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Intelligent Design: Struggling with Junk DNA

Posted: 09/23/11 11:56 AM ET

Not two pages into Jonathan Wells' new book, The Myth of Junk DNA, the reader comes across the bold statement that speciation by natural selection has never been observed, and a few pages later that Gregor Mendel, the father of genetics, "found Darwin's theory unpersuasive, and Darwinists ignored his theory for half a century."

How odd.

In fact, Mendel was not at all unpersuaded by Darwin's arguments for the fact of evolution ("descent with modification") or his theory of natural selection to explain it. As geneticist Daniel J. Fairbanks wrote in his book Relics of Eden, he not only read Origin of Species, he was aware of the significance that his own studies on garden peas meant for the evolutionary theory. What Mendel did find unpersuasive was Darwin's later enthusiasm for pangenesis as a mode of inheritance. Wells seems to have misread his history.

As for speciation never being observed, this, too, would come as a shock to anyone familiar with the extensive work being done in the field by H. Allen Orr and by Matthew L. Niemiller, for two examples. But Wells is being very selective in this book, defining evolution by natural selection alone. As we will see, he is quite careful to avoid discussing the other mechanisms of evolution.

So, the reader is not encouraged by inaccuracies like this so early on in the book.

The Myth of Junk DNA is published by Discovery Institute Press, a branch of the Discovery Institute, the creationist-funded organization in Seattle for which Wells works. The book makes two claims. The first is that since the 1970s, avid "Darwinists" have assumed that all non-coding DNA was functionless junk, and that this was further evidence for a notoriously "unguided" process of evolution. But now, to everyone's surprise, Wells argues, researchers are finding that much of the non-coding sequences in the human genome turn out to have interesting functions after all.

In Chapter 5, for example ("Pseudogenes -- Not So Pseudo After All"), Wells cites recent research showing that some pseudogenes, no-longer functional duplicates of coding genes, are turning out to have real functions. This is fine. But -- he fails to point out what a trivial percentage this represents against the 20,000 other pseudogenes (and transposable elements) littered throughout the genome for which scientists have found no apparent functions. Pseudogenes themselves are in the genomic minority: nearly half of the human genome consists of "transposable elements", DNA sequences that can make copies of themselves. One such transposable element, called Alu, is present in more than 1 million copies in each human genome. At the end of this chapter, the reader is left with the misleading impression that biologists are well on their way to finding functions for the entire human genome.

Secondly, Wells claims that because of his first point, that uncritical "Darwinists" were wrong about the non-functionality of so many genes for so long, there is good reason to believe that Darwin's theory itself is in serious dispute.

In contrast, as genomic specialists like T. Ryan Gregory (whose work on genome size Wells walks around very gingerly indeed) have long pointed out, scientific views on the proportion of the genome that is functional are diverse, and that discussions about functions for all sorts of DNA elements have been prominent in the scientific literature for decades. You would never learn this from Wells' book.

Genomes with no junk, for example, do not necessarily imply intelligent design; they would fit quite well with the view of those biologists, like Richard Dawkins, who argue that natural selection really is the prime driver of evolution -- because if junk DNA really were functionless, presumably natural selection would have weeded out those organisms that have too much of it. Indeed, this has been the default assumption for many biologists since the discovery of DNA that does not encode proteins.

On the other hand, the presence of copious amounts of junk DNA fits well with those biologists who think the other mechanisms of evolution, such as genetic drift or the spread of transposable elements, are major drivers of genome evolution, and that much apparently useless DNA would pass on from one generation to the next, as long as it was not overly harmful to reproductive fitness.

This is not a trivial point. Wells never discusses anything other than natural selection. He carefully avoids the other mechanisms of evolution. One looks in vain, for example, of any account of genetic drift or neutral theory. It's not even listed in the index. Why? Perhaps because both of these mechanisms are highly stochastic, or random: the really unpredictable, chancy mechanisms of evolution that creationists object to the most. And pseudogenes are generated randomly.

To his credit, Wells often points out that the authors of the large number of papers he cites are themselves not moved to doubt evolution because of their work.

That said, it's simply bizarre to read an author who rejects one of the bedrock principles of Darwin's theory -- common ancestry, but is nevertheless happy to cite evidence for common ancestry when it's convenient to his argument. In chapter 4, ("Introns and the Splicing Code", p. 42), we're told that "In 2007, Europeans scientists found eleven sequences in the introns of a gene involved in organ development that were conserved from pufferfish to humans."

