Jonathan Wells’ weird notions about development

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Jonathan Wells recently gave a talk in Albuquerque at something called the “Forum on Science, Origins, and Design”, a conference about which I can find absolutely nothing on the web. I wasn’t there, of course, and I don’t get invited to these goofy events anyway, but I did get a copy of Wells’ powerpoint presentation from an attendee. It’s titled “DNA Does Not Control Embryo Development” — shall we look at it together? It’s really a hoot.

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Jonathan Wells has been exposed to a little bit of knowledge, just enough for him to regurgitate a few common phrases that are current in the developmental biology literature, and to pretend that he is profound and revolutionary. Nothing could be further from the truth — his title comes straight out of mainstream evo-devo. It’s actually rather funny, since there is a tiny bit of truth in what he says, but what’s true isn’t original with him, and it certainly doesn’t have the implications he thinks.

He starts with a few quotes to show that some scientists tend to have both a naive view of development, and tend to simplify a bit when speaking in public. Here’s James Watson:

We know that the instructions for how the egg develops into an adult are written in the linear sequence of bases along the DNA of the germ cells.

And Ken Miller:

Our genome is an “amazing script, carrying within it all of the instructions for building a human being.”

And Francis Collins:

The recipe for building the animal body is controlled by remarkably few genes.

Woo-hoo. These are all good scientists who are not developmental biologists, and who are guilty of the dreadful sin of over-simplification. It’s entirely true, however, that there is a tendency to reduce the role of the genes to an excessively narrow view of “control”, and it’s an attitude that many modern biologists would like to see broadened.

Wells missed a trick, though. There’s an even better source for this idea, in Richard Lewontin’s excellent little book, The Triple Helix: Gene, Organism, and Development(amzn/b&n/abe/pwll):

One of the most eminent molecular biologists, Sydney Brenner, speaking before a group of colleagues, claimed that if he had the complete sequence of DNA of an organism and a large enough computer then he could compute the organism. The symbolic irony of this remark is that it was made in the opening address of a meeting commemorating the 100th anniversary of Darwin’s death. A similar spirit motivates the claim by yet another major figure in molecular biology, Walter Gilbert, that when we have the complete sequence of the human genome “we will know what it means to be human.” Just as the metaphor of development implies a rigid internal predetermination of the organism by its genes, so the language used to describe the biochemistry of the genes themselves implies an internal self-sufficiency of DNA.

The rest of the book is very good, and continues along the same lines to point out the interdependency of genes, cytoplasm, and environment.

Oh, but wait — Wells can’t use that. If his point is that he and his creationist ilk are clever iconoclasts, it does no good to reveal that there are huge numbers of biologists, including evolutionary biologists, who have been arguing that the metaphor of control is invalid.

Besides, it’s silly for an IDist to be complaining about metaphor. The primary foundation of their rationalizations is an extended and inappropriate metaphor, that you can call molecules “machines” and pretend that that means they were built by designers in little factories.

Wells has a grander plan than to rebuke a few molecular biologists for sloppy language, though. Here’s the key point in his talk.

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See the “logic”? If some people think DNA controls development, and if those same people accept evolution, than by showing that DNA does not control development, then evolution must be false. It’s Wells’ familiar game of throwing dirt in random directions and hoping it will stick on a few biologists, so he can claim the whole field is wrong. It’s a rather absurd premise.

It’ll be interesting to see how he plans to claim this erroneous metaphor is central to “Darwinism”, since Darwin did not know anything DNA or genes, and didn’t have this metaphor at all. One solution, of course, is to just skip over the first 60 or 70 years of evolutionary biology and jump to the neo-Darwinian synthesis, when genes were incorporated into the theory.

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Uh, OK. It’s a summary of the synthesis that doesn’t mention Fisher and Wright and population genetics, Dobzhansky on genetics and speciation, Mayr and biogeography, Simpson and paleontology. It’s a bit cartoonish, especially since the first two points are purely Darwinian and precede the synthesis, and the fourth was also worked out prior to the synthesis by people like Morgan and Muller. And the third point…hey, wait a minute. Where’d that come from? That isn’t part of the neo-Darwinian synthesis!

