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Showing posts sorted by relevance for query "junk dna". Sort by date Show all posts
Showing posts sorted by relevance for query "junk dna". Sort by date Show all posts

Monday, January 29, 2024

"People also ask" about junk DNA

I'm interested in the spread of science misinformation on the internet. The misinformation about the human genome is a good example that illustrates the problem. There are many other examples but I happen to know a lot about this particular one.

Anyone trying to find out about junk DNA will find it impossible to get a correct answer by searching the internet. The correct answer is that the amount of junk DNA in the human genome is controversial: some scientists think that most of our genome is functional while others think that as much as 90% is junk. The scientific evidence strongly favors the junk side of the controvesy and that's very well explained in the Wikipedia articles on Junk DNA and Non-coding DNA.

Monday, May 16, 2022

Wikipedia editors want to supress an article on junk DNA

I've been trying to fix the Wikipedia artilce on Noncoding DNA but it's quite a challenge because the page is controlled by editors who are opposed to junk DNA and I am accused of starting an "edit war" that goes against the consensus. On a parallel track, I have proposed creating a separate Wikipedia article on junk DNA where we can present the evidence for and against junk. This is being disussed under the "Talk" thread on the "Non-coding DNA" article.

Here's an exchange bewteen me [Genome42] and one of the editors who exerts control over the noncoding DNA page. It's shows you what we are up against.

Let's get back to the main topic. Is there anyone here who objects to creating a separate page for junk DNA? If you object, please explain why because it seems to me that we really need such a page in order to explain to viewers what the main issues are in the controversy. We need some place to put all the evidence showing that 90% of the human genome is junk and to explain why many scientists reject this evidence.Genome42 (talk) 20:18, 15 May 2022 (UTC)

I looked at pubmed and searched for "junk dna" to see how prominent this topic even is. It seems the term is declining in usage in the scientific literature [7] (see the "results by year"). This is despite all of the abundant media coverage it still gets. I would say that if the usage in the scientific literature was rising then perhaps it would be good a good idea, but the reverse is happening. I see an increasing number of papers calling for abandoning the term altogether too. Just an FYI, one of the original reasons for the merge of the junk DNA to this article was that it was causing too much confusion and edit warring as a separate page. When merged you could have the general article on noncoding DNA without the fireworks and a section isolating the controversies coming from it rather than having 2 pages on the same topic with the Junk DNA article mixing controversy with general information on noncoding DNA.Ramos1990 (talk) 21:28, 15 May 2022 (UTC)

Are you serious? Do you really believe that the debate is over and junk DNA doesn't exist just because the opinions you prefer to read are against junk? You don't seem to be knowledgeable about this topic. I can help you get up to speed. Read these articles on my blog.

Also, you seem to be genuinely confused about the difference between junk DNA and noncoding DNA. Think of it this way. Genomes can be divided into centromeric DNA and non-centromeric DNA and the junk is located in the non-centromeric DNA. Does that mean we should have an article on non-centromeric DNA where we discuss junk? We can also split the genome between regulatory DNA and non-regulatory DNA but I don't see you calling for an article on non-regulatory DNA where we discuss junk DNA.

The only reason why you favor discussing junk DNA in a article on non-coding DNA is because you think that junk DNA was once defined as non-coding DNA and this article will prove that some non-coding DNA has a function - therefore it is not all junk. That's an extremely biased, and incorrect, view. No knowledgeable scientist ever defended the claim that all noncoding DNA was junk. Do you think we didn't know about noncoding genes, regulatory sequences, and origins of replication back in the 1960s?

Genomes can be separated into functional DNA and junk DNA and that's where the debate is. The non-coding DNA fraction is a heterogeneous mixture of functional elements and junk DNA and it's very confusing to mix them. An article on junk DNA will discuss all of the various functional regions of the genome and how common they are in the human genome. We will see that if you add them all up you only get to about 5% of the genome. The article will discuss the evidence for junk DNA and the arguments against claims for abundant function. None of that is appropriate in an article on non-coding DNA.

It's easy for me to see why there was "edit warring" over a junk DNA article. It's because many of the editors here are opposed to junk DNA so they try to suppress the legitimate scientific debate. You need to recognize that what you are doing here is expressing a very personal and biased opinion about the topic of junk DNA and you are using your position to start edit wars in order to censure any views in favor of junk DNA. Genome42 (talk) 14:49, 16 May 2022 (UTC)


Sunday, April 29, 2007

Noncoding DNA and Junk DNA

Scientific American has published another short note on junk DNA [Jumping 'Junk' DNA May Fuel Mammalian Evolution]. RPM noticed that there was no reference to the actual study being quoted in the article so it wasn't possible to verify the accuracy of the reporting [Junk DNA in Scientific American]. I couldn't find it either when I looked last week but it has now appeared on the PNAS website [Thousands of human mobile element fragments undergo strong purifying selection near developmental genes]. RPM also complained about the over-use of the term "junk DNA" in the Scientific American Article. That's what I want to discuss.

The author of the Scientific American article, JR Minkle, has responded on the Scientific American website [The DNA Formerly Known as Junk]. Minkle is a science writer who has covered a lot of stories in many different fields. As far as I know Minkle has not written very much about biology before summarizing the work in the PNAS paper. There was a time when all the science in that journal was written by scientists who were experts in the field [The Demise of Scientific American]. Anyway, that's not the main point here. JR Minkle has listened to the critics and made a decision to avoid the term "junk DNA" from now on.

That's a bad decision. RPM never asked anyone to avoid the word "junk." He merely called for appropriate use. Ryan Gregory has serious doubts about the usefulness of the term as he explains in his excellent article A word about "junk DNA".. If you want to keep up with the discussion about junk DNA you need to read that article—but you don't need to agree with everything in it. :-)

Gregory has also commented on the Scientific American article by proposing a new term, Junctional DNA, to describe DNA that probably has a function but that function isn't known. According to him, this avoids the confusion between using "junk" DNA to describe DNA that we really know to be junk (pseudogenes) and DNA for which no function has been discovered so we assume it has none.

I think we don't need to go there. It's sufficient to remind people that lots of DNA outside of genes has a function and these functions have been known for decades. Thus, it is highly inappropriate to assume that all non-genic DNA is junk and no scientist should ever do this. Note that I'm avoiding the term "noncoding" DNA here. This is because to me the term "coding DNA" only refers to the coding region of a gene that encodes a protein. Thus, in my mind, there are many genes for RNAs that are not properly called coding regions so they would fall into the noncoding DNA category. Also, introns in eukaryotic genomes would be "noncoding DNA" as far as I'm concerned. I think that Ryan Gregory and others use the term "noncoding DNA" to refer to all DNA that's not part of a gene instead of all DNA that's not part of the coding region of a protein encoding gene. I'm not certain of this.

The importance of the term "junk DNA" is to highlight the fact that it has not evolved by natural selection. This is a point I made in one of my first blog postings way back in November [Bill Dembski Needs Help, Again] and again a few days later [The IDiots Don't Understand Junk DNA] [Two Kooks in a Pod].

This isn't original. Everyone knows that junk DNA poses a major threat to both Intelligent Design Creationism and adaptationism [Junk DNA Disproves Intelligent Design Creationism] [Evolution by Accident]. Read Gregory's article for the short concise version of this dispute. What it means is that junk DNA threatens the worldviews of both Dembski and Dawkins!

Science writers often get trapped into thinking like an adaptationist when it comes to junk DNA. Remember that according to the adaptationist worldview the existence of huge amounts of truly nonfunctional DNA in a genome must be a problem. It can't be explained if natural selection is a powerful driving force behind most of evolution. You can't propose that all minor changes in behavioral genes, for example, have been selected and then turn around and admit that 95% of the human genome is junk!

Adaptationists celebrate every discovery that some little bit of DNA has found a function. That's because in their heart of hearts they think that almost all of the junk DNA will eventually be found to have a function. This is one of the reasons why papers like the PNAS paper mentioned above get so much attention.

