It’s just a stage. A phylotypic stage. Part I.

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Disputes and controversies in science are always a good thing. They're fun to read about (and to write about), and they're bellwethers of the health of the enterprise. Moreover, they tend to stimulate thought and experimentation. Whether scientists are bickering about evo-devo, or about stem cells in cancer, or about prebiotic chemistry, and whether or not the climate is genial or hostile, the result is valuable.

Now of course, some controversies are invented by demagogues for political purposes. The dispute in such cases is far less interesting and clearly less profitable, even if participation by scientists is necessary.

This week, two papers in Nature weighed in on a major scientific controversy that has its roots in pre-Darwin embryology, fueled by some gigantic scientific personalities and even tinged with what some would call fraud. This intense scientific dispute spawned a sort of doppelganger, a manufactured controversy that is just one more invention of anti-evolution propagandists. The Nature cover story gives us a great opportunity to look into the controversies, real and imagined, and to learn a lot about evolution and development and the things we're still trying to understand about both.

The scientific dispute is an old one, dating to when scientists first began to study embryonic development in earnest. Embryologists like the great Karl Ernst von Baer noticed that the embryos of very different animals often looked so similar that they could hardly be distinguished from each other. A chicken embryo, at some point, looks an awful lot like a human embryo. What does this mean? Two schools of thought (roughly speaking) entered into competition, with evolution as the major subtext. One set of ideas envisioned development as recapitulation: development was a sort of re-play of evolution, with the organism recapitulating its evolutionary history as it took shape. Recapitulation theory was the brainchild of Ernst Haeckel, whose view of development was codified as his Biogenetic Law and sloganeered as "Ontogeny recapitulates phylogeny." Against recapitulation were the views of von Baer and others; von Baer formulated his own set of laws, the third of which repudiates recapitulation rather directly. Everyone agreed that embryos of different animals often looked quite alike; the dispute was about what this meant. And it seems that those who opposed evolutionary explanations (like von Baer) were eager to point to difference and divergence during development, while those who championed evolutionary views wanted to emphasize the shocking similarities between, say, chickens and mammals when compared at key embryological junctures.

Haeckel, famously, went on to point to those similarities as evidence for common ancestry and, infamously, to create a certain illustration of that evidence. His picture, thought by even some embryologists to be partly fraudulent (more accurately, "doctored"), is now a staple of anti-evolution propaganda. You can read all about that elsewhere; suffice it to say that Haeckel's drawings have long since been "corrected" without creating any problems for evolutionary theory. (For a much more detailed treatment of this saga, see Richardson and Keuck, Biological Reviews, 2002.)

RichardsonPhylotypicLineupFromGilbert300px.jpg

But interestingly, the debates about recapitulation morphed (wink) over the years into a distinct but related disagreement about whether animal development passes through a stage that is common to - or typical of - the lineage of the organism. Because although Haeckel's recapitulation idea didn't survive, it remained clear that development seemed to reflect evolutionary commonalities. Consider the photos on the right. (The figure was created by Michael K. Richardson, who led the research group that critiqued Haeckel's drawings in 1998.) While the various embryos shown all end up looking quite different - looking like the adult form, in other words - they seem to "start" at a place that's notably similar. (Compare the embryos in the first row.) That starting point is not the beginning of development, and in fact those different kinds of embryos got to that starting point via rather different beginnings. In other words, it seems that animal embryos pass through roughly three phases of development: an early phase that can vary from group to group (say, between birds and mammals), a late phase in which group-specific forms are established, and a middle phase that is eerily similar among groups. That middle phase has come to be known as the "phylotypic stage" of development, meaning that it is a stage at which the embryo looks like a typical example of its evolutionary group. For insects, this is thought to be the "extended germband" stage; for vertebrates, it's roughly the tailbud stage. The point is that there is a middle phase of development during which animal embryos of varying morphological destinies look very similar, even if their earlier stages seemed very distinct. This model of developmental trajectories, compared across groups, is known as the "hourglass model," nicely depicted by Richardson and colleagues in the cartoon on the left.

