me of my suspicion. Creationism is set of theological beliefs regarding a creation story written down in the 6th or 5th century B.C.E., accepted on faith and in the face of contravening facts by a tiny minority of people with any scientific background. Its mechanisms (God did it) are untestable and to the extent that it makes claims testable against the empirical world it has been falsified a thousand times over.

On the other hand evolutionary theory is a scientific explanation for a vast number of facts that is testable against further observations of the empirical world and used by the vast majority of the relevant scientific community as a guide to further research…whether you “care” for it or not.

That you would casually place them on the same level is yet another huge red flag.

Andy: As a student, the only thing that I am concerned about is true scientific facts that have been tested at a laboratory to the molecular level.

We are only three sentences in and we have three red flags. In my experience people who use terms such as “true scientific facts” (as opposed to what, “false scientific facts”?) tend to not to be particularly familiar with either the facts or what counts as scientific.

However, that is a nit compared to the philosophical problems with your above statement. Why on Earth would you limit yourself to what is testable in a laboratory at a molecular level? Better yet, why should anyone else take your narrow limits as to what to be concerned with seriously? Using your bizarre limitations, we would be throwing out vast swaths of empirical data, and not just in biology.

Molecules are great but they are not a perfect path to knowledge nor are they the only path.

Furthermore, the point of science is not simply collecting random facts, rather it is about explaining the facts that we observe [insert Darwin quote about collecting pebbles here]. In this case, we have detailed anatomical, physiological and genetic similarities between the pharyngeal structures of terrestrial vertebrate (hereafter “amniotes“) embryos and non-amniote vertebrates (amphibians and “fish”), set against a particular paleontological backdrop that needs a coherent explanation.

You do not like creationism, great. That should be a given and I am with you. However if you do not like evolutionary theory, then what is your better explanation for the gill-like appearance of the pharyngeal structures of amniote embryos (and everything else evolution explains)?

You cannot just sit back and say, “I don’t buy any of it” and expect to be taken seriously, especially in face of the apparent success of evolutionary theory.

Andy: My teacher presented this same example about the gill slits during a microbial genetics lecture.

I am not sure how the “gill slits” of vertebrate embryos are relevant to the genetics of microbes but OK…

AndyI was just exhausted of listening, so, I raised my hand and said that the information was outdated and more up-to-date data has been collected explaining that they are no longer gill slits, and they are pharyngeal pouches.

Huh, did you read my article to which you are supposedly responding? You are literally arguing semantics here. Regardless of what we call these structures in the embryos of amniotes, they exist, they resemble—in detail—the developing gills of non-terrestrial vertebrates, and we want to understand why this would be so.

AndyHe asked what was my source, and my reply was, with all due respect, professor, but your source is 150 years old and newer information was out that did not concentrate on a belief based teaching. He stopped and said he will do some more research and get back to us. He continued with the lecture as it was intended.

I am sorry but “your source is 150 years old”, even if true, is not an argument; old ≠ incorrect. FA = -FB (for every action there is an equal and opposite reaction) gets robotic probes to Mars despite the fact that Newton came up with the formula over three hundred years ago.

Furthermore, what is this “belief based teaching” to which you refer? Once again, if you read my article you would know that referring to these structures as “gill-slits” is not dependant on a belief in either creation or evolution as is evidenced by the fact that pre-Darwin creationists called them this.

Oh, and what is your source Andy?

AndyI agree; they look like gills until you dissect it, and then they look like pouches. I know in biology we name a lot of things base on morphological characteristics, and that is a great easy way to remember things.

No, no, no, again did you even read my article? Here, look at this diagram again:

Source bionalogy.com, with modifications.

Source bionalogy.com, with modifications.

There are clefts (or grooves) on the outside of the pharynx (red arrows) with corresponding pouches on the inside (blue arrows). These clefts and pouches are each separated by membranes that, in mammals, normally remain unperforated with the first (tympanic) membrane forming the so-called eardrum. Some of the post tympanic membranes do normally perforate and then reclose in some birds and reptiles embryos. They also temporarily perforate in the gill-bearing larvae of some amphibians and, of course, in fish they stay perforated and become gills.

Since I know some people are queasy about diagrams here are a few photographs of coronal sections done on various mammal embryos. First, an electron microscope picture of what I think is a stage 13 human embryo (Etchevers, 2008)(blue arrow points to the pharyngeal pouch and red to the corresponding cleft).

(Etchevers, 2008)

For comparison, here are some stained sections from a mouse (left, Zhang et al. 2005) and a pig (right, Shone & Graham 2014) at a similar point of development; once again blue arrows for pouches and red for clefts. Also, note in these photos that the aortic arches—the blood vessels—are visible within the pharyngeal arches (green arrows).

