I know I've said this before, but I continue to be astonished at the ignorance of creationists. Those who oppose evolution most vehemently don't understand it in spite of the fact that they are convinced it has to be wrong.
This is most obvious with the Intelligent Design Creationists because they like to use science-sounding jargon to convince us that they know what they are talking about. They claim that they can refute evolutionary biology using scientific evidence. Instead they just reveal their ignorance.
They've been doing it for decades in spite of the fact that many people have tried to educate them. I don't get it.
Recently, I tried to explain how the difference between the chimpanzee and human genomes is consistent with what we know about population genetics, mutation rates, and Neutral Theory. I was aware of the fact that this stuff would all be news to most Intelligent Design Creationists but it was still an opportunity to try, once again, to teach them about modern evolutionary theory.
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Monday, March 31, 2014
Monday's Molecule #235
Last week's molecule [Monday's Molecule #234] was insect juvenile hormone. The winners are Frank Schmidt and Raul Félix de Sousa (still an undergraduate?). They live in foreign countries so they won't be coming to lunch.
This week's molecule (right) is very common. You have to identify the entire molecule including the specific polynucleotide. Emphasis is on the word "specific"—there's only one possibility. I'm betting that there won't be very many correct answers for this one.
Email your answer to me at: Monday's Molecule #235. 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.)
This week's molecule (right) is very common. You have to identify the entire molecule including the specific polynucleotide. Emphasis is on the word "specific"—there's only one possibility. I'm betting that there won't be very many correct answers for this one.
Email your answer to me at: Monday's Molecule #235. 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.)
Friday, March 28, 2014
God's not dead
God's not dead is a movie that's gaining some notoriety in the USA. Here's a synopsis ...
This sort of thing happens quite a bit in the movies. It's pretty rare to find a university professor portrayed as a good person, or even a smart person who knows their stuff. If you are one of those university students who watch the movie and are convinced that you can win a debate with a professor on the subject "Do gods exist?" then please contact me and we'll set up a time and place for you to make the attempt. I'm pretty sure I can find a smart professor at most major universities.
Present-day college freshman and devout Christian, Josh Wheaton (Shane Harper), finds his faith challenged on his first day of Philosophy class by the dogmatic and argumentative Professor Radisson (Kevin Sorbo). Radisson assigns him a daunting task: if Josh will not admit that "God Is Dead," he must prove God's existence by presenting well-researched, intellectual arguments and evidence over the course of the semester, and engage Radisson in a head-to-head debate in front of the class. GOD'S NOT DEAD weaves together multiple stories of faith, doubt and disbelief, culminating in a dramatic call to action.I haven't seen the movie (yet) but I'm guessing that the 18 year-old Christian student wins the debate against his "dogmatic" professor.
This sort of thing happens quite a bit in the movies. It's pretty rare to find a university professor portrayed as a good person, or even a smart person who knows their stuff. If you are one of those university students who watch the movie and are convinced that you can win a debate with a professor on the subject "Do gods exist?" then please contact me and we'll set up a time and place for you to make the attempt. I'm pretty sure I can find a smart professor at most major universities.
Wednesday, March 26, 2014
Science education and indigenous knowledge
Yesterday afternoon I attended a forum on Science and Mathematics teaching in Ontario schools. It was put on by The Centre for Science, Mathematics and Technology (SMT) Education at the Ontario Institute for Studies in Education (OISE) at the University of Toronto (Toronto, Canada).
OISE is one of the places responsible for training teachers in Ontario. It offers advanced degrees (Masters. Ph.D.) in education. I thought this might be a good opportunity to network with the people responsible for teaching science in our high schools.
Here's a description of the forum ...
OISE is one of the places responsible for training teachers in Ontario. It offers advanced degrees (Masters. Ph.D.) in education. I thought this might be a good opportunity to network with the people responsible for teaching science in our high schools.
Here's a description of the forum ...
Tuesday, March 25, 2014
Religion & Prayer in Canadian Public Spaces: Exploring Issues of Secularism, Neutrality and Equality
The Canadian Secular Alliance is hosting a talk by Lauren Forbes tomorrow evening in rm 4171 of the Medical Sciences Building at the University of Toronto. (My building, one floor below my office.) Contact me if you want to meet up before the talk.
It's important to note that Ms. Forbes is going to DEFEND things like prayer at city council meetings. Come out and hear the other side of the issue. She is a Master's student at the University of Ottawa.
Read her article: To Pray or Not to Pray, is that the Question?: How the Increasing Desire for State Neutrality Affects Prayer Before Council Meetings in Canada. Here's the abstract ...
It's important to note that Ms. Forbes is going to DEFEND things like prayer at city council meetings. Come out and hear the other side of the issue. She is a Master's student at the University of Ottawa.
Read her article: To Pray or Not to Pray, is that the Question?: How the Increasing Desire for State Neutrality Affects Prayer Before Council Meetings in Canada. Here's the abstract ...
Historically, in western liberal democratic states, Christian prayers have often been recited at the opening of various public institutions' meetings. However, the recitation of such prayers is now being questioned on the grounds of being too particular in promoting specific religious denominations; of promoting a particular religion over another; and even of promoting religion in states where no longer everyone subscribes to one. Many such disputes spring from the growing desire for equality and neutrality in increasingly diverse and secular societies. This paper focuses on the recent legal disputes in Canada, concerning the recitation of prayers before the commencement of primarily council meetings. It examines Canadian tenets of neutrality and consequently secularism, questioning what each looks like (or could look like) and whether they require public spaces to be religion-free in order to hold true, or whether they can be inclusive to both religious and worldviews of non-belief in these public spaces (i. e. council meetings in this context). In this paper the relevant legal cases are analyzed and current solutions to the disputes are discussed. Concerns are raised and finally, solutions that may be more neutral and that equally do justice to both freedom of religion and freedom of conscience are considered.
Monday, March 24, 2014
What is epigenetics?
Several students in my class decided to write essays on epigenetics. This was very brave of them since nobody seems to have a good definition of epigenetics and much of the hype about epigenetics is not very scientific. I'm also more than a little skeptical about some of the claims that have been made.
Here's a video. What do you think? Is this a useful contribution to our understanding of a complex issue? Is the inheritance of methylation sites at restriction/modification loci in bacteria an example of epigenetics? After E. coli divides, both cells inherit some lac repressor molecules and the lac operon is not expressed provided the parent wasn't exposed to lactose. Is this epigenetics?
Here's a video. What do you think? Is this a useful contribution to our understanding of a complex issue? Is the inheritance of methylation sites at restriction/modification loci in bacteria an example of epigenetics? After E. coli divides, both cells inherit some lac repressor molecules and the lac operon is not expressed provided the parent wasn't exposed to lactose. Is this epigenetics?
Monday's Molecule #234
Last week's molecules [Monday's Molecule #233] were oxaloacetate, ethanol, lactate, alanine, and acetyl-CoA. All of them can be synthesized in a reaction using pyruvate as a substrate (two steps to make ethanol). All of them are precursors to pyruvate and hence glucose. The winner is Jean-Marc Neuhaus. I will be buying him four meals next time I visit Switzerland. I'm thinking it will be two raclettes and two fondues with lots of wine.
This week's molecule (left) is probably not very familiar to most of you so I don't anticipate many correct answers. You can use the common name. Email your answer to me at: Monday's Molecule #234. 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.)
This week's molecule (left) is probably not very familiar to most of you so I don't anticipate many correct answers. You can use the common name. Email your answer to me at: Monday's Molecule #234. 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.)
Thesis defense - 40th anniversary
Today is the 40th anniversary of my Ph.D. oral defense.1 The event took place in the Department of Biochemical Sciences at Princeton University back in 1974.
It began with a departmental seminar. When the seminar was over I retired with my committee to a small classroom for the oral exam.
I don't remember everyone who was on my committee. My Ph.D. supervisor (Bruce Alberts) was there, as was my second reader, Abe Worcel. I know Uli Laemmli was there and so was Arnie Levine. I'm pretty sure the external member of the committee was Nancy Nossal from NIH in Bethesda, MD (USA). It's a bit of a blur after all these years.
