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Monday, December 09, 2013

Monday's Molecule #226

Last week's molecule was sucrose 6-phosphate or α-D-glucopyranosyl-(1→2)-β-D-fructofuranoside 6-phosphate [Monday's Molecule #225 ]. The winner is Jean-Marc Neuhaus (again). He appears to be the only Sandwalk reader who has a copy of my book!

Today's molecule (below) looks a bit strange. It should be obvious that this is not a "natural" molecule. What is it and what does it do? You don't need to give me a long systematic name. The common name will do quite nicely.


Email your answer to me at: Monday's Molecule #226. I'll hold off posting your answers for at least 24 hours. The first one with the correct answer wins. I will only post the names of people with mostly correct answers to avoid embarrassment. The winner will be treated to a free lunch.

There could be two winners. If the first correct answer isn't from an undergraduate student then I'll select a second winner from those undergraduates who post the correct answer. You will need to identify yourself as an undergraduate in order to win. (Put "undergraduate" at the bottom of your email message.)

Sunday, December 08, 2013

Steven Pinker defends "neo-Darwinism," whatever that is

Jerry Coyne posted a couple of tweets (see below) from Steven Pinker (photo) at Dawkins responds to Dobbs.

We shouldn't be surprised at the first one since Pinker is an evolutionary psychologist with a strong tendency to adaptationism. I don't know exactly what he means by "neo-Darwinism" (does he?) but I strongly suspect that it's very much like Darwinism. I'd love to know whether he thinks Neutral Theory and random genetic drift have been successful challenges to neo-Darwinism. If not, then it must mean that neo-Darwinism has incorporated those views. In that case, neo-Darwinism must have begun in the 1970s and somebody picked a very bad name for this view of evolutionary theory.

I think it's more likely that Pinker is just not thinking about Neutral Theory and random genetic drift when he says that challenges to neo-Darwinism have all failed to hold water.

The second tweet means that molecular biologists never knew about tRNA genes or ribosomal RNA genes or the genes for other RNAs that have won Nobel Prizes. I find this very surprising. It's true that some biochemists and molecular biologists are a bit behind in their field but I don't think it's fair to say that "molecular biologists" (i.e. the knowledgeable experts in the field) re-defined the word "gene" in that way.



Friday, December 06, 2013

Valley girl talk

Last summer we took a short drive through the San Fernando Valley on our way from Thousand Oaks to Griffith Park. I happened to mention "valley talk" ("uptalk") but none of us could do a good job of talking like a teenage girl from the valley.

That's a shame because now it looks like Valley girl speak is, like, on the rise! I believe it. Not only have I heard girls speak like this on the university campus here in Toronto but I've even heard this language in Ottawa and that's about as far away from California as you can get.

I hope my granddaughter and grandson don't grow up speaking like this. They live in Los Angeles.


Moon Unit Zappa Valley Girl by mrjyn


Have you ever seen the Grand Canyon? Did it make you believe in god?

Last year we took a helicopter ride to the Grand Canyon [The Magic Canyon Ride ]. None of us converted to Christianity or any other religion.

We may be the exception. According to Time magazine, "It’s hard to be an atheist when you’re looking at the Grand Canyon."

See what Friendly Atheist has to say about this: Time Magazine Says ‘There Are No Atheists at the Grand Canyon,’ Claims that ‘Awe Equals Religion’.

My son and daughter-in-law took a mule ride down into the Grand Canyon. I don't think they were converted either.

Are there any former atheists out there who were converted by the Grand Canyon? Which god(s) did you choose?


Die, selfish gene, die!

"Die, selfish gene, die!" is the provocative title of an article by science writer David Dobbs [Die, selfish gene die!].

Dobbs begins with ....
The selfish gene is one of the most successful science metaphors ever invented. Unfortunately, it’s wrong.
The article attracted the attention of Jerry Coyne who effectively dismantles the strange ideas promoted by Dobbs. Read all about it at: David Dobbs mucks up evolution, part I and David Dobbs mucks up evolution, part II.

As it turns out, this is just another example of a science writer who has been mesmerized by the latest effort to overthrow modern evolutionary theory by some scientist promoting their own work. In this case it's Mary Jane West-Eberhard.

But there's a more serious issue here and I'm not sure that Jerry Coyne recognizes it. The selfish gene metaphor can be interpreted in several different ways. Here's how Richard Dawkins describes it in the preface to the 1989 edition of The Selfish Gene.
The selfish gene theory is Darwin's theory, expressed in a way that Darwin did not choose but whose aptness, I should like to think, he would instantly have recognized and delighted in. It is in fact a logical outgrowth of orthodox neo-Darwinism, but expressed as a novel image. Rather than focus on the individual organism, it takes a gene's-eye view of nature.
Lot's of people misunderstand the selfish gene metaphor. They think it means that organisms behave selfishly but that's not what Dawkins meant at all.