(Left, Zhang et al. 2005 – right, Shone & Graham 2014)

These are not just “pouches”! There are arteries (the blood vessels shown above), muscles, nerves and cartilaginous structures found on either side of the cleft/pouch pairs in the embryonic gills of “fish” and the corresponding pharyngeal arches of amniote embryos.

How do you get from this to, “they look like gills until you dissect it, and then they look like pouches” without ignoring all of these observable facts? These things exist and you need to explain them Andy.

AndyThe only thing that really gets to me is that either creationist or evolutionist keeps trying to push the subject in school.

The reason a competent science teacher (i.e. one who teaches evolutionary theory) would bring them up is because they are structures that have interested biologists since they were first discovered and whose existence is elegantly explained by descent from a common ancestor (evolution).

AndyHonestly, I paid for one of my books close to $300. I feel that my book should be filled with up-to-date information that has been tested, and that is going to help me in the future and not filled with propaganda of any kind.

The pharyngeal structures of amniote embryos are not propaganda. They exist and are observable by anyone with eyes to see. For example, please note that the photographs of the pharyngeal sections of mouse and pig embryos I reproduced above were both taken from papers published within the twenty-first century. Any modern textbook on vertebrate developmental biology is likely to have similar photos or diagrams of these structures.

AndyI guess it is easier to print the old stuff than to update the books to what they are intended to do, and that is to provide useful information that can help us treat diseases and give our patients a fighting chance.

Sorry Andy regardless of whether it comes from an older source or a current one, pharyngeal clefts, or “gill slits” exist in amniote embryos whether or not you want to accept the facts or the current best explanation for them, so please spare us the overwrought “won’t someone think of the ill people?!” shtick.

AndyTo this day, I haven’t seen a mermaid or an angel either in nature or in a lab, so, I will have to dismiss both claims as pending research and proper laboratory testing.

53435573

Yeah so at this point, I am starting to have doubts that you are for real Andy and not just a troll looking for attention. What the hell does a mermaid have to do with anything Andy? Please tell me you are not seriously suggesting that evolutionary theory somehow supports the existence of mermaids [Hint: the exact opposite is the case]. Because if you think it does, you may want to rethink your career path—perhaps something in the arts?

AndyPlease don’t take this the wrong way. I am a paying student who is discordant with the never-ending stories.

As I said, after the mermaid comment I am no longer sure how to take you Andy. Perhaps your response or lack thereof will clarify that question.

Regardless I want to thank you Andy. Formulating my response to you has made me consider adding a few things to my “gill-slit” article that I think could use some expansion or clarification. So anyway, Poe, troll or sincere, something positive has come from your comment, thanks.

References

Etchevers, Heather (2008) Development of the branchial arches (slide presentation downloaded on 10-29-16)

Shone, Victoria & Graham, Anthony (2014) Endodermal/ectodermal interfaces during pharyngeal segmentation in vertebrates, Journal of Anatomy, 225(5):479-91

Zhang, Zhen et al. (2005) Tbx1 expression in pharyngeal epithelia is necessary for pharyngeal arch artery development, Development, 132:5307-5315

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Answering Creationist Questions

Someone named Stephen has asked some questions on my “creationist questions” page and I am moving my response up to the main page.

Hello Stephen!

Just to get a couple points of order out of the way I want to note that you asked three questions at once and only one (#3) touches on evolutionary biology, violating my question guidelines in multiple ways right off the bat. However, I said might grant some leeway and I will in this case.

Stephen: First, to clarify, I am a college student, almost through with my history degree (as a major), I have a minor in geology, and I have taken enough courses to almost have minors in philosophy and anthropology (just establishing that I am not an uneducated internet troll…. at least not completely). This does not make me an authority on the debate between evolution and creationism, but I have studied enough to be fairly well versed in the arguments that each side uses.

OK, good to know; as it would mean that there is no reason you should be making any glaring errors in those areas, yes?

Stephen: I was home-schooled by choice and was taught evolution and creation equally…

You were taught about a mature and productive scientific field and the relatively brief creation story from the Hebrew scriptures (backed up, no doubt, with the pseudoscience, misrepresentations and misinformation of “creation science”), “equally”?

You should understand that from my perspective that doesn’t make a lot of sense.

Stephen: I studied the sides and decided to pick the side that, I believe, has the least number of holes in its arguments. I decided to become a creationist, but I still see both sides and am willing to keep my mind open to all possibilities.

Well then, my question would be what are some of the supposed “holes” in evolutionary theory? Please do not tell me they are of the sort usually put forward by “creation scientists”, I have a library full of those bogus arguments.

Again, from my perspective creationism is collection of long refuted empirical claims (young Earth, Flood geology) backed by a premise (“God did it”) that is fundamentally untestable and therefore scientifically useless.  

Stephen: Question 1: How do you define science (yes, I am talking about the AIG argument between “testable/repeatable science” and “historical/perceived science”)? I do mean you specifically, as different words mean different things to different people, and “standard definitions” do not always fully encapsulate this idea.