I remember being fairly confident about the exam. After five and a half years I was pretty sure that everyone on my committee wanted to get rid of me and the easiest way to do that was to let me pass. Bruce stood to gain $3000 per year of research money and Uli was going to get back the basement of his house where Ms. Sandwalk and I had been living for the past month.
The toughest questions were from Uli Laemmli, which should not come as a surprise to anyone who knows him. He has this annoying habit of expecting people to understand the basic physics and chemistry behind the biochemical sciences. Fortunately, my inability to answer most of his questions didn't deter him from voting to pass me.
This photograph was taken at a party that evening. I look pretty calm at that point but this may have had a lot to do with the various refreshments that were being served.
The amazing thing about the photograph—as I'm sure you all agree—is how little I've changed since then—apart from a haircut.
Back in those days we didn't spend a lot of time writing a thesis. I started in the middle of January and the entire process of writing and defending took nine weeks. My thesis was bound and delivered to the library about one week after the Ph.D. oral.
The second page of my thesis has only three words on it. It says, "To Leslie Jane." This is Ms. Sandwalk. She really should have her name on the cover 'cause I couldn't have graduated without her. Typing my thesis was only one of her many contributions. There are 257 pages in my thesis and she typed every one. As a matter of fact, she typed them twice, one draft and then the final version.
The figures in my thesis were all hand drawn. I've included one (below) to illustrate what I was doing during those five and a half years.
The Alberts lab was interested in DNA replication during bacteriophage T4 infections of E. coli. We knew that replication was carried out by a complex protein machine that assembled at a replication fork but we didn't know all the players or what they did.
The T4 proteins required for DNA replication were known from genetic studies. The most important genes were genes 30 (ligase), 32 (single-stand DNA binding protein), 41, 43 (DNA polymerase), 44, 45, and 62. The products of the unknown genes were called 41P, 44P, 45P and 62P.
We wanted to purify and characterize those proteins; my target was the product of gene 41, or 41P.
We had a cool assay, developed mostly by a postdoc in the lab named Jack Berry. What we did was to prepare a cell lysate from cells that had been infected by bacteriophage carrying an amber mutation in one of the genes. This lysate could not support DNA synthesis, as measured by incorporation of 32P nucleotides, unless we added back the missing component. This is the basis of an in vitro complementation assay that worked for each of the unknown proteins.
In my case, I used traditional protein purification methods to isolate fractions of proteins and them tested them for activity in the complementation assay. The figure below shows the elution profile of proteins bound to a hydroxylapatite column. The peak centered on fraction 61 is the activity of the complementation assay. It indicates that 41P elutes early as a sharp peak in the elution profile.
The complementation assay doesn't tell us anything about the function of 41-protein, only that it complements an extract that's deficient in 41P. Strictly speaking, it doesn't even tell us that the activity is due to the product of gene 41 since it could be something else that complements in vitro.
Fortunately we had another way of identifying 41P. I started my purification with extracts from 17 liters of infected cells. To this I added extracts from cells that had been labeled with radiaoctive amino acids. One batch was from a wild-type infection where all T4 proteins are labeled with 14C amino acids. The other batch is from an infection with an amber mutation in gene 41. In this case every protein except 41P is labeled with 3H amino acids.
You can adjust the settings on a scintillation counter so they distinguish between 14C and 3H but there's some overlap. The equations for calculating the contribution of each isotope in each window are relatively simple. All you need are good standards to get the distribution. One of the most fun things I did as a graduate student was to write a computer program (in Fortran) that did these calculations automatically and plotted them on a plotter. This was back in the time when computers were housed in large separate buildings and required dozens of people to look after them.
If you look of the elution profile in the figure you'll see there's an excess of 14C over 3H in the same fractions where the complementation activity is located. What this means is that the wild-type extract has a protein at that position that's not found in the am41 extract. It's another way of identifying the product of gene 41.
The double label technique was useful 35 years ago but nobody does it anymore. It was fun while it lasted.
(I never did figure out what 41P did during DNA replication but a few years after I left a postdoc identified 41P as a helicase—an enzyme that unwinds DNA ahead of the replication fork. The enzyme is now called gp41 for "gene product.")
It began with a departmental seminar. When the seminar was over I retired with my committee to a small classroom for the oral exam.
I don't remember everyone who was on my committee. My Ph.D. supervisor (Bruce Alberts) was there, as was my second reader, Abe Worcel. I know Uli Laemmli was there and so was Arnie Levine. I'm pretty sure the external member of the committee was Nancy Nossal from NIH in Bethesda, MD (USA). It's a bit of a blur after all these years.
I remember being fairly confident about the exam. After five and a half years I was pretty sure that everyone on my committee wanted to get rid of me and the easiest way to do that was to let me pass. Bruce stood to gain $3000 per year of research money and Uli was going to get back the basement of his house where Ms. Sandwalk and I had been living for the past month.
The toughest questions were from Uli Laemmli, which should not come as a surprise to anyone who knows him. He has this annoying habit of expecting people to understand the basic physics and chemistry behind the biochemical sciences. Fortunately, my inability to answer most of his questions didn't deter him from voting to pass me.
This photograph was taken at a party that evening. I look pretty calm at that point but this may have had a lot to do with the various refreshments that were being served.
The amazing thing about the photograph—as I'm sure you all agree—is how little I've changed since then—apart from a haircut.
Back in those days we didn't spend a lot of time writing a thesis. I started in the middle of January and the entire process of writing and defending took nine weeks. My thesis was bound and delivered to the library about one week after the Ph.D. oral.
The second page of my thesis has only three words on it. It says, "To Leslie Jane." This is Ms. Sandwalk. She really should have her name on the cover 'cause I couldn't have graduated without her. Typing my thesis was only one of her many contributions. There are 257 pages in my thesis and she typed every one. As a matter of fact, she typed them twice, one draft and then the final version.
The figures in my thesis were all hand drawn. I've included one (below) to illustrate what I was doing during those five and a half years.
The Alberts lab was interested in DNA replication during bacteriophage T4 infections of E. coli. We knew that replication was carried out by a complex protein machine that assembled at a replication fork but we didn't know all the players or what they did.
The T4 proteins required for DNA replication were known from genetic studies. The most important genes were genes 30 (ligase), 32 (single-stand DNA binding protein), 41, 43 (DNA polymerase), 44, 45, and 62. The products of the unknown genes were called 41P, 44P, 45P and 62P.
We wanted to purify and characterize those proteins; my target was the product of gene 41, or 41P.
We had a cool assay, developed mostly by a postdoc in the lab named Jack Berry. What we did was to prepare a cell lysate from cells that had been infected by bacteriophage carrying an amber mutation in one of the genes. This lysate could not support DNA synthesis, as measured by incorporation of 32P nucleotides, unless we added back the missing component. This is the basis of an in vitro complementation assay that worked for each of the unknown proteins.
In my case, I used traditional protein purification methods to isolate fractions of proteins and them tested them for activity in the complementation assay. The figure below shows the elution profile of proteins bound to a hydroxylapatite column. The peak centered on fraction 61 is the activity of the complementation assay. It indicates that 41P elutes early as a sharp peak in the elution profile.
The complementation assay doesn't tell us anything about the function of 41-protein, only that it complements an extract that's deficient in 41P. Strictly speaking, it doesn't even tell us that the activity is due to the product of gene 41 since it could be something else that complements in vitro.
Fortunately we had another way of identifying 41P. I started my purification with extracts from 17 liters of infected cells. To this I added extracts from cells that had been labeled with radiaoctive amino acids. One batch was from a wild-type infection where all T4 proteins are labeled with 14C amino acids. The other batch is from an infection with an amber mutation in gene 41. In this case every protein except 41P is labeled with 3H amino acids.