Genes (DNA) carry all the essential hereditary information, and a “genetic program” controls embryo development.

Wells just tossed that in. We know that is not true, and we’ve known it for a long, long time. I mean, Wells is supposed to be a developmental biologist — he must know about, to name one example, the work of EG Conklin on ascidians around 1900, in which he mapped out the distribution of cytoplasmic determinants in the egg. The synthesis said almost nothing about development, and here’s Wells trying to pull a fast one and tell you that not only was development a key underpinning of the theory, but that a false metaphor was specifically part of the story.

It wasn’t. He’s making stuff up.

Shall we see some more made-up stuff?

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Heh. First day of class, first lecture in my developmental biology course, all I talk about is genomic equivalence. It’s very basic stuff: the cells in your body all have the same genes, but different cellular phenotypes. That’s the cool stuff in development, thinking about the way cell fates switch under regulatory control.

I don’t call it a “paradox”, though. Why would I? It’s like saying that the existence of “if” statements in computer science is a paradox! Conditional expression of subsets of genes is central to development — it’s hard to imagine differentiation occurring without it.

Here’s another weird one.

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This is a complete misrepresentation of the Klotz paper — it says no such thing. Here’s what the paper is actually about.

In addition to the DNA in the nucleus, cells also need many other components to function. One set of these extranuclear elements are various proteins associated with the cytoskeleton, an internal framework of tubular rods that run throughout the cell. In particular, there is a specific structure called the centrosome that is a kind of cytoskeletal organizing center — sort of like a seed crystal that acts as a starting point for growth. One special role for the centrosome is as an anchor point for the fibers upon which chromosomes shuttle about during cell division.

Sperm cells carry a centrosome as well as a nucleus. That centrosome appears to be important in triggering cell divisions. What Klotz and his coinvestigators did was take unfertilized frog eggs, prick them to trick them into responding as if sperm entry had occurred, and injected them with the centrosomic proteins. They demonstrated that the centrosomes were important for driving early cell divisions — they did not get complete frogs. Cell divisions eventually arrested, but some of the pseudo-fertilized eggs got as far as the tadpole stage.

We do similar things with zebrafish. Sometimes you want embryos that have only the maternal genes, and the way you do this is to suppress a meiotic division (so that the egg will be diploid rather than haploid), and fertilize it with sperm that has been so thoroughly irradiated that its genetic material has been destroyed, and all it is doing is carrying a centrosome and some other activating factors into the egg.

These experiments emphatically do not demonstrate that DNA does not matter — the cells have a full complement of maternal DNA. It does not demonstrate that the paternal centrosome is sufficient to generate a complete animal. This claim is complete bunk. Don’t just take my word for it: here’s the conclusion to the Klotz paper.

Taken together, these results are consistent with the idea that the whole or part of the centrosome structure acts as a seed to start the centrosome duplication cycle in Xenopus eggs.

That’s a more modest and far more appropriate interpretation of the results.

Next!

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Cool. Hox genes are always fun. Wells then gives an overview of the classification of genes by Nusslein-Volhard and Wieschaus, who found that there were early maternal effect genes, gap genes that block out broad chunks of the anterior-posterior axis, segmentation genes that partition the embryo into repeating elements, segment polarity genes that assign identity within a segment, and then the Hox genes, which give the segments special identities in the body plan. And then, this is his conclusion:

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This is an old theme for Wells. Hox genes aren’t the very first genes turned on in the embryo, so they must not be that important; in his previous books, he’s tried to make a similar case that because Haeckel’s phylotypic stage (the pharyngula in chordates) isn’t the earliest stage, and that there is more variation between classes of organisms in the earlier stages, evolution is false. It doesn’t follow.