Conserved from pufferfish to humans. That is: gene sequences preserved across quite a stretch of the tree of life and across many species -- being cited favorably by a creationist who... rejects common ancestry. But perhaps Wells doesn't think his readers will notice the irony.

Finally, there is throughout the book a distracting anti-science rhetoric and attacks on scientists who have provided some of the nicest confirmations of predictions based on evolutionary theory.

In the appendix, for example, "The Vitamin C Pseudogene", Wells attacks both University of Chicago biologist Jerry Coyne and Brown University biologist Kenneth Miller for citing the GULO gene as evidence for evolution.

The so-called GULO sequence codes for an enzyme that, along with three others, helps many animals synthesize vitamin C. Humans, and several relatives on the primate tree, have an inactivated version of the gene, with the result that we can't synthesize our own vitamin C, and we need to eat foods with the vitamin to make up for what would be a crippling deficiency.

How is this related to evolution? We share this inactivated gene with our closest relatives. Not only do chimpanzees have the same inactivated gene, it lies on the same corresponding chromosome. Coyne and Miller have rightly pointed out that this is powerful evidence of common ancestry. Miller also pointed out in his book Only a Theory, that the inactivation of this gene in some but not all animals poses a puzzle to ID theorists. Wells takes exception to this, claiming, implausibly, that ID would be fine with a random scattering of mutated genes in some species but not others. He justifies this by citing an idea he himself does not take seriously: the fanciful speculation of ID proponent Michael Behe that life started with a single cell that was front-loaded with all the genetic code needed to produce all descendant organisms on Earth. (Wells, Casey Luskin, William Dembski, and other leading figures at the Discovery Institute all reject common ancestry.)

He further writes: "In addition to mischaracterizing ID, Miller went well beyond the published scientific evidence available at the time. For example, as of 2008 (when Miller's book appeared), there were no published data on the gorilla's need for dietary vitamin C."

This is false. Wells may not have been able to find any published evidence on the need for vitamin C in the diet of the gorilla, but it exists.

Linus Pauling wrote about this in 1970 ("Evolution and the Need for Ascorbic Acid," PNAS 67: 1643), and cited an earlier 1949 paper by G. H. Bourne in support of the observation that gorillas do indeed have a need for significant amounts of vitamin C in their diets.

Further, it was, in fact, general knowledge that humans' primate relatives also need vitamin C when Ohta and Nishikimi published their 1999 paper (Biochimica et Biophysica Acta 1472: 408) in which they noted that "humans, other primates, and guinea pigs" cannot synthesize vitamin C. In their study they noted that their results "provide molecular evidence that the primates' loss of GLO which resulted in the incapability of vitamin C synthesis goes back to dates at least before separation of apes and old world monkeys."

In other words, Miller's statement that gorillas do indeed need vitamin C -- just as would be predicted by evolutionary theory -- was well-established in the literature when Miller wrote his book.

To close: The Myth of Junk DNA cannot be recommended for anyone who takes evolutionary biology seriously. But it will do what the Discovery Institute wants it to do: provide further rationalizations for creationists who loath common ancestry, who loath natural selection, who loath indeed the whole process that led to the generation of what Darwin called "endless forms most beautiful."

 
 
 

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Not two pages into Jonathan Wells' new book, The Myth of Junk DNA, the reader comes across the bold statement that speciation by natural selection has never been observed, and a few pages later that G...
Not two pages into Jonathan Wells' new book, The Myth of Junk DNA, the reader comes across the bold statement that speciation by natural selection has never been observed, and a few pages later that G...
 
 
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11:24 AM on 09/28/2011
It wasn't mentioned in the article, but it should probably be touched on....why do creationists go to such great lengths insisting all DNA must be used?

I honestly never understood the argument, but apparently if God poofed our DNA into existence fully formed, He would never add anything that might not be useful. This has never made sense to me, since the more recent version of creationism admits to at least microevolution, so they have already given up on the creation of "junk" in the DNA, even if only in small bits. It is counter to their argument to then insist there is no junk. For that matter, I'm not sure why perfection has to have zero junk. The perfect garden uses compost :-P
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behavingbadly
reality doesn't care what you believe
11:16 AM on 09/28/2011
Excellent examination and a good read.
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behavingbadly
reality doesn't care what you believe
11:14 AM on 09/28/2011
An omniscient, perfect being would never make a mess like this.
10:52 PM on 09/25/2011
John, I appreciated this article. I am one of the "biologos" types, though with no formal affiliation. I've been doing a little blogging from the perspective of an evangelical Christian who has no problem with biological evolution. See https://jesuslovesdarwin.wordpress.com/ if you are interested. I'm planing on reposting your article later this week.
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John Farrell
11:54 AM on 09/26/2011
Gregory,
Thanks so much. And for the link.
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Edward Goodwin
What is the sound of one micro-bio clapping?
06:53 AM on 09/25/2011
This reminds me of an article I read in a creationist newsletter from the 1960's warning those who were giving public presentations to avoid sharing the stage with astronomers.