You can adjust the settings on a scintillation counter so they distinguish between 14C and 3H but there's some overlap. The equations for calculating the contribution of each isotope in each window are relatively simple. All you need are good standards to get the distribution. One of the most fun things I did as a graduate student was to write a computer program (in Fortran) that did these calculations automatically and plotted them on a plotter. This was back in the time when computers were housed in large separate buildings and required dozens of people to look after them.
If you look of the elution profile in the figure you'll see there's an excess of 14C over 3H in the same fractions where the complementation activity is located. What this means is that the wild-type extract has a protein at that position that's not found in the am41 extract. It's another way of identifying the product of gene 41.
The double label technique was useful 35 years ago but nobody does it anymore. It was fun while it lasted.
(I never did figure out what 41P did during DNA replication but a few years after I left a postdoc identified 41P as a helicase—an enzyme that unwinds DNA ahead of the replication fork. The enzyme is now called gp41 for "gene product.")
1. This post is an almost identical copy of one that was posted five years ago. You'll probably see another in 2019, and especially 2024.
Sunday, March 23, 2014
IDiots respond to the evidence for evolution of chimpanzees and humans
Last month I explained how the difference in DNA sequence between chimps and humans corresponds to what we would predict from evolutionary theory. I challenged the Intelligent Design Creationists to explain not only that the sequences are similar but that the degree of similarity is evidence of evolution.
None of the "scientists" on the creationist websites responded to my challenge but eventually—after being prodded—Vincent Torley (a philospher) picked up the challenge. I tried to explain why his response was inadequate.
Here are the three relevant posts.
Why are the human and chimpanzee/bonobo genomes so similar?
So, why are the human and chimpanzee/bonobo genomes so similar? A reply to Professor Larry Moran
An Intelligent Design Creationist explains why chimpanzees and humans are so similar
None of the "scientists" on the creationist websites responded to my challenge but eventually—after being prodded—Vincent Torley (a philospher) picked up the challenge. I tried to explain why his response was inadequate.
Here are the three relevant posts.
Why are the human and chimpanzee/bonobo genomes so similar?
So, why are the human and chimpanzee/bonobo genomes so similar? A reply to Professor Larry Moran
An Intelligent Design Creationist explains why chimpanzees and humans are so similar
Saturday, March 22, 2014
An Intelligent Design Creationist explains why chimpanzees and humans are so similar
The genomes of chimpanzees and bonobos are remarkably similar to the human genome. In terms of sequence similarity, they are more than 98% identical in the regions that can be aligned. This, of course, is due to the fact that they descend from a common ancestor in the recent past (about 5 million years ago).
Intelligent Design Creationists don't agree. Many of them do not accent common descent and macroevolution so they make up stories that account for the similarity based on what they think god might have been thinking when he created chimps and humans.
But the scientific evidence for evolution is much stronger than just overall sequence similarity. The number of differences (about 50 million substitutions) corresponds pretty closely with what we expect from evolutionary theory (population genetics) and known mutation rates [Why are the human and chimpanzee/bonobo genomes so similar?]. If the Intelligent Design Creationists are going to dismiss this confirmation of evolutionary theory then they are going to have to be much more inventive.
Intelligent Design Creationists don't agree. Many of them do not accent common descent and macroevolution so they make up stories that account for the similarity based on what they think god might have been thinking when he created chimps and humans.
But the scientific evidence for evolution is much stronger than just overall sequence similarity. The number of differences (about 50 million substitutions) corresponds pretty closely with what we expect from evolutionary theory (population genetics) and known mutation rates [Why are the human and chimpanzee/bonobo genomes so similar?]. If the Intelligent Design Creationists are going to dismiss this confirmation of evolutionary theory then they are going to have to be much more inventive.
Friday, March 21, 2014
John Wilkins writes about accommodationism
John Wilkins has written a series of posts about the war between science and religion.
Accommodating Science overview
I find the arguments confusing because I'm never quite sure what John defines as "science." I think he's referring to the things that scientists do. This is the narrow definition of science and I think it explains why he claims that there are aspects of religion that do not conflict with science.
Accommodating Science overview
I find the arguments confusing because I'm never quite sure what John defines as "science." I think he's referring to the things that scientists do. This is the narrow definition of science and I think it explains why he claims that there are aspects of religion that do not conflict with science.
ASBMB Core Concepts in Biochemistry and Molecular Biology: Homeostasis
Theme
Better BiochemistryThe American Society for Biochemistry and Molecular Biology (ASBMB) has decided that the best way to teach undergraduate biochemistry is to concentrate on fundamental principles rather than facts and details. This is an admirable goal—one that I strongly support.
Last October I discussed the core concepts proposed by Tansey et al. (2013) [see Fundamental Concepts in Biochemistry and Molecular Biology]. The five concepts are:
Better BiochemistryThe American Society for Biochemistry and Molecular Biology (ASBMB) has decided that the best way to teach undergraduate biochemistry is to concentrate on fundamental principles rather than facts and details. This is an admirable goal—one that I strongly support.
Last October I discussed the core concepts proposed by Tansey et al. (2013) [see Fundamental Concepts in Biochemistry and Molecular Biology]. The five concepts are:
- evolution [ASBMB Core Concepts in Biochemistry and Molecular Biology: Evolution ]
- matter and energy transformation [ASBMB Core Concepts in Biochemistry and Molecular Biology: Matter and Energy Transformation]
- homeostasis [ASBMB Core Concepts in Biochemistry and Molecular Biology: Homeostasis]
- biological information [ASBMB Core Concepts in Biochemistry and Molecular Biology: Biological Information]
- macromolecular structure and function [ASBMB Core Concepts in Biochemistry and Molecular Biology: Molecular Structure and Function]
Science still doesn't get it
The latest issue of Science contains an article by Yudhijit Bhattacharjee about Dan Graur and his critique of the ENCODE publicity disaster of September 2012. The focus of the article is on whether Dan's tone is appropriate when discussing science.
Let me remind you what Science published back on September 7, 2012. Elizabeth Pennisi announced that ENCODE had written the eulogy for junk DNA. She quoted one of the leading researchers ...
Let me remind you what Science published back on September 7, 2012. Elizabeth Pennisi announced that ENCODE had written the eulogy for junk DNA. She quoted one of the leading researchers ...
Thursday, March 20, 2014
What do Intelligent Design Creationists really think about macroevolution?
Intelligent Design Creationism is a huge tent that shelters all sorts of creationists ranging from Young Earth Creationists to those who could be called Theistic Evolution Creationists.1 Many of them accept common descent so they clearly don't have much of a problem with most of macroevolution.
On the other hand, there are a lot of Intelligent Design Creationists who don't accept macroevolution. It seems to me that this could only be because they are Young Earth Creationists or they believe in some other strange idea where god(s) make every species.
It's hard to figure out what they mean.
Let's look at a recent post by philosopher Vincent Torley. He didn't like my posts about macroevolution [What is "macroevolution"? ] [A chemist who doesn't understand evolution] so he decided to set me straight: Does Professor Larry Moran (or anyone else) understand macroevolution?.
On the other hand, there are a lot of Intelligent Design Creationists who don't accept macroevolution. It seems to me that this could only be because they are Young Earth Creationists or they believe in some other strange idea where god(s) make every species.
It's hard to figure out what they mean.
Let's look at a recent post by philosopher Vincent Torley. He didn't like my posts about macroevolution [What is "macroevolution"? ] [A chemist who doesn't understand evolution] so he decided to set me straight: Does Professor Larry Moran (or anyone else) understand macroevolution?.
Monday, March 17, 2014
Cosmos presents evolution
The second episode of the new Cosmos series is Some of the Things That Molecules Do.
It's about evolution and it's not bad. I have four comments.
A missed opportunity. Natural selection is important and Neil deGrasse Tyson did a pretty good job of explaining it. It wouldn't have taken a big effort to mention that there's more to evolution than natural selection. He could, for example, have pointed out that some breeds of dogs are prone to certain genetic diseases or health problems because some bad mutations were accidentally fixed alone with the good ones. He could have pointed out that our eyes have a blind spot.