I want to keep the term "junk DNA" to refer to all functionless DNA. That includes DNA for which we have direct and indirect evidence of no function (pseudogenes, most of intron DNA, corrupted transposons etc.) and it also includes the rest of the DNA for which no function has currently been discovered and we think it's junk because it's not conserved (among other reasons). Junk DNA is not noncoding DNA and anyone who claims otherwise just doesn't know what they're talking about.

The term "junk DNA" forces people to think about the underlying causes of evolution. It makes them stop to appreciate the fact that modern organisms could have evolved with useless DNA in their genomes and the only way this could have happened is if there's a lot more to evolution than just natural selection and adaptation. It's a good term. It's an accurate term. It's a useful term. And it makes people think.

Thursday, March 31, 2011

Junk & Jonathan: Part 1—Getting the History Correct

This is the first in a series of postings about a new book by Jonathan Wells: The Myth of Junk DNA. The book is published by Discovery Institute Press and it should go on sale on May 31 2011. I'm responding to an interview with Jonathan Wells on Uncommon Descent [Jonathan Wells on his book, The Myth of Junk DNA – yes, it is a Darwinist myth and he nails it as such].

The first question is "what is junk/noncoding DNA?" And the answer is,
“Non-coding” in this context means “non-protein-coding.” An important function of our DNA is to specific the sequences of subunits (amino acids) in the proteins that (along with other types of molecules) make up our bodies. When molecular biologists discovered in the 1970s that about 98% of our DNA does not code for proteins, some biologists called non-protein- coding DNA “junk.”
This is misleading. You can consult the excellent article by Ryan Gregory on the origin of the term "junk DNA" to see what it meant in 1972: A word about "junk DNA". The bottom line is that the original meaning of the term "junk DNA" was much closer to what we now call pseudogenes. "Non-coding DNA" is that portion of the genome that does not encode amino acids. In the original paper by Susumu Ohno (1972) there was plenty of discussion about functional noncoding DNA (centromeres, regulatory sequences, spacer DNA). In addition, every scientist in 1972 knew that there were functional genes for tRNAs and ribosomal RNAs in the noncoding DNA.

There was never a time when knowledgeable molecular biologists equated "junk" DNA and "noncoding" DNA. That doesn't mean that there weren't slip-ups from time to time as less knowledgeable scientists published articles on genome organization. There are even modern scientists (and science writers) who make the mistake of confusing "noncoding" with "junk."

My point is that if you are going to answer the question accurately then you should represent the consensus view of most scientists who know that lots of noncoding DNA has a function. You should also attempt to present the modern view of junk DNA instead of implying that forty year old concepts still hold sway. The modern view is that junk DNA is that part of our genome that has no known function. It does not include noncoding regions like regulatory sequences, RNA genes, centromeres. telomeres, origins of replication, recombination hotspots, splice sites, minimal intron length, and scaffold attachment regions (SARs).

The interviewer is Denyse O'Leary and her sympathies are clear in the followup question, "Why was it called “junk” in the first place? And why does all this remind me of one of those auction program episodes where someone is storing leftover carpet nails in what turns out to be a Ming dynasty vase? My mom loves those."

Jonathan Wells answers,
According to Charles Darwin’s theory, all living things are descendants of common ancestors that have been modified solely by unguided natural processes that include variation and selection. In the modern version of his theory—neo-Darwinism— genes control embryo development, variations are due to differences in genes, and new variations originate in genetic mutations. In the 1950s, neo-Darwinists equated genes with DNA sequences (Francis Crick called DNA “the secret of life”) and assumed that their biological significance lay in the proteins they encoded. The 98% of our DNA that does not code for proteins was attributed to molecular accidents that have accumulated in the course of evolution.

“The amount of DNA in organisms,” neo-Darwinist Richard Dawkins wrote in 1976, “is more than is strictly necessary for building them: A large fraction of the DNA is never translated into protein. From the point of view of the individual organism this seems paradoxical. If the ‘purpose’ of DNA is to supervise the building of bodies, it is surprising to find a large quantity of DNA which does no such thing. Biologists are racking their brains trying to think what useful task this apparently surplus DNA is doing. But from the point of view of the selfish genes themselves, there is no paradox. The true ‘purpose’ of DNA is to survive, no more and no less. The simplest way to explain the surplus DNA is to suppose that it is a parasite, or at best a harmless but useless passenger, hitching a ride in the survival machines created by the other DNA.” (The Selfish Gene, p. 47)

Since the 1980s, however, and especially after completion of the Human Genome Project in 2003, biologists have discovered many functions for non-protein-coding DNA. If the Ming vase is a living cell and the leftover carpet nails are “junk DNA,” it turns out that the nails are not only made of gold, but they also make an essential contribution to the beauty of the vase.
There's so much wrong with this answer that it's difficult to know where to begin. Maybe I'll just summarize in point form and elaborate in the comments if anyone wants to discuss it further.
  • Implying that junk DNA has anything to do with Darwin's theory of evolution by natural selection is totally wrong. No matter how you define "neo-Darwinism" the fact remains that most biologists who believed in adaptation were very skeptical of junk DNA precisely because it didn't fit with Darwin's view of evolution. The idea that as much as 90% of our genome could be junk was very much a minority view in the 1970s and it's probably still a minority view.
  • Dawkins was writing about selfish DNA when he wrote that passage in The Selfish Gene. Selfish DNA is not junk DNA. It has an adaptive purpose and a function. It is completely wrong to claim that Richard Dawkins was a big fan of junk DNA in the 1970s. Dawkins makes that very clear in The Extended Phenotype when he proposes various explanations for the extra DNA in our genome.1
  • The statement, "The 98% of our DNA that does not code for proteins was attributed to molecular accidents that have accumulated in the course of evolution" is wrong. There was never a group of knowledgeable scientists who thought that all noncoding DNA was due to accidents. Beginning in the 1970s, there were some who thought that a majority of our genome is junk and some (I am one) still think that as much as 90% could be junk. It's worth emphasizing that this view (that most of our genome is junk) was promoted by a relatively small number of scientists and never adopted as the consensus view of the majority of biologists.
  • It is misleading to imply that many functions of noncoding DNA have been recently discovered. The only discovery that could even remotely fall into that category would be additional categories of small RNAs that weren't known before. The well-characterized examples account for less than 2% of the genome. Everything else is speculative and controversial.
Denyse asks, "What caused the change of view about junk DNA? Can you suggest a couple of key findings?" And Wells replies,
In a word, evidence. The first to emerge was the fact that almost all of an organism’s DNA is transcribed into RNA. (So although most of it may be non-protein-coding, it codes for RNA.) From a Darwinian perspective, this is surprising: Why would an organism struggling to survive devote so many of its internal resources to producing supposedly useless RNA? Indeed, since 2003 it has become clear that non-protein-coding RNAs perform many essential functions in living cells.
Among those of us who advocate junk DNA there are very few who have changed their minds in the past decade. Why is that? It's because we simply don't believe that the "evidence" of widespread transcription is meaningful. Those scientists who oppose the concept of plentiful junk DNA may have taken comfort from the transcription data but their minds weren't changed either. The truth is that there was, and is, a genuine scientific controversy and it has not been settled in spite of what the Intelligent Design Creationists tell you.
Pseudogenes constitute one type of so-called “junk DNA.” These are segments of DNA that resemble segments that elsewhere (or in other organisms) code for protein. Yet RNAs transcribed from some pseudogenes have been found to function in regulating how much protein is produced by the DNA segments they resemble.
Even if you added up all of the known examples of this phenomenon from every investigated species and stuffed them into a single genome it wouldn't amount to more than 0.01% of the genome. And there's no reason to think that the phenomenon is anything more than an interesting exception.
Repetitive DNA, in which a non-protein-coding sequence is repeated many times, is another type of so-called “junk DNA.” Yet repetitive DNA is now known to regulate many essential functions, including embryo implantation in mammals.
Also misleading. A few examples from diverse species do not make a difference. Indeed these exceptions tend to "prove the rule" rather than overthrow it. Wells is deliberately misleading his audience but he's in good company since there are many scientists who do the same thing. In order to have a serious impact on the junk DNA debate it's not sufficient to show that a few bits of repetitive DNA have gained a function in some species. You have to show that this generalizes to the 50% of the genome that's made up of repeated DNA of various sorts.
There is also growing evidence that non-protein-coding DNA can perform functions that are independent of its sequence. One example is the region of a chromosome (called a “centromere”) that attaches it to other structures in the cell. Another example is the retina in the eyes of nocturnal mammals, in which non-protein-coding DNA acts like a liquid crystal to focus scarce rays of light.
There are many known functions of noncoding DNA. They've been known for decades. As a general rule, the proponents of junk DNA seem to be better informed about these regions of the genome than their opponents. It hasn't made a difference in the past and it doesn't now. (Centromeres account for about 2% of the genome. They fall into the 10% that's known not to be junk.)