In the context you seem to be asking (that of Answers in Genesis’ idiosyncratic redefinition of science), I would say that science is a process wherein people derive coherent explanations about the state of the natural world which are testable by further, intersubjective, observations of the natural world. This holds regardless of whether the particular phenomenon under examination is something that occurred in the past or is currently ongoing.

In science, one does not have to be able to repeat the occurrence of something in order to explain it. What is necessary is that the observations that are made to test the explanation be repeatable by anyone who makes the effort, i.e. not subjective revelations knowable only to an individual or an elect few.

As with forensic science used against criminals, one need not repeat the crime in order to make observations (of finger prints, DNA, etc.) to build a case as to who the most likely perpetrator is.

The same is true when one is trying to explain the current state of nature be it biological, geological or astronomical. We do not need to repeat, in full, the processes that lead to the current state of affairs in order to piece together a case against the most likely “perpetrator”.

Of course, in practice, there is more to it than that but I am not writing a book on the philosophy of science.

Professional creationists want to muddy the waters on this because their explanations either have failed to hold up against observations of the natural world, or are simply not testable by such observations. In other words, their ideas are either failed science or non-science and so they try to tear down good science in an attempt to mislead people into believing that their ideas have merit.    

Stephen: Question 2: Why do scientific laws exist: gravity, thermodynamics, etc. if no one created them (yes it does seem like a silly question, but believe it or not, I have found this question to be helpful)?

This is a question about cosmology and is essentially asking why the universe is the way it is. My answer is, I do not know. Cosmologist are working on such questions and they may or may not be able to answer some or all of them someday, however I see no reason to assume that if they do find answers to them that they will include the idea that the universe was “created” by a conscious being of some sort.

Any explanations that cosmologists do come up with will have to be testable by observations of the natural world in order to be scientific. “God did it” does not meet that criterion.

Stephen: Question 3: How do you believe that things such as a conscience, idea of self-awareness, and the ability to fully reason came to be? Yes, this is a philosophical question, because philosophy is the first “science” and was the root of all the other disciplines.

I don’t know if the ability to “fully reason” actually exists and I would quibble with you that these are necessarily philosophical questions. I would say that the evidence suggests that these things are evolved characteristics as we see them in a continuum in the animal world with humans merely being at one end of the spectrum.

Stephen: In addition, evolution influences much more than biology, geology, and physics (to name a few of the traditional sciences) in its scope, and all aspects of the theory need to be considered.

I disagree. Biology, geology and (to a lesser degree) physics influence evolutionary theory but not the other way round. Evolutionary theory had to be consistent with the facts of biology (obviously) but also geology and physics in order to be considered successful. Theories of geology (plate tectonics etc.) or physics (relativity etc.) do not need to factor in evolutionary theory but rather stand or fall based on observations from those fields.

If inconsistencies between evolutionary theory and say, plate tectonics, were discovered, then those would have to be worked out, but physical geologists who are trying to solve geological problems do not sit around worrying about how their findings might affect those of biologists. They find what they find and it is up to the biologists to figure out whether their own theories can be made to fit with the new data or must to be scrapped in favor of new ones.

What you are talking about reflects the conspiracy theory thinking of creationists, wherein all of modern science is some sort of evolutionist plot to discredit the Biblical account of creation, it isn’t.

The actual problem is that the facts of nature, biological, geological and physical, simply are not consistent with creationism and creationists have adopted this conspiracy idea as a way to avoid facing that fact.

Stephen: Especially since the idea of “origins” is one of the three fundamental questions of philosophy (IE: Where did I come from? Why am I here? Where am I going?).

“Where did I come from?” is an empirical question answered by science; proximally by reproductive biology and evolutionary theory more distally by astronomical and cosmological theories. You would have to be more specific to get answers that are more specific.

“Why am I here?”—assuming it is not merely a rephrasing of the previous question—is a question that assumes something not in evidence, that there is some externally imposed purpose to our existence. It could be that there is no “why” and therefore the question is incoherent.

“Where am I going?”, again this assumes that you are going anywhere. Barring evidence that anyone is going anywhere this question is also incoherent.

Stephen: By the way, I have heard your comparison of “playing chess with pigeons” before (in relation to evolutionists). Is that saying original (to you) or did you get it from elsewhere? If so, where?

The answer to that may be found in the tab at the top of my blog titled “Playing Chess with Pigeons?“. It is taken from something first written by Scott Weitzenhoffer in reference to creationists; so if you have seen it being used in any other way it was pilfered directly or indirectly from him.

 

Round 2 of: What “hope” do you have being an evolutionist?

herrad2Well, Ms. Korzeniewski has made a couple of responses and I will give her one more spot in the PCwP limelight, however after this the discussion, if there is one, will probably stay in the comments.