The Theory of Evolution is not a fact. Neil deGrasse Tyson said that the theory of evolution is a fact. This is not correct. Evolution is a fact. Evolutionary theory attempts to explain how evolution occurs. Some of the explanations, like natural selection, are facts but many aspects of modern evolutionary theory are still hotly debated in the scientific community.
We don't understand the origin of life. The episode closed with deGrasse Tyson saying the we don't understand how life began and there's nothing wrong with admitting that we don't know something. Excellent!
There are better ways of drawing DNA. I don't like the way DNA is pictured in the first two episodes, especially in the opening sequence. It looks like the bases grow out of the backbone and fuse to form base pairs. They could have drawn a more accurate representation without losing any visual appeal.
I give the episode a B+.
It's about evolution and it's not bad. I have four comments.
A missed opportunity. Natural selection is important and Neil deGrasse Tyson did a pretty good job of explaining it. It wouldn't have taken a big effort to mention that there's more to evolution than natural selection. He could, for example, have pointed out that some breeds of dogs are prone to certain genetic diseases or health problems because some bad mutations were accidentally fixed alone with the good ones. He could have pointed out that our eyes have a blind spot.
The Theory of Evolution is not a fact. Neil deGrasse Tyson said that the theory of evolution is a fact. This is not correct. Evolution is a fact. Evolutionary theory attempts to explain how evolution occurs. Some of the explanations, like natural selection, are facts but many aspects of modern evolutionary theory are still hotly debated in the scientific community.
We don't understand the origin of life. The episode closed with deGrasse Tyson saying the we don't understand how life began and there's nothing wrong with admitting that we don't know something. Excellent!
There are better ways of drawing DNA. I don't like the way DNA is pictured in the first two episodes, especially in the opening sequence. It looks like the bases grow out of the backbone and fuse to form base pairs. They could have drawn a more accurate representation without losing any visual appeal.
I give the episode a B+.
Monday's Molecule #233
Last week's molecules [Monday's Molecule #232] were all-trans and 13-cis retinal. Retinal is the active protein donor/acceptor in bacteriorhodopsin. The all-trans form is shifted to the 13-cis form when a photon of light is absorbed. The retinal molecules are arranged within the membrane-bound bacteriorhodpsin in a way that binding and release of a proton results in transport from the cytoplasm to the exterior. The creation of a proton gradient drives ATP synthesis.
The winner is Philip Johnson from Switzerland.
This week's molecule (left) is actually a collection of molecules. Name all five molecules and tell me what they have in common from a biochemical perspective. Common names will do.
Email your answer to me at: Monday's Molecule #233. 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.)
Reading Books
Yesterday we watched two episodes of House of Cards and two of our favorite TV shows; Amazing Race and The Good Wife. We also watched a show about working on a Tudor farm and I watched the second episode of Cosmos.
According to Veronica Abbas, I wasted valuable time when I could have been reading [Recommended Reading]. She links to an article by Erin Kelley who says, Reading Books Doesn't Just Make You Literate: It Reduces Stress, Promotes Good Health, and Makes You More Empathetic. I haven't read a book in over four months and I haven't read a novel in years.
I'm doomed to be illiterate, stressed, in poor health, and the opposite of empathetic.1 It also explains why I don't volunteer to work for a non-profit organization.
According to Veronica Abbas, I wasted valuable time when I could have been reading [Recommended Reading]. She links to an article by Erin Kelley who says, Reading Books Doesn't Just Make You Literate: It Reduces Stress, Promotes Good Health, and Makes You More Empathetic. I haven't read a book in over four months and I haven't read a novel in years.
I'm doomed to be illiterate, stressed, in poor health, and the opposite of empathetic.1 It also explains why I don't volunteer to work for a non-profit organization.
1. I'm pretty sure Veronica would agree with "illiterate."
On teaching creationism in American public universities
I think that universities are places where diversity of opinion should be encouraged and where fringe ideas should be protected. I'm very much opposed to letting outside interests (i.e. politicians and lawyers) decide what should and should not be taught on a university campus.
Clearly there are limits but those should be decided by faculty who understand the concept of academic freedom. It's not a good idea to offer astronomy courses on an Earth-centered solar system or geology courses based on the idea that the Earth is only 6000 years old. Those ideas are just too far out on the fringe. You're unlikely to find any university professors who want to teach such courses.
However, there are lots of other controversies that aren't so easily dismissed. If some of the more enlightened Intelligent Design Creationists want to teach a science course at my university, I would not try to prevent them. Just as I didn't try to prevent Michael Behe and Bill Dembski from speaking on my campus.
Clearly there are limits but those should be decided by faculty who understand the concept of academic freedom. It's not a good idea to offer astronomy courses on an Earth-centered solar system or geology courses based on the idea that the Earth is only 6000 years old. Those ideas are just too far out on the fringe. You're unlikely to find any university professors who want to teach such courses.
However, there are lots of other controversies that aren't so easily dismissed. If some of the more enlightened Intelligent Design Creationists want to teach a science course at my university, I would not try to prevent them. Just as I didn't try to prevent Michael Behe and Bill Dembski from speaking on my campus.
Sunday, March 16, 2014
A chemist who doesn't understand evolution
James Tour is an organic chemist. He is a Professor of Chemistry and Professor, Professor of Mechanical Engineering & Materials Science, and Professor of Computer Science at Rice University (Houston, United States). James Tour is attracting a lot of attention on the Intelligent Design Creationist websites because he is sympathetic to their main claim; namely, that evolution is wrong [see A world-famous chemist tells the truth: there’s no scientist alive today who understands macroevolution].
Tour is one of the few genuine scientists who signed the Discovery Institute’s "A Scientific Dissent from Darwinism" (2001) that stated, "We are skeptical of claims for the ability of random mutation and natural selection to account for the complexity of life. Careful examination of the evidence for Darwinian theory should be encouraged." (There are very,very, few biologists who signed.)
What exactly, does Jame Tour mean? He wrote an article on his website that explains his position: Layman’s Reflections on Evolution and Creation. An Insider’s View of the Academy. I think it's interesting to discuss what he said.
He begins with ...
Tour is one of the few genuine scientists who signed the Discovery Institute’s "A Scientific Dissent from Darwinism" (2001) that stated, "We are skeptical of claims for the ability of random mutation and natural selection to account for the complexity of life. Careful examination of the evidence for Darwinian theory should be encouraged." (There are very,very, few biologists who signed.)
What exactly, does Jame Tour mean? He wrote an article on his website that explains his position: Layman’s Reflections on Evolution and Creation. An Insider’s View of the Academy. I think it's interesting to discuss what he said.
He begins with ...
Saturday, March 15, 2014
Philip Ball writes about molecular mechanisms of evolution
It's been almost a year since I commented on an Nature article by Philip Ball [see DNA: Nature Celebrates Ignorance]. Here's part of what I wrote back then ...
The main premise of the article is revealed in the short blurb under the title: "On the 60th anniversary of the double helix, we should admit that we don't fully understand how evolution works at the molecular level, suggests Philip Ball."The worst thing about the Nature article was the misuse of the Central Dogma of Molecular Biology. The second worst thing was the "revelation" that genes are regulated by regulatory sequences as if that was a new discovery. (He mentions the ENCODE results.)
What nonsense! We understand a great deal about how evolution works at the molecular level.
How does molecular biology overthrow the Modern Synthesis?
I think the hardened version of the Modern Synthesis is inadequate to describe 21st century evolutionary biology. I think that it didn't adequately recognize Neutral Theory and random genetic drift and it didn't place enough emphasis on macroevolution and the possibility of hierarchical modes of evolution.
There are a whole host of scientists who want to overthrow the Modern Synthesis for a variety of other (stupid) reasons. Most of them have no idea that the Modern Synthesis has (or should have) been replaced 40 years ago.
Here's another example from last week's issue Science (March 7, 2014). Susan M. Rosenberg and Christine Queitsch have an article entitled "Combating Evolution
to Fight Disease" (Rosenberg and Queitsch, 2014). They begin with ....