Denyse's last question is about me. "Can you interpret this for me, from Larry Moran (University of Toronto evolutionary biologist): “I don’t demand civility, but I do demand accuracy. When Denyse and her friends say that Darwinists promoted junk DNA I have to draw the line.” But he must be referring to my observation that originated in Francis Collins’s (US government’s chief 2000 genome mapper’s [!]) statements in a well-received and widely read book. Are there two types of truths at work here? Evidence, and … what? "
When I use the term “Darwinist,” I mean someone who accepts and defends the theory I describe in my answer to Question 2. Crick and Orgel were Darwinists in this sense; so are Miller, Dawkins, Coyne, and Avise—all of whom have promoted the myth of junk DNA. When Collins published The Language of God in 2006, he not only promoted junk DNA but also wrote that “Darwin’s theory of evolution, that is, descent from a common ancestor with natural selection operating on randomly occurring variations” is “unquestionably correct” (pp. 127, 141). Sure sounds like a Darwinist to me.

Collins also wrote that intelligent design is a “God of the gaps” position that is doomed to collapse with further advances in science (p. 193). But Collins has it exactly backwards: He and other promoters of the myth of junk DNA have put their faith in a “Darwin of the gaps” argument that must now retreat in the face of new advances in genome research.
Several of these scientists have written about pseudogenes and the fact that their existence provides strong support for evolution and strong evidence against the existence of an intelligent designer. Most (all?) biologists understand that pseudogenes are an example of junk DNA. Wells has chosen the one example of junk DNA where there's an overwhelming consensus. They are junk.

But that's not what the scientific debate is about. Pseudogenes are not a myth. They are a fact, and they make up as much as 2% of the mammalian genome. The scientific debate is about whether most of our genome is really junk DNA. I think Francis Collins supports this idea, with some reservations, but I don't know about Jerry Coyne or Kenneth Miller or Richard Dawkins. John Avise is, of course, one the main proponents of junk DNA being a majority of our genome. His book Inside the Human Genome: A Case for Non-intelligent Design was published just last year (2010). It's for those needing an antidote after reading the upcoming train wreck by Jonathan Wells.

It is extremely misleading to claim that "Darwinists" promoted the idea that most of our genome is junk. Most biologists are skeptical of that claim and that's especially true of those who would be comfortable calling themselves "Darwinists."

Denyse closes with one of her characteristic comments.
Okay, everyone, back to work tomorrow in Darwinworld, where facts like these do not matter in the least.
That's why I call them "IDiots." Facts matter to real scientists. The tough part about being a scientist is deciding what's a fact and what's not. Well showed us that he was not up to the task of behaving like a real scientist when he wrote Icons of Evolution and I suspect he's about to provide us with another example of misinformation and selective reading of the scientific literature.


1. Dawkins recognizes that there is some junk in our genome—pseudogenes are a good example—but that does not mean he buys into the idea that a huge percentage of our genome is just junk.

Monday, October 24, 2011

The Myth of Junk DNA by Jonathan Wells

This is the final installment of my review of The Myth of Junk DNA by Jonathan Wells (Discovery Institute Press, 2011). The other posts are listed at the bottom of this summary and in the theme posting "Genomes & Junk DNA."

Most of the IDiots at the Discovery Institute feel threatened by the existence of large amounts of junk DNA in some eukaryotic genomes, including our own. That's why they are determined to refute this idea by showing that most putative junk DNA actually has a function. Jonathan Wells feels confident enough about his reading of the scientific literature to announce that junk DNA is a "myth" and he's written a book to promote this idea.

Wells never defines "junk DNA" correctly. The correct definition of "junk" is DNA that has no known function. Wells pretends that the original definition of junk DNA was "noncoding" DNA. Thus, all those bits of noncoding DNA that have a function are evidence that refutes the notion of junk DNA.

The truth is that no knowledgeable scientist ever suggested that regulatory regions, origins of replication, centromeres, telomeres, genes that produce functional RNA molecules, and chromatin organizing regions were ever classified as junk DNA. They all knew that there was lots of noncoding DNA that had a well-defined function. Right from the beginning of his book, Wells is attacking a strawman and misleading his readers.

Tuesday, July 02, 2013

Will There Be a Junk DNA Debate in Chicago?

Quite a few people think that there's going to be a serious debate about junk DNA at the SMBE meeting in Chicago next week. One of the sessions has a provocative title, "WHERE DID 'JUNK' GO?", but if you look at actual session titles it doesn't look like there's going to be much of a debate.

It's true than the session organizer, Wojciech Makalowski, advertised the session as a dicussion about junk DNA ....

Saturday, March 25, 2023

ChatGPT lies about junk DNA

I asked ChatGPT some questions about junk DNA and it made up a Francis Crick quotation and misrepresented the view of Susumu Ohno.

We have finally restored the Junk DNA article on Wikipedia. (It was deleted about ten years ago when Wikipedians decided that junk DNA doesn't exist.) One of the issues on Wikipedia is how to deal with misconceptions and misunderstandings while staying within the boundaries of Wikipedia culture. Wikipedians have an aversion to anything that looks like editorializing so you can't just say something like, "Nobody ever said that all non-coding DNA was junk." Instead, you have to find a credible reference to someone else who said that.

I've been trying to figure out how far the misunderstandings of junk DNA have spread so I asked ChatGPt (from OpenAI) again.

Sunday, November 12, 2023

ChatGPT is still making up quotations from scientists

I wondered whether ChatGPT had improved in the last six months so I asked it again about junk DNA. The answers reveal that ChatGPT is still lying and spreading false information.

What is junk DNA?

ChatGPT: "Junk DNA" is a term that was historically used to describe portions of the DNA sequence that do not code for proteins or have any known function. These non-coding regions were once thought to be vestiges of evolutionary processes or simply genetic "leftovers" with no apparent purpose.

However, it's important to note that the term "junk DNA" is now considered outdated and somewhat misleading. Advances in genomics and molecular biology have revealed that many non-coding regions of DNA have important functions, even if they do not encode proteins. These regions may contain regulatory elements that control the activity of genes, play a role in the three-dimensional structure of the genome, or have other functional significance.

The Human Genome Project and subsequent genomic research efforts have shown that a significant portion of the genome is involved in the regulation of gene expression, development, and other cellular processes. The term "non-coding DNA" or "non-coding regions" is now preferred over "junk DNA" to emphasize that these sections of the genome have functions that are not immediately apparent and are still an active area of research.

In summary, while some regions of the genome were once thought to be functionless "junk," ongoing scientific research is uncovering the complexity and functional significance of non-coding DNA.

So, the answer is "no," ChatGPT hasn't gotten any better. Even after we worked on a Wikipedia entry for junk DNA, ChatGPT is still responding with the standard non-scientific perspective on junk DNA. It implies that the term junk DNA originally meant all non-coding DNA and that the discovery of function in non-coding regions is due to recent advances in genomics and molecular biology.

I asked for some specific evidence that this was, indeed, the historical definition of junk DNA.

Can you give me some direct quotes from scientists who said that all non-coding DNA was junk?

ChatGPT: The idea that non-coding DNA was "junk DNA" was a historical perspective that gained traction in the early days of molecular biology when researchers primarily focused on protein-coding genes. It's important to note that while the term "junk DNA" was used, scientists were aware that there were likely unknown functions in non-coding regions. Over time, advances in genomics and molecular biology have revealed the complexity and functionality of non-coding DNA.

