More Recent Comments

Wednesday, April 30, 2008

Nobel Laureate: Bernardo Houssay


The Nobel Prize in Physiology or Medicine 1947.
"for his discovery of the part played by the hormone of the anterior pituitary lobe in the metabolism of sugar"

Bernardo Alberto Houssay (1887 - 1971) received the Nobel Prize in Physiology or Medicine for his work on pituitary gland hormones that affect carbohydrate metabolism. He shared the prize with Carl and Gerty Cori.

Houssay was mainly responsible for recognizing that the anterior lobe of the pituitary gland secreted a peptide hormone that antagonized insulin. We now know that this hormone is growth hormone [Monday's Molecule #69]. It has general effects on growth and development as well as regulating carbohydrate metabolism in adults.

Bernardo Houssay was a citizen of Argentina. He was known as an outspoken liberal and an advocate of democracy. Houssay was fired from his academic position when Juan Perón took over as dictator in 1945 but he remained in Argentina working in a private laboratory. The Nobel Prize award in 1947 was seen, quite rightly, as a repudiation of Juan Perón and his policies. This was very controversial in Argentina [see Bernardo Alberto Houssay for one of many biographies].


Nobel Laureates
The presentation speech was given by Professor H. Theorell, Head of the Biochemical Nobel Department of the Royal Caroline Institute.
Your Majesty, Your Royal Highnesses, Ladies and Gentlemen.

The teaching body of the Caroline Institute has decided to award one half of the 1947 Nobel Prize for Physiology or Medicine to Professor Carl Cori and Dr. Gerty Cori «for their discovery of the course of the catalytic conversion of glycogen», and the other half to Professor Bernardo Houssay «for his discovery of the part played by the hormone of the anterior pituitary lobe in the metabolism of sugar».

The work of these prize-winners is within the same centrally important sphere, namely the metabolism of sugar in the body. They have elucidated the enzymatic reactions between glucose and glycogen, and have shown how these reactions are controlled by physiological factors. Faulty sugar metabolism may lead to diabetes, with its universally known symptoms. Everyone now knows, too, that in the majority of cases it has been possible to keep this disease in check by insulin since its discovery by Banting and MacLeod, to whom the Nobel Prize was awarded in 1923. It would be a grave mistake, however, to believe that this brilliant discovery unravelled the immense complex of problems concerning sugar metabolism. Certainly it is long known that insulin decreases the blood sugar level, but until recently the mechanism of this effect was veiled in mystery.

The task of sugar metabolism is to supply energy for the activities of life. One cannot make the slightest muscular movement without the combustion of an appropriate amount of sugar. It is readily understandable that one of our most urgent tasks is to elucidate this branch of metabolism. A clear light has been thrown on previously obscure points in our knowledge, by the discoveries for which the prizes are awarded this year.

Ninety years ago the great French physiologist, Claude Bernard, discovered that the liver and muscles contain a starch-like substance, which he called glycogen, the «sugar former». Every molecule of glycogen consists of a large number of grape sugar molecules, which are united together to be stored up in that form until they are needed. When needed, the glycogen disintegrates again into grape sugar, or glucose, to use a more scientific name. In this way the glucose content of the blood can be kept fairly constant in spite of an uneven supply. The credit for having revealed how the interplay between the glucose and the glycogen takes place falls to Professor and Doctor Cori. From the works of Robison and Embden in the 1920's it was known that the sugar in living cells and tissues, e.g. in yeast and in muscle, appears under certain circumstances bound to phosphoric acid. Closer analysis showed that in these combinations the phosphoric acid was bound to the sixth in the chain of the six carbon atoms of the sugar molecule.


This latest work of the Cori's is directly connected with the discovery of the effect of the hypophysis on the utilization of sugar by Professor Bernardo A. Houssay, who has also been awarded a prize. The hypophysis, or the pituitary gland, is a small secreting gland at the base of the brain, where it lies sunk in a bony hollow in the most sheltered spot in the whole body. Its importance justifies its sheltered position, but its size is far from impressive: that of a bean in man, a pea in the dog, and a radish seed in the toad Bufo marinus.

People sometimes cite, more or less jokingly, the statement by Cartesius, the famous philosopher, that the soul lies in the pineal gland. Now it does so no more than in any other individual organ, but if Cartesius had chanced, instead, to guess at the hypophysis, which looks much the same and is situated immediately in front of the pineal gland, he would have been nearer the truth, for in spite of its diminutive size the hypophysis exercises a number of vital functions and occupies a commanding position in relation to the other endocrinous glands. By means of its hormones the hypophysis controls the thyroid, the sex glands and the cortex of the suprarenal glands; it regulates the formation of milk and the growth of the whole body. By means of extremely beautiful experiments Houssay has shown that it also plays a prominent role in the conversion of sugar.

It was the discovery of insulin which aroused Houssay's interest in the hypophysis. As early as in the 1880's the great French research worker, Pierre Marie, had found that the excretion of sugar in the urine was a regular symptom in acromegalia, which is due to a disturbance in the function of the hypophysis, and therefore a connection between the function of the hypophysis and the metabolism of sugar might be suspected.

Houssay has worked chiefly with dogs and a large kind of toad, Bufo marinus, which is plentiful in the Argentine. In many series of experiments the hypophysis, or sometimes only its anterior lobe, was removed by operation. In the case of dogs, especially, the operation calls for highly developed technical skill if the result is not to be «the operation was successful, but the patient died». Houssay then found that the animals which had been operated on were abnormally sensitive to insulin and died with symptoms of bloodsugar deficiency from doses which were quite harmless for normal animals. In conformity with this, the glycogen content in the liver was abnormally low. A corresponding pathological picture is met with in the case of Simmond's disease in man. Dogs and toads exhibited the same kind of reaction, as have all the rest of the vertebrates hitherto investigated. This proves that Houssay had discovered a universal biological mechanism.

The discovery that a daily implantation of anterior lobe of hypophysis from toads on the operated animals protected the latter from the dangerous effect of insulin, was also of immense importance.

Thus the hormone of the anterior lobe of the hypophysis was clearly antagonistic to the hormone of the pancreas, insulin. This was confirmed and illustrated by a further series of ingenious experiments. Davidoff and Cushing had observed already in 1927 that if diabetes was provoked in dogs by the removal of a part of the pancreas, the symptoms were moderated if part of the hypophysis was also taken away. However, these experiments were not entirely conclusive, since as a rule the diabetes provoked in this way may disappear spontaneously. Houssay and Biasotti obtained definite elucidation by means of a more radical procedure. The whole hypophysis was first removed and subsequently the pancreas. For three whole days after the latter operation no sugar appeared in the urine, which is always the case if the pancreas is removed from an animal which still has its hypophysis.

