Laurence Hurst is a Professor of Evolutionary Genetics in the Department of Biology and Biochemistry at The University of Bath (United Kingdom). He did his graduate studies under W.D. Hamilton at Oxford so it's safe to assume that he has adaptationist leanings.
Hurst wrote a comment in BMC Biology where he criticized the logic employed by those of us involved in the junk DNA debate [Open questions: A logic (or lack thereof) of genome organization]. Here's part of what Hurst says about logic ...
As a graduate student I was advised that if you don’t understand why an animal does what at first sight looks like behavior contrary to its best interests, then you should presume that it is you, not the animal, that is stupid. Look harder, the wisdom goes, and you will discover natural selection’s cunning logic.
That's bad advice, as Stephen Jay Gould and Richard Lewontin pointed out 35 years ago [The Spandrels of San Marco and the Panglossian Paradigm: A Critique of the Adaptationist Programme]. But, like many adaptationists, Hurst is willing to concede that this kind of reasoning may not apply at the molecular level.
While this may be good advice to those studying organismic behavior or anatomy, when we approach genomic anatomy and behavior it will not do.
Indeed, typically when thinking about genomes people often make the opposite presumption. Intergenic DNA was dismissed as irrelevant junk and many transcripts are presumed to be just so much noise. Synonymous mutations have been assumed to be neutrally evolving and where in a genome a gene sits is considered to be largely irrelevant. But are these assumptions more witness to a lack of understanding rather than robust statements about how genomes function and evolve? You are, after all, alive reading this, testament to the fact that your genome is doing something right.
So then, what features of our and other genomes are functionally relevant and which just so much noise? More importantly, when selection does act, why is it acting?
Hurst seems to be assuming that we know nothing about most of the genome and he makes the erroneous assumption that junk DNA advocates dismiss all intergenic DNA as junk. These are the hallmarks of someone who is uniformed about the debate over junk DNA. There is strong positive evidence for junk and those arguments need to be addressed (e.g. genetic load, C-Value Paradox). There is also strong evidence for functional intergenic sequences (origins, centromeres. telomeres, SARs, regulatory regions, etc.) and that evidence is part of the debate. None of the advocates of junk DNA claim that all intergenic DNA is junk.
We know that half of our genome is composed of bits and pieces of defective transposons. That's not ignorance. Broken genes are ... broken genes. They don't work. They are junk. We know enough about genes to recognize the difference between active functional transposons and those that carry lethal mutations of are missing large pieces of their coding region. It's logical to conclude that about half of our genome is junk based on those facts alone.
We know enough about transcription to know that spurious transcription and production of junk RNA transcripts are an inevitable consequence of the basic biochemistry of DNA binding proteins. That's not ignorance.
We know enough about nearly neutral mutations and molecular evolution to know the the existence of an approximate molecular clock means that most synonymous mutations and amino acid substitutions are fixed by random genetic drift. That's not due to a lack of understanding. Hurst has published evidence that some of these seemingly neutral mutations affect function but he ignores the evidence that most behave as if they were neutral.
The fact that you are alive does, indeed, mean that your genome is doing something right. It's good enough for survival of our species. It does not mean that all of your genome is functional.
To his credit, Hurst recognizes that the ENCODE scientists were wrong and that the null hypothesis is NOT natural selection.
The challenge is difficult. Assuming that sites involved in interactions are all functional isn’t good enough. By this, the logic employed by ENCODE, following a collision between a car and a pedestrian, a car’s bonnet would be ascribed the 'function' of projecting a pedestrian many meters and the pedestrian would have the 'function' of deforming the car’s bonnet. Similarly, we expect, for example, accidental transcription factor-DNA binding to go on at some rate, so assuming that transcription equals function is not good enough. The null hypothesis after all is that most transcription is spurious and alternative transcripts are a consequence of error-prone splicing. Conversely, assuming unbound sequence, such as nucleosome-free regions, to be lacking in function can mislead, as they can be critical for the proper control of gene expression.
I get the feeling that Hurst is uncomfortable with the idea that most of our genome is junk [see Hacking the Genome] but he's at least on the right track when he recognizes that there's still a legitimate scientific debate.
Hat Tip: Dan Graur: Laurence Hurst’s Error: The Inability to Distinguish between a Stupid Animal, a Dead Animal, and the Elephant in the Room
Dan Graur has written a post on The Evolution of "Evolutionist". He points out that the term "evolutionist" and "evolutionism" used to refer to those who accept the fact of evolution and support evolutionary theory.