There are a whole host of scientists who want to overthrow the Modern Synthesis for a variety of other (stupid) reasons. Most of them have no idea that the Modern Synthesis has (or should have) been replaced 40 years ago.
Here's another example from last week's issue Science (March 7, 2014). Susan M. Rosenberg and Christine Queitsch have an article entitled "Combating Evolution
to Fight Disease" (Rosenberg and Queitsch, 2014). They begin with ....
Friday, March 14, 2014
Michael Egnor is an expert on cluelessness
The war between science and religion is fought on many fronts. One of the most remarkable campaigns is the attempt by religious zealots to discredit evolution (and science). We see this played out on creationist websites ranging from the most absurd Young Earth Creationist sites to the somewhat more subtle websites of the Intelligent Design Creationists.1
I can understand why believers want to defend their beliefs—we all do that. The part I don't get is the incredible stupidity of the main defenders of Intelligent Design Creationism and Young Earth Creationism. Not all of them, of course, but enough to make me slap my head.
Let's take Michael Egnor as an example. He is perfectly entitled to defend his Roman Catholic beliefs and to try and poke holes in evolution. But why does he have to use such stupid arguments? Why is such a person promoted on the main Intelligent Design Creationist website, Evolution News & Views (sic). Is he really the best they've got?
Let's look at his latest post: Clueless in Toronto. He begins with ....
I can understand why believers want to defend their beliefs—we all do that. The part I don't get is the incredible stupidity of the main defenders of Intelligent Design Creationism and Young Earth Creationism. Not all of them, of course, but enough to make me slap my head.
Let's take Michael Egnor as an example. He is perfectly entitled to defend his Roman Catholic beliefs and to try and poke holes in evolution. But why does he have to use such stupid arguments? Why is such a person promoted on the main Intelligent Design Creationist website, Evolution News & Views (sic). Is he really the best they've got?
Let's look at his latest post: Clueless in Toronto. He begins with ....
Thursday, March 13, 2014
The "selfish gene" is not a good metaphor to describe evolution
Last December David Dobbs wrote an article entitled "Die, selfish gene die!" in which he promoted some really stupid ideas about evolution. Jerry Coyne wasted little time in showing why Dobbs was way off the mark.
Unfortunately, Dobbs didn't make the best case against the concept of the selfish gene and Jerry Coyne didn't recognize that there was a real problem.
Now the issue has resurfaced because Aeon has announced another dead horse that needs beating [Dead or Alive? Is it time to kill off the idea of the ‘Selfish Gene’? We asked four experts to respond to our most controversial essay].
Once again Jerry Coyne is up to the challenge, taking on four "experts" without breaking a sweat [The “selfish gene” redux: Aeon magazine collects opinion on the metaphor].
And, once again, everyone misses the real point.
Here's what Jerry says in his latest post.
However, I think that "selfish gene" is often used as a metaphor for all of evolution and not just for natural selection. I think that most people who read Dawkins' book take it to be about EVOLUTION and not just natural selection. They understand that Dawkins is promoting a gene-centric view of evolution—and that's okay—but they come away from reading the book by thinking that all genes are selfish.
As most of you know, I prefer to emphasize Evolution by Accident. That's not to say that natural selection (selfish genes) isn't important, it is. What I believe is that there is a lot more to evolution than just selfish genes and we should not use the selfish genes metaphor as a stand-in for all of evolution.
Once you grasp that idea, it becomes much less useful to use the term "selfish gene" as a metaphor for anything, even natural selection and adaptation. That's why I think we should stop using the term "selfish gene."
Unfortunately, Dobbs didn't make the best case against the concept of the selfish gene and Jerry Coyne didn't recognize that there was a real problem.
Now the issue has resurfaced because Aeon has announced another dead horse that needs beating [Dead or Alive? Is it time to kill off the idea of the ‘Selfish Gene’? We asked four experts to respond to our most controversial essay].
Once again Jerry Coyne is up to the challenge, taking on four "experts" without breaking a sweat [The “selfish gene” redux: Aeon magazine collects opinion on the metaphor].
And, once again, everyone misses the real point.
Here's what Jerry says in his latest post.
I won’t reprise my criticisms, except to say that the metaphor of genes acting as if they are "selfish" when subject to natural selection remains perfectly good, whether or not those genes (or any bit of DNA) are part of the genome that makes proteins, regulates other genes, or comprises any bit of DNA that has the ability to get itself replicated more often than its competitors.This is correct as far as it goes. The "selfish gene" is a reasonable metaphor if you want to think about natural selection and adaptation. It's quite reasonable to metaphorically describe genes as "selfish" in such cases.
However, I think that "selfish gene" is often used as a metaphor for all of evolution and not just for natural selection. I think that most people who read Dawkins' book take it to be about EVOLUTION and not just natural selection. They understand that Dawkins is promoting a gene-centric view of evolution—and that's okay—but they come away from reading the book by thinking that all genes are selfish.
As most of you know, I prefer to emphasize Evolution by Accident. That's not to say that natural selection (selfish genes) isn't important, it is. What I believe is that there is a lot more to evolution than just selfish genes and we should not use the selfish genes metaphor as a stand-in for all of evolution.
Once you grasp that idea, it becomes much less useful to use the term "selfish gene" as a metaphor for anything, even natural selection and adaptation. That's why I think we should stop using the term "selfish gene."
What is "macroevolution"?
Denyse O'Leary on Uncommon Descent wonders Is “macroevolution” even a meaningful term? It’s time to ask.
Here's the problem as creationists see it ...
True, there was a time when biologists thought that Darwinian natural selection was all there is in evolution. They even thought that all of evolution, from changes within populations to the evolution of new phyla, could be explained solely by natural selection acting on allele frequencies within populations (Darwinism).
Most evolutionary biologists have moved on in the past half century and they now realize that macroevolution is a separate field that combines genetics, population genetics, geology, ecology and a host of other fields in order to explain the history of life. So, Denyse, it's true that macroevolution happens by means other than Darwinism even though natural selection is an important component of macroevolutionary explanations.
The only news here is that it takes IDiots so long to catch up with evolutionary biologists.
Back in the days of talk.origins, this topic (macroevolution) came up so frequently that I wrote a little essay to explain it in a way that even the most profound IDiot could understand. The latest version is from 2006: Macroevolution.
Wouldn't it be nice if the creationists could make an attempt to understand modern evolutionary theory instead of just repeating the same old tired arguments that they used 50 years ago?
Here's the problem as creationists see it ...
The evolution that Darwin’s theory accounts for (natural selection acting on random mutation) is, in the real world, small changes that don’t add up to much over the long term.I can't tell you how frustrating it is to see this kind of crap over, and over, and over. We have been trying to teach evolutionary biology to the IDiots for decades but they seem to be totally incapable of listening.
That is why the term "macroevolution" had to be invented. It was a leap of faith to assume that Darwinian "microevolution" would become "macroevolution" instead of just being washed out by other types of change (what usually really happens).
But gradually scientists are becoming less afraid to talk about this: Macroevolution apparently happens, but not by Darwinian means.
G’bye, Darwin. We packed the crumpets for ya.
Will it soon be: So long, Darwin-in-the-schools pressure groups? Gee, how they’ll be missed in the legislatures and courts.
No, wait, we’ll all be too busy figuring out what really happens in the history of life. It’s a fascinating story and now – for once – we might get to read it without all the interruptions.
True, there was a time when biologists thought that Darwinian natural selection was all there is in evolution. They even thought that all of evolution, from changes within populations to the evolution of new phyla, could be explained solely by natural selection acting on allele frequencies within populations (Darwinism).
Most evolutionary biologists have moved on in the past half century and they now realize that macroevolution is a separate field that combines genetics, population genetics, geology, ecology and a host of other fields in order to explain the history of life. So, Denyse, it's true that macroevolution happens by means other than Darwinism even though natural selection is an important component of macroevolutionary explanations.
The only news here is that it takes IDiots so long to catch up with evolutionary biologists.