In 1931, in the course of their work on the growth hormone of the hypophysis, H. M. Evans and his co-workers in U.S.A. found that the extract which naturally was still impure - provoked diabetes if injected into animals. At the same time and independently of Evans, Houssay and his co-workers arrived at similar results. After injections of extract from the anterior lobe of the hypophysis, the diabetes persisted, in many cases for months, and this was found to be due to injury to the insulin-producing cells in the pancreas.

The active factor in the hypophysis is so extremely sensitive that all the preparations must be made at a low temperature, if they are not to be spoiled. Therefore a number of research workers, who were less careful than Houssay on this point, did not at first succeed in confirming his results. It may be added that the Cori's had to grapple with the same difficulties in the preparation of their extract of hypophysis, which to some extent confirms that both groups of workers were dealing with the same active substances.

A short description of the most important results of many years of scientific work can never give a complete idea of the days and nights of labour which is most frequently fruitless. Diligence and patience are indispensable components in the mental equipment of the research worker. These alone seldom or never lead to pioneer discoveries, however, because it is impossible to deal thoroughly and systematically with all the conceivable alternatives, at least in the case of biological problems. The possibilities are all too many. Intuition is the indispensable lode-star, promising new goals to be reached by a labyrinth of paths, the majority of which are blind alleys.

In work characterized by unremitting diligence, brilliant skill, and masterly acumen, today's prize-winners in physiology or medicine have shown themselves to possess all the qualities of the great research worker in natural sciences. They have thrown light on previously undreamt of connections between the inaccessible world of the enzymes and the hormones. The task of the doctor to prevent, heal or alleviate disease demands a knowledge of the functions of the body; this year's prize-winners have opened new fields in which Ernest Starling's happy expression «The physiology of today is the medicine of tomorrow» will prove its truth.

Professor Carl Cori and Doctor Gerty Cori. During the past decade the scientific world has followed your work on glycogen and glucose metabolism with an interest that has gradually increased to admiration. Since the discovery of glycogen by Claude Bernard ninety years ago, we have been almost totally ignorant of how this important constituent of the body is formed and broken down. Your magnificent work has now elucidated in great detail the extremely complicated enzymatic mechanism involved in the reversible reactions between glucose and glycogen. Your synthesis of glycogen in the test tube is beyond doubt one of the most brilliant achievements in modern biochemistry. Your discovery of the hormonal regulation of the hexokinase reaction would seem to lead to a new conception of how hormones and enzymes cooperate.

In the name of the Caroline Institute I extend to you hearty congratulations on your outstanding contribution to biochemistry and physiology.

Professor Houssay. That great philanthropist, Alfred Nobel, had a great personal interest in physiology. Few things gave him so great a pleasure as being able to witness the brilliant development of this science in the nineteenth century. In the development of physiology, Professor Houssay, you have played a very active part, particularly regarding the work which you have brought into prominence and which is now to be honoured by the Nobel Prize.

The hypophysis is a small gland, but its importance is not related to its size, since it regulates many of our most important functions. Amongst these functions, which you have studied and analysed in a clear and striking manner, is the dominant role the gland plays in our metabolic processes.

On behalf of the Caroline Institute I congratulate you on receiving the Nobel Prize which is presented to you today, and which is a sure sign that your name will ever remain engraved in the annals of physiology.

Professor Carl Cori and Doctor Gerty Cori; Professor Houssay. I now have the honour of asking you to accept the prize from the hands of His Majesty our gracious King.

Tuesday, April 29, 2008

Richard Dawkins—polite and gracious to a fault

Some of you might remember Peter McKnight. He's a columnist for the Vancouver Sun (Canada) and he wrote a piece last year defending Marcu Ross and his Ph.D. degree [Peter McKnight on the Marcus Ross Issue].

My interactions with Peter McKnight have been quite enjoyable so it is with considerable satisfaction that I point you to his latest article on Richard Dawkins [How to reconcile Richard Dawkins?]. Peter puts his finger squarely on the discrepancy between what Dawkins says in public about religion and what he says in private.

I like the private Richard Dawkins when it comes to a position on religion as the root of all evil, and atheists as being free of violence.

Unlike the public Dawkins, I don't oppose superstitious beliefs because they lead to evil—I oppose them because there's no evidence that those beliefs are correct.

[Hat Tip:]

Monday, April 28, 2008

Should Undergraduate Programs Be Easier?

We have a biochemistry program for undergraduates. It would be called a major at most universities but at the University of Toronto we call it a Biochemistry Specialist Program. Here's an outline with the number of credits, where (1) is a standard two-semester course ...

1st year
Calculus (1), Biology (1), Physics (1), Chemistry (1)

2nd year
Biochemistry (1), Organic Chemistry (0.5), Physical Chemistry (0.5), Cell & Molecular Biology (1)

3rd year
Biochemistry Laboratory (0.5), Proteins (0.5), Nucleic Acids (0.5), Molecular Biology (1), 1.5 extra credits from a list of science courses

4th year
Advanced Biochemistry Laboratory (1), four (0.5) credit courses from a list of biochemistry and molecular biology courses

Here's the problem. Enrolment in this program is dropping because the students perceive it as being too hard. A number of easier, less rigorous, programs have recently become available in other departments. These other programs are being promoted as excellent choices for an undergraduate degree. Students are being told that these easy program will be just as acceptable as the more difficult ones when they apply to graduate school. (That won't be true in our department.)

Students believe that they will get higher grades in these other programs and that will make it easier to get into medical school or graduate school.

What should we do? There's a possibility that our program will disappear if we do nothing. On the other hand, making it a lot easier by dumbing down the material and giving higher grades goes against the principles that many of us believe in.

Have any other schools faced this situation? What did you do? What do the students think?

Who Do You Know?

The Friendly Atheist asks ...
Who is the most famous person you know (who would admit to knowing you back)?
You can see my answer over there. Sandwalk readers might like to jump in and drop a few names.

Monday's Molecule #69

This colorful molecule plays an important role in regulating carbohydrate metabolism, among other things. Your task for today is to identify the molecule. Be as specific as possible (what species?).

Identify the Nobel Laureate(s) who was/were awarded a Nobel Prize for discovering fundamental properties of this molecule without knowing the sequence or the structure. [Hint: The award was very controversial in the home country of the Nobel Laureate(s).]

Here's part of the PDB file to help you.

The first person to correctly identify the specific molecule and name the Nobel Laureate(s) wins a free lunch at the Faculty Club. Previous winners are ineligible for one month from the time they first collected the prize. There is only one ineligible candidates for this week's reward.


Nobel Laureates
Send your guess to Sandwalk (sandwalk (at) and I'll pick the first email message that correctly identifies the molecule and names the Nobel Laureate(s). Note that I'm not going to repeat Nobel Laureates so you might want to check the list of previous Sandwalk postings.

Correct responses will be posted tomorrow along with the time that the message was received on my server. I may select multiple winners if several people get it right.

Comments will be blocked for 24 hours. Comments are now open.

UPDATE: This week's winner is David Schuller of Cornell University (again). He correctly identified the molecule as human growth hormone and the Nobel Laureate is Bernardo Houssay (1947). Thanks to all the others who sent in their guesses.