Here are a couple of historical quotes that reflect the perspective on non-coding DNA from earlier times:

Francis Crick (1970): In a 1970 paper, Francis Crick, one of the co-discoverers of the structure of DNA, stated, "The ultimate aim of the DNA investigators is to identify, with some precision, the genetic material. At present, it looks as if at least 90% of the DNA in any organism is useless."

Susumu Ohno (1972): Geneticist Susumu Ohno, in his book "Evolution by Gene Duplication" (1972), stated, "The failure to recognize this [the abundance of 'junk DNA'] for so long has misled the investigators studying the higher order chromosomal structure... No doubt the junk DNA sequences in the heterochromatin and at the centromeres are examples of 'selfish' DNA."

It's important to understand that these quotes represent a historical perspective, and scientific understanding has evolved significantly since then. The term "junk DNA" has since been reconsidered as researchers have discovered various functions within non-coding regions of the genome. Scientists today emphasize the importance of non-coding DNA in regulatory processes, genome stability, and other essential biological functions.

Neithe of these quotes support the idea that all non-coding DNA was thought to be junk. The direct quote from Crick in 1970 seems suspicious so I asked for clarification.

Can you supply the complete reference to the Francis Crick quotation that you just gave me?

ChatGPT: I apologize for any confusion, but I made an error in my previous response. After a thorough review, I couldn't find a direct quote from Francis Crick expressing the sentiment that "at least 90% of the DNA in any organism is useless." It appears there might have been a misunderstanding or misattribution in the information I provided.

Francis Crick and James Watson, in their groundbreaking work, were primarily focused on understanding the structure of DNA, and while there were discussions about non-coding regions, the notion of "junk DNA" as we understand it today wasn't explicitly articulated by Crick in the manner suggested.

I appreciate your diligence in seeking accurate information, and I apologize for any confusion caused by the error in my response. If you have any further questions or if there's anything else I can assist you with, please let me know.

The only way you would know that ChatGPT was making up direct quotations would be if you asked for confirmation. The average person would just assume that the fake quote was accurate. It would be fun to grade a student essay that used such a quotation!

When I asked these question last March, ChatGPT also made up false quotations that didn't even support it's claim that all non-coding DNA was thought to be junk [ChatGPT lies about junk DNA].

Can you supply the complete reference to the Susumu Ohno quotation that you just gave me?

ChatGPT: Certainly, Susumu Ohno's quote about "junk DNA" is attributed to his book "Evolution by Gene Duplication," published in 1970. I must clarify that the quote I provided earlier is a paraphrased version based on the general sentiment expressed in his work rather than an exact wording. Unfortunately, I couldn't locate the precise quote within the text.

If you're interested in exploring Ohno's thoughts on this matter in more detail, you may want to refer to his book "Evolution by Gene Duplication," which was influential in discussions about the evolutionary significance of gene duplication and, by extension, the role of non-coding DNA.

This is another example of a made-up quotation and it doesn't address the main issue. ChatGPT is unable to provide any evidence that all non-coding DNA was thought to be junk DNA.

The behavior of ChatGPT should be a major concern. If we are going to rely on artificial intelligence in the future then we better make sure that the information it gathers is correct.


Monday, August 05, 2019

Religion vs science (junk DNA): a blast from the past

I was checking out the science books in our local bookstore the other day and I came across Evolution 2.0 by Perry Marshall. It was published in 2015 but I don't recall seeing it before.

The author is an engineer (The Salem Conjecture) who's a big fan of Intelligent Design. The book is an attempt to prove that evolution is a fraud.

I checked to see if junk DNA was mentioned and came across the following passages on pages 273-275. It's interesting to read them in light of what's happened in the past four years. I think that the view represented in this book is still the standard view in the ID community in spite of the fact that it is factually incorrect and scientifically indefensible.

Friday, August 07, 2020

Alan McHughen defends his views on junk DNA

Alan McHughen is the author of a recently published book titled DNA Demystified. I took issue with his stance on junk DNA [More misconceptions about junk DNA - what are we doing wrong?] and he has kindly replied to my email message. Here's what he said ...

Wednesday, August 24, 2022

Junk DNA vs noncoding DNA

The Wikipedia article on the Human genome contained a reference that I had not seen before.

"Finally DNA that is deleterious to the organism and is under negative selective pressure is called garbage DNA.[43]"

Reference 43 is a chapter in a book.

Pena S.D. (2021) "An Overview of the Human Genome: Coding DNA and Non-Coding DNA". In Haddad LA (ed.). Human Genome Structure, Function and Clinical Considerations. Cham: Springer Nature. pp. 5–7. ISBN 978-3-03-073151-9.

Sérgio Danilo Junho Pena is a human geneticist and professor in the Dept. of Biochemistry and Immunology at the Federal University of Minas Gerais in Belo Horizonte, Brazil. He is a member of the Human Genome Organization council. If you click on the Wikipedia link, it takes you to an excerpt from the book where S.D.J. Pena discusses "Coding and Non-coding DNA."

There are two quotations from that chapter that caught my eye. The first one is,

"Less than 2% of the human genome corresponds to protein-coding genes. The functional role of the remaining 98%, apart from repetitive sequences (constitutive heterochromatin) that appear to have a structural role in the chromosome, is a matter of controversy. Evolutionary evidence suggests that this noncoding DNA has no function—hence the common name of 'junk DNA.'"

Professor Pena then goes on to discuss the ENCODE results pointing out that there are many scientists who disagree with the conclusion that 80% of our genome is functional. He then says,

"Many evolutionary biologists have stuck to their guns in defense of the traditional and evolutionary view that non-coding DNA is 'junk DNA.'"

This is immediately followed by a quote from Dan Graur, implying that he (Graur) is one of the evolutionary biologists who defend the evolutionary view that noncoding DNA is junk.

I'm very interested in tracking down the reason for equating noncoding DNA and junk DNA, especially in contexts where the claim is obviously wrong. So I wrote to Professor Pena—he got his Ph.D. in Canada—and asked him for a primary source that supports the claim that "evolutionary science suggests that this noncoding DNA has no function."

He was kind enough to reply saying that there are multiple sources and he sent me links to two of them. Here's the first one.

I explained that this was somewhat ironic since I had written most of the Wikipedia article on Non-coding DNA and my goal was to refute the idea than noncoding DNA and junk DNA were synonyms. I explained that under the section on 'junk DNA' he would see the following statement that I inserted after writing sections on all those functional noncoding DNA elements.

"Junk DNA is often confused with non-coding DNA[48] but, as documented above, there are substantial fractions of non-coding DNA that have well-defined functions such as regulation, non-coding genes, origins of replication, telomeres, centromeres, and chromatin organizing sites (SARs)."

That's intended to dispel the notion that proponents of junk DNA ever equated noncoding DNA and junk DNA. I suggested that he couldn't use that source as support for his statement.

Here's my response to his second source.

The second reference is to a 2007 article by Wojciech Makalowski,1 a prominent opponent of junk DNA. He says, "In 1972 the late geneticist Susumu Ohno coined the term "junk DNA" to describe all noncoding sections of a genome" but that is a demonstrably false statement in two respects.

First, Ohno did not coin the term "junk DNA" - it was commonly used in discussions about genomes and even appeared in print many years before Ohno's paper. Second, Ohno specifically addresses regulatory sequences in his paper so it's clear that he knew about functional noncoding DNA that was not junk. He also mentions centromeres and I think it's safe to assume that he knew about ribosomal RNA genes and tRNA genes.

The only possible conclusion is that Makalowski is wrong on two counts.

I then asked about the second statement in Professor Pena's article and suggested that it might have been much better to say, "Many evolutionary biologists have stuck to their guns and defend the view that most of human genome is junk." He agreed.

So, what have we learned? Professor Pena is a well-respected scientist and an expert on the human genome. He is on the council of the Human Genome Organization. Yet, he propagated the common myth that noncoding DNA is junk and saw nothing wrong with Makalowski's false reference to Susumu Ohno. Professor Pena himself must be well aware of functional noncoding elements such as regulatory sequences and noncoding genes so it's difficult explain why he would imagine that prominant defenders of junk DNA don't know this.