Back in the days of talk.origins, this topic (macroevolution) came up so frequently that I wrote a little essay to explain it in a way that even the most profound IDiot could understand. The latest version is from 2006: Macroevolution.
Wouldn't it be nice if the creationists could make an attempt to understand modern evolutionary theory instead of just repeating the same old tired arguments that they used 50 years ago?
The suggestion that macroevolution should be divorced from microevolution provides Creationists only with a debating point. It allows Creationists to say that there are some evolutonary theorists who distinguish the mechanisms studied in classical population genetics from those they take to be involved in large-scale evolutionary change ... But this is not to suppose that the distinction drawn by heterodox evolutionists is that favored by the Creationists.
Philip Kitcher (1982) p.150
Wednesday, March 12, 2014
Everything you thought you knew about sex is probably wrong
The evolution of sexual reproduction is one of the great mysteries of biology. I've been teaching this to undergraduates for several decades but it seems that most undergraduates don't get the message. Most of them think that sex has been explained and the answer is that sexual reproduction generates diversity.
I usually give them some reviews to read and, invariably, the experts who write the reviews will say that sex is a great unsolved mystery. If the experts think that this is a mystery then why do so many people think they have the answer?
Here's what Douglas Futuyma says in the 2nd edition of Evolution (p. 340).
I usually give them some reviews to read and, invariably, the experts who write the reviews will say that sex is a great unsolved mystery. If the experts think that this is a mystery then why do so many people think they have the answer?
Here's what Douglas Futuyma says in the 2nd edition of Evolution (p. 340).
Prayer at Mississauga City Council
I am reliably informed that meetings of the Mississauga City Council1 still begin with a prayer. I'm not sure why city councilors feel the need for extra divine guidance since Mayor Hazel McCallion2 is already present in the room.
Like most places in Canada, Mississauga is a diverse community with a substantial number of nonbelievers and a substantial number of non-Christians. Prayer has no place in a secular society and beginning a City Council meeting with prayer sends out all the wrong messages. Imagine that you are a nonbeliever waiting to petition City Council over some grievance and you have to watch your council member praying before you can speak.
Like most places in Canada, Mississauga is a diverse community with a substantial number of nonbelievers and a substantial number of non-Christians. Prayer has no place in a secular society and beginning a City Council meeting with prayer sends out all the wrong messages. Imagine that you are a nonbeliever waiting to petition City Council over some grievance and you have to watch your council member praying before you can speak.
Tuesday, March 11, 2014
What did Joe Felsenstein say about sex?
Today we talked about the evolution of sex. The take-home message is that sex is one of the most difficult problems in biology. We really don't know why sex evolved and why it's so important in eukaryotes.
The evolution of recombination is part of the discussion. It's not necessarily the same as the evolution of sex but many of the explanations for the evolutionary origin of sex invoke homologous recombination.
When I asked my students to explain the evolution of sex they mostly came up with arguments about why it is advantageous to generate genetic diversity in a population. Some of this diversity requires recombination to create new combinations of alleles on the same chromosome. The problem with this argument is that for every new combination produced, an old one will be restored. As John Maynard-Smith pointed out in 1968, when genes/alleles are in linkage equilibrium then recombination does not result in a change in allele frequencies (i.e. evolution).
This led Joe Felsenstein to write the following in 1988.
The evolution of recombination is part of the discussion. It's not necessarily the same as the evolution of sex but many of the explanations for the evolutionary origin of sex invoke homologous recombination.
When I asked my students to explain the evolution of sex they mostly came up with arguments about why it is advantageous to generate genetic diversity in a population. Some of this diversity requires recombination to create new combinations of alleles on the same chromosome. The problem with this argument is that for every new combination produced, an old one will be restored. As John Maynard-Smith pointed out in 1968, when genes/alleles are in linkage equilibrium then recombination does not result in a change in allele frequencies (i.e. evolution).
This led Joe Felsenstein to write the following in 1988.
It is worth noting that Maynard Smith's argument invalidates the earliest genetic argument for the evolution of recombination, that advanced by East (1918). That argument is also the one commonly found in textbooks, which tend to be a bit out of date (in this case, by over 50 years). East argued that recombination creates new genotypes. So it does. An AB/ab parent will have among its gametes not only the two types that formed it, AB and ab, but also Ab and aB if there is recombination between the two loci. But if the population is in linkage equilibrium, then somewhere else an Ab/aB parent will be undergoing recombination, which will remove Ab and aB gametes and replace them by AB and ab. These two processes will exactly cancel each other if the two types of double heterozygote, coupling (AB/ab) and repulsion (Ab/aB) are equally frequent. This will happen precisely when the population is in linkage equilibrium. In that case no new genotypes arise by recombination.Is it true that what students are being taught is wrong? What did Joe Felsenstein really mean?
...
We have that anomalous situation that a detailed population genetic analysis analysis reveals not only that the standard explanation for the evolution of recombination will not work, but also that there is a good evolutionary reason for believing that modifiers will be selected to eliminate recombination.
Felsenstein, J. (1988) "Sex and the evolution of recombination." in The Evolution of Sex: An Examination of Current Ideas. R.E. Michod and B.R. Levin eds. 74-86. [PDF]
Marc Garneau and the Liberal Party of Canada support basic research
Last night I was at a small gathering of Liberal supporters at the Paramount restaurant on Yonge Street in Toronto. The event was organized by Omar Alghbra my former MP in Mississauga. The guest of honour was Liberal MP Marc Garneau who was Canada's first astronaut. He represents the Montreal riding of Westmount—Ville-Marie.
Marc Garneau is one of a small handful of MPs in the Federal Parliament who has a Ph.D. (Electrical Engineering, Imperial College of Science and Technology, London, England) He has always been a strong supporter of science and technology and I know that he is involved in forming science policy for the Liberals under Justin Trudeau. This was my chance to put in a good word for funding basic science so I made my pitch. I described to him how the current funding situation is hurting basic science research in the universities [Canada is destroying a generation of scientists].
It wasn't really necessary. Garneau is a strong supporter of basic science and, if elected, the Liberal Party intends to reverse the policies of the current Conservative Party under Stephen Harper. They will change the distribution of funds at NSERC and CIHR to support more curiosity motivated research and to move away from the emphasis on using science funding to support business. According to Garneau, they will also reverse the Harper decision to force NRC into short-term goal oriented technology development and return it to a broad organization that also invests in basic research.
I was impressed by the fact that Marc Garneau was just as passionate about basic research as I am. I'm confident that the Liberal Party understands the problem and will, if elected, take steps to improve the current situation. The next step is to make sure that the Harper government is booted out of office before they can do even more damage.
Marc Garneau is one of a small handful of MPs in the Federal Parliament who has a Ph.D. (Electrical Engineering, Imperial College of Science and Technology, London, England) He has always been a strong supporter of science and technology and I know that he is involved in forming science policy for the Liberals under Justin Trudeau. This was my chance to put in a good word for funding basic science so I made my pitch. I described to him how the current funding situation is hurting basic science research in the universities [Canada is destroying a generation of scientists].
It wasn't really necessary. Garneau is a strong supporter of basic science and, if elected, the Liberal Party intends to reverse the policies of the current Conservative Party under Stephen Harper. They will change the distribution of funds at NSERC and CIHR to support more curiosity motivated research and to move away from the emphasis on using science funding to support business. According to Garneau, they will also reverse the Harper decision to force NRC into short-term goal oriented technology development and return it to a broad organization that also invests in basic research.
I was impressed by the fact that Marc Garneau was just as passionate about basic research as I am. I'm confident that the Liberal Party understands the problem and will, if elected, take steps to improve the current situation. The next step is to make sure that the Harper government is booted out of office before they can do even more damage.
Monday, March 10, 2014
Bye bye RNA world
I think it's time we started being serious about the limitations of the RNA world as a possible explanation for the origin of life. It's simply not possible to imagine a scenario where the first catalysts are RNA molecules because that requires a primordial soups full of nucleosides and sugar molecules. It requires the spontaneous synthesis of nucleotides and their polymerization.