They would invariably bring up the point that in a six thousand year old universe, give or take the lifespan of one desert dwelling, semi-nomadic patriarch, we would not be able to see objects that are further than six thousand light years distant. They had no coherent answer for this, so they were admonished to avoid it completely.

The really astonishing thing is that these people never stop to ask themselves an obvious question; I they have to work this hard and tell so many lies to "discredit" the opposition, is it just possible that the opposition is right?
Tara Hunkoff
I could have been Sheila Noyeau
09:43 PM on 09/24/2011
The GULO dust-up is just one example of the poverty of the Intelligent Design Argument.

Dawkins and others have utterly destroyed the notion of an interventionist, omniscient, omnipotent being who created the universe and now attends to the concerns of its inhabitants like a combination judge and parent.
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Antikytera
05:35 PM on 09/24/2011
We have alot to thank dedicated scientists and writers for.
Good work!
Thanks from Norway
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John Farrell
07:39 AM on 09/25/2011
Thanks for reading, I appreciate it!
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metogamekun
non-violence takes guts
10:05 AM on 09/24/2011
Isn't it hard to argue with a creationist when they can always answer any argument with, "But that was part of God's plan"?
thebigbike
ran away to be a cowboy
02:49 PM on 09/24/2011
a "god" who would "create" beings that the "god" "knows" to be imperfect, so that the "god" can be worshipped by these imperfect beings?
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pakaal
Pigs, in cages, on antibiotics
03:21 PM on 09/24/2011
Considering the ID folks are still arguing against science, we can say for sure that if there IS a god around somewhere, that god surely knows by now we're imperfect.
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D Kennedy
Whose streets? OUR streets.
01:28 AM on 09/24/2011
I would also like to point out your use of the word "random" - and how so many people love to use it as if it is a real term. Things in our world operate by the laws of physics - "A" happens leading to "B". Everything works off of a defined set of factors. Nothing "random" has occurred.. unless you want to descend into the world of quantum physics - which has it's own entanglement. A coin flip is not "random" - with all factors known the result is most assuredly deterministic. The same is the case for all things in the universe, that is until we reach the quantum level.. which is clearly science which has changed our entire understanding of things.

Even "random" change is by no means "random" - it is exact and determinable if all factors are strictly known. We say "random" when all these factors are not known.. and thus "unpredictable" to us.
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D Kennedy
Whose streets? OUR streets.
01:25 AM on 09/24/2011
Though people may go back and forth with this argument.. I would like to point out my simple observation that anyone can understand that discredits evolution.

All Change is not "make or break."

In other words, the theory of evolution has the view that change in all species is facilitated by natural selection/mutation. This would mean ALL changes.. no matter how trivial.. were the result of these processes, even if it were a development such as eyebrows.. it would mean that the mutated lineage HAD eyebrows.. and those that did not simply died out for the lack there of.

Though this example may seem silly.. it has to be to make the point. It's the viewpoint of evolution that every change originated in this sense... every change no matter how little it actually contributed to survival. Were it not the case then we would have two splintered lineages - one with the mutation and one without.

This is not what we observe. Apparently the eyebrowless human died out.. for he was an inferior design.

Another issue - all mutations are local.

If a change occurs it would affect only that specific offspring and the future offspring. This would lead to different species in different locations whose only difference was this genetic change - it would not be a genetic change which somehow UPDATES all those without this mutation throughout the world. (I'll avoid getting into my problems with lateral/horizontal gene transfer here)
06:33 AM on 09/24/2011
evolution is NOT facilitated by natural selection/mutation, evolution describes the sum total of all events that produce changes in allele frequencies within organismic entities: This can be plasmid, viral, bacterial, protist, animal, and even ecosystems. mutations caused by transposons, transcription errors, translocations, etc can potentially become drivers of allele frequencies in organismic entities and if they are, they too will be "drivers of evolution".

With that said, all change need not be "make or break", many processes that drive allelic changes do not affect the fitness of the organism: silent mutations are changes in the gene but not in the protein that is coded. Mutations on the signal peptide can also produce no negative effect because the protein may already have enough information to traverse the endoplasmic reticulum.