Hox genes are activated relatively late in early development. That’s still early, at 4-5 weeks of development in humans. There are many other genes that are expressed later still, and they are seriously dependent on an appropriate earlier pattern of Hox gene expression. Developmental processes build on prior processes; this isn’t surprising at all.

It is true that flies have some positional information laid out before fertilization. This is also not a new revelation; I already mentioned the work of Conklin on ascidians, so we’ve known for over a century that many animals are mosaic, getting a headstart on spatial differentiation with a specific distribution of some informational molecules. This isn’t magic (AKA intelligent design), however — it’s generated by an asymmetrical arrangement of supporting cells in the ovary. Not all animals do this. One example: mammals! Our eggs don’t seem to have much, if any, spatial information initially, and all of the cells in the early blastula are mostly equivalent. Differences emerge progressively by interactions with each other and with neighboring tissues.

This next slide is amusing.

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Next time I see Fred Nijhout, I’m going to have to let him know that he is being cited by creationists. I think he’ll find it funny. Maybe.

That quote is from an excellent paper by Nijhout in which he takes the abuse of metaphors to task, and points out the flaws of the “control” and “program” models of the genome. Here’s the abstract.

In describing the flawless regularity of developmental processes and the correlation between changes at certain genetic loci and changes in morphology, biologists frequently employ two metaphors: that genes ‘control’ development, and that genomes embody ‘programs’ for development. Although these metaphors have an admirable sharpness and punch, they lead, when taken literally, to highly distorted pictures of developmental processes. A more balanced, and useful, view of the role of genes in development is that they act as suppliers of the material needs of development and, in some instances, as context-dependent catalysts of cellular changes, rather than as ‘controllers’ of developmental progress and direction. The consequences of adopting this alternative view of development are discussed.

Re-reading this paper, it looks like many of the correct ideas in Wells’ talk are lifted directly from it; the incorrect ones seem to be Wells’ own weird biased misinterpretation. What’s important, though, is that it actually invalidates Wells’ overall conclusion. He wants to claim that evolution is built partially on this premise of genetic “control”, yet here is a paper by a well-known evolutionary developmental biologist not only explaining that “control” is a poor metaphor, but discussing how evolutionary theory is made richer by a better and more accurate understanding of developmental processes! It’s as if Wells is ignoring everything Nijhout was writing except for a few statements that he could lift out of context and pretend that they are an attack on the foundation of evolutionary thought. (Yeah, I know. Big surprise.)

Let’s deal with Wells’ conclusion, finally.

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The floor plan of the embryo is in the form of spatial information that precedes DNA differentiation. This is not always true. It’s only the case in some animals. It doesn’t matter, though, since maternal factors are also the product of evolution…and are also produced by maternal genes.

Some of this spatial information is carried by the centrosome and cortex. This is true. It’s been recognized by biologists for a long, long time. Once again, the ID research program uncovers the obvious that real biologists have been discussing for a century.

There is evidence that both the centrosome and cortex are heritable independently of the DNA. Well, sort of true. Also sort of wrong. He’s making the complement of the mistake he’s accusing biologists of making. Just as you can’t say all the hereditary information is confined to DNA, you also can’t say that it’s the domain of the centrosome or cortex. The centrosomal proteins are gene products! What we’re really dealing with is a tangled web of interdependent processes.

So DNA does not determine all the essential characteristics of living things. It is necessary but not sufficient for embryo development. Yes. Again with the obvious, Mr Wells! Look, vehicle. Look, road. Which one is in charge of the route you will take from point A to point B? You need both. And biologists, including evolutionary biologists, have been aware of this for a long time.

The idea that genetic programs control embryo development is not an inference from evidence, but a deduction from neo-Darwinian evolutionary theory. Breathtaking nonsense. Neo-Darwinian evolutionary theory says nothing of the kind, especially since it says almost nothing about development at all. You can actually see classical evolutionary biology as only saying there is a measurable correlation between the hereditary material (whatever it is; it wouldn’t even have to be nuclear) and the phenotype. The causal mechanisms that translate genes into form and function is the domain of developmental biology, which most other biological disciplines have simply treated as an abstraction.