Jerry Coyne explains this in his book Why Evolution Is True (p. 226) ....
As Dawkins shows clearly, the "selfish" gene is a metaphor for how natural selection works. Genes act as if they're selfish molecules: those that produce better adaptations act as if they're elbowing out other genes in the battle for future existence. And, to be sure, selfish genes can produce selfish behaviors. But there is also a huge scientific literature on how evolution can favor genes that lead to cooperation, altruism, and even morality.
There are two main criticisms of the selfish gene metaphor and both of them are quite valid. It's the reason why Dawkin's view hasn't caught on the the evolutionary biology textbooks. It usually merits nothing more than a footnote.

The most damning criticism comes from evolutionary biologists who point out that the primary unit of selection is the individual and not the gene. Stephen Jay Gould and Richard Lewontin are prominent opponents of what they see as an unnecessary reductionism in Dawkins' writing. Clearly, hierarchical theory (Gould) is inconsistent with the selfish gene metaphor because evolution can also operate at the level of groups and species (according to Gould and others). There are plenty of other evolutionary biologists who object to selfish genes for these reasons.

The second objection comes from the focus on natural selection and "Darwinism" (or neo-Darwinism). Many evolutionary biologists have a pluralistic view of modern evolutionary theory. That view includes random genetic drift where the appropriate metaphor might be "lucky gene" or "accidental gene." The problem with the Dawkins' metaphor, according to these critiques, is not that "selfish genes" don't exist, it's that the metaphor is not appropriate for evolution in general.

While I admire Jerry's take-down of Dobbs, I'm not sure that he (Jerry Coyne) fully appreciates these other criticisms of the selfish gene. Here's what Coyne wrote ...
Let me add one thing, though. I’m constantly puzzled these days by how often people argue that the neo-Darwinian synthesis is wrong, and that we need a new paradigm. Genetic assimilation, epigenetics, horizontal gene transfer—all of these buzzwords are evoked as reasons to jettison our “conventional” view of evolution. But always, when you look at the data, the evidence that these phenomena will overturn neo-Darwinism is nonexistent.

I’ve already written a lot on the epigenetics hype, and have shown that there’s no evidence that a single adaptation in nature involves the fixation in the DNA of an epigenetic alteration of the genome that isn’t initially inherited. Yet people keep banging on about epigenetics.

I’m not sure why the hype continues, but perhaps it has to do with the fact that the main paradigm of evolution—the neo-Darwinian synthesis—is largely consolidated, and is correct. Sure, there are surprises to come, and interesting new phenomena, but there’s no “quantum mechanics” of evolution on the horizon. Some theories don’t need to be overthrown because they’re generally right. Perhaps people don’t like working in a field where there’s no new “paradigm” to forge, and Kuhn has ruined us all!

The "neo-Darwinism is dead" trend may have to do with ambition, or perhaps with boredom. I don’t know. What I do know is that the many recent challenges to neo-Darwinism have all failed to hold water, but people keep pouring liquid into that sieve.
The problem here is that Jerry doesn't really say what he means by "neo-Darwinism." Most of his writing suggests that he's talking about natural selection, albeit updated by a knowledge of genetics. He does mention, from time to time, random genetic drift and other aspects of modern evolutionary theory but I'm not sure if he appreciates the fact that some legitimate evolutionary biologists really do think that neo-Darwinism is dead.

Here's the Wikipedia description of neo-Darwinism. It illustrates the problem.
Neo-Darwinism is the 'modern synthesis' of Darwinian evolution through natural selection with Mendelian genetics, the latter being a set of primary tenets specifying that evolution involves the transmission of characteristics from parent to child through the mechanism of genetic transfer, rather than the 'blending process' of pre-Mendelian evolutionary science. Neo-Darwinism can also designate Darwin's ideas of natural selection separated from his hypothesis of Pangenesis as a Lamarckian source of variation involving blending inheritance.
I think we should refer to modern evolutionary theory as "modern evolutionary theory" in order to make sure we're not talking about "Darwinism," "neo-Darwinism," or the hardened version of the "Modern Synthesis." Modern evolutionary theory includes an important role for random genetic drift, Neutral Theory, and population genetics.

We could clarify a lot of discussion if we stopped talking about extending "Darwinism" or extending the Modern Synthesis or proclaiming once again that the selfish gene has died. In fact, the selfish gene has died, it died almost thirty years ago but most people don't know that. RIP.


Do you understand this Nature paper on transcription factor binding in different mouse strains?

I've published a few papers on the regulation of transcription of a mouse gene and students in my lab have done the standard promoter-bashing experiment to define transcription factor binding sites. I did ny Ph.D. in a lab that specialized in DNA binding proteins. I've kept up with the basic ideas in eukaryotic gene expression in order to teach undergraduate courses on that topic and in order to write appropriate information in my textbook.