I think the explanation is that this connection between noncoding DNA and junk DNA is so entrenched in the popular and scientific literature that it is just repeated as a meme without ever considering whether it makes sense.


1. The pdf appears to be a response to a query in Scientific American on February 12, 2007. It may be connected to a Scientific American paper by Khajavinia and Makalowski (2007).

Khajavinia, A., and Makalowski, W. (2007) What is" junk" DNA, and what is it worth? Scientific American, 296:104. [PubMed]

Monday, February 12, 2007

Junk DNA: Scientific American Gets It Wrong (again)

In "Ask the Experts" somebody asked What is junk DNA, and what is it worth?. The question was answered by "expert" Wojciech Makalowski of Pennsylvania State University. Here's the answer ...
In 1972 the late geneticist Susumu Ohno coined the term "junk DNA" to describe all noncoding sections of a genome, most of which consist of repeated segments scattered randomly throughout the genome.
This is very misleading. First, nobody today would argue that all noncoding DNA is junk and I very much doubt that Ohno made that argument in 1972 (the orignal paper is hard to get). We know tons of examples of noncoding DNA that isn't junk.

Second, the focus on repetitive DNA is inappropriate. Lots of junk DNA is non-repetitive; pseudogenes are a prime example. Makalowski has a particular bee in his bonnet over repetitive DNA but that shouldn't be allowed to warp his judgement when responding to a question in Scientific American.
Although very catchy, the term "junk DNA" repelled mainstream researchers from studying noncoding genetic material for many years. After all, who would like to dig through genomic garbage?
Nonsense. Researchers have been exploring noncoding DNA intensely for the past 40 years. That's why we know so much about regulatory sequences. Regulatory sequences are noncoding DNA that control gene expression.

Furthermore, even when it comes to true junk DNA, properly defined, hundreds of papers have been published. Lots of us have been very interested in junk DNA—at least in part in order to find out whether it has a function. This work led to the indentification of hundreds of pseudogenes, the unimportance of most intron sequences, and the degeneracy of LINES and SINES. There's lots more. I don't know of any researchers that were "repelled" from studying junk DNA. Many took it as a challenge.
Thankfully, though, there are some clochards who, at the risk of being ridiculed, explore unpopular territories. And it is because of them that in the early 1990s, the view of junk DNA, especially repetitive elements, began to change. In fact, more and more biologists now regard repetitive elements as genomic treasures. It appears that these transposable elements are not useless DNA. Instead, they interact with the surrounding genomic environment and increase the ability of the organism to evolve by serving as hot spots for genetic recombination and by providing new and important signals for regulating gene expression.
Serving as hotspots for genetic recombination is not a "function" of most junk DNA. Furthermore, it's not at all clear that increasing recombination at a particular site will have any effect on future survival. Finally, signals for regulating gene expression have been known for decades. These signals are not junk DNA.
Genomes are dynamic entities: new functional elements appear and old ones become extinct. And so, junk DNA can evolve into functional DNA. The late evolutionary biologist Stephen Jay Gould and paleontologist Elisabeth Vrba, now at Yale University, employed the term "exaptation" to explain how different genomic entities may take on new roles regardless of their original function—even if they originally served no purpose at all. With the wealth of genomic sequence information at our disposal, we are slowly uncovering the importance of non-protein-coding DNA.
The occasional piece of junk DNA may be co-opted to become part of a newly evolved function. This does not mean that all junk DNA has a function. That's a classic error in logic more common in freshmen undegraduates than in "expert" Professors.
... These and countless other examples demonstrate that repetitive elements are hardly "junk" but rather are important, integral components of eukaryotic genomes. Risking the personification of biological processes, we can say that evolution is too wise to waste this valuable information.
From time to time we will find examples of some little bit of junk DNA that acquires a function. This does not mean that all junk DNA has a function. And it certainly doesn't mean that all DNA has now been shown to be "important, integral components of eukaryotic genomes." Most of our DNA is still junk. It turns out that evolution really isn't so smart after all.

Thursday, August 06, 2020

More misconceptions about junk DNA - what are we doing wrong?

I'm actively following the views of most science writers on junk DNA to see if they are keeping up on the latest results. The latest book is DNA Demystified by Alan McHughen, a molecular geneticist at the University California, Riverside. It's published by Oxford University Press, the same publisher that published John Parrington's book the deeper genome. Parrington's book was full of misleading and incorrect statements about the human genome so I was anxious to see if Oxford had upped it's game.1, 2

You would think that any book with a title like DNA Demystified would contain the latest interpretations of DNA and genomes, especially with a subtitle like "Unraveling the double Helix." Unfortunately, the book falls far short of its objectives. I don't have time to discuss all of its shortcomings so let's just skip right to the few paragraphs that discuss junk DNA (p.46). I want to emphasize that this is not the main focus of the book. I'm selecting it because it's what I'm interested in and because I want to get a feel for how correct and accurate scientific information is, or is not, being accepted by practicing scientists. Are we falling for fake news?

Thursday, June 23, 2022

The Function Wars Part X: "Spam DNA"?

The authors of a recent paper think we need a new term "spam DNA" to describe some features of the human genome.

Fagundes, N.J., Bisso-Machado, R., Figueiredo, P.I., Varal, M. and Zani, A.L. (2022) What We Talk About When We Talk About “Junk DNA”. Genome Biology and Evolution 14:evac055. [doi: 10.1093/gbe/evac055]

“Junk DNA” is a popular yet controversial concept that states that organisms carry in their genomes DNA that has no positive impact on their fitness. Nonetheless, biochemical functions have been identified for an increasing fraction of DNA elements traditionally seen as “Junk DNA”. These findings have been interpreted as fundamentally undermining the “Junk DNA” concept. Here, we reinforce previous arguments that this interpretation relies on an inadequate concept of biological function that does not consider the selected effect of a given genomic structure, which is central to the “Junk DNA” concept. Next, we suggest that another (though ignored) confounding factor is that the discussion about biological functions includes two different dimensions: a horizontal, ecological dimension that reflects how a given genomic element affects fitness in a specific time, and a vertical, temporal dimension that reflects how a given genomic element persisted along time. We suggest that “Junk DNA” should be used exclusively relative to the horizontal dimension, while for the vertical dimension, we propose a new term, “Spam DNA”, that reflects the fact that a given genomic element may persist in the genome even if not selected for on their origin. Importantly, these concepts are complementary. An element can be both “Spam DNA” and “Junk DNA”, and “Spam DNA” can also be recruited to perform evolved biological functions, as illustrated in processes of exaptation or constructive neutral evolution.

The authors are scientists at the Federal Univesity of Rio Grande do Sul in Brazil. They are concerened about the origins of junk DNA and whether true selected effect functions (strong selected effect = SSE) conflict with the definition of junk DNA. Here's how they put it,

Paradoxically as it may seem, under the SSE definition, elements that contribute positively to fitness and are maintained by purifying selection would still count as “junk” only because they did not originate as an adaptation.

This is essentially correct according to how many philosophers define selected effect functions but that issue was resolved by focusing on purifying selection as the important criterion and ignoring the history of the trait (= maintenance function, MF). There is only a 'paradox' if you stick to the philosophy definition of function (i.e. SSE) and even then, the paradox only exists if the SSE definition is the only way to identify junk DNA. [see: The Function Wars Part IX: Stefan Linquist on Causal Role vs Selected Effect] The authors recognize this since they include a good discussion of this other definition (MF) and its advantages. Nevertheless, they propose a new term called "spam DNA" to help clarify the problem.

"Spam DNA" represents every genomic element which has not been selected for during its origin in the genome, even if it currently participates in relevant biological functions.

All of the DNA in the light blue box is spam DNA. Note that it includes DNA that is currently functional as long as it originated from junk DNA as they define it. Also, some junk DNA isn't spam DNA as long as it arose from the inactivation of DNA that used to have a function. Thus, pseudogenes aren't junk and neither are bits and pieces of transposons.