I’d like to know what Wells actually said at his conclusion. I have to infer from his slides that he’s making a strange argument that heredity is not the product of DNA, and therefore the evolutionary evidence from genes and molecules is invalid. I know, that sounds awesomely stupid and it’s hard to believe anyone could stand up in public and say it, but that’s the thrust of his presentation. Then again, Wells has been willing to say lots of stupid things in his books, so I shouldn’t be surprised that he’d do likewise in his lectures.

40 Comments

Well’s motto seems to be, “When all you have is a hammer, every problem in the world looks just like your thumb.”

Are you surprised that someone who went back for a PhD to destroy Darwinism has problems with some of the details?

Father’s words, my studies, and my prayers convinced me that I should devote my life to destroying Darwinism, just as many of my fellow Unificationists had already devoted their lives to destroying Marxism. When Father chose me (along with about a dozen other seminary graduates) to enter a Ph.D. program in 1978, I welcomed the opportunity to prepare myself for battle.

Darwinism: Why I Went for a Second Ph.D. by Jonathan Wells, Ph.D.-Berkeley, CA at the Sun Myung Moon Unification Church website.

Seems to me that instead of destroying Darwinism, he is far more successful in destroying his own ‘credibility’.

As a Christian, I find it sad to see fellow religious people behave so foolishly and let their faith guide their science and the detriment of both

The Sun Myung Moon unification church isn’t a religion it’s a proper full-on scientology-like cult.

http://en.wikipedia.org/wiki/Unific[…]#Controversy -

i’m not a big fan of cults in general, I was brought up as a Jehovahs witness till i was 16, hence my interest in anti-creationism.

I recently read this book http://en.wikipedia.org/wiki/Combat[…]Mind_Control by a guy who was a high ranking Unificationist in the 70’s. Highly fascinating.

Seems like the DNA / cellular components argument is just a software / computer argument – that DNA is constrained and to a degree directed by the cellular machinery that interprets it. A useful fine point but the answer to someone making a fuss over it is “well DUH”.

Cheers – MrG / http://gvgpd.proboards.com

So who was at this “conference?” Was it just a snake-oil talk directed at at the creationist choir?

In regard to Wells’ rationale for destroying Evolution, here’s the text from his own website. BTW, I’m surprised the dishonesty institute lets a mooney participate, but I guess the means justify the end?

http://www.tparents.org/library/uni[…]s/DARWIN.htm

This just in, famous scientist discovers that you not only need a computer program but you also need a computer to run it on. He concludes that the computer program doesn’t actually do anything so why bother with it! It couldn’t possibly contain the instructions for making a computer anyway.

Anyone who is ignorant enough to be fooled by this nonsense deserves to be fooled. Unfortunatley, in this country they still get to vote. Oh well, at least we now know the answer to the question posed to Wells: Have you no shame? At least he didn’t trot out the infamous magic invisible hologram crap.

But it looks like science, so it must be correct!

Who were the dozen other seminary graduates, anyway? Did they actually get Ph.D.s? Are they sleeper agents?

Oh wait – maybe they became real scientists!

It’s a well-established fact that embryonic development is controlled by the chemtrails the stork flies through delivering the baby.

“What we’re really dealing with is a tangled web of interdependent processes.”

There it is! But it is all coded for in the DNA, even the processes that produce epigenetic inheritance. The major point of confusion, as always, is the implicit message in simplifying the science: that we have a complete understanding of what’s going on. Its the hubris of bad science education. When Sydney Brenner can be sat down in front of a computer, a single genome database, and crank out a description of the critter (no Blast search), when systems biology is finally producing useful models - then I will feel comfortable with suggesting that we understand something that can be called “control”. Maybe miRNA will get us there. Maybe we don’t have a clue what’s going to be discovered tomorrow. That’s what I find exciting about science: that what we know is small compared to what we don’t know. Its a pitty that this can’t be a larger part of science education: that what we have at the moment is simply the best we’ve worked out so far. Combine this with an understanding of peer review, and how research is accomplished within the scientific community, and you have an understanding of science the evolution denial campaign can’t drive off the rails.