HourglassModelCartoonRichardson-etal250px.gif

Why all the controversy? Well, the disputes all seem to be related to the fact that the model is mostly descriptive. And so, one criticism is that the model is based on what embryos look like, and not strongly anchored in carefully-defined and -measured characters. Moreover, some critics have noted that the comparisons were often restricted to popular laboratory species, such that when the analysis was expanded to include a broader set of species, the similarities in the waist of the hourglass become less striking. In other words, the dispute centered on the basis of the model. Critics were disputing the very existence of the phylotypic stage.

Oh, and while this interesting scientific debate was ongoing, some propagandists were shadowboxing with Haeckel's ghost, shrieking about fraud while creating in the minds of their dupes the illusion of a different debate: one about whether development and evolution are conceptually linked. Along the way, these busy demagogues suggested that the phylotypic stage is an illusion, cherry-picking their data more shamelessly than Haeckel ever did. In any case, these folks were exploiting the real scientific dispute: whether the phylotypic stage can be defined more rigorously, in a way that links the similarities (whatever they are) to common ancestry.

NatureCoverPhylotypic.jpg

And that brings us to the cover story in this week's issue of Nature. The cover image depicts a version of Haeckel's infamous illustration. The issue includes two reports, very different in their approach and in the animals they examined. Both reports provide striking support for the hourglass model, by showing that the phylotypic stage is indeed characterized by distinctive and fascinating patterns of gene expression. Part II will explore those two papers.

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Image credits: 1) embryo images from Gilbert, Developmental Biology, 6th Edition, online at PubMed; 2) cartoon from Richardson et al. 1998.

46 Comments

Why are there no Wikipedia entries for phylotypic stage and hourglass model? And why can’t Nature let a few miserable articles go for free?

And why can’t Nature let a few miserable articles go for free?

Or at least charge something reasonable! How about $1 per article rather than a ridiculous $18-$32.

Is there anyone who actually pays that?

Those who are interested are either students or teachers - who get theirs free through their schools, or a very, very few, independent researchers (like myself) who either beg copies off student/teacher friends or drive down to the local university library and download a free copy.

Now if they only charged a dollar or two, I might just pay to save myself a drive (or the pestering of friends).

That way they might actually make a little money - though it’s not like there are millions of people out there waiting for a chance to download a technical paper on developmental biology - still I bet they would actually make more than they do now.

because wiki is not the be all and end all of human knowledge?

this is a close as you’re gonna get to coverage of this stuff on wiki:

http://en.wikipedia.org/wiki/Evolut[…]ntal_biology

oh, and while lambasting of overpriced journals is a great thing, I would also recommend putting some effort into supporting the open journal movement:

http://www.doaj.org/

http://www.openarchives.org/

…and here’s a previous, FREE paper on the subject that goes into a bit more of the basics:

http://rspb.royalsocietypublishing.[…]341.full.pdf

which is an example of what Steve refers to with: “In other words, the dispute centered on the basis of the model. Critics were disputing the very existence of the phylotypic stage.”

…one last item, Jerry Coyne also discusses this work in case more coverage is desired:

http://whyevolutionistrue.wordpress[…]lass-figure/

*grr*

thoughts pop in one at a time in my head these days.

…ever wonder why PZ’s blog is named what it is?

http://en.wikipedia.org/wiki/Pharyngula

which, btw, is probably also why you can’t find a specific “phylotropy” wiki page.

…one last item, Jerry Coyne also discusses this work

by Matthew Cobb

*doh*

right.

though Jerry does weigh in directly on the subject in that thread.

Ichthyic said:

because wiki is not the be all and end all of human knowledge?

You mean there’s more?!