This isn't helpful. The current debate is about how much of our genome is junk so who cares about the history of individual sequences? A significant amount of what we currently define as junk DNA may have come from once-active transposons but we may never be able to trace the history of each piece of junk DNA. Does it fall into the first category in the figure (functional to junk) or is it spam DNA? Is this really important? No,it is not.

Function Wars
(My personal view of the meaning of function is described at the end of Part V.)

Thursday, February 07, 2008

Theme: Genomes & Junk DNA

Junk in Your Genome

Transposable Elements: (44% junk)

      DNA transposons:
         active (functional): <0.1%
         defective (nonfunctional): 3%
      retrotransposons:
         active (functional): <0.1%
         defective transposons
            (full-length, nonfunctional): 8%
            L1 LINES (fragments, nonfunctional): 16%
            other LINES: 4%
            SINES (small pseudogene fragments): 13%
            co-opted transposons/fragments: <0.1% a
aCo-opted transposons and transposon fragments are those that have secondarily acquired a new function.
Viruses (9% junk)

      DNA viruses
         active (functional): <0.1%
         defective DNA viruses: ~1%
      RNA viruses
         active (functional): <0.1%
         defective (nonfunctional): 8%
         co-opted RNA viruses: <0.1% b
bCo-opted RNA viruses are defective integrated virus genomes that have secondarily acquired a new function.
Pseudogenes (1.2% junk)
      (from protein-encoding genes): 1.2% junk
      co-opted pseudogenes: <0.1% c
cCo-opted pseudogenes are formerly defective pseudogenes those that have secondarily acquired a new function.
Ribosomal RNA genes:
      essential 0.22%
      junk 0.19%

Other RNA encoding genes
      tRNA genes: <0.1% (essential)
      known small RNA genes: <0.1% (essential)
      putative regulatory RNAs: ~2% (essential) Protein-encoding genes: (9.6% junk)
      transcribed region:  
            essential 1.8%  
            intron junk (not included above) 9.6% d
dIntrons sequences account for about 30% of the genome. Most of these sequences qualify as junk but they are littered with defective transposable elements that are already included in the calculation of junk DNA.
Regulatory sequences:
      essential 0.6%

Origins of DNA replication
      <0.1% (essential) Scaffold attachment regions (SARS)
      <0.1% (essential) Highly Repetitive DNA (1% junk)
      α-satellite DNA (centromeres)
            essential 2.0%
            non-essential 1.0%%
      telomeres
            essential (less than 1000 kb, insignificant)

Intergenic DNA (not included above)
      conserved 2% (essential)
      non-conserved 26.3% (unknown but probably junk)

Total Essential/Functional (so far) = 8.7%
Total Junk (so far) = 65%
Unknown (probably mostly junk) = 26.3%
For references and further information click on the "Genomes & Junk DNA" link in the box

LAST UPDATE: May 10, 2011 (fixed totals, and ribosomal RNA calculations)





November 11, 2006
Sea Urchin Genome Sequenced

The sea urchin genome is 814,000 kb or about 1/4 the size of a typical mammalian genome. Like mammalian genomes, the sea urchin genome contains a lot of junk DNA, especially repetitive DNA. The preliminary count of the number of genes is 23,300. This is about the same number that we have in our genomes. Only about 10,000 of these genes have been annotated by the sea urchin sequencing team.

Saturday, July 30, 2022

Wikipedia blocks any mention of junk DNA in the "Human genome" article

Wikipedia has an article on the Human genome. The introduction includes the following statement,

Human genomes include both protein-coding DNA genes and various types of DNA that does not encode proteins. The latter is a diverse category that includes DNA coding for non-translated RNA, such as that for ribosomal RNA, transfer RNA, ribozymes, small nuclear RNAs, and several types of regulatory RNAs. It also includes promoters and their associated gene-regulatory elements, DNA playing structural and replicatory roles, such as scaffolding regions, telomeres, centromeres, and origins of replication, plus large numbers of transposable elements, inserted viral DNA, non-functional pseudogenes and simple, highly-repetitive sequences.

This is a recent improvement (July 22, 2022) over the original statement that simply said, "Human genomes include both protein-coding DNA genes and noncoding DNA." I noted in the "talk" section" that there was no mention of junk DNA in the entire article on the human genome so I added a sentence to the end of the section quoted above. I said,

Some non-coding DNA is junk, such as pseudogenes, but there is no firm consensus over the total mount of junk DNA.1

Monday, May 16, 2011

See the IDiots Gloat over Jonathan Wells


This is part of my discussion about The Myth of Junk DNA by Jonathan Wells. I still haven't read the book—it won't be released in Canada until May 31st.

Over on Evolution News & Views (sic) David Klinghoffer is already counting his chickens [Junk DNA and the Darwinist Response so Far].
Over the weekend, Jonathan Wells's The Myth of Junk DNA broke into the top five on Amazon's list of books dealing with genetics -- a list normally dominated at its pinnacle by various editions of Richard Dawkins' The Selfish Gene. Not bad, Jonathan.
Not bad indeed, except I can't tell if it's true. When I check the top selling recently published books I don't see The Myth of Junk DNA in the top five. Never mind, I'm sure there will be many skeptics like me who will buy the book just for a good laugh.

UPDATE: The latest information shows that Wells' book is ranked 23rd under "Genetics." I'm sure the IDiots just made a simple arithmetic error when they said it had broken into the top five.
The juxtaposition with Dawkins' Selfish Gene is appropriate, notwithstanding the demurrals of biochemist Larry Moran et al. Dawkins and other Darwinists, such as Jerry Coyne, have indeed posited that neo-Darwinian theory predicts that swaths of the genome will turn out to be functionless junk. The Junk DNA argument has been a pillar of the Darwin Lobby's efforts to seduce public opinion and influence public policy. Professor Moran wants to imagine that Dawkins never held that neo-Darwinism predicts junk DNA. But that's not how other Darwinists see it. (Compare, for example, Dennett's Darwin's Dangerous Idea, page 316.)
The IDiots have a bit of a problem. In order to make this book look important they have to first establish that the concept of abundant junk DNA in our genome was a "pillar" of support for evolution. That's hard to do when their understanding of evolution is so flawed that they don't see the difference between "Darwinism" and evolution by random genetic drift.

Their claim that evolutionary theory PREDICTED the presence of huge amounts of junk DNA in our genome is just plain false. They been told this but they keep repeating their error. There's a word for that kind of behavior.

It's easy to see how they got confused. It's because they're IDiots. It's partly because they don't understand that an argument for inheritance of a few pseudogenes is not the same as an argument that more than 50% of our genome is junk. There are plenty of scientists who will use the pseudogene argument to challenge Intelligent Design Creationism but who don't believe that MOST of our genome is junk.

It's also partly because the IDiots don't know the difference between selfish DNA and junk. Here's what Daniel Dennett says on page 316 of Darwin's Dangerous Idea.
The presence of functionless DNA in the genome is no longer regarded as a puzzle. Dawkins (1976) selfish-gene theory predicts it, and elaborations on the idea of "selfish DNA" were simultaneously developed by Doolittle and Sapeinza (1980) and Orgel and Crick (1980) (see Dawkins 1982, ch. 9, for the details).
Selfish DNA is not junk DNA. The classic examples of selfish DNA are active transposons and integrated viruses. These bits of DNA have a function—even if it's only to propagate themselves. As you can see from my summary [What's in Your Genome?]. I don't count them as junk.

It's remarkable that Klinghoffer quotes Chapter 9 of The Extended Phenotype (1982) since Dawkins take pains to point out that much of the junk DNA in our genome could have a function. This is exactly the sort of skepticism one would expect from a Darwinist.
This does not mean, however, that the so-called junk DNA is not subject to natural selection. Various 'functions' for it have been proposed, where 'function' means adaptive benefit to the organism.
He goes on to describe several of the proposals that are common arguments against junk DNA. If the DNA has a function and it's adaptive, then it is not junk. Selfish DNA is not junk.