This is the most bizarre, mind-warping straw man I’ve ever seen (at least from the ID camp). As a biology major, this was painful to read. It’s like a delusion on steroids.

How low is Wells going to sink?

As a math geek trying to learn biology, I’m glad that such a great intro to the biology behind development has finally been written, providing plenty of jumping-off points for me to head off on my own research. However, this is also one of the things that bugs me about Panda’s Thumb: though it is frequently a source of great articles on sound science, such a write-up almost always has to be preceded by an ID proponent distorting the science enough to provoke a response. Any chance of a sister site, focusing less on the politics, and more on organizing the science into a learn-it-yourself starter kit?

I wonder how the other DI fellows can listen to Wells without starting to laugh. Especially when he talks about centrioles jerking off. BTW, didn’t he mention his Rivista work?

Any chance of a sister site, focusing less on the politics, and more on organizing the science into a learn-it-yourself starter kit?

mharri, depending upon where you are in your learn-it-yourself procession, check out TalkOrigins.org which has a lot of good information (though it is aimed at debunking creationist crap). It is well supported, and I really like that. The Evolution 101 website (http://evolution.berkeley.edu/evosi[…]/index.shtml) is excellent - I have my students use it as a reference quite often.

There are other good sites but those are the first 2 that come to mind. Many great books on the subject as well.

Actually, I think as PZM hints in his comments, there’s some interesting questions here. The cell is a self-replicating machine and it uses DNA as its “memory tape”, but in its replication process it’s an interesting question of how much of the process is wired into the non-DNA cell machinery – maybe it’s (a bit) more than just a “boostrap loader” scheme. However, as PZM also clearly points out, the end result of the cellular systems and the DNA is a new cell that can replicate again, its existence being (not exclusively but strongly) dependent on DNA. Almost literally chicken-&-egg.

But this is not to endorse the lecture that is the topic of this thread, its message being effectively: DEM SCIENTISTS IS STOOPID DONT LISTEN TO DA BUMS.

Cheers – MrG / http://gvgpd.proboards.com

Am surprised the bozos at the Deception Institute have not (yet) hit you with a DMCA take down notice of copyright violation etc. Their material is carefully prepared to be fed to credulous audience. They are really scared of real scientists looking at it and debunking it. (Of course, they feel no compunction in stealing videos from Harvard or Johns Hopkins and slap their own name on the intro screen).

I can’t wait for Johnny Wells to admit that the real answer to it all is Klingon Cosmology. Having him make such an inane set of remarks as these is sadly all too comparable to having Kurt Wise trying to explain how Punctuated Equilibria fits with his Young Earth Creationist beliefs.

mharri said:

Any chance of a sister site, focusing less on the politics, and more on organizing the science into a learn-it-yourself starter kit?

Forgive my self-promotion, you can try this:

http://www.vectorsite.net/tadarwin.html

Earlier editions had several final chapters specifically on the Darwin Wars but I got sick of it, yanked them and rendered them down into a one-chapter document:

http://www.vectorsite.net/tadarwinw.html

It’s much easier on the stomach. If you check them out, feedback is welcome.

Cheers – MrG / http://www.vectorsite.net/gblog.html

mharri -

The sites that have been recommended to you look excellent, but as a former biology undergraduate and MD pathologist, I have to tell you, it isn’t that easy to find user friendly overviews that aren’t too simplified for the truly interested.