I’ve done a little reading on evo-devo, but have never come across the hourglass model or phylotypic stage. The rest of the names and terms in Steve’s post I’ve at least heard of.

but have never come across the hourglass model or phylotypic stage.

It’s probably because the terms are kind of cross-disciplinary, as it were.

The hourglass model is much older than the modern evo-devo synthesis; the term is not usually referred to outside standard developmental biology texts, so you won’t run into it outside of discussions of exactly what these papers are about, or basic developmental biology courses.

“phylotypic” is not actually a recognized stage of development, but is more of a descriptive thesis from a more purely evolutionary discipline that could apply to several stages of development (though most often and historically applied to the pharyngula stage), so you won’t run into it commonly while perusing literature on developmental biology.

so, without a basic college level course in either evolutionary biology or developmental biology, I could easily imagine not running across the terms; I hadn’t even thought about it.

You mean there’s more?!

why, yes! shocked me too.

;)

Does this phylotypic stage - the narrowest point of the “hourglass” - represent, more or less, something like the phylum (or thereabouts) throughout the animal kingdom? I’m wondering whether one could tag a certain level of taxonomy as being something like:

Organisms which share a common phylotypic stage belong to the same phylum (or whatever).

What metrics would you use, TomS? Seems to me there’d be a lot of differences even in “common” phylotypic stages.

P. Z. Myer’s illustrated pharyngula stage is clearly identifiable as a minnow, family Cyprinidae (zebra danios are minnows). So it is considerably more specific than phylum. I’m not a minnow expert, so I cannot say if it is identifiable as a member of some sub group of minnows.

Troy Britain said:

And why can’t Nature let a few miserable articles go for free?

Or at least charge something reasonable! How about $1 per article rather than a ridiculous $18-$32.

Is there anyone who actually pays that?

Those who are interested are either students or teachers - who get theirs free through their schools, or a very, very few, independent researchers (like myself) who either beg copies off student/teacher friends or drive down to the local university library and download a free copy.

Now if they only charged a dollar or two, I might just pay to save myself a drive (or the pestering of friends).

That way they might actually make a little money - though it’s not like there are millions of people out there waiting for a chance to download a technical paper on developmental biology - still I bet they would actually make more than they do now.

I’ve always thought that about academic publishing in general. This is a big problem in linguistics (probabaly in other fields; it’s just that the books I want are in linguistics). The “words beginning with ‘n’” volume of the Hittite Etymological Dictionary is $166. Perhaps the market for this sort of thing is small, and they figure they can make their money from university libraries who feel they have to have the book (one more reason for high tuitions), but with a more reasonable prices they would sell more copies. This would also bring more people into the field, giving it some fresh ideas.

There is also the question of interest. How am I going to get interested in what science (or any field) is up to if I can’t afford the journals or articles? Right now I have to limit myself to the Journal of Indo-European Studies, but I would dearly love to be able to afford some important ones (such as Zeitschrift fur Celtische Philologie) that are hard to find. Better (i.e., cheaper) access to acadmic journals might result in more funding, since people who became interested in the subjects would be more likely to support government investment. Plus it would expose people to the way work in academia is done, and perhaps fight pseudoscience.

I know that journals and academic publishers aren’t charities, but I have to wonder if their economic models aren’t short-sighted.

Re, Hourglass graphic: I am not a biologist. I don’t get the hourglass graphic. I would have thought the zygotes would be on top, and after the constriction (the phylotypic stage) we would have different species at the bottom. Hey? Who flipped my hour glass?

Re, Cost of journals: The cost of transmitting, replicating and sharing information has dropped several orders of magnitude over the last few decades. But the cost of collecting and compiling information has stayed constant or has gone up. We still don’t have a good model for paying for the info collection. If the consumers of info could somehow come up with a model to pay for the information creation a priori, may be we would be able to take full advantage of the ever decreasing cost of distribution.