Sunday, April 27, 2008

Gene Genie #30


The 30th edition of Gene Genie has been posted at Gene Expression [Gene Genie #30].
Welcome to the 30th Gene Genie!
The beautiful logo was created by Ricardo at My Biotech Life.

The purpose of this carnival is to highlight the genetics of one particular species, Homo sapiens.

Here are all the previous editions .....
  1. Scienceroll
  2. Sciencesque
  3. Genetics and Health
  4. Sandwalk
  5. Neurophilosophy
  6. Scienceroll
  7. Gene Sherpa
  8. Eye on DNA
  9. DNA Direct Talk
  10. Genomicron
  11. Med Journal Watch
  12. My Biotech Life
  13. The Genetic Genealogist
  14. MicrobiologyBytes
  15. Cancer Genetics
  16. Neurophilosophy
  17. The Gene Sherpa
  18. Eye on DNA
  19. Scienceroll
  20. Bitesize Bio
  21. BabyLab
  22. Sandwalk
  23. Scienceroll
  24. biomarker-driven mental health 2.0
  25. The Gene Sherpa
  26. Sciencebase
  27. DNA Direct Talk
  28. Greg Laden’s Blog
  29. My Biotech Life
  30. Gene Expression

Does science make belief in God obsolete?

The John Templeton Foundation has a website where "leading scientists and scholars" discuss the question "Does science make belief in God obsolete?" [A Templeton Conversation] One of these prominent intellectuals is Ken Miller and his answer is "Of course not."

One of our regular readers (Oldcola) left a comment on this site where he criticized the views of Ken Miller. His comment was initially posted intact but within a few days a heavily edited version replaced the original comment. The man responsible for editing the comment is Gary Rosen.

Apparently, the Templeton Foundation objected to the claim that they were soft on creationism, according to Oldcola. Oldcola requested that his edited comment be removed, and it was.

You can read an extended critique of Ken Miller's position on Oldcola's blog Coffee and Sci(ence) [Does science make belief in God obsolete?]. It's an excellent essay.

Incidentally, although it's not directly relevant to Miller's position, and it's not something that he clearly states, I find that theists of all sorts make the same false assumption when discussing the conflict between science and religion. They almost always assume that their atheist friends started life as theists and then lost their faith. Thus, they assume that there is something about science that disproves the default assumption; namely, that God exists.

While this might be true of many atheists, especially in the USA, it's not true of many others in Europe and elsewhere. Many atheists never bought into a belief in supernatural beings in the first place. This will be more and more likely as time goes on and the children of atheists have children of their own. When scientists like Ken Miller have to explain why science makes them go from being an atheist to a beleiver, it becomes much more difficult. Just look at the contortions that Francis Collins had to come up with.

Here's the point. It's up to theists to start making the case for the existence of God instead of just whining about those who have lost their faith. Let's say you've been raised in a home where superstitious beliefs are not valued. Then you start studying science seriously when you get to university. Is there anything about science that points to the existence of supernatural beings given that you haven't been brainwashed to believe in them as a child? I don't think so.

As Oldcola points out, many theists are simply afraid to abandon their comforting delusions. They believe science teaches us that the universe has no purpose—they are correct—and for them this depressing thought is sufficient to prove that science must be wrong. What they fail to understand is that the thought is only "depressing" if you've been brainwashed to to believe that there is a purpose in the first place.

Is Anyone Stupid Enough to Fall for This?

I received this message today ...
Dear UTORONTO.CA Email Account Owner,

This message is from UTORONTO.CA messaging center1 to all UTORONTO.CA email account owners. We are currently upgrading our data base and e-mail account center. We are deleting all unused UTORONTO.CA email account to create more space for new accounts.

To prevent your account from closing you will have to update it below so that we will know that it's a present used account.


Email Username :

EMAIL Password :

Address :

Department :

Attention!!! Account owner that refuses to update his or her account within ten days of receiving this Notification will lose his or her account permanently.

Thank you for using UTORONTO.CA!

Notification Code:VX2G99AAJ

Sandra Jacobson
My question is serious. Is there any data out there to suggest that scams2 like this actually succeed? Are there people who respond to these notices by sending off their email passwords?

Also, what's the purpose behind this attempt to get email passwords? What do they plan to do with them? Are they hoping that the email passwords will give them access to the user accounts or do they just like to read email messages?

1. The sender is "Online Services (" A domain that does not exist. The reply-to address is "" I've often wondered how these scams work. How do the perps get the replies if the return address is bogus?

2. It's easier to recognize that this is a bogus message because of the language—obviously not written by someone whose native language is English—but even if it was grammatically correct most people would know that it's a scam, right?

Saturday, April 26, 2008

Darwin's Garden

In order to walk on the sandwalk you have to pass through Darwin's garden behind Down House. Most visitors take advantage of the opportunity to pass through the greenhouses and the potting shed as well. Darwin was a passionate gardener and he did many experiments with plants. Some of his original varieties are still growing in the garden.

The New York Botanical Garden has mounted an exhibit of Darwin's experiments on plants [What Darwin Saw Out Back]. I'll have to see if Mrs. Sandwalk wants to take a trip to New York to see it with me.

[Hat Tip: Don Henry]

Ben Stein Meets Charles Darwin

Do you remember this image from the Expelled trailer? [Expelled: The Movie] It's a picture of Ben Stein looking at the statue of Charles Darwin in the cafeteria of the Natural History Museum in London (UK).

The group over at the The Beagle Project ran a contest to come up with a funny caption for the photo and the result has just been announced [Caption (absolutely no) contest!]. It's excellent—very close to what I would have said if I had the wit and talent to enter the contest.
A fortnight ago we launched a caption contest for the provocative image below, originally taken from Time's negative review of Expelled. We received twenty-six highly humorous entries, but there was one that towered, marble head and shoulders, above the rest, both for its comic value and also for the amount of work involved in realising it.
I'm not going to give away the answer because you all need to scoot on over to The Beagle Project log and donate some money while you're there.

Fibrin and Blood Clots

The formation of blood clots in mammals is an example of a complex pathway that does not seem to be very well "designed." This hasn't stopped the intelligent design creationists who often use it as an example of irreducible complexity. They conclude that the clotting pathway cannot possibly have evolved.

Last year I posted a bunch of articles on blood clotting because I needed to learn about it myself. Since then I've kept an eye on the literature but I've been too lazy to write up all the new information that comes out on a regular basis. Fortunately, André Brown has come to the rescue. He published a paper on the elastic properties of fibrinogen last year (Brown et al. 2007) and now he reviews a recent paper by his collaborator, John Weisel, that has just come out in Science. André's blog is Biocurious, a blog about biology written by two physics graduate students. The post url is New Perspective on Blood Clot Mechanics.