I've been interested in genome organization for several decades and I've been following the literature on pervasive transcription and transcription factor binding in whole genome studies. I'm reasonably familiar with the techniques although I've never done them myself.

I'm not bragging; I'm just saying that I know a little bit about this stuff so when I saw this paper in one of the latest issues of Nature I decided to look more carefully.
Heinz, S., Romanoski, C., Benner, C., Allison, K., Kaikkonen, M., Orozco, L. and Glass, C. (2013) Effect of natural genetic variation on enhancer selection and function. Nature 503:487-492. [doi: 10.1038/nature12615]

Wednesday, December 04, 2013

Jason Rosenhouse defends Chris Mooney

Jason Rosenhouse read Chris Mooney's article on 7 Reasons Why It's Easier for Humans to Believe in God Than Evolution and liked it. Mooney was arguing that it's easier to believe in god(s) than in evolution because our evolutionary history selected for traits that predisposed us to think more like IDiots than like scientists.

I disagreed [Why don't people accept evolution? ]. Here's what I wrote last week ....

Cherry picking and the safety of low level electromagnetic radiation

While I was researching the previous article on the safety of GM foods, I came across the website of Magda Havas. Here's how she describes herself ...
Magda Havas is Associate Professor of Environmental & Resource Studies at Trent University where she teaches and does research on the biological effects of environmental contaminants. Dr. Havas received her Ph.D. from the University of Toronto, completed Post-Doctoral research at Cornell University, and taught at the University of Toronto before going to Trent University in Peterborough, Canada.

...

Dr. Havas’s research since the 1990s is concerned with the biological effects of electromagnetic pollution including radio frequency radiation, electromagnetic fields, dirty electricity, and ground current. She works with diabetics as well as with individuals who have multiple sclerosis, tinnitus, chronic fatigue, fibromyalgia and those who are electrically hypersensitive. She also conducts research on sick building syndrome as it relates to power quality in schools.

Since the mid 1990s Dr. Havas has taught about electromagnetic pollution in several courses at Trent University and has supervised Reading Courses and Honours Thesis Projects in this area. One of the courses deals specifically with the biological effects of electromagnetic fields and electromagnetic radiation. This is one of the few courses available in North America at a senior undergraduate level critically examining the effects of non-ionizing radiation.
Here comes the fun part. She has made a video in which she explains why we need to pay attention to all the scientific studies showing harmful effects of power lines, cell phones, WiFi etc. She uses Popper's criterion of falsifiability to justify her rejection of all articles that show no harmful effect and she turns cherry-picking completely upside down to support .... cherry-picking!

Don't you just love the title of this video?


In case you don't get it, here's a bit of extra reading.
Magda Havas’ New EHS Study Has Serious Flaws
Trust Me, I’m A Doctor: Magda Havas And WiFi


Is there any reliable scientific evidence that genetically modified food poses a health risk?

I recently had a discussion about the safety of food derived from genetically modified organisms. My opponent, whose identity I will conceal (hi Rachel!), argued that GM foods are unsafe and that there's scientific evidence to back this up. Naturally, this evidence is being concealed by Monsanto and other private companies in the same way that tobacco companies tried to hide the evidence that smoking causes lung cancer.

My position is that I'm not aware of any reliable scientific studies showing that GM foods are dangerous to your health and, furthermore, in a free and open democracy with a free press it seems highly unlikely that such evidence is being suppressed. It seems even more unlikely that scientists would be part of this conspiracy.

Michael Eisen defends 23andMe against the FDA

The US Food and Drug Administration has asked 23andMe to stop marketing their genetic test product. The company will test your DNA for the presence of several genetic markers that might indicate a predisposition to disease. The FDA is concerned that 23andMe is not doing enough to ensure that its tests are accurate and the advice it gives is medically sound.

Michael Eisen is on the Scientific Advisory Board for 23andme. He responds to the controversy: FDA vs. 23andMe: How do we want genetic testing to be regulated?.

I think some of his points are worth discussing. My position is that the links between certain diseases and certain SNPs are not well-established. The scientific literature on this topic is not all that great and many of the published results have not been repeated. What this means is that private companies like 23andMe are under pressure to be the first to include a new link in their database but may not be exercising the appropriate amount of skepticism.

Tuesday, December 03, 2013

How do creationists interpret Lenski's long-term evolution experiment?

Lenski's long-term evolution experiment has resulted in dozens of publications in high quality journals. It has led to significant insights into evolutionary processes [e.g. Lenski's long-term evolution experiment: the evolution of bacteria that can use citrate as a carbon source]. You may be wondering how Intelligent Design Creationists react to these results since most IDiots have a natural aversion to evidence.