Let's be very clear about one thing. The scientific dispute is not over the existence of junk DNA. That's well established. The dispute is over how much of our genome is junk (DNA with no function). In order to refute the idea that MOST of our genome is junk, you have to show that most of it has a function of some sort. I'm looking forward to Jonathan Wells' book where he is going to prove to us that >50% of our genome has a function. (Not holding my breath!)
So far, with none of them having actually read the book (though P.Z. Myers threatens to do so), the Darwin apologists' response to The Myth of Junk DNA has followed along four lines of defense.

1) The usual insults. In his blog Larry Moran of the Department of Biochemistry at the University of Toronto, a grown man and from the looks of him not a young one either, repetitively derides Jonathan as an "IDiot." (How embarrassing for this mature gentleman, you might think. Can you imagine Jonathan Wells or anyone else prominent in the ID community replying in kind, designating Professor Moran as "Larry Moron" or similar? The question is self-answering and tells you a lot about how desperation kindles anger among these people.)
You know, there's one sure way to prove you're not an idiot. The IDiots have been trying for over twenty years to show that they understand science. I'll gladly stop calling them idiots as soon as they deserve it.

Speaking of insults. There's one sure way to ensure that you aren't going to be insulted and that's to stop calling evolutionary biologists "Darwinists" and stop saying that they don't understand their own discipline. I find that extremely insulting and I'm not going to refrain from responding in kind.

I don't know what Jonathan Wells is going to say in his latest book but here's a few examples of insults in Icons of Evolution.
There is a pattern here, and it demands an explanation. Instead of continually testing their theory against the evidence, as scientists are supposed to do, some Darwinists consistently ignore, explain away, or misrepresent the biological facts in order to promote their theory. One isolate example of such behavior might be due simply to overzealousness. Maybe even two. But ten? Year after year? (p. 230)

Fraud is a dirty word, and it should not be used lightly. In the cases described in this book, dogmatic promoters of Darwinism did not see themselves as deceivers. Yet they seriously distorted the evidence—often knowingly. If this is fraud when a stock promoter does it, what is it when a scientist does it? (p. 234)

If dogmatic promoters of Darwinian evolution were merely distorting the truth, that would be bad enough. But they haven't stopped there. They now dominate the biological sciences in the English-speaking world, and use their position of dominance to censor dissenting viewpoints. (p. 235)

The truth is that a surprising number of biologists quietly doubt or reject some of the grander claims of Darwinian evolution. But—at least in America—the must keep their mouths shut or risk condemnation, marginalization, and eventual expulsion from the scientific community. This happens infrequently, but often enough to remind everyone that the risk is real. (p. 239)
Klinghoffer continues with his four lines of defense that we "Darwinists" apparently use to defend the existence of abundant junk DNA (>50%) in our genome.
2) Denying that junk DNA ever figured preeminently in the Darwinist's quiver of arguments against design. Moran, for example, asserts, "There was never a time when knowledgeable molecular biologists equated 'junk' DNA and 'noncoding' DNA." Huh, that's strange. I'm not aware of anyone who has scientifically polled the community of professional biologists on the subject. But I do know that in the struggle for public opinion over the question of Darwin versus Design, junk DNA has again and again been employed, by all the most eminent protagonists on the Darwinian side, as a bludgeoning weapon against intelligent design. Never mind The Selfish Gene, in his most recent book, The Greatest Show on Earth (2009), Dawkins observed that "the greater part...of the genome might as well not be there, for all the difference it makes," and that this fact is "useful for...embarrassing creationists."

Similarly, in Why Evolution Is True (2009), Jerry Coyne offers it, again, as a "prediction" of neo-Darwinian theory that we'll find the genome littered with useless "vestigial genes."
I said that knowledgeable scientists never said that all non-coding DNA is junk. Klinghoffer says, blah, blah, blah, not even addressing my statement.

You can't make this stuff up. At every single opportunity the IDiots demonstrate that they deserve the title.
3) When not denying that junk DNA is a prime, staple argument for Darwin apologists, Professor Moran wants to have it the opposite way. In the same series of blog posts attacking "the IDiot" Jonathan Wells, Moran maintains his own belief that the genome is indeed overwhelmingly useless junk. "Some (I am one)," he writes, "still think that as much as 90 percent could be junk." He insists that "it's not sufficient to show that a few bits of repetitive DNA have gained a function in some species."

Dr. Moran's problem is that he has neither read Jonathan's book nor, it seems, followed the cascade of evidence from the scientific publications. It's a heck of a lot more than just "a few bits of repetitive DNA" that have been shown to be functional. In a brief (and enviably readable and accessible) 115-page book, Jonathan Wells offers over 600 references to recent peer-reviewed literature.

Twenty-five thousand studies further down the road from where we are now, no one knows how much of the genome will turn out to be truly functionless and therefore genuinely worthy of the appellation "junk." But for Darwinists, the speedily mounting evidence against junk DNA is an ominous portent. As Casey Luskin and others have put it, it's the trend that stands out prominently here, on which the likes of Larry Moran have so far been in denial.
Theme

Genomes
& Junk DNA
I've tried and tried to get the IDiots to have a serious, scientific, discussion about the evidence for and against abundant junk DNA in our genome. Some of them have tried but their arguments soon degenerate into insults about my lack of knowledge of the scientific literature. This is in spite of the fact that I have dozens of postings on the subject over the past few years and nobody has ever shown that I've been ignorant of the science behind the controversy. We may disagree about the interpretation but that's not what I'm being accused of here.

As soon as I read the book I'll post a bunch of articles pointing out why it's wrong. That will give the IDiots, like Jonathan Wells, a chance to debate the points I make and show that he is right and I am wrong. I'm looking forward to it.
4) Finally, in my own small contribution to this debate, I made a facetious comment here about how the identification of Osama bin Laden's corpse by DNA fingerprinting, using his "junk DNA" as the media habitually referred to it, provided a welcome news hook for the publication of Jonathan's book. This provoked braying responses from the Darwin Lobby. For example, our journalist friend Lauri Lebo, challenged as ever in her reading-comprehension skills, somehow understood that I was saying the usefulness of non-coding DNA for this forensic purpose proved it isn't junk.

P.Z. Myers tried to show that the usefulness of non-coding DNA for genetic fingerprinting is another demonstration that the stuff really is junk, being "subject to random changes at a higher rate than coding DNA, because it is not subject to functional constraints."
Every now and them some IDiots get something right—even if it's just by accident. One example is when Klinghoffer describes his posting as "my own small contribution."
But whether "junk DNA" is functional is exactly the question at issue, isn't it? The fact that our DNA is pervasively transcribed, as Jonathan Wells points out in Chapter 3 of his book, itself suggests pervasive functionality. As has become clear, too, DNA may serve in various functions even if it does not code for functional RNA.
It will be fun to read how Wells deals with the issue of spurious transcription based on his understanding of how RNA polymerase and transcriptional activators bind to DNA. I'm certainly looking forward to learning about the reliability of those genome studies on transcription and I'm sure Wells is going to discuss conflicting data in the scientific literature. After all, Wells has a Ph.D. in molecular biology so he must know about the real scientific controversy, right?

As for functions that don't require transcription, I highly recommend my short summary of these in What's in Your Genome. We've known about them for decades but apparently the IDiots think this is a new discovery.
So far, the Darwinist response fails to appreciate that Jonathan is in the act of very seriously blunting a Darwinian icon. What, in this context, is an icon? It's a mainstay in the public debate about Darwinian evolution that turns out, on inspection, to be based not on solid science but on puffery, illusion or deception.

This is another icon that, as Jonathan shows, was in the process of being blunted by biologists who are not ID advocates, well before Dr. Wells gathered the evidence together so concisely and conveniently in these pages.
Whatever. Wells' first book, Icons of Evolution was full of lies and I suspect this one will be too. Only one of the ten so-called icons was "blunted" by Wells and that one was the Haeckel drawings. Even then, Wells seriously distorted the significance of those fake drawings by claiming that there was now no evidence of similarities in the development of all mammals.


Friday, March 29, 2024

Why do Intelligent Design Creationists still lie about junk DNA?

Intelligent Design Creationists are heavily invested in refuting junk DNA because it casts doubt on their model of an intelligently designed human. Over the years they have advanced all kinds of arguments against junk DNA and some ID supporters actually address the real scientific issues (e.g. Jonathan Wells). However, most Intelligent Design Creationists are as ignorant about the scientific dispute over junk DNA as they are about evolution and lots of other science issues that conflict with their underlying religious beliefs.