Blood Clotting
The image above shows blue strands of fibrin trapping red blood cells (red) and platelets (pink) to form a clot. It is from Yuri Veklich and John W. Weisel, University of Pennsylvania School of Medicine [Building better clots]. The structure of fibrinogen (below) hints at the complexity. Follow the link in the "Theme Box" to learn more.

Brown, A.E.X., Litvinov, R.I. Discher, D.E. and Weisel, J.W. (2007) Forced Unfolding of Coiled-Coils in Fibrinogen by Single-Molecule AFM. Biophys J. 92: L39–L41. [doi: 10.1529/biophysj.106.101261]

Friday, April 25, 2008

Fun with Polls

The Expelled website has a poll asking "Do you think the theory of Intelligent Design should be taught in our education system?"

When PZ Myers discovered it, the "yes" voters were ahead three to one. Now that the Pharyngula readers have voted [Crash this poll], the results are very different. Eat your heat out Ben Stein!!

Do We Need Genetic Counselors?

The blogs promoting genetic testing usually think that we don't need genetic counselors to interpret the results and advise on what to do. For the most part, they seem happy to leave it up to the individual to decide on a course of action if they discover they have a particular genetic trait. I don't agree. I think this is much more complicated and I'm pretty skeptical about the motives of the private, personal genetics, for-profit, companies.

The Sciphu Weblog has an interesting posting on this issue [Now this is why we need genetic counselors]. It's worth reading.

Top 100 Public Intellectuals

The Foreign Policy website has a list of the top 100 public intellectuals from around the world [The Top 100 Public Intellectuals: Bios].

The Canadians are: Malcolm Gladwell, Michael Ignatieff, Steven Pinker, and Charles Taylor. I would have included Irshad Manji, Bob Rae, and Don Cherry.

I included Don Cherry because he would fit right in with David Petraeus who is listed as a top 100 public intellectual.

There are several scientists and people who write about science and religion: Pope Benedict XVI, Noam Chomsky, Richard Dawkins, Daniel Dennett, Jared Diamond, Christopher Hitchens, James Lovelock, Lee Smolin, Harold Varmus, J. Craig Venter, E.O. Wilson. It's interesting that Francis Collins and Ken Miller aren't on the list since the main criterion for inclusion seems to be that the person has written a book and they have Miller & Collins have both written books.

I would have included Richard Lewontin, Bruce Alberts, and David Suzuki. Are there any others who should be on the list? Who should be deleted to make room?

[Hat Tip: Sean at Cosmic Variance]

Wednesday, April 23, 2008

Writing with Amino Acids

Eva has a picture of a bracelet that spells out "I am starstuff" using the structures of several amino acids and their single-letter identifier. Some of you may be wondering exactly how that phrase is written since there seems to be an unusual letter in there. Check out Etsy Wednesday - I Am Starstuff for the answer.

Nobel Laureate: Lord Alexander Todd


The Nobel Prize in Chemistry 1957.

"for his work on nucleotides and nucleotide co-enzymes"

Lord Alexander Todd (1907 - 1997) was awarded the 1957 Nobel Prize in Chemistry for his work on the the chemical structure of nucleotides and nucleic acids, particularly the phosphate derivatives. Todd is best known for working out the linkage between nucleotides in RNA and DNA but he is also responsible for proving that the sugar moieties are particular ring structures called β-D-ribofuranosides and β-D-deoxyribofuranosides [Monday's Molecule #68]. His lab in Cambridge (UK) synthesized all of the common nucleotides.

The chemical structure of DNA was known by the time Watson & Crick began working on the three-dimensional structure in 1952.

The presentation speech was delivered by Professor A. Fredga, member of the Nobel Committee for Chemistry of the Royal Swedish Academy of Sciences.THEME: Nobel Laureates
Your Majesties, Your Royal Highnesses, Ladies and Gentlemen.

Nucleotides and nucleotide coenzymes are words that may seem strange and abstruse, but these compounds are of great importance to all of us. We have such substances everywhere in our bodies and they regulate many of the processes of life. The term is derived from nucleus, which here refers to cell-kernels or nuclei. The Nobel Prize of this year has nothing to do with atomic nuclei, nuclear fission or hydrogen bombs. Nucleotides are regularly found in the chromosomes of the cell-kernels, where they are connected with the units of heredity, but also in the cell plasma. In combination with proteins they constitute the virus molecules and many coenzymes are nucleotides of low molecular weight but with a special structure. Thus they are a group of substances of very great biological importance, perhaps the most important of all.

The nucleotides have been known for nearly 90 years and they have been frequently studied by both chemists and biologists, but for a long time they were, from the chemist's point of view, an underdeveloped field of research. The difficulties were too great. Gradually it was established that they are built up of three different kinds of "building-stones" of quite different chemical character: phosphoric acid, a sugar, and a heterocyclic base containing nitrogen. I cannot express it more popularly, except to mention that these bases are compounds related to caffeine. Two different sugars are found, ribose and desoxy-ribose, and about half a dozen different bases. The simple building-stones may then be combined in hundreds or thousands to form macromolecules, the nucleic acids.

It is, however, not enough to know the building-stones; we must also know how they are connected to each other. The building-plan, the pattern or whatever you prefer to call it, must be very essential for the behaviour of the macromolecule in chemical and biological processes. The sugars and the heterocyclic bases are both somewhat complicated molecules, which may be connected to each other in several different ways, and finally it must be established how the phosphoric acid is bound. The task is very difficult; the combination of three quite different kinds of building-stones in one macromolecule gives it a very special character and neither the traditional methods of organic chemistry, nor those of inorganic chemistry are directly applicable. It is, however, pre-eminently a task for an organic chemist, and for more than ten years Sir Alexander Todd has held a leading position in this field.

Some idea of the building-plan may be obtained by examining the products formed by partial degradation of the macromolecule into small fragments containing a limited number of building-stones. Conclusive evidence can, however, only be obtained by synthetic methods, by building up possible combinations of sugars and bases - with or without phosphoric acid and comparing them with the degradation products. It is of course imperative to use such methods that the structure of the synthetic products is irrefutable.

The work has been very comprehensive, and many special methods have been evolved, but it is hardly possible to give a non-chemist a clear idea of the brilliant experimental work accomplished. Perhaps I should specially mention the methods for introducing phosphoric acid, the phosphorylation. In recent years, the fundamental role of phosphoric acid in the biochemical processes has become more and more evident, and the new phosphorylation methods - now approximating to those used in the biosynthetic procedures - are also of interest outside the special domain of nucleotide chemistry.

The building-plan of the nucleic acids is now established, at least in its outlines. We have a long chain, where the links are alternately sugar and phosphoric acid, and to each sugar molecule is attached a heterocyclic base as a small pendant. Thus there is an equal number of acid and basic groups. The different building-stones are always connected according to the same pattern and the difference between various nucleic acids must therefore be due to the kinds of bases and their relative arrangement. The number of different types is small - in a certain chain usually only four different bases occur - but in a macromolecule with thousands of appendant base molecules the number of possible combinations must be very great. We are familiar with the coding potentialities of the Morse alphabet, which has only two symbols, dots and dashes.