That ain't happening.
You can salvage the RNA world by postulating that it arose AFTER primitive metabolic pathways were established using peptide catalysts but that's the best you can do. There's a nice article in The Scientist that describes the problem [RNA World 2.0].
Here's a teaser ....
Changing Ideas About The Origin Of Life
Was the Origin of Life a Lucky Accident?
That ain't happening.
You can salvage the RNA world by postulating that it arose AFTER primitive metabolic pathways were established using peptide catalysts but that's the best you can do. There's a nice article in The Scientist that describes the problem [RNA World 2.0].
Here's a teaser ....
The RNA world, first posited by Francis Crick1 and others in the late 1960s, remains an attractive hypothesis. Many of the chemical hurdles that once challenged the laboratory synthesis of the molecule under presumed primordial conditions are being overcome, and in vitro evolution experiments are yielding RNA molecules that perform numerous functions, including copying themselves or other RNAs. "I don’t think there can be much doubt that RNA was a major central player as both a catalyst and an early replicator," says Nick Lane, a biochemist at the University College London whose research falls under the “metabolism first” label. "So the RNA world is absolutely correct, as far as I’m concerned, in that."
But the notion that RNA, on its own, spontaneously assembled and evolved on early Earth has fallen out of favor. More likely, whatever conditions spawned compounds as complex as nucleotides also generated other organics, perhaps early forms of modern amino acids and fatty acids, the constituent parts of proteins and membranes. "I’m not sure how many people anymore believe in a pure RNA world. I certainly don’t," says Lane. "I think the field has drifted away from that, and there’s now an acknowledgment it had to be ‘dirty.’ "
Changing Ideas About The Origin Of Life
Was the Origin of Life a Lucky Accident?
Monday's Molecule #232
Monday's Molecule #231 [Monday's Molecule #231] was the Shine-Delgarno sequence found a few nucleotides upstream of the initiation codon in many bacterial mRNAs. It interacts (base pairs) with a sequence on the 3′ end of 16S RNA to help form the translation initiation complex. This means that bacteria can have polycistronic mRNAs (from operons) and internal translation initiation. The winners were Keith Conover and Nevraj Kejiou. That's two weeks in a row that an undergraduate from the University of Toronto has won. I will be taking them to lunch. I encourage undergraduates from far, far away to hurry up and send in an answer to this week's molecule!
This week's molecule (left) is covalently bound to the lysine side chain of a protein. It exists in two distinct configurations that can be interconverted by a well-known chemical reaction. Name the two different configurations (common names only) and explain the significance of the reaction.
Email your answer to me at: Monday's Molecule #232. 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.)
This week's molecule (left) is covalently bound to the lysine side chain of a protein. It exists in two distinct configurations that can be interconverted by a well-known chemical reaction. Name the two different configurations (common names only) and explain the significance of the reaction.
Email your answer to me at: Monday's Molecule #232. 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.)
Did you lose an hour of sleep?
Saturday night was the night when most people in North American turned their clocks forward one hour for "Daylight Saving Time."1 TV, radios, and newspapers are whining about the fact that everyone was going to lose an hour's sleep. Some of the comments on my radio station advise people to avoid driving today (Monday) because you might be suffering from sleep deprivation.
This all seems very strange to me. Is it true that most people are so unfamiliar with traveling across time zones that turning your clock back one hour is a really big deal?
And what's this about losing one hour's sleep? When I got out of bed on Sunday morning it was about one hour later (on the clock) than the time I usually wake up on Sunday morning. I didn't lose an hour's sleep. The only people who lost an hour's sleep on Saturday night are those who wake up every Sunday morning to an alarm clock. Are you one of those people?
It's a little bit different on Monday morning when, I imagine, most people have to wake up to an alarm clock in order to get to work. I'm not one of those people. However, even on Sunday night the only way you lose an hour's sleep is if you went to bed an hour later than normal.
Somewhere along the way I have lost an hour of my day but it's not going to come out of sleep time. That would be silly. If I ever feel sleep deprived I'll just go to bed earlier.
How about the rest of you? Do you really give up an hour of sleep in the days following the shift to Daylight Savings Time?
This all seems very strange to me. Is it true that most people are so unfamiliar with traveling across time zones that turning your clock back one hour is a really big deal?
And what's this about losing one hour's sleep? When I got out of bed on Sunday morning it was about one hour later (on the clock) than the time I usually wake up on Sunday morning. I didn't lose an hour's sleep. The only people who lost an hour's sleep on Saturday night are those who wake up every Sunday morning to an alarm clock. Are you one of those people?
It's a little bit different on Monday morning when, I imagine, most people have to wake up to an alarm clock in order to get to work. I'm not one of those people. However, even on Sunday night the only way you lose an hour's sleep is if you went to bed an hour later than normal.
Somewhere along the way I have lost an hour of my day but it's not going to come out of sleep time. That would be silly. If I ever feel sleep deprived I'll just go to bed earlier.
How about the rest of you? Do you really give up an hour of sleep in the days following the shift to Daylight Savings Time?
More accurately known as "Daylight Shifting Time."
Friday, March 07, 2014
How to survive in the blogosphere
Later on today I'm giving a talk at Western University (London, Ontario, Canada)1 The subject is blogging.
I realized while preparing my talk that there were lots of things I didn't know for sure so here are some questions that you may be able to help with.
Most popular biology blogs
I don't know for sure which biology blogs are the most popular. I'm pretty sure that Pharyngula is still on top with respect to the number of views per day and I'm pretty sure that Why Evolution Is True is in the top ten but what about others? Do any of you know?
Best biology blogs
The best blogs aren't necessarily the most popular. I have my own opinion about the best blogs but my fear is that I've missed some blogs that I should be reading. What do you think? What are the best biology blogs?
Why do you read and comment?
I've talked to a lot of bloggers so I'm pretty sure I have a good idea about why we write blogs. But I realized that I was much less sure about why people read blogs and why people comment on blogs. What do you get out of reading blogs and why do you post comments? Do you think all scientists and science students should read the science blogs? (I don't.)
Have blogs changed anything?
Have blogs had much of an impact on science? I can think of a few examples such as the Arsenic Affair and the ENCODE Publicity Hype Fiasco where bloggers had an impact but I'm not sure these are significant in the log run. Is blogging just another kind of social interaction that really doesn't change the way science is done?
I realized while preparing my talk that there were lots of things I didn't know for sure so here are some questions that you may be able to help with.
Most popular biology blogs
I don't know for sure which biology blogs are the most popular. I'm pretty sure that Pharyngula is still on top with respect to the number of views per day and I'm pretty sure that Why Evolution Is True is in the top ten but what about others? Do any of you know?
Best biology blogs
The best blogs aren't necessarily the most popular. I have my own opinion about the best blogs but my fear is that I've missed some blogs that I should be reading. What do you think? What are the best biology blogs?
Why do you read and comment?
I've talked to a lot of bloggers so I'm pretty sure I have a good idea about why we write blogs. But I realized that I was much less sure about why people read blogs and why people comment on blogs. What do you get out of reading blogs and why do you post comments? Do you think all scientists and science students should read the science blogs? (I don't.)
Have blogs changed anything?
Have blogs had much of an impact on science? I can think of a few examples such as the Arsenic Affair and the ENCODE Publicity Hype Fiasco where bloggers had an impact but I'm not sure these are significant in the log run. Is blogging just another kind of social interaction that really doesn't change the way science is done?
1. Formerly the University of Western Ontario. The talk is in the North Campus Building room 114 at 11:30 am.
Wednesday, March 05, 2014
The crystal structure of E. coli RNA polymearse σ70 holoenzyme
THEME:
Transcription
The Journal of Biological Chemistry (JBC) publishes a little booklet of the "best of jbc." The latest copy arrived in the mail a few days ago and it alerted me to a paper published one year ago on the structure of Escherichia coli RNA polymerase σ70 holoenzyme (Murikami, 2013).1
The control of transcription initiation is a very important topic in biochemistry and molecular biology and the events in E. coli are the model for transcription initiation in all other species. We know more about RNA polymerase and promoter sites in E. coli than in any other species.