That some changes CAN confer an advantage is not in dispute here, what I dispute is your claim that evolution posits that any change MUST confer an advantage. No reputable scientist has seriously considered the latter in the last 80 years! They all recognize that some changes can be beneficial, some are neutral, and many are detrimental.
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D Kennedy
Whose streets? OUR streets.
03:24 AM on 09/25/2011
If the changes are not "make or break" and do not affect the overall "fitness of the organism" then the result would be TWO lineages. We do not witness this.

So.. for all the pretty words - you missed the point.

Done. Explain your disagreement with that sentiment.
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D Kennedy
Whose streets? OUR streets.
03:10 AM on 09/27/2011
skaai - at this point.. after my million messages.. I wish there was a way I could sum everything up with one sentence, but obviously the topic is too big for that. But I can't resist trying..

Evolution is a patchwork that ends up sounding like nothing more than excuses.

Neutral change is weeded out - yet big change isn't possible without incremental small changes.
Small changes would only be likely to be kept if they drastically change survival rate - and that would only be likely if they prevent disease or something similar. Any slight change is slight.. and has no real purpose in being held over, also DNA is built to correct mistakes.. it knows they are bad, why is it evolution doesn't? Afterall.. evolution created DNA.. right?
These small "non" changes have to theoretically be built up one on top of each other - until presto it has enough change to be a meaningful change.

Yep, I can't sum it up - it's all ridiculous - because all the rules contradict and cave in upon themselves...They are conveniently cited to give a reason for change.. or maybe for no change. ah well, never mind. - don't stop believin lol
06:35 AM on 09/24/2011
(part 2)
There's a more important point that we have not covered, that just because we don't think a mutation confers an advantage doesn't mean it never will or doesn't now. in the 1940s, Esther and Joshua Lederberg showed that E. coli mutated spontaneously all the time, yet they couldn't figure out why it did this. Eventually they discovered that the "T1 bacteriophage" (a bacteria eating virus) was one of many of the predators of E. coli that was hampered by E. coli's mutations. This has been synthesized into what is colloquially called "the red queen hypothesis" another often-misunderstood proposal that suggests parasitic loads (in this paragraph, i refer to all microorganisms as 'parasites' including worms, bacteria and protists, i know it's taxonomically incorrect) have driven evolutionary mutation rates.... this is because most parasites are very specific to the molecular structure of their hosts and so if the host changes the point of contact the parasite uses, the parasite might fail and die. The point here is that random mutations make it harder for parasites to thrive and so most organisms subject to parasites (99.99% of all organisms) will mutate some parts of their genome constantly, regardless of whether there is a parasite in the ecosystem or not. These mutations will often appear "neutral" because we don't know enough about the organism: remember that we still have not observed the life cycles for 95% of all bacterial species! many are too hard to culture and study!
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D Kennedy
Whose streets? OUR streets.
03:34 AM on 09/25/2011
And.. if the change was 'neutral' it would amount to two separate lineages.

So.. that's a lot of typing to miss the main idea.

If one group has.. for example.. eyebrows, and the other does not - and the effect is fundamentally neutral then there is no accounting for why one lineage would die out.

The change would not be make or break.. it would not hinder survival - nor would it any reasonable way 'help'. The energy expended, I imagine, would be the solace you would take in this argument.. although that effectively works out to another 'make or break' argument and thus - the same thing.

Common sense can see that these types of irrelevant neutral changes would produce a vast variety - in OUR species as well. It would not mean that all alternatives die off.

Does a scientifically minded person reach a level of intellect where they simply can't see the forest for the trees? I repeat.. if the change is effectively neutral - then it's neutral - hence no favoritism can be shown by evolution - and thus would produce two distinct lineages.
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12:00 PM on 09/23/2011
Another intellectually dishonest cherry-picking exercise. Merchantgs of Doubt shows clearly how these guys use gross misrepresentation in non-peer-reviewed media to create intentionally misleading, factually and scientifically baseless beliefs for political or specific economic purposes. Another couple books, Toxic Sludge is Good for You and Trust Us We're Experts by John Stauber show how the whole perception management industry came to be and why it should be called perception mismanagement. Anyone wanting dishonesty in depths that require good swimming ability can read this or watch FOX. They just have to be aware that they may not be qualified for any position requiring scientific knowledge wen they're done.

The National Academy of Science and the Union of Concerned Scientists offer real information in an instant.

The issues are quite complex. The Greatest Show on Earth (and many other books) by Richard Dawkins quite simply decimates this author.

The most amazing thing is that this tripe even gets reviewed as potentially serious material.