Through Sir Alexander's work a solid foundation is laid for the future development in this field. Starting from this work, other scientists have advanced very fascinating theories as to the arrangement of the chains; it seems that they may be coiled up as a helix with the bases inside. This model can perhaps explain how a nucleic acid chain can bring about the formation of another similar chain or even of a protein. We are here approaching very fundamental biological questions.

The synthetic methods have also been successfully applied to the preparation of low-molecular nucleotide coenzymes, for instance the cozymase, which plays a part in alcoholic fermentation and other biochemical processes. The ways are now open for synthetic preparation of the different types occurring in nature. It is also possible to synthesize coenzymes with slightly modified structure and study the effect of these modifications on the activity, and hence gain better insight into the mode of action of the enzymes.

Sir Alexander Todd. Some fifteen years ago you started your work in nucleotide chemistry. You saw the great importance of this topic and you did not underrate the difficulties. Today the chemical structure of these compounds is established - in any case in its outlines - and a solid foundation is laid for future work by biochemists and biologists. Results of utmost interest have already been reported and others will follow.

An organic chemist is perhaps most impressed by your studies in phosphorylation. We know today that phosphoric acid is engaged in most biochemical processes, but we know rather little of how it works. Some years ago, you expressed the opinion that the methods used by the living organism owe their air of magic largely to our lack of knowledge of the simple chemistry of the esters of phosphoric acids. You have learned to handle these esters with amazing skill, and I am sure that in due time the air of magic will disperse.

In recognition of your services to chemistry and to natural science as a whole, the Royal Swedish Academy of Sciences has decided to bestow upon you the Nobel Prize for Chemistry for your work on nucleotides and nucleotide coenzymes. To me has been granted the privilege of conveying to you the most hearty congratulations of the Academy, and of inviting you to receive your prize from the hands of His Majesty the King.

Why Do People Laugh at Creationists?

This video asks the question and gives a pretty good answer.

[Hat Tip: Mike's Weekly Skeptic Rant]

Tuesday, April 22, 2008

Carl Zimmer at Carleton University

Carl Zimmer recently gave the Discovery Lecture at my alma mater, Carleton University in Ottawa (Ontario, Canada).

Carl has been experimenting with posting the video on his blog [Slouching Towards Total Video Immersion]. See his successful attempt at [Slouching Toward Total Video Immersion, the Next Step]. Carl's talk is about new developments in evolutionary biology. I'm pleased to report that Carl's talks are as interesting as his writing.

Saving Drosophila

According to all the normal rules of taxonomy, the name of the species Drosophila melanogaster should be changed to Sophophora melanogaster [Sophophora, the New Model Organism.

As reported by evolgen there is a movement underway to save Drosohila. Here's the actual proposal from the International Commission of Zoologial Nomenclature [Case 3407].
Case 3407

Drosophila Fallén, 1823 (Insecta, Diptera): proposed conservation of usage

Kim van der Linde
Department of Biological Science, Florida State University, Tallahassee, Florida 32306–1100, U.S.A.

Gerhard Bächli
Zoological Museum, Winterthurerstraße 190, 8057 Zürich, Switzerland

Masanori J. Toda
Institute of Low Temperature Science, Hokkaido University, N19 W8, Kita-ku, Sapporo 060–0819, Japan

Wen-Xia Zhang
College of Life Sciences, Peking University, Beijing, 100871, China Toru Katoh COE for Neo-Science of Natural History, Hokkaido University, N10 W8,
Kita-ku, Sapporo 060–0810, Japan

Yao-Guang Hu
Institute of Low Temperature Science, Hokkaido University, N19 W8, Kita-ku, Sapporo 060–0819, Japan

Greg S. Spicer
Department of Biology, San Francisco State University, 1600 Holloway Avenue, San Francisco, California 94132–1722, U.S.A.

Abstract. The purpose of this application, under Article 70.2 of the Code, is to conserve the current usage of the widely used name Drosophila Fallén, 1823 (a genus of flies widely used in biological research, particularly in genetics and developmental biology) by the designation of Drosophila melanogaster Meigen, 1830 as the type species of Drosophila. Detailed phylogenetic studies show that the genus Drosophila as currently defined is paraphyletic. Splitting the genus requires that the subgenus Sophophora Sturtevant, 1939 must be ranked as a separate genus. The type species of
Sophophora is by original designation Drosophila melanogaster Meigen, 1830. Ranking Sophophora as a genus and changing the name of Drosophila melanogaster to Sophophora melanogaster would result in major nomenclatural instability due to the breadth and vast number of publications, using this combination. In addition, many refer to ‘Drosophila’ when ‘Drosophila melanogaster’ is actually meant; the two names are used interchangeably. It is therefore proposed that Drosophila melanogaster Meigen, 1830 is designated as the type species of Drosophila.

Keywords. Nomenclature; taxonomy; DROSOPHILIDAE; Drosophila; Sophophora; Drosophila melanogaster; Drosophila funebris; fruit flies.
Join the worldwide protest on April 31st and march to your capital city to save Drosophila!!!!

Monday, April 21, 2008

Monday's Molecule #68

This is an easy one. Your task for today is to identify the molecule shown on the right. Be as specific as possible.

In addition you have to identify the Nobel Laureate who was awarded a Nobel Prize for—among other things—working out the chemical structure of this molecule.

The first person to correctly identify the specific molecule and name the Nobel Laureate wins a free lunch at the Faculty Club. Previous winners are ineligible for one month from the time they first collected the prize. There are two ineligible candidates for this week's reward.


Nobel Laureates
Send your guess to Sandwalk (sandwalk (at) and I'll pick the first email message that correctly identifies the molecule and names the Nobel Laureate(s). Note that I'm not going to repeat Nobel Laureates so you might want to check the list of previous Sandwalk postings.

Correct responses will be posted tomorrow along with the time that the message was received on my server. I may select multiple winners if several people get it right.

Comments will be blocked for 24 hours. Comments are now open.

UPDATE: This was much harder than I expected. The winner is Marc Perry, co-author of the textbook from which the drawing is taken. He recognized it as a strand of DNA—I assume everyone got at least that far. Marc figured out that the Nobel Laureate had to be Sir Alexander Todd. He adds,
This was an excellent quiz because it forced me to learn a relevant fact that I was previously ignorant of. I never recall learning of this individual and his work, but based on the fact that there would be no repeats on the list of Sandwalk Laureates, _and_ on my intimate use of the website for (for my course on personalities in science, HMB305--shameless plug here), I was able to use the power of a search engine and the process of elimination to inform my guess.
If you're a student at the University of Toronto take Marc's course next year. You can also take the course that we teach together: HMB210H "Popular Scientific Misconceptions."