At least in the academics most people who create the information are the graduate students and their tenured professors. They might actually think the info has been “paid for” and be willing to share it freely. But publishing it in a blog does not have the same prestige of publishing in “Nature”. Why is that?

Because we are acting like female sage grouse birds who choose to mate with the male most admired by most other female sage grouse birds in a lek!

If we collectively come up to fund a web site to publish such articles, and cite papers in that site in our papers, we could print our own money. The coin of our realm is not a federal currency note that would buy you a loaf of bread in the grocery store. It is prestige, it is recognition. We create it. We, collectively, are our own federal reserve. The cost of distribution has fallen so much we can finally dispense our recognition and prestige directly without mediating it through some currency.

I think the readers of this group would be the one among all other sciences to get it.

@TomS: While the phrase “phylotypic stage” is most often applied to vertebrate development, and therefore refers to something common to a phylum, the concept can apply more widely. Here’s a quote from a paper on the subject from Michael Richardson’s group:

The phylotypic stage is, in principle, applicable to any group of organisms and has been described for insects (Sander 1983), annelids and arthropods (Anderson 1973) and vertebrates (Ballard 1981; Kimmel et al. 1995), among others.

I share everyone’s frustration with Nature and its opposite-of-open-access stance, and you may have heard of large boycotts of Nature journals for related reasons. Most maddening is their refusal to provide open access to the archive after any amount of time; all the Cell journals do this, for example. To be fair to Nature, they do have some nice collections (called Specials) with free stuff, organized by topic, and their Scitable site is exemplary. (Scitable includes a lot of free articles from Nature journals.)

As for ravilyn’s suggestion: I think that’s already being done. Check out PLoS and BMC collections for prominent examples.

David Fickett-Wilbar said:

… it’s just that the books I want are in linguistics). The “words beginning with ‘n’” volume of the Hittite Etymological Dictionary is $166.

I once managed to acquire Fascicle 1 (Ša to Šaptamenzu) of Volume Š of the U Chicago Hittite Dictionary for a mere $40. That was definitely a one-off phenomenon, however.

Scitable includes a lot of free articles from Nature journals.)

most aren’t though, from my recollection.

it’s very hit and miss.

I’d just remind folks to support open access, and the relevant links I posted are earlier in this thread.

one of these days, I’m some pirate somewhere is going to get interested enough to blow the lid off journal privacy, and then the publishers of these journals are REALLY going to regret not thinking to reduce the costs to consumers.

I’m actually quite surprised it hasn’t already happened.

The hourglass shape is obviously a product of intelligent design and not Darwinism. How could all embryos converge to this particular shape in a cognitively isolated environment. Haeckel’s biogenic law would appear provide a Darwinian explanation but even PZ Myers admits it fails. There is no way embryonic developent could work this way by pure random chance without cognitive input.

darwinism.dogbarf() said:

The hourglass shape is obviously a product of intelligent design and not Darwinism. How could all embryos converge to this particular shape in a cognitively isolated environment.

There is no way embryonic developent could work this way by pure random chance without cognitive input.

The unsurprising fact that dogbarf can’t think of an explanation is not evidence of anything.

One way is that there are two contrasting forces at work here:

1. Change is greater in later stages of development because a change earlier in development is much more disruptive than a change later in development. So it has been pointed out long ago that more changes will tend to accumulate in later stages of embryos, with early and middle stages showing greater similarity.

2. Bu the very earliest stages are under strong natural selection to adapt to the differing conditions of existence of the embryo. Mammalian eggs have to implant in a uterus, while chicken eggs have a large yolk until hatching, so that the early embryo is under great pressure to adapt to these different environments.

The result is an hourglass. Obviously there is no selection pressure to maintain a stage that illustrates the reality of evolution, but the above pressures happen to work out that way.

(And Haeckel’s “biogenetic law” is not something for which we “admit it fails” – it was dead in the water 80 years ago and evolutionary and developmental biologists are glad to be rid of it).