Denyse O'Leary wasn't impressed [The Latest From Lenski’s Lab]. She doesn't know very much about science so she has to rely on the opinions of other IDiots. In this case, she relies on Ann Gauger who published a comment on the website of The Biologic Institute [Inovation or Rennovation].

Lenski's long-term evolution experiment: the evolution of bacteria that can use citrate as a carbon source

Richard Lenski set up twelve flasks of E. coli B back in 1988. They were allowed to grow overnight in minimal medium containing 139μM glucose and 1,700 μM citrate. The glucose was the only carbon source that the parent strain could use and it limited growth of the cultures. The citrate was present as a standard chelating agent. The bacteria could not take up citrate and use it as an additional carbon source.

Every day the culture was diluted by transferring one ml to 99 ml of fresh medium (1/100). There were 6.64 generations per day or 2,423 generations per year (slightly more in a leap year).

These cultures were under strong selective pressure. Individual bacteria that could grow faster would out-compete other bacteria in the culture and take over. Lenski expected that each culture would show a variety of different solutions to the selective pressure with many common mutations and many that could be unusual.

Monday, December 02, 2013

Ask a stupid question ... can anyone guess the answer?

I just love the IDiots. They never cease to amaze, and amuse, me. Here's the latest from David Klinghofer at: Intelligent Design as an Orange Flag.
The mention of ID seems to give many writers and commentators what they regard as a green light to blather on without taking a moment to grasp what they're writing about. Denouncing ID is one thing. Denouncing it without comprehending what the phrase refers to, which is amazingly common, is quite another.

I continue to find this amazing. What other subject, both controversial and somewhat recondite, seems to license apparently smart people to write and speak in such an uninformed way?
Gee, I wonder what other subject causes apparently smart people to behave like IDiots? What other subject gives people a green light to blather on when they don't have the slightest clue what they are talking about? Is there another subject that some people denounce without comprehending what it means? Hmmm .....

Can anyone think of such a subject?


Was Louis Agassiz better in the concrete?

Back in the nineteenth century (i.e. more than one hundred years ago) there was a biologist named Louis Agassiz who didn't like Darwin's radical ideas about evolution. Agassiz, a very famous professor at Harvard, thought that there were major gaps n the fossil record and he lamented the apparent lack of transitional fossils. What he was looking for were fossils of direct ancestors of modern species and not their close cousins.

Stephen Meyer thinks this old debate is still relevant today so he writes it up in Darwin's Doubt as if nobody in the past one hundred years ever thought of an explanation. It fooled Denyse O'Leary (not hard) so she blogged about it today [Louis Agassiz: The selective incompleteness of the fossil record].

This reminds me of a famous photograph of the statue of Louis Agassiz embedded upside down in the courtyard in front of the zoology building at Stanford University. The statue tumbled from its place above the entrance during the San Francisco earthquake of 1906.

According to legend, a passing scientist remarked that,
Louis Agassiz was great in the abstract but not in the concrete.1
Actually, it would be even better to say that Agassiz looks better in the concrete than in the abstract [see Agassiz in the Concrete and Persecution of Religious Scientists]. By the 1920s (earlier in Europe) Agassiz's reputation had been severely damaged by his willingness to let religious convictions dictate his science.2


1. The story is apocryphal (a polite word for "false"). The quotation has been attributed to several men, including the President of Stanford, but all have denied it. Nevertheless, it's too good a story to abandon just because it happens to be untrue!

2. Stephen Jay Gould held the Alexander Agassiz Professor of Zoology Chair at Harvard from 1982 until his death in 2002. Alexander Agassiz was Louis Agassiz's son. Alexander served as President of the National Academy of Sciences.

Monday's Molecule #225

Last week's molecule was EF-Tu (elongation factor-thermo unstable). EF-Tu binds to all tRNA molecules in the cell and helps position them in the A-site of the ribosome-mRNA complex during protein synthesis. Its release is coupled to GTP hydrolysis. Eukaryotes contain homologous proteins with different names (e.g. EF-1α). The winner was Jon Nuelle from Texas. The undergraduate winner was Ariel Gershon for the second week in a row.

Today's molecule (below) is an intermediate in a very important pathway that's only found in some species. This is one of those times when you need to supply the common name AND the correct scientific name that specifies the exact molecule shown in the figure.

Email your answer to me at: Monday's Molecule #225. I'll hold off posting your answers for at least 24 hours. The first one with the correct answer wins. I will only post the names of people with mostly correct answers to avoid embarrassment. The winner will be treated to a free lunch.

There could be two winners. If the first correct answer isn't from an undergraduate student then I'll select a second winner from those undergraduates who post the correct answer. You will need to identify yourself as an undergraduate in order to win. (Put "undergraduate" at the bottom of your email message.)