However, he also notes that ...
Since 2000, it is impossible to find the terms “"evolutionist" and "evolutionism" used by anyone except by creation apologists.... I would greatly like to know when exactly was the evolution of "evolutionist" completed and the term acquired its present negative connotation.
I prefer the term "evolutionary biologist" to describe scientists who are experts on evolution. For those non-experts who accept the basic principles of biology, chemistry, physics, geology etc. we don't need a term other than "rational." It's silly to describe them as "gravitationists" or "plate tectonicists" or "thermodynamicists."
Do you ever refer to yourself as an evolutionist?
The National Center for Science Education (NCSE) is looking for a new executive director to replace Eugenie Scott [Help wanted: executive director].
It's gonna be tough filling those shoes.
PZ Myers has discovered an article published in Christian News. The title of the article is: Groundbreaking Genetic Discoveries Challenge Ape to Human Evolutionary Theory. Here's the opening paragraph ...
Fresh findings in the field of genetics have directly challenged yet another key evolutionary hypothesis by showing that the differences between humans and apes cannot be easily accounted for under the theory of evolution.
The paper they are referring to is Farré et al. (2013) and it shows the exact opposite of what the creationists claim. The paper demonstrates reduced recombination rates in those parts of the human and chimp chromosomes where genomic rearrangements have occurred. That's exactly what has been observed for the past 75 years. (See my post on balancer chromosomes, which describes artificial Drosophila chromosomes that were constructed to supress recombination.)
Read PZ's post on the subject to see just how stupid the creationists can be: Do the creationist shuffle and twist!.
I really don't get it. Why does the creationist movement publish material that is blatantly wrong? Even though I mock them repeatedly, I don't really think that every one of them is stupid. Where are the smart ones who review articles like the one published in Christian News? Will we see a retraction or an apology now that their error has been exposed by PZ and by some of the people who commented on the Christian News website?
Farré, M., Micheletti, D., Ruiz-Herrera, A. (2012) Recombination Rates and Genomic Shuffling in Human and Chimpanzee--A New Twist in the Chromosomal Speciation Theory. Mol. Biol. Evol. 30:853-864.
There are dozens of trees like this in Venice, California (USA) in the neighborhood where my grandchildren live. Can you name this tree (common name and species name)?
Can you come up with an adaptationist explanation for why this tree is so different from most other trees and bushes?
RMS Queen Mary first sailed across the North Atlantic on May 27, 1936. At the time she was one of the largest ocean liners.
Now she lives in "retirement" as a tourist attraction in Long Beach, California (USA) where I took this photo yesterday.
The Canadian College of Naturopathic Medicine is not affiliated with the University of Toronto but naturopath students do study anatomy in my building (Medical Sciences Building) on the downtown campus. The College rents Convocation Hall for their graduation ceremonies. The latest graduation ceremonies were on May 23, 2013 (see Graduation Day!.
In order to graduate, students at the Canadian College of Naturopathic Medicine need to pass courses in a number of areas. Here are two of the things they study ...
Asian Medicine/Acupuncture
Students learn about the philosophy and principles of Asian medicine: Yin and Yang theory, the meridians and channels system, the five-element theory and the symptoms and signs involving the 12 master meridians. Applying these principles in the context of patient assessment and treatment is emphasized, with acupuncture and therapeutic botanicals being the main approaches.
Homeopathic Medicine
The history, principles and philosophy of homeopathy are discussed in depth. Practical application of homeopathic principles in patient assessment and management is emphasized for acute and constitutional cases. Skills are developed in case analysis, repertorization, materia medica search, remedy differentiation and selection and prescribing the appropriate posology.
This is pseudoscience and quackery. The University of Toronto should not be lending its implicit stamp of approval to such nonsense.
I realize that the university rents out Convocation Hall for all kinds of events but most of them are so detached from the university that no one will mistake the event as an endorsement by the university. This is different. Convocation Hall is where the university's own graduation ceremonies take place (the name is a clue!). The average person will assume that the University of Toronto supports the Canadian College of Naturopathic Medicine and that our faculty has no problem with graduating quack "doctors."
This practice should stop.
Back in the late 1980's, I read Molecular Evolutionary Genetics by Masatoshi Nei. He introduced me to the concept that the history of life is driven by mutation and that the old-fashioned view of mutationism needs to be looked at more carefully. A decade later, Arlin Stoltzfus took up the cause and he has published a number of papers on the topic.