A few days ago (March 26, 2024), the Discovery Institute's Center for Science and Culture published a short video on "The MYTH of Junk DNA" where they ignored most of the science and appealed to the majority of creationists who don't care about the truth. We have enough data to conclude that the Discovery Institute isn't just ignorant of the real science but is actually lying in this video. We know this because there are prominent Senior Fellows of the Center for Science and Culture who know that the material in this video is wrong and/or mispleading.

Saturday, September 17, 2011

Lab Times Screws Up the Discussion of Junk DNA

 
Lab Times is a magazine that reports on news for life scientists in Europe. Their current issue (Sept. 14, 2011) has an "analysis" called Past, present and future Everything you ever wanted to know about the non-coding stretches of DNA. The author is Frederick Gruber who appears to be a science writer drawing on information supplied by various researchers.

You know the article is going to be misleading as soon as you read the opening paragraph.
When the first draft of the human genome finally became available, there were many surprises, one of them being the ridiculously large amount of DNA that did not code for proteins – or anything at all. It seemed like the genome was just a huge chaotic mess sprinkled with tiny nuggets!
The reason this is misleading is because it totally misrepresents the history of the human genome. It's been four decades since we first became aware of the fact that only 1-2% of the human genome encoded proteins. This was hardly a surprise—in fact it was one of the principle arguments against sequencing the human genome. (What was the point of wasting all that money on DNA sequences that were mostly junk?)

One of the unfortunate characteristics of the junk DNA deniers is that they are completely unaware of the historical arguments in favor of junk DNA (e.g. False History and the Number of Genes, Genetic Load, Neutral Theory, and Junk DNA). Everyone who understood the problem was quite happy to find verification when the first draft of the human genome was published. It's exactly what the knowledgeable experts predicted.

The article raises the standard question that seems to have only recently occurred to some researchers; namely, what is all that DNA doing? It's mostly junk—at least that's the conclusion reached by many scientists back in the 1970s and most of what we've discovered since then has supported that view.

Wednesday, June 13, 2007

WIRED on Junk DNA

Junk DNA is the DNA in your genome that has no function. Much of it accumulates mutations in a pattern that's consistent with random genetic drift implying strongly that the sequences in junk DNA are unimportant. In fact, the high frequency of sequence change (mutation plus fixation) is one of the most powerful bits of evidence for lack of function.

Catherine Shaffer is a science writer who describes herself like this on her website,
I am a writer specializing in biotechnology, genetics, genomics, and other molecular, biological sciences. I have experience with news and features. My strengths include a meticulous attention to detail, an absolutely fanatical devotion to scientific accuracy, and enthusiasm. Readers appreciate my clean, uncluttered prose; my crisp, novelistic style; and (sometimes) my zany sense of humor. I am a writer who always meets deadlines and is organized and dependable.

I studied biochemistry at the graduate level at the University of Michigan, and worked in the pharmaceutical industry for several years. I am especially knowledgeable about genomics, proteomics, biotechnology, drug discovery, and chromatographic separations.
She has written an article for WIRED on junk DNA [One Scientist's Junk Is a Creationist's Treasure]. Here's how the article begins,

Without your "junk DNA" you might be reading this article while hanging upside down by your tail.

That's one of the key findings of the opossum genome-sequencing project, and a surprising group is embracing the results: intelligent-design advocates. Since the early '70s, many scientists have believed that a large amount of many organisms' DNA is useless junk. But recently, genome researchers are finding that these "noncoding" genome regions are responsible for important biological functions.

The opossum data revealed that more than 95 percent of the evolutionary genetic changes in humans since the split with a common human-possum ancestor occurred in the "junk" regions of the genome. Creationists say it's also evidence that God created all life, because God does not create junk. Nothing in creation, they say, was left to chance.

"It is a confirmation of a natural empirical prediction or expectation of the theory of intelligent design, and it disconfirms the neo-Darwinian hypothesis," said Stephen Meyer, director of the Center for Science and Culture at the Discovery Institute in Seattle.

Advocates like Meyer are increasingly latching onto scientific evidence to support the theory of intelligent design, a modern arm of creationism that claims life is not the result of natural selection but of an intelligent creator. Most scientists believe that intelligent design is not science. But Meyer says the opossum data supports intelligent design's prediction that junk DNA sequences aren't random, but important genetic material. It's an argument Meyer makes in his yet-to-be-published manuscript, The DNA Enigma.
Hmmmm ... This is so confused that it's difficult to know where to begin. First, the connection between my junk DNA and whether I am an opossum completely escapes me. I don't know of any credible scientist who claims that it's changes in junk DNA that makes us so different from the common ancestor of opossums. (And none who claim that we are descended from opossums.)

Second, the implication that most junk DNA is turning out to have a function is completely false and the confusion about the difference between junk DNA and noncoding DNA is inexcusable from someone who claims to be an expert on genomics [see Noncoding DNA and Junk DNA, The Deflated Ego Problem].

Third, the idea that large amounts of evolution in junk DNA supports Intelligent Design Creationism is crazy. But, in fairness, I don't think Shaffer is making the connection between the sequence variation and Intelligent Design Creationism; instead, she's making the (factually incorrect) connection between the discovery of some functions in noncoding, nonjunk, DNA and Intelligent Design Creationism (IDC). I think Steve Meyer is suggesting that IDC predicts that junk DNA will have a function and that's why he's being quoted here in the article (see above).
Scientists have made several discoveries about what some call the "dark matter of the genome" in recent years, but they say the research holds up the theory of natural selection rather than creationism.
When sequences in noncoding DNA are conserved, this is taken as evidence of negative selection. In that sense, it supports the theory of natural selection. However, most of the sequence comparisons show that junk DNA is not conserved. This does not support the theory of natural selection. It supports Neutral Theory and the mechanism of evolution by random genetic drift.

The article then describes one recent study suggesting that some noncoding DNA is not junk (Lowe et al. 2007). It appears to be the justification for writing the article since it compares short stretches of sequences in the human and opossum genomes. This is not news so I won't bother commenting.
With scientists increasingly believing that so-called junk DNA regulates other genes, among other functions, creationists like Michael Behe, a biochemistry professor at Lehigh University in Pennsylvania and author of the controversial new book on intelligent design, The Edge of Evolution, are more than happy to point out their errors.

"From the very beginning Darwinism thought whatever it didn't understand must be simple, must be nonfunctional," Behe said. "It's only in retrospect that Darwinists try to fit that into their theory."
The concept of junk DNA is not based on ignorance in spite of what the IDiots say. It's based on good scientific evidence and deduction. Of course most IDiots wouldn't recognize scientific evidence even if it bit them on the ...

Is this just a way of getting in another quote from a prominent advocate of Intelligent Design Creationism? Why is Shaffer so interested in the IDiots? This seems to be more than just seeking out controversy since the proper way to do that would be to interview real scientists who can put the work into perspective and comment on it's significance (see below).
Part of the difficulty in studying junk DNA is that it's impossible to prove a negative, i.e., that any particular DNA does not have a function.

That's why T. Ryan Gregory, an assistant professor in biology at the University of Guelph, believes that nonfunctional should be the default assumption. "Function at the organism level is something that requires evidence," he said.
That's how a real scientist speaks [see A word about "junk DNA" and Comments on "Noncoding DNA and Junk DNA"].

This is getting to be a familiar pattern among science writers. Many of them seem to be incapable of sorting out the actual science from the rhetoric. In this case the problem is exacerbated by introducing IDiots as though their opinion had a bearing on the subject. Not only that, the poor science writing stands in sharp contrast to the claim that, "My strengths include a meticulous attention to detail, an absolutely fanatical devotion to scientific accuracy, and enthusiasm."

Lowe, C.B., Bejerano, G. and Haussler, D. (2007) Thousands of human mobile element fragments undergo strong purifying selection near developmental genes. Proc. Natl. Acad. Sci. (USA) 104:8005-8010. [PubMed]