Canada's Secret Plan for World Domination

 
The secret is out [Donuts To Dollars].

Our Friendly Neighbors In Canada Are About To Wage An International Food Fight Over Your Morning Coffee

(CBS) Americans are about to be dragged into an international food fight … and it's our friendly neighbors in Canada who are throwing down the gauntlet. Jeff Glor reports our Cover Story:

There was some chance that the story would be ignored since it only appeared on CBS News but that turned out to be a forlorn hope. John Pieret of Thoughts in a Haystack has taken on the role of a modern Paul Revere [Rally 'Round the Flag].

Now the whole world knows the secret.

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Monday's Molecule #126

 
Today's molecule is actually four molecules. Your task is to identify the four molecules shown in the cartoon. Explain what they are doing in the figure. Be sure to name the species or you won't get credit for a correct answer.

These molecules are directly connected to one of the most significant Nobel Prizes in the 20th century. The Nobel Laureate didn't know the names of these molecules but that doesn't diminish the achievement. Identify the Nobel Laureate and the connection between Monday's Molecules and the work for which the prize was awarded.

The first person to identify all four molecules and the Nobel Laureate, wins a free lunch at the Faculty Club. Previous winners are ineligible for six weeks from the time they first won the prize. Please note the change in the length of time you are ineligible. The idea is to give more more people a chance to win.

There are eight ineligible candidates for this week's reward: Dima Klenchin of the University of Wisconsin, Madison, Adam Santoro of the University of Toronto., Michael Clarkson of Waltham MA (USA), Òscar Reig of Barcelona, Maria Altshuler of the University of Toronto, Mike Fraser of the University of Toronto, Jaseon Oakley of the University of Toronto, and Bill Chaney of the University of Nebraska.

Bill Chaney has donated his free lunch to a deserving undergraduate so I'm going to continue to award an additional free lunch to the first undergraduate student who can accept it. Please indicate in your email message whether you are an undergraduate and whether you can make it for lunch.

THEME:

Nobel Laureates
Send your guess to Sandwalk (sandwalk (at) bioinfo.med.utoronto.ca) and I'll pick the first email message that correctly identifies the molecule(s) and names the Nobel Laureate(s). Note that I'm not going to repeat Nobel Prizes so you might want to check the list of previous Sandwalk postings by clicking on the link in the theme box.

Correct responses will be posted tomorrow.

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

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[Image Credit: De Robertis, E.M. and Kuroda, H. (2004)]

I can't wait to see this ...

 
This looks really good, judging from the trailer. Like PZ Myers I'm a little nervous about how it will turn out but I'll certainly be watching it as soon as it's available.

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Amway sells genetic tests?

 
Many blogs have been shamelessly promoting genetic testing and giving free advertising to the for-profit companies that have been exploiting the technology. Some of the bloggers are indirectly or directly associated with those companies.

Of course we all know where this is going. It's only a matter of time before a rash of private companies catch on to this get-rich scheme and decide to reap the profits.

Daniel MacArthur of Genetic Future has identified one of these companies: Amway sells genetic tests?. Read his posting and read the response from the company (Interleukin Genetics) in the comments.

This is just the tip of the iceberg. It's going to get much worse. I wonder if the cheerleader bloggers are going to take the lead in calling for government controls?

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The British Chiropractic Associates Issues a Warning

 
The British Chiropractic Associates (BCA) is the group that sued science journalist Simon Singh for pointing that their practices were not evidence based. Although the initial court ruling was favorable to the BCA, the subsequent fall-out is probably making them regret their decision to silence critics.

The latest round has the BCA sending out the following warning to their members—a warning that should not have been necessary if chiropractors have been behaving like they should.

he BCA would remind members of their obligations under the Advertising Standards Authority (ASA) section 50 (relating to Health & Beauty Products and Therapies: see

Members are strongly encouraged to review their current marketing materials (whether they are paper- or web-based to ensure that they are compliant with both ASA and GCC requirements. Note that the ASA has no jurisdiction over editorial materials placed on members own websites.

When reviewing your materials it may be helpful to consider the following:

1. Are there any claims made that cannot be justified by reference to evidence? Remember, the GCC requires chiropractors to practice evidence based care, which is defined as "clinical practice that incorporates the best available evidence from research, the preferences of the patient and the expertise of practitioners (which includes the individual chiropractor himself).

2. Be mindful of making promises that you cannot be sure of delivering on;

3. Be wary of listing conditions that are controversial and away from mainstream chiropractic care e.g. dyslexia/dyspraxia unless you have research to back this up. If you have made references to prolonged crying, sleep and feeding problems, breathing difficulties and frequent infections, as these are symptoms rather than condition specific, we suggest you remove these references.

4. Do not refer to yourself as a specialist in any particular form of chiropractic;

5. Do not use unfamiliar words for common conditions;

6. Do not unjustly criticise other healthcare professionals;

7. If you refer to subluxations, provide information to explain what they are.

8. Take care in the use of the Doctor title. Ensure that there is no way there can be any doubt that you are a chiropractor, and not a registered medical practitioner. Do not use the doctor title in paper advertising without explicitly stating that you are a chiropractor.

How much of this controversy is going to spill over into North America? Isn't it time that American and Canadian chiropractors started to feel the heat?

Here's an example of a "wellness clinic" in my neighborhood: Erin Mills Optimum Health. They offer chiropractic (Dr. Peever, Dr. Caven, Dr. Cote), chiropody/foot care, naturopathy (including homeopathy) (Dr. Almond), massage therapy, and reflexology.