The major textbooks in genetics, cell biology, molecular biology, biochemistry, and so on are usually very good to excellent, and if you see something you don’t already know in them, you should keep reading. Wikipedia has many great biological articles. As always, the signs of a good Wiki article are that there are plenty of real, usable citations and links to other credible sources, and that spelling and grammar indicate a well-edited entry. And the science articles on PZ Myers’ blog are great.

But between the fairly generalized terminology in the textbooks and the terse technical jargon of original research papers, there is a gap that can be filled only with a fair amount of effort. It’s probably quite doable via the internet these days. But not without a lot of effort. One of the many reasons I was a biology major (with occasional switches to psychology because I was interested in neuroscience) was that I realized that biology was one of the things I liked that I was least likely to be able to effectively learn on my own.

Creationist and ID arguments are so stupid that they can be rebutted on the basis of textbook level knowledge (actually often on the basis of high school textbook level knowledge). So studying rebuttals to creationists is very useful, but not for gaining a very in-depth knowledge of the biomedical sciences. Indeed, a majority of creationist arguments, and as far as I can tell, ALL ID arguments, can be rebutted on the basis of logic alone.

By the way, back when I thought creationists actually cared about creationism, and weren’t just saying whatever they thought would advance their social and political agenda, I used to recommend basic biomedical textbooks to them. None were ever interested.

mharri said:

As a math geek trying to learn biology, … Any chance of a sister site, focusing less on the politics, and more on organizing the science into a learn-it-yourself starter kit?

I am just a rocket scientist :-) (Aerospace engineer ended up computaional geometry and mesh generation really) not a math geek.

The web sites are fine and dandy, (and free), but nothing to beat a book to get started on evo biology. My strong rec: Jared Diamond (The Third Chimpanzee, Guns Germs and Steel, Why Sex is fun), Richard Dawkins (Climbing the Mount Improbably, The Blind Watchmaker), and recent books by Neil Shubin, etc. (Diamond is not strictly bio, it is more anthropology, history and linguistics.) My very first book of this genre The Naked Ape by Desmond Morris.

Don’t know if it will work for you, for me it is Desmond Morris, Diamon, Dawkins, Dennet

A book I really liked was Ants by Bert Hölldobler and Edward O. Wilson. It discussed fairly complex topics like kin selection and the evolution of eusociality (e.g. why ants are so nice to each other, one of the great “problems” confronting Darwin). Also, and this is somewhat lacking, I feel, in other pop-sci books, it has many examples of how the Modern Theory of Evolution is used practically to generate hypotheses.

It’s also easy to read for such an encyclopedic work.

But obviously, it’s a book about ants so you’d need a general introduction first.

(e.g. why ants are so nice to each other, one of the great “problems” confronting Darwin)

I have to wonder if it would make sense to consider it analogous to cells being “nice” to each other in multi-cellular organisms.

Henry

The resources are appreciated, and I will be looking into them. However, my comments were more a reaction to the lack of organization inherent in the weblog format. (Sorry about the misleading wording; I still have to learn to write for an audience that’s not telepathic.)

And in an attempt to figure out just what I’m trying to say, I just discovered the “Search” box, which addresses what I was trying to say (I think). So, sorry about that, let me try to re-rail the discussion.

You have here a patient dissection of nonsense, with enough information for the curious reader to explore further (I myself am browsing through the results of a Google search on “differential gene expression” as a result of your article). The best part has to be that it’s laced with what I automatically think of as keywords. And, though Nijhout’s paper is hard to reach (curse you, Wiley InterScience!), the honest reader can at least verify the abstract. And even though the skill of “choosing the right organism” still strikes me as evidence that biologists are closet wizards (and denial just confirms it!), the resulting science is a thing of beauty.

mharri Wrote:

As a math geek trying to learn biology, I’m glad that such a great intro to the biology behind development has finally been written, providing plenty of jumping-off points for me to head off on my own research.

In addition to the books recommended above, a “math geek” might appreciate the textbook “Molecular Evolution” by Wen Hsiung Li. Some of the math is beyong my grasp, but as a chemist I like the the molecular perspective.