Oops, typing mistake: “But the earliest stages …”

Oops-squared: “But the very earliest stages …”

I’m eagerly awaiting part 2.

We all already realize that common developmental features are some of the strongest evidence for common descent, e.g. Hox genes.

Whether a definable stage of vertebrate development is “even more conserved” on grounds other than morphology seems to be the point that this article is building up to, and that seems highly plausible for the reasons Joe Felsenstein points out, but since the non-morphology stuff isn’t up yet, it’s hard to say much.

Wouldn’t it be more of an “ant shape” than an hourglass shape? After all, I imagine pretty much every vertebrate zygote is similar. So it starts off similar, gets dissimilar, goes through talibud stage, gets dissimilar again.

Joe Felsenstein said:

darwinism.dogbarf() said:

The hourglass shape is obviously a product of intelligent design and not Darwinism. How could all embryos converge to this particular shape in a cognitively isolated environment.

There is no way embryonic developent could work this way by pure random chance without cognitive input.

The unsurprising fact that dogbarf can’t think of an explanation is not evidence of anything.

One way is that there are two contrasting forces at work here:

1. Change is greater in later stages of development because a change earlier in development is much more disruptive than a change later in development. So it has been pointed out long ago that more changes will tend to accumulate in later stages of embryos, with early and middle stages showing greater similarity.

2. Bu the very earliest stages are under strong natural selection to adapt to the differing conditions of existence of the embryo. Mammalian eggs have to implant in a uterus, while chicken eggs have a large yolk until hatching, so that the early embryo is under great pressure to adapt to these different environments.

The result is an hourglass. Obviously there is no selection pressure to maintain a stage that illustrates the reality of evolution, but the above pressures happen to work out that way.

(And Haeckel’s “biogenetic law” is not something for which we “admit it fails” – it was dead in the water 80 years ago and evolutionary and developmental biologists are glad to be rid of it).

You assume that these changes occur by the random forces of natural selection and not the information in their genomes. Let’s try an experiment; we will take a chunk of concrete and throw it in a vat with all of the chemicals in the uterus and see if it turns into a pharyngula-stage embryo. If it doesn’t, can we not assume that information has something to do with it? Information that produced the hourglass shape that in any other context (a real hourglass) would be indicative of intelligent design?

darwinism.dogbarf() said: Let’s try an experiment; we will take a chunk of concrete and throw it in a vat with all of the chemicals in the uterus and see if it turns into a pharyngula-stage embryo. If it doesn’t, can we not assume that information has something to do with it?

That is the most incoherent argument I’ve heard … well, at least today.

Back to conspiracy theorists. I do have to admit that this tops the “Jackie actually shot JFK” conspiracy theory … but it might match the “JFK wasn’t really shot, it was all staged” conspiracy theory.

darwinism.dogbarf() said:

You assume that these changes occur by the random forces of natural selection and not the information in their genomes. Let’s try an experiment; we will take a chunk of concrete and throw it in a vat with all of the chemicals in the uterus and see if it turns into a pharyngula-stage embryo. If it doesn’t, can we not assume that information has something to do with it? Information that produced the hourglass shape that in any other context (a real hourglass) would be indicative of intelligent design?

And you assume that natural selection is random. That is incorrect. Let’s try an experiment. Let’s look at the spatio/temporal expression pattern of the genes responsible for producing these developmental stages. If they show the hour glass pattern as well, then that is strong evidence for descent with modification and the evolution of developmental pathways. Have a look at part II genius.

See the thing is, this is not a pattern that is predicted by intelligent hypotheses. If it were, creationists could have been the ones to discover the pattern, not poo poo it. Of course they would have also been the ones to discover the gene expression patterns as well what with their cutting edge developmental research and all.

Joe has provided good reasons why this pattern is expected from descent with modification. Can you provide any good reason why this pattern should be expected from intelligent design? Is god as fond of hour glasses as she is of beetles?