As of today (June 13, 2009) the home page on their website contains the following testemonial.

I have Irritable Bowel Syndrome and began researching on the internet for anyway I could get any relief from my symptoms. A co-worker of mine recommended me to see a Chiropractor after I had missed a couple of days of work. With my regular adjustments and my regulated diet, I noticed a positive change in my health. I am feeling better and more comfortable with myself. I would recommend to anyone who suffers from IBS to come in and see a Chiropractor, you have nothing to lose.

The British Chiropractic Associates would not be pleased.

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Richard Brown Defends Chiropractic

 
Read In defense of chiropractic by chiropractor Richard Brown in New Scientist.

SINCE the British Chiropractic Association (BCA) decided to sue science writer Simon Singh for libel, scientists and journalists have unleashed a torrent of criticism against chiropractic. Much of this is misinformed and needs to be corrected.

Many critics - including Edzard Ernst (New Scientist, 30 May, p 22) - hark back to the origins of chiropractic. This has the clear intention of suggesting that modern chiropractors cling to the 19th century idea that spinal misalignments are responsible for the majority of diseases. While a tiny minority retain this view, most are aware that such claims have long since been debunked.

This is the same Richard Brown who works at The Landsdown Clinic in Gloucestershire, UK. Here's a list of the treatments they offer at that clinic ....

Aromatherapy

Aromatherapy is the use of essential oils, extracts from the flowers, fruits, leaves, stems and roots of flowers, shrubs and trees. The therapeutic use of aromatic oils dates back to ancient times and was particularly popular in Ancient Egypt and the Far East. Aromatherapy massage is a gentle, flowing treatment that may help to relieve pain and alleviate tension and fatigue. The use of essential oils creates a feeling of calming energy and has a powerful effect on both body soul.

Reflexology

Reflexology is a complementary therapy that uses pressure points on the feet to help activate the circulation and nervous system. By using the feet as a map of the whole body, reflexology consists of the application of manual techniques to enhance a state of physical and mental balance.

Therapeutic Massage

Therapeutic massage is the use of hands to manipulate soft tissues of the body, particularly muscles. It can be used for relaxation, stimulation or rehabilitation of the whole body or part of it. Particularly effective in managing stress-related tension, massage promotes suppleness, aids flexibility and stimulates circulation. Therapeutic massage may be beneficial for a range of body systems and as well as treating muscular aches and pains, it can be useful in helping circulation and digestion.

Hot Stone Therapeutic Massage

Despite it being one of the fastest-growing massage techniques, hot stone therapy is an ancient healing art. It uses a combination of warm stones and various massage techniques which provide deep therapeutic effects and create harmony and balance.

Hopi Ear Candling

Being a hollow tube, the centre of an ear candle is simply a column of air rather than a solid mass. When lit at the top, the rising air column inside the candle begins to heat up. As the candle burns down, it continues to heat up the top of the rising air column of the centre of the candle. The rising air column creates a very mild suction action at the base, which help loosen compacted earwax. This experience is a gentle, relaxing treatment for everyone, including children.

Indian Head Massage

Indian Head Massage is a traditional touch therapy, which has been practised for thousands of years. It is gentle, yet firm and powerful, therapeutic massage of the shoulders, arms, neck, scalp, ears, hair and face which will leave you feeling soothed and rebalanced. This is an extremely enjoyable and deeply relaxing treatment that gives you a sense of calm and relaxation.

It's certainly NOT the Richard Brown at the Brown Chiropractic Center in Brockon, MA (USA) south of Boston. That practice offers to help you with allergies, asthma, bedwetting, pregnancy and a host of other problems.

I wonder if the British Richard Brown, who is never referred to as "doctor" on his website, would approve of the American "Dr." Richard Brown? I wonder if the American "Dr." Brown is aware of the fact that some of these 19th century claims have been debunked?

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Nobel Laureate: Jens Skou

 

The Nobel Prize in Chemistry 1997.

"for the first discovery of an ion-transporting enzyme, Na+, K+ -ATPase"




Jens C. Skou (1918 - ) won the Nobel Prize in Chemistry his work on the Na⁺,K⁺ ATPase (sodium potassium ATPase). He discovered that this membrane protein pumped sodium ions out of cells and pumped potassium ions into cells. The pump was driven by hydrolysis of ATP.

Skou shared the Nobel Prize with Paul Boyer and John Walker who worked out the mechanism of ATP synthase—the enzyme that makes ATP.

The press release describes Skou's work in some detail.
THEME:
Nobel Laureates

Na+, K+-ATPase, the first molecular pump to be discovered

It was known as early as the 1920s that the ion composition within living cells is different from that in the surroundings. Within the cells the sodium concentration is lower and the potassium concentration higher than in the liquid outside. Through the work of the Englishmen Richard Keynes and Alan Hodgkin at the beginning of the 1950s (Hodgkin received the Nobel Prize in 1963) it was known that when a nerve is stimulated sodium ions pour into the nerve cell. The difference in concentration is restored by sodium being transported out once again. That this transport required ATP was probable since the transport could be inhibited in the living cell by inhibiting the formation of ATP.

With this as the starting point Jens C. Skou searched for an ATP-degrading enzyme in the nerve membrane that could be associated with ion transport. In 1957 he published the first article on an ATPase, which was activated by sodium and potassium ions (Na + , K + -ATPase). He was the first to describe an enzyme that can promote directed (vectored) transport of substances through a cell membrane, a fundamental property of all living cells. Numerous enzymes have since been demonstrated to have essentially similar functions.

Skou used as experimental material