Transcription
The Journal of Biological Chemistry (JBC) publishes a little booklet of the "best of jbc." The latest copy arrived in the mail a few days ago and it alerted me to a paper published one year ago on the structure of Escherichia coli RNA polymerase σ70 holoenzyme (Murikami, 2013).1
The control of transcription initiation is a very important topic in biochemistry and molecular biology and the events in E. coli are the model for transcription initiation in all other species. We know more about RNA polymerase and promoter sites in E. coli than in any other species.
Monday, March 03, 2014
Monday's Molecule #231
Monday's Molecule #230 (Jan. 27, 2014) [Monday's Molecule #230] was 2-carboxy-3-ketoarabinitol 1,5-bisphosphate. It's an intermediate in the reaction catalyzed by ribulose 1,5-bisphosphate carboxylase-osygenase (Rubisco), the key enzyme in the Carvin cycle. This is the molecule created by adding CO2 to the 2-carbon atom of ribulose 1,5-bisphosphate. The winners were Bill Gunn closely followed by the first correct answer from an undergraduate, Ariel Gershon. Ariel is a student at the University of Toronto so it looks like I'm going to have to buy a lunch.
This week's molecule (below) is a sequence. Name the sequence in red and briefly describe it's function.
Email your answer to me at: Monday's Molecule #231. 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.)
This week's molecule (below) is a sequence. Name the sequence in red and briefly describe it's function.
Email your answer to me at: Monday's Molecule #231. 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.)
Carnival of Evolution #69
This month's Carnival of Evolution is hosted by a BIOCHEMIST (yeah!) named "Lab Rat" (S.E. Gould) at Lab Rat. Read it at 69th Carnival of Evolution: Darwin’s Day Edition.
If you want to host a Carnival of Evolution please contact Bjørn Østman. Bjørn is always looking for someone to host the Carnival of Evolution. He would prefer someone who has not hosted before but repeat hosts are more than welcome right now! Bjørn is threatening to name YOU as host even if you don't volunteer! Contact him at the Carnival of Evolution blog. You can send articles directly to him or you can submit your articles at Carnival of Evolution although you now have to register to post a submission. Please alert Bjørn or the upcoming host if you see an article that should be included in next month's. You don't have to be the author to nominate a post.
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Welcome to the 69th edition of the Carnival of Evolution! As February 12th was Darwin’s birthday, this is a Darwin’s Day carnival edition. To start with there’s a celebration of all things Darwinian at Synthetic Daisies, and a letter to the man himself for his 205th birthday.The next Carnival of Evolution will be at ????
If you want to host a Carnival of Evolution please contact Bjørn Østman. Bjørn is always looking for someone to host the Carnival of Evolution. He would prefer someone who has not hosted before but repeat hosts are more than welcome right now! Bjørn is threatening to name YOU as host even if you don't volunteer! Contact him at the Carnival of Evolution blog. You can send articles directly to him or you can submit your articles at Carnival of Evolution although you now have to register to post a submission. Please alert Bjørn or the upcoming host if you see an article that should be included in next month's. You don't have to be the author to nominate a post.
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Carnival of Evolution #68
I forgot to post a link to last month's Carnival of Evolution. It was hosted by a computational biologist who posts at Byte Size Biology. Read it at Carnival of Evolution, February 2014 Edition.
If you want to host a Carnival of Evolution please contact Bjørn Østman. Bjørn is always looking for someone to host the Carnival of Evolution. He would prefer someone who has not hosted before but repeat hosts are more than welcome right now! Bjørn is threatening to name YOU as host even if you don't volunteer! Contact him at the Carnival of Evolution blog. You can send articles directly to him or you can submit your articles at Carnival of Evolution although you now have to register to post a submission. Please alert Bjørn or the upcoming host if you see an article that should be included in next month's. You don't have to be the author to nominate a post.
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Wow, I haven’t posted anything in quite a while. Things are busy outside blogoland. But committing this blog to the February edition of the Carnival of Evolution just made me do it, so here goes. We’ll do this by scales, bottom up.The next Carnival of Evolution (#70, April, 2014) will be at some unknown place.
If you want to host a Carnival of Evolution please contact Bjørn Østman. Bjørn is always looking for someone to host the Carnival of Evolution. He would prefer someone who has not hosted before but repeat hosts are more than welcome right now! Bjørn is threatening to name YOU as host even if you don't volunteer! Contact him at the Carnival of Evolution blog. You can send articles directly to him or you can submit your articles at Carnival of Evolution although you now have to register to post a submission. Please alert Bjørn or the upcoming host if you see an article that should be included in next month's. You don't have to be the author to nominate a post.
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Death of the genome paper
There was a time when sequencing a gene was just about all you needed to get a publication. Getting a high quality sequence of a typical protein-encoding gene (cDNA) took several years of work—almost sufficient for a Ph.D. thesis.
By the 1990's, that was routine and you needed much more to get a paper published. The genome era had begun and a good paper in a high impact journal required the complete sequence of an entire genome.
Today, you can't get a genome sequence published because it's so easy that undergraduates can do it.
David Smith of Western University (London, Ontario, Canada) laments the death of the genome paper while recognizing that sequencing has probably been abused (Smith, 2013). He makes some good points ...
By the 1990's, that was routine and you needed much more to get a paper published. The genome era had begun and a good paper in a high impact journal required the complete sequence of an entire genome.
Today, you can't get a genome sequence published because it's so easy that undergraduates can do it.
David Smith of Western University (London, Ontario, Canada) laments the death of the genome paper while recognizing that sequencing has probably been abused (Smith, 2013). He makes some good points ...
One of the drawbacks of genome papers, however, is that they can create a mindset of sequence first, ask questions later. I once attended a Masters thesis defense where the external examiner asked the candidate why he sequenced the chloroplast genome of this particular species and what hypothesis was he trying to test. The student, looking startled, answered, "Because the genome hadn't been sequenced before and we didn't know what it looked like." After the defense, I overheard the examiner in the hallway venting to another professor. "We've created a culture of serial genomicists," she exclaimed. "Everyone's jumping from one genome sequence to the next, looking to score a major publication."I still like to read genome papers but lately I've been put off by the lack of reliable information in most of those papers. One of things I'm interested in is the number genes, especially the number of unique genes. Unfortunately, the annotation usually relies on computer-generated gene predictions and those are notoriously unreliable.
Regardless of this opinion, genome papers have provided much of the raw data that have shaped our view of genetics and evolution over the past 20 years. And they can also be a joy to read. Many of my favorite journal articles are genome papers. I remember, when I was a grad student in phycology, eagerly awaiting publication of the genome for Chlamydomonas—the superstar of green algae—and reading it incessantly once it was released, gleaning new insights each time through. There is something intimate and personal in learning about a species' genome. And similarly, if you are part of the team describing the genome, there is a feeling that you're giving the readers a first glimpse at an uncharted territory, with its unique landscape of genes, introns and intergenic regions.
But all of this may be coming to an end. Next generation DNA sequencing techniques have made it easy, fast and cheap to sequence genomes. Today, just about any scientist can walk out their laboratory doors, point to a living thing and say, “I will sequence you!” High-throughput technologies have flooded the academic market with genome papers. And the top journals have responded by only accepting papers describing the most novel, earth-shattering genomes. The less spectacular genomes, much like B-movies, go directly to video, or rather directly to GenBank. This sequencing-vs-publishing arms race has been going on for a long time.
...
Is it time to write the genome paper obituary? Maybe not quite yet. Every now and then they still claw their way into top journals. But the end is not far off, and when it does come, I'm sure that I speak for all of us genome geeks when I say, "Farewell, GP. It was fun while it lasted."
Smith, D.R. (2013) Death of the genome paper. Frontiers in Genetics 4:1-2. [doi: 10.3389/fgene.2013.00072]
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