If you want to read more about mutationism then you can't find a better source than the series of posts by Arlin on Sandwalk from 2010. The last one, The Mutationism Myth VI: Back to the Future, contains links to all of the others. Be warned, it will be hard to resist the idea of mutationism after you read Arlin's explanation. It will hurt your brain.
I just learned that Masatoshi Nei is about to publish a new book called Mutation-Driven Evolution. Here's the description on Amazon ...
Theme
MutationThe purpose of this book is to present a new mechanistic theory of mutation-driven evolution based on recent advances in genomics and evolutionary developmental biology. The theory asserts, perhaps somewhat controversially, that the driving force behind evolution is mutation, with natural selection being of only secondary importance. The word 'mutation' is used to describe any kind of change in DNA such as nucleotide substitution, gene duplication/deletion, chromosomal change, and genome duplication. A brief history of the principal evolutionary theories (Darwinism, mutationism, neo-Darwinism, and neo-mutationism) that preceded the theory of mutation-driven evolution is also presented in the context of the last 150 years of research. However, the core of the book is concerned with recent studies of genomics and the molecular basis of phenotypic evolution, and their relevance to mutation-driven evolution. In contrast to neo-Darwinism, mutation-driven evolution is capable of explaining real examples of evolution such as the evolution of olfactory receptors, sex-determination in animals, and the general scheme of hybrid sterility. In this sense the theory proposed is more realistic than its predecessors, and gives a more logical explanation of various evolutionary events.
Mutation-Driven Evolution is suitable for graduate level students as well as professional researchers (both empiricists and theoreticians) in the fields of molecular evolution and population genetics. It assumes that the readers are acquainted with basic knowledge of genetics and molecular biology.
I can't wait to get my hands on a copy of this book. Look for a review in a few months.
Let's look at a recent post on Evolutin News * Views (sic): From Discovering Intelligent Design: Opposition from the Scientific Establishment. As the title suggests, this is an excerpt from one of the books being heavily promoted by the IDiots.
They have a problem. How do the IDiots explain why 99.9% of biologists oppose Intelligent Design Creationism? It's because they all have a materialistic bias that prevents them from following the evidence wherever it may lead. Read this bit ...
ID challenges a reigning scientific paradigm. But as sociologist Steve Fuller says, ID is not anti-science, but rather anti-establishment. ID theorists want more scientific investigation, not less. They simply want the freedom to follow the evidence without harassment or philosophical restrictions.
An ID-based view of science promises to open new avenues of scientific investigation. Without materialist paradigms governing science, perhaps more scientists would have sought function for structures like "junk" DNA and vestigial organs, rather than assuming they were non-functional evolutionary relics.
Let me remind you that the presence of junk DNA in our genome was not anticipated by those who believed in the importance of natural selection. What happened was that the evidence became too substantive to ignore so scientists had to accept the presence of junk DNA in spite of the fact that most of them expected selection to eliminate it.
Now if you insist on believing in an intelligent design paradigm then you simply can't follow the evidence wherever it may lead because junk DNA isn't part of your worldview. In other words, the example used by the IDiots in this post is the exact opposite of the point they are making.
Oops!
Now you know why we call them IDiots.
I've always been a bit embarrassed to admit that my own department doesn't adopt my textbook in their introductory biochemistry courses. The honors course uses the 4th edition of Voet & Voet but it's only "recommended," not required. The large introductory course for non-specialists recommends several textbooks, including mine.
The arguments against having a required textbook have often focused on the idea that none of the current textbooks covers the material that's being taught—especially in the large course. Our large (1300 students) course tended to emphasize human physiology from a biochemical perspective. Many of the lectures in the metabolism section involved specific case studies.
Some economist named George Gilder has read Darwin's Doubt, the latest IDiot book. Gilder says ...
I spend my life reading science books. I've read many hundreds of them over the years, and in my judgment Darwin's Doubt is the best science book ever written. It is a magnificent work, a true masterpiece that will be read for hundreds of years.
See David Klinghoffer gloat about this at: George Gilder: Darwin's Doubt Is "Best Science Book Ever Written," "Will Be Read for Hundreds of Years".
Are you still wondering why I call them IDiots?
UPDATE: George Gilder is one of the co-founders of the Discovery Institute and the author of the book (Stephen Meyer) works for the Discovery Institute. Just saying .. I'm sure the relationship has no bearing on Gilder's review and I'm sure it's completely above board for someone like George Gilder to be quoted in a blurb on the cover. If there was anything wrong then surely David Klinghoffer would have mentioned it in his blog post. (This is one of those cases where "IDiots" might be too kind.)