If that is so, then please enlighten us as to how you would offer scientifically rigorous hypotheses based on the so-called “principles” of Intelligent Design:

darwinism.dogbarf() said:

The hourglass shape is obviously a product of intelligent design and not Darwinism. How could all embryos converge to this particular shape in a cognitively isolated environment. Haeckel’s biogenic law would appear provide a Darwinian explanation but even PZ Myers admits it fails. There is no way embryonic developent could work this way by pure random chance without cognitive input.

Joe Felsenstein has provided some important, and compelling embryological arguments that refute your assertion, replete in its breathtaking inanity. I suggest you read them carefully and then find yourself in agreement. Otherwise you are nothing more than an intellectually-challenged Dishonesty Institute IDiot Borg drone.

You assume that these changes occur by the random forces of natural selection and not the information in their genomes.

utter gibberish.

Dogbarf is presumably a parody, but if not, he’s a real idiot.

You assume that these changes occur by the random forces of natural selection and not the information in their genomes.

This literally makes no sense. No-one is suggesting that information in the genome doesn’t guide development.

Let’s try an experiment; we will take a chunk of concrete and throw it in a vat with all of the chemicals in the uterus and see if it turns into a pharyngula-stage embryo.

And the result you get will be evidence against ID/creationism. You won’t get an embryo, therefore the hypothesis that modern life can appear magically out of nothing will be further weakened.

If it doesn’t, can we not assume that information has something to do with it?

This question makes no sense.

Information that produced the hourglass shape that in any other context (a real hourglass) would be indicative of intelligent design?

So -

1) Who is the designer?

2) Precisely what did the designer design?

3) When did the designer design it?

4) How did the designer design it?

5) Can you give me an example of something that the designer might not have designed?

Dogbarf is presumably a parody

for their sake, I actually hope so.

Information that produced the hourglass shape that in any other context (a real hourglass) would be indicative of intelligent design?

Congrats. That must be one of the most ridiculous arguments pro-ID I’ve ever heard.

But it is a great point in favour of my hypothesis that IDist are pro-ID because they are inherently unable to grasp the concepts of analogy and metaphor. Just out of interest, do you also believe that because histograms of samples with a normal distribution like body height (example) can be described as bell-shaped that body height is intelligently designed?

JLT said:

Information that produced the hourglass shape that in any other context (a real hourglass) would be indicative of intelligent design?

Congrats. That must be one of the most ridiculous arguments pro-ID I’ve ever heard.

But it is a great point in favour of my hypothesis that IDist are pro-ID because they are inherently unable to grasp the concepts of analogy and metaphor. Just out of interest, do you also believe that because histograms of samples with a normal distribution like body height (example) can be described as bell-shaped that body height is intelligently designed?

You seem to be a Type 2 evolutionist (dominated by evil) as opposed to a Type 1 evolutionist like Ichthyic (dominated by stupid). You actually tried o make an argument. As for you example, I would say since a normal distribution indicates randomness, the heights of Swedes has not been intelligently designed.

You actually tried o make an argument. As for you example, I would say since a normal distribution indicates randomness, the heights of Swedes has not been intelligently designed.

how do you know it’s not being cleverly hidden in the noise?

I hear the Abrahamic god is quite the trickster like that, getting his minions to hide fossils everywhere, and working so hard to make it look just like natural selection can explain the changes in so many traits, and the evolution of so many species.

*shakes fist*

how are we to know this isn’t all a trick, and the universe wasn’t created last Thursday?

I would say since a normal distribution indicates randomness

Blaspheming wretch! How dare you deny that the BELLS which call us to worship are intelligently designed?

Ichthyic said:

You actually tried o make an argument. As for you example, I would say since a normal distribution indicates randomness, the heights of Swedes has not been intelligently designed.

how do you know it’s not being cleverly hidden in the noise?

Well, we don’t, but that is a question of religion, not science. The science of intelligent design can only infer design based on similarities to things known to be designed.