Her first response was basically a second-hand threat of exquisite mind flailing torture of infinite duration at the hands of her all loving deity, apparently for the unpardonable crime of daring to use the brain that her deity supposedly gave me.

Needless to say I do not find this a terribly compelling argument in favor of creationism.

Ms. Korzeniewski, once again, please try to understand such threats cause just as much concern for the non-believer as say, the threat of hell from the Islamic version of God, probably causes you. That is none at all.

If you want to make any impression on someone who does not already share your beliefs, you are going to have to use evidence, logic and reason, not threats from what they consider an imaginary being.

We shall now proceed to the non-threat potions of her comments.

Read on»

One more time with Biele

Creationist Arthur Biele responded to my response, to his response of my critique of something he wrote on horse evolution [inhales abruptly].

Thankfully he respected my wishes that he not post another book length set of arguments in the comments to my post. He has of course taken this as a blanket refusal on my part to allow him to respond:

Biele: Since you refuse me a full response to your article…

Mr. Biele, I only asked that you not post another extremely lengthy response, in the comments section of my blog and indeed this is a rule of mine, one not restricted to you. If you look at my comments policy you’ll see that this is a  request I make of everyone who comments on my blog. Still, I welcomed you to respond to one or two specific points, which we could then discuss further; something which I think would be a more productive way to continue our debate.  And I also specifically mentioned other options you could take if you wanted to respond at length.

Once again, you are free to start your own blog (they’re free) or web page and post as long a response to me as you like. Alternatively you could post your comments to the Talk Origins Newsgroup (or some other similar open forum), and simply leave a link in my comments as to where your response could be found (and then I might respond further here).

So it is really your choice.

Now, despite your complaints, you did in fact make a comment of a limited nature about punctuated equilibrium which I am happy to respond to.

Biele: …the PE’s views that theory is not at all complementary to Darwinisn evolution, but was meant to replace it.

Yes, I am aware that this is the caricature of punctuated equilibrium that antievolutionists like you believe in; the problem is it is a caricature, not reality. You see, Mr. Biele, for someone who has some understanding of both the neo-Darwinian synthesis and PE (and who has read the relevant literature), your portrayal of the situation is nonsensical.

Biele: In the plaeontologists views, evidence for Darwin’s gradualistic theory of evolution is refuted by the fossil record.

In some paleontologists’ views, the evidence for what Eldredge and Gould referred to as “phyletic gradualism” is refuted by the fossil record. Not Darwinian evolution as a whole, just what they termed its supposed phyletic gradualism. Furthermore, there are many, including myself, that think that Eldredge and Gould fashioned a bit of a straw-man in their characterization of the main-line synthetic theory.

Biele: The PE theory was a means to save The General Theory of Evolution by proposing a new means by which evolution occurs. Of course that theory of evolution also has its’ critical faults too.

[Sigh] I’m sorry Mr. Biele, but this is simply nonsense. Once again, Stephen Jay Gould:

Faced with these facts of evolution and the philosophical bankruptcy of their own position, creationists continually rely upon distortion and innuendo to buttress their rhetorical claim.  If I sound sharp or bitter, indeed I am – for I have become a major target of these practices.

I count myself among the evolutionists who argue for a jerky or episodic, rather than a smoothly gradual, change of pace.  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 one percent of the average lifespan for a fossil invertebrate species – more than 10 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.

We proposed the theory of punctuated equilibrium largely to provide a different explanation for pervasive trends in the fossil record.  Trends, we argued, cannot be attributed to gradual transformation within lineages, but must arise from the differential success of certain kinds of species.  A trend, we argued, is more like climbing a flight of stairs (punctuations and stasis) than rolling up an inclined plane

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.  Yet a pamphlet entitled: “Harvard Scientists Agree Evolution Is a Hoax” states: “The facts of punctuated equilibrium which Gould and Eldredge . . . are forcing Darwinists to swallow fit the picture that Bryan insisted on, and which God has revealed to us in the Bible.” – Gould (1983) “Evolution As Fact And Theory” in Hen’s Teeth and Horses Toes, pp.253-262, (Emphasis mine)

And now, 27 years later, Arthur Biele continues the distortion.

Biele: I was preparing a reply in my mind as I read each of your arguments and noting the many sophistical defenses you used in your long awaited reply. A long reply deserves an equal response, And it would have taken me a few days due to my busy schedule. But as you told me what amounts to be ‘take a hike’, that your site is reserved for your own views and accolades, I will honor your wishes. I indeed do plan to actually ‘take a hike’ as it would be good for my health.

As I said it’s your choice. You have several options open to you to give as long a response as you might like to my previous post, and of course you are welcome to respond on the more limited issue of PE discussed here in the comments below, just keep it concise.

If not, it’s no sand off my beach.