Last Monday I went back to my old high school (Nepean High School in Ottawa, Canada) to visit with students in various biology classes. My host was Susanne Gerards who teaches grade 11 biology and grade 12 biology. She's also the lead author on the biology textbook [Biology 12] that the students use in the grade 12 courses.
I was "guest lecturer" in two grade 12 biology classes and one grade 11 biology class. The grade 12 students had just finished the sections on biochemistry and molecular genetics (information flow) so they were up on most things that I blog about. I was surprised at the amount of information they had just leaned—it's comparable to what we teach in our introductory biochemistry course except that there's less emphasis on structures and nothing on enzyme kinetics.
The students were wonderful. Many of them are going to take science courses in university. (They all had their university acceptances.) Only a few of them are interested in medicine.1
The grade 11 students had finished their section on evolution. Most of them thought that evolution was driven by changes in the environment but they had at least been exposed to random genetic drift. It took a little prompting to that get that out of them. (I think Susanne was a bit embarrassed!). My impression was that the students understood quite a bit about evolution and this was a pleasant surprise.
One of the classes had just finished a discussion about junk DNA when a student raised it in class. He claimed that recent evidence proved that most of our genome has a function. I think the students were still a bit confused about genomes but at least they talked about it. (We didn't talk about it much when I was there.)
I'm pretty sure that the most important thing the students learned was that you actually get paid to be a graduate student! They were also surprised about the relatively high salaries that professors earn when they're hired. I'm hoping that some of them will pursue a career in science.
Susanne Gerards and I had an excellent lunch in Westboro where the restaurants and shops are quite a bit more upscale than they were in the 1960s when I lived there. We also had a lot of fun talking about science after class. With teachers like that I'm confident that Ontario high school students are getting a good science education.
1. Hardly any of them were going to the University of Toronto in spite of the fact that it's the best university in Canada. I'm not sure why they were avoiding it. The most popular universities were Queen's, McGill, and Waterloo.
The so-called "C-Value Paradox" was described over thirty years ago. Here's how Benjamin Lewin explained it in Genes II (1983).
The C value paradox takes its name from our inability to account for the content of the genome in terms of known function. One puzzling feature is the existence of huge variations in C values between species whose apparent complexity does not vary correspondingly. An extraordinary range of C values is found in amphibians where the smallest genomes are just below 109bp while the largest are almost 1011. It is hard to believe that this could reflect a 100-fold variation in the number of genes needed to specify different amphibians.
Since then we have dozens and dozens of examples of very similar looking species with vastly different genome sizes. These observations require an explanation and the best explanation by far is that most of the genomes of multicellular species is junk. In fact, it's the data on genome sizes that provide the best evidence for junk DNA.
It's not difficult to find a proper definition of evolution. All you have to do is check your basic introductory textbooks on evolution. Google is not your friend in this case 'cause there's a lot of misinformation out there. If you're really interested in a scientific definition of evolution why not go right to the primary source?
Most textbooks use some version of the following for the minimal DEFINITION of evolution [see What IS Evolution?].
Evolution is a process that results in heritable changes in a population spread over many generations.
Now, we all know that Intelligent Design Creationists are keen on real science. They certainly don't want to mislead their flock. Let's see how they define evolution in the latest book they are promoting [From Discovering Intelligent Design: Define Your Terms].
Like most graduate departments, we are constantly evaluating and modifying our graduate program but rarely do we step back and look at the big picture. What are we trying to accomplish?
Graduate education, like undergraduate education, has been subjected to serious study over the past few decades. Guttlerner and Van Vactor (2013) have just published a brief review in Cell that summarizes the goals and how they are trying to achieve them at Havard.
The authors begin by pointing out the importance of a concept-driven curriculum.
The modernization of science education requires a shift from a content-driven curriculum to an interdisciplinary, concept-driven curriculum (Association of American Medical Colleges and Howard Hughes Medical Institute, 2009; American Association for the Advancement of Science, 2009; National Research Council, 2003, 2009). Such a curriculum organizes information around unifying concepts and frees educators from the insurmountable task of presenting the complete breadth of an ever-expanding scientific knowledge base (D’Avanzo, 2008). Concept-driven education is increasingly seen as fundamental for contemporary research scientists and physicians (Association of American Medical Colleges and Howard Hughes Medical Institute, 2009).