For an alternative view that is not pseudoscience (the author considers it an extension of Darwinian evolution, not a replacement) try “The Origins of Order” by Stuart Kauffman.

For an online newsgroup where you can comment and ask questions there’s sci.bio.evolution. Those who want to defend or criticize ID/creationism are redirected to talk.origins.

mharri:

D’oh, I should have read your last comment before adding to your already huge reading list.

But that brings up a question to the group, if you all don’t mind be going a bit OT.

What books, papers and websites do the anti-evolution sites recommend as resources? Most evolution resources do not address ID/creationism, but are there any equivalents from the anti-evolution community that do not address - make that obsess over - evolution?

…of course genes supply cells with chemical materials. They’re genes. They’re… acids.

My head hurts.

Frank J said: What books, papers and websites do the anti-evolution sites recommend as resources?

Start with the Bible, of course.

Anything by Michael Behe, William Dembski, Phillip E. Johnson, Jonathon Wells, Henry Morris, D. James Kennedy

Anything published by Answers In Genesis, Institute for Creation Research, Creation Research Society, Coral Ridge Ministry, Discovery Institute

Anti-Evolution: A Reader’s Guide to Writings Before and After Darwin by Tom McIver

The Case for a Creator by Lee Strobel

Charles Darwin was a seminary student!

“Not only do these people believe in A, but they also believe in B.

That is not just a coincidence; there is a logical and historical connection between the two.”

Now that is logical … to a liitle kid. When I was much younger, A = Santa Claus and B = Jesus Christ, and the second statement still held true.

If Wells were an ignorant and speak out of ignorance you might try to enlighten and teach him about the role of DNA in development. However, he commits these transgressions in spite and distorts the results of real research just to fit his bizarre notions of the creation myth. I applaud the effort by PZ Myers to clear and expose the lies of Wells and the DIsco Institute.

“Not only do these people believe in A, but they also believe in B.

Ah, but what they don’t believe in is connecting the dots. ;)

Is this any weirder than believing, as you do, that you can learn about evolution by studying embryos?

Oh right, can’t learn about stuff by studying the evidence. Glad somebody pointed that out.

Reading the article got me wondering. We know there are large regions of “non-coding” (??) DNA. That is (as I understand it) these regions do not code for any proteins in mature organisms. Some of that “non-coding” DNA is being found to control the expression of other stretches of coding DNA. My question: do we know enough yet to say whether much of the “non-coding” DNA is or is not used during embryonic development? Is that still an open question? Thanks for your patience.

Ok, let us say DNA does not control embryo development. Does this mean if I’m an atheist blonde homosexual and I decide to become a Christian Fundamentalist I can, by simply making this change, rearrange my DNA and become a God accepting black haired heterosexual? Or do I need counseling from the Discovery Institute or Ted Haggert to get me back on the biblical rather than the scientific track?

Scott wrote:

“My question: do we know enough yet to say whether much of the “non-coding” DNA is or is not used during embryonic development?”

Yes.

Yawn said:

Is this any weirder than believing, as you do, that you can learn about evolution by studying embryos?

Yawn, I’ll put this as kindly and gently as I can. Your contributions here are not doing much to dispel the stereotype of the creationist as cretinous and ignorant.
As to your comment, here goes. Yes, studying embryos tells us a lot about evolution. Morphology is determined during development. The genetic instructions that determine whether a bud of tissue becomes a wing, a fin, or a leg are carried out at this time. The modification of these instructions is where a lot of evolution happens. Think of a number of trains all leaving the same station but winding up in widely disparate destinations. A train’s destination is determined by the switches that are thrown (or not thrown) along the way. Something roughly analogous happens during development and studying embryos helps scientists learn about this and thus learn a lot about evolution.

I kind of liked the term somebody used the other day: “Invincible ignorance.”

Cheers – MrG / http://www.vectorsite.net/gblog.html

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