Prince Charles

Having watched six episodes of John Adams, I'm thoroughly immersed in anti-monarchy rhetoric. Usually, I defend my Queen as a viable alternative to a system of government that doesn't make a distinction between a head of state and political leader. I like the idea that the head of state is ceremonial and non-political.

However, the presumptive heir to the current monarch leaves a lot to be desired. Now he's gone and published more superstitious nonsense that clearly demonstrates his deficiency in the intelligence category1 [Prince of Wales's guide to alternative medicine ‘inaccurate’].
The Prince of Wales is being challenged today to withdraw two guides promoting alternative medicine, by scientists who say that they make misleading and inaccurate claims about its benefits.

The documents, published by the Prince and his Foundation for Integrated Health, misrepresent scientific evidence about therapies such as homoeopathy, acupuncture and reflexology, say the authors of a new evaluation of alternative treatments.

In a letter to The Times, Edzard Ernst, Professor of Complementary Medicine at the University of Exeter, and Simon Singh, a science writer and broadcaster, call on the Prince to recall the publications, one of which was produced with a £900,000 grant from the Department of Health.
You know you're in big trouble when a Professor of Complementary Medicine thinks your documents are inaccurate!

1. Fortunately, his sons seem to have gotten a good dose of intelligence genes from their mother. That's saying a lot.

[Hat Tip: Skepchick]

Overthrowing the Central Dogma

I believe that the Central Dogma of Molecular Biology is widely misunderstood [Basic Concepts: The Central Dogma of Molecular Biology]. It is usually interpreted to mean that information must flow exclusively from DNA to RNA to protein. But he original definition by Francis Crick was ...
... once (sequential) information has passed into protein it cannot get out again (F.H.C. Crick, 1958)
Fig. 1. Information flow and the sequence hypothesis. These diagrams of potential information flow were used by Crick (1958) to illustrate all possible transfers of information (left) and those that are permitted (right). The sequence hypothesis refers to the idea that information encoded in the sequence of nucleotides specifies the sequence of amino acids in the protein.
I think we should retain the original definition.

A biology teacher has been discussing this issue with me and he points out that the term "Central Dogma" is defined by consensus. If the vast majority of scientists define it incorrectly, then that becomes the new definition. I agree, but I'm not yet prepared to concede defeat.

My correspondent made an interesting observation. He noted that the Nobel Prize committee has awarded three Nobel Prizes for, in part, overthrowing the Central Dogma of Molecular Biology. This is very interesting. What's the value of continuing to refer the the "Central Dogma" if it has, indeed, been refuted?

Here are the three examples. The first is from a 1975 press release announcing the Nobel Prizes to Howard Temin, David Baltimore, and Renato Dulbecco [The Nobel Prize in Physiology or Medicine 1975].
Howard Temin was since the end of the 1950ies concerned with studies of tumour viruses which contain the alternative type of genetic material, i.e. RNA. He noticed that certain characteristics of tumour cells arising after infection with this type of virus suggested a possible persistence of virus genetic material in them. It was very difficult however to understand how the genetic information of viruses containing RNA could form a part of the hereditary material of the tumour cells. In order to explain this Temin postulated that the genetic information of an RNA virus capable of giving transformation could be copied into DNA, and that this DNA in a manner similar to that described for a DNA tumour virus could become integrated into the genetic material of cells. This proposal by the overall majority of scientists was considered as heresy since it was in conflict with the central dogma accepted in the field of molecular biology in those days. This dogma implied that information transfer in nature occurred only from DNA to RNA and not in the other direction.
Note that Crick's original paper (see above) allowed for information flow from RNA back to DNA so Temin's work did not overthrow the original concept of theoretical information flow. It did conflict with the incorrect version of the Central Dogma that had been promoted by Jim Watson. It was Temin's work, and the subsequent hype about the Central Dogma, that prompted Crick to publish his 1970 paper.

The second example comes from the press release for 1989 Nobel Prizes to Sydney Altman and Thomas Cech in 1989 [Ribonucleic acid (RNA) - a biomolecule of many functions].
The genetic information in the DNA strand is arranged as a long sentence of three-letter words (e.g. CAG ACT GCC), each corresponding to one of the twenty amino acids which build the proteins. This means that there is a flow of genetic information from the DNA to the proteins, which in turn provide the structural framework of living cells and give them their different functions in the organism. However, this flow of genetic information cannot occur unless the DNA code is transcribed to another code in another type of nucleic acid - RNA (ribonucleic acid). This connection between the nucleic acids (the molecules of heredity) and the proteins (the molecules of structure and function) is what has been called the central dogma of the biosciences.
The genetic information in the DNA molecules determines the composition and function of the proteins. Altman and Cech have now modified this by showing that the RNA molecules not only transmit the genetic information but can also function as biocatalyst.
The third example comes from the press release of the 2006 Nobel Prize to Andrew Fire and Craig Mello for thier work on intrefering RNA [The Nobel Prize in Physiology or Medicine 2006]. In this case, the press release does not claim that Fire and Mello overthrew the Central Dogma but it does give an incorrect version of the Central Dogma of Molecular Biology. This is ironic since, according to the Noble Prize committee, the Central Dogma had been called into question in 1975 and 1989.
The genetic code in DNA determines how proteins are built. The instructions contained in the DNA are copied to mRNA and subsequently used to synthesize proteins (Fig 1). This flow of genetic information from DNA via mRNA to protein has been termed the central dogma of molecular biology by the British Nobel Laureate Francis Crick. Proteins are involved in all processes of life, for instance as enzymes digesting our food, receptors receiving signals in the brain, and as antibodies defending us against bacteria.
It is not true that Francis Crick referred to this process of information flow as the Central Dogma.

Is any of this important? Yes, I think it is. I think there is too much sloppiness in science these days. There are too many instances where sloppy thinking is acceptable. On this particular issue you can't have it both ways. Either the Watson definition of the Central Dogma of Molecular Biology was correct, in which case it has been discredited to such an extent that it's no longer useful. Or, the original Crick version is correct, in which case the work of Temin, Altman, Cech, Fire, and Mello have nothing to do with the Central Dogma.

If a scientist is going to write about the Central Dogma of Molecular Biology then they better be damned sure that they understand it. If they are going to quote the original papers (Crick 1958, 1970) then it might be a very good idea to read them.

Crick, F.H.C. (1958) On protein synthesis. Symp. Soc. Exp. Biol. XII:138-163
Crick, F. (1970) Central Dogma of Molecular Biology. Nature 227, 561-563. [PDF file]

Saturday, April 19, 2008

Discovery Institute Praises Expelled

The President of the Discovery Institute, Bruce Chapman, has posted a message extolling the virtues of the movie expelled [Discovery Salutes Expelled].
The producers of Expelled have high hopes as the film opens today.

Practical questions of theater exposures and audience awareness are things that we, as a think tank, cannot assess, of course. But we are cheering the filmmakers on. First signs look positive. The over-the-top attacks of most official reviewers--offended by the film's message, not its quality--may turn out to help in some quarters. These are the exact same reviewers who commonly tell us not to object to offensive Hollywood products, but just to judge a film for its production quality. By now a large share of the population is wise to such hypocritical standards.
So, how is the film doing so far? Not so good. You can read the reviews of Expelled on the "Expelled Exposed" website created and maintained by the National Center for Science Education (NCSE). The reviewers ratings are making this one of the worst films ever.

The people at NCSE have been working hard to debunk all the false claims in Exposed and so far they're doing an excellent job.

Friday, April 18, 2008

Evolution at the Chautauqua Institution

The program for Week 9 (Aug. 17-23) at the Chautauqua Institution has been posted [Week Nine: Darwin and Linnaeus: Their Impact on Our View of the Natural World].

Here's the lineup of lectures in the main amphitheater (morning) and the Hall of Philosophy (afternoon).

Monday Aug. 18
10:45 am: Kenneth Miller, prof. of biology, Brown University; author, Finding Darwin's God.
Tuesday Aug. 19
10:45 am: Beth Shapiro, asst. prof. of biology, Penn State Univ.; researcher in field of ancient DNA.
2:00 pm: Carl Zimmer, science journalist, author, Evolution: The Triumph of an Idea.
Wednesday Aug. 20
10:45 am: Edward Larson, prof. of law, Pepperdine Univ; Pulitzer Prize-winner for Summer for the Gods.
2:00 pm: Barbara J. King, prof. of anthropology, College of William & Mary; author, Evolving God
Thursday, Aug. 21
10:45 am: Spencer Wells, population geneticist; director of Genographic Project.
2:00 pm: Eugenie C. Scott, executive director, National Center for Science Education.
Friday, Aug. 22
10:45 am: Mattias Klum, National Geographic Society photographer; documentary filmmaker, The Linnaeus Expedition.
2:00 pm: Michael Ruse, professor of philosophy, Florida State University; director of program in history and philosophy of science, Bristol Univ.

Throughout the week you can further improve your mind by taking special courses. You might be interested in course #1948 on What Is Evolution. I can guarantee you a good time in the course. We will finish at 2 pm on Tuesday, Thursday, and Friday.

For entertainment there's the Philadelphia Dance Company on Monday night, the very excellent Chautauqua Symphony on Tuesday night, a Vince Gill concert on Friday night, and an evening with Bill Cosby on Saturday night.

I'm also going to be there for week 4 on The Ethical Frontiers of Science.

Thursday, April 17, 2008

An Example of Framing by Matt Nisbet

Last summer I blogged about a survey of 149 professional, prominent, evolutionary biologists [Evolutionary Biologists Flunk Religion Poll].
The great majority of the evolutionists polled (78 percent) chose A, billing themselves as pure naturalists. Only two out of 149 described themselves as full theists (F), two as more theist than naturalist (D) and three as theistic naturalists (B). Taken together, the advocacy of any degree of theism is the lowest percentage measured in any poll of biologists' beliefs so far (4.7 percent).
The study was done by Gregory W. Graffin and William B. Provine and you can read the full report in American Scientist [ Evolution, Religion and Free Will]. The study quotes the findings of Larson in 1998 where only 5.5% of biologists in the National Academy of Sciences believe in God.

An earlier study of average scientist by Larson showed that 40% believe in a god and 45% do not [NEW SURVEY: SCIENTISTS "MORE LIKELY THAN EVER" TO REJECT GOD BELIEF]. Couple these results to the fact that somewhere between 30% and 50% of the general population of Western European countries are atheists and agnostics [Atheists and Agnostics] and I think it would be fair to say that the majority of evolutionary biologists do not believe in god. The data supports the statement that, among evolutionary biologists, the consensus is lack of belief in god. This probably applies to all professional scientists.

Now, let's look at how Matt Nisbet spins the story [Francis Collins: The Angry Atheists Do Not Speak for Us]. He opens by quoting an interview with Francis Collins, a deluded scientist, who, quite predictably, says ...
I also think that those of us who are interested in seeking harmony here have to make it clear that the current crowd of seemingly angry atheists, who are using science as part of their argument that faith is irrelevant, do not speak for us. Richard Dawkins, Sam Harris and Christopher Hitchens do not necessarily represent the consensus of science; 40 percent of scientists are believers in a personal God. A lot more are rather uncomfortable about the topic but certainly would not align themselves with a strong atheistic perspective.
Collins is talking about the "angry atheists" when he claims that they don't represent the consensus. Then he spins the argument to make it look like most scientists are believers, or at least have some doubts. Of course, when Collins says they "do not speak for us" he doesn't mean members of the National Academy of Scientists or prominent evolutionary biologists. No, he's referring to the broader survey that included many other categories of scientist. Among that group, there are still more non-believers (45%) than believers (40%).

Matt Nisbet then says ...
As Collins accurately notes, the argument by Dawkins, PZ Myers, and other atheist hardliners that science undermines the validity of religion, even respect for religion, is at odds with the consensus view in the scientific community.

For example, as the recent National Academies report on evolution concludes: "The evidence for evolution can be fully compatible with religious faith. Science and religion are different ways of understanding the world. Needlessly placing them in opposition reduces the potential of each to contribute to a better future."
I don't think Nisbet is representing the consensus view in the scientific community—at least not in the scientific community of professional evolutionary biologists. In that community the overwhelming majority are non-believers in god(s). This is how framing works, is it different from lying?

Furthermore, Nisbet is picking up on a paragraph in Science, Evolution and Creationism, a recent publication of the National Academy of Sciences. That paragraph is, itself, a "frame" and a misrepresentation of the consensus view among scientists as many of us have pointed out [How the National Academy of Sciences Framed their Book on Evolution]. The polls clearly show that the vast majority of members of the National Academy of Sciences are atheists. Thus, Nisbet is putting his own spin frame on the topic and quoting more inaccurate spin framing to support his position. I guess this is how framing is supposed to work.

I don't want any part of it. It's way too close to "lying." Matt Nisbet goes on to beat up on his regular victims by saying ...
Dawkins and Myers are entitled to their opinion and as a fellow atheist I strongly support their right to voice criticism of religion. Yet at some point they need to consider the unintended consequences of their preferred brand of atheist punditry, and to recognize the pragmatism of the consensus message from the National Academies and other leading science organizations.

In their campaign, Dawkins and Myers may honestly believe that they are speaking truth to religion and that by adding their voice to the argument culture, they can raise awareness among the non-religious while potentially shifting society towards greater secularization. However, in coming decades, if the goal is to defend the teaching of evolution in schools and to maintain public trust in science and scientists, their message likely serves as a liability towards that end.
Matt, you are completely wrong about this. The "consensus message" of the National Academies and other leading science organizations is flat-out wrong. Most scientists do not believe in God and among prominent evolutionary biologists Francis Collins is part of a 5.5% minority. You may have convinced the authors of Science, Evolution and Creationism to mislead the public about the beliefs of scientists but you'll never convince the scientists themselves to go along with it.

If the goal is to maintain "public trust in science and scientists" then speaking the truth is always better than framing.

I Prefer People Who Sign their Names to Comments and Blogs

Given a choice between anonymous bloggers (and commenters) and those who sign their real names, I prefer to deal with those who use their real names. In part, this is because I admire their willingness to stand behind what they say regardless of the possible consequences. I do understand that it's easy for a tenured Professor to say this but I've never hidden behind anonymity even when I was an undergraduate, a graduate student, a postdoc, or an untenured Professor.

Greg Laden discusses anonymous bloggers in Some of my best friends are pseudonymous bloggers. I pretty much agree with his position. His posting is well worth reading.

I also agree with his stance on arguing from authority. In the real world, it makes a difference if someone is someone is putting forth an argument based on years of experience in the field or not. Nobody has time to evaluate all of the facts on every issue. We have to learn who we can trust and who we can't. The connection between this and anonymous blogging is obvious.

Please do not interpret this as a blanket recommendation to trust everyone in a position of authority. Similarly, I'm well aware of the fact that non-experts often make insightful contributions to a debate. The issue is much more complex than that. We don't need to list all the exceptions to the general principle that wisdom and experience usually count for something.

[Cartoon Credits: (top)Anonymity and Sovreignty (bottom) Cerebral Kitchen Productions]

Evolutionary Teapot

There's an exhibit of china and pottery inside the Legion of Honor museum in San Francisco. One of the items that caught the attention of Leslie is a funny looking teapot.

The teapot itself isn't that unusual but there's an inscription on the bottom that refers to evolution. Apparently, there was a bit of hysteria and over-reaction to Darwin's ideas in the 1880's and this teapot pokes fun at that era.

Legion of Honor: San Francisco

Last Sunday we visited the Legion of Honor art museum in San Francisco. We went specifically to see the Annie Leibovitz: A Photographer’s Life, 1990–2005 exhibit but there were lots of other wonderful sights to see. The building is a 3/4 scale copy of the Palais de la Légion d’Honneur in Paris.

There are two works of art in the main courtyard. The most impressive is a casting of Rodin's Thinker, which I interpret to be an icon for rationalism and a warning to creationists. The second is clearly an impressionist view of the Flying Spaghetti Monster

Evolution: 24 myths and misconceptions

If you think you understand it, you don't know nearly enough about it.
New Scientist has just published an excellent series of articles on evolution [Evolution: 24 myths and misconceptions]. These are some of the best explanations of evolution that I've ever seen in a popular magazine. Thus, it's all the more tragic that they spoil it all by putting a false picture of evolution (right) on the website.

Shared misconceptions:

Everything is an adaptation produced by natural selection
We tend to assume that all characteristics of plants and animals are adaptations that have arisen through natural selection. Many are neither adaptations nor the result of selection at all.
Natural selection is the only means of evolution
Much change is due to random genetic drift rather than positive selection. It could be called the survival of the luckiest.
Natural selection leads to ever-greater complexity
In fact, natural selection often leads to ever greater simplicity. And, in many cases, complexity may initially arise when selection is weak or absent.
Evolution produces creatures perfectly adapted to their environment
You don't have to be perfectly adapted to survive, you just have to be as well adapted as your competitors. The apparent perfection of plants and animals may be more a reflection of our poor imaginations than of reality.
Evolution always promotes the survival of species
The phrase "survival of fittest" is widely misunderstood (see 'Survival of the fittest' justifies everyone for themselves). Many wrongly assume it means that evolution always increases the chances of a species surviving.

Evolution sometimes results in individuals or populations becoming less fit and may occasionally even lead to extinction.
It doesn't matter if people do not understand evolution
At an individual level, it might not matter much. However, any modern society which bases major decisions on superstition rather than reality is heading for disaster
"Survival of the fittest" justifies "everyone for themselves"
The "fittest" can be the most loving and selfless, not the most aggressive and violent. In any case, what happens in nature does not justify people behaving in the same way
Evolution is limitlessly creative
It might seem like there is no end to nature's inventiveness but there are some features that could probably never evolve, at least on Earth.
Evolution cannot explain traits such as homosexuality
There are numerous evolutionary mechanisms that might explain homosexual behaviour, which is common in many species of animals.
Creationism provides a coherent alternative to evolution
The only thing that creationists agree on is that they don't like evolution. Even Genesis gives two contradictory accounts of creation.

Creationist myths:

Evolution must be wrong because the Bible is inerrant
This argument is undermined by the hundreds of errors and inaccuracies and contradictions found in Bible. It is anything but "inerrant".
Accepting evolution undermines morality
Actually people in more secular countries appear to behave more morally. And even if this claim was true, that would not alter the facts or justify their suppression.
Evolutionary theory leads to racism and genocide
Darwin's ideas have been invoked as justification for all sorts of policies, including some very unpleasant ones. But evolutionary theory is a descriptive science. It cannot tell us what is right and wrong.
Religion and evolution are incompatible
There are various ways in which the known facts about evolution can be reconciled with theistic religions. Some of these ways might be illogical and irrational, but they are no more illogical and irrational than other aspects of religions.
Half a wing is no use to anyone
Just as objects designed for one purpose can be used for another, so genes, structures and behaviours that evolve for one purpose become adapted to do another.
Evolutionary science is not predictive
It might not be possible to predict exactly what life will look like in a billion years but what counts are the predictions that can be made.
Evolution cannot be disproved so is not science
There are all sorts of findings and experiments that could have falsified evolution. In the century-and-a-half since Darwin published his theory, not one has.
Evolution is just so unlikely to produce complex life forms
By weeding out harmful mutations and assembling beneficial ones, natural selection acts like an "improbability drive" that can, given enough time, produce results that appear utterly impossible at first glance.
Evolution is an entirely random process
No and yes. Natural selection is a rigorous testing process that filters out what works from what doesn’t, driving organisms to evolve in particular directions. However, chance events play a big role too.
Mutations can only destroy information, not create it
Biologists are uncovering thousands of examples of how mutations lead to new traits and even new species. This claim not only flies in the face of the evidence, it is also a logical impossibility.
Darwin is the ultimate authority on evolution
Modern evolutionary theory is built on some - but not all - of Darwin's ideas, but has gone far beyond them.
The bacterial flagellum is irreducibly complex
Actually, flagella vary widely from one species to another, and some of the components can perform useful functions by themselves. They are anything but irreducibly complex.
Yet more creationist misconceptions
Evolution is just a theory: Yes it is, like Einstein's theory of special relativity. By theory, scientists mean an explanation backed by evidence. What creationists mean is that evolution is just a hypothesis, unsupported by evidence - which it is not. Evolution is a fact as well a theory.
Evolution violates the second law of thermodynamics
The second law of thermodynamics states that entropy, a measure of randomness, cannot decrease in a closed system. Our planet is not a closed system.