I hear the Abrahamic god is quite the trickster like that, getting his minions to hide fossils everywhere, and working so hard to make it look just like natural selection can explain the changes in so many traits, and the evolution of so many species.

*shakes fist*

how are we to know this isn’t all a trick, and the universe wasn’t created last Thursday?

Have you tried asking him?

Well, we don’t, but that is a question of religion, not science.

then how does religion answer it?

The science of intelligent design can only infer

not much of a “science” then, eh?

Have you tried asking him?

who? Ganesh?

pick one:

http://www.magictails.com/creationlinks.html

The science of intelligent design can only infer design based on similarities to things known to be designed.

Okay, but when real scientists study something “designed”, whether it’s a human site or a bird’s nest, they can answer these questions, so why do you ignore them?

1) Who is the designer?

2) Precisely what did the designer design?

3) When did the designer design it?

4) How did the designer design it?

5) Can you give me an example of something that the designer might not have designed?

darwinism.dogbarf() said:

The science of intelligent design can only infer design based on similarities to things known to be designed.

So, there are some things that are designed and some that are not? Which are which? Name something that is definitely NOT designed, and explain how you can tell.

Of course, I don’t expect you to answer that question. In the other thread you’ve been repeatedly asked to provide the explanation you claimed to have, and you fled in terror.

So, there are some things that are designed and some that are not? Which are which?

Behe actually addressed this question on the stand in Dover, and did a pretty honest job of it. He testified that design is an immediate, visible, innate property. The test for design is simply to LOOK at it. If it was designed, you can tell right off.

Behe also testified that the “immediately self-evident” test for design or non-design seems to be correlated nearly 100% with a particular religious faith, a link Behe was unable to explain or understand. But lacking this faith blinds one to the self-evident; one must See The Light before the property of Design can be properly grokked.

Flint said:

So, there are some things that are designed and some that are not? Which are which?

Behe actually addressed this question on the stand in Dover, and did a pretty honest job of it. He testified that design is an immediate, visible, innate property. The test for design is simply to LOOK at it. If it was designed, you can tell right off.

Behe also testified that the “immediately self-evident” test for design or non-design seems to be correlated nearly 100% with a particular religious faith, a link Behe was unable to explain or understand. But lacking this faith blinds one to the self-evident; one must See The Light before the property of Design can be properly grokked.

Ah, so “design” is equivalent to “magic”. And did Behe ever bother naming anything that lacked this magic? Has any cdesign proponentsist ever even come close to doing so?

It impossible to infer anything based on comparison to “designed” objects if EVERY object is designed, and it is similarly impossible to make such inferences without a clear and objective method of distinguishing “designed” objects from those that are not. “My magic invisible friend tells me, but not you” does not constitute such a method.

It impossible to infer anything based on comparison to “designed” objects if EVERY object is designed, and it is similarly impossible to make such inferences without a clear and objective method of distinguishing “designed” objects from those that are not.

Yeah, this has been a serious problem. The test for design, in practice (though rarely admitted) is purely theological. According to one’s particular flavor of creationist faith, the degree to which something is designed is a matter of the attention one’s faith presumes that one’s god CARES about it.

Behe’s “test” illustrated this quite clearly. He judged whether he was looking at the “purposeful arrangement of parts”, which in turn required that he understand the purpose for which the arrangement was intended. Presumably, a bunch of rocks sitting around on the ground were not Designed to be as they are, because Behe’s faith finds no purpose to those shapes or locations.

BUT there are creationists who do feel that all of reality was designed at Creation; every grain of sand, every snowflake. Behe at the opposite extreme finds Design in the bacterial flagellum, but not in the rest of the bacterium! And the only means so far devised for reconciling these differences is for both parties to say to the other “I know in my heart that you are wrong; my god assures me my opinion is correct.”

“My magic invisible friend tells me, but not you” does not constitute such a method.

Well, it’s not a GOOD method, because there’s no conflict resolution mechanism. Both sides go on to say “My magic invisible friend is telling you just what He’s telling me, but YOU ARE NOT LISTENING!” How else could it be?

The big tent is constantly springing leaks.

harold said:

The science of intelligent design can only infer design based on similarities to things known to be designed.

Okay, but when real scientists study something “designed”, whether it’s a human site or a bird’s nest, they can answer these questions, so why do you ignore them?

1) Who is the designer?

This is a religious question beyond the scope of science.

2) Precisely what did the designer design?

Anything in which the complex specified information is significantly above the level in the environment.

3) When did the designer design it?

4) How did the designer design it?

Since complex specified information is a path-independent state variable this can not be determined. All that can be determined is if something was designed.

5) Can you give me an example of something that the designer might not have designed?

Yes, anything in a random explosion. For example, if you dynamite a pile of corpses that have all the same chemical compounds that exist in live people, you can not bring them back to life. Yet evolutionists maintain all life came into existence exactly that way.

darwinism.dogbarf() said:

harold said:

The science of intelligent design can only infer design based on similarities to things known to be designed.

Okay, but when real scientists study something “designed”, whether it’s a human site or a bird’s nest, they can answer these questions, so why do you ignore them?

1) Who is the designer?

This is a religious question beyond the scope of science.

If you want to claim that Intelligent Design is an explanation, let alone a science, yet, excuse yourself from answering “Who is the designer” on religious grounds, you have invalidated Intelligent Design as an explanation. To continue claiming that it is a science while refusing to answer questions on religious grounds is to perpetuate an especially stupid farce.

If a Jewish paleontologist were to say, “The prehistoric fauna of Israel are not kosher, therefore, no one should be allowed to study them because they are unclean, everyone and their Jewish mother would laugh him out of the scientific community.

2) Precisely what did the designer design?

Anything in which the complex specified information is significantly above the level in the environment.

This answer is unhelpfully vague, as it begs the question of “what is a significant level in the environment?”

My previous experiences tell me that you’re just bullshitting us to hide the fact you know absolutely nothing about Biology to begin with.

3) When did the designer design it?

4) How did the designer design it?

Since complex specified information is a path-independent state variable this can not be determined. All that can be determined is if something was designed.

This is a non-answer, laced with jargon to unsuccessfully hide the fact that you can not answer these or any other questions with Intelligent Design.

After all, the gist of Intelligent Design is to close your eyes and all other sensory organs, and chant “Evolution can’t happen because GODDIDIT” over and over and over and over again.

5) Can you give me an example of something that the designer might not have designed?

Yes, anything in a random explosion. For example, if you dynamite a pile of corpses that have all the same chemical compounds that exist in live people, you can not bring them back to life. Yet evolutionists maintain all life came into existence exactly that way.

Both claims are extremely pathetic strawmen, not to mention extraordinarily inaccurate. They are as insultingly inaccurate as claiming that Christianity should be outlawed because all Christians are sun-hating vampires who drink the blood of liberal children.

If you’re making a jab at the Big Bang, the Big Bang is irrelevant to understanding Biology (or Geology, or Paleontology) beyond being a footnote explaining where all the matter of the Universe ultimately came from.

If you’re making a jab at the “Cambrian Explosion,” it is only an explosion from a geological perspective, referring to the appearance of complex shelled animals over the course of 20 million years from the beginning of the Cambrian period, during the transition of Ediacaran faunas to more typical Cambrian faunas.

In other words, your attempts at insulting “evolutionists” [sic] and evasive non-answers betray both a profound ignorance of science, and a profound desire to remain ignorant.

About this Entry

This page contains a single entry by Steve Matheson published on December 10, 2010 3:42 PM.

December issue of Evolution: Education and Outreach out was the previous entry in this blog.

It’s just a stage. A phylotypic stage. Part II: The flies is the next entry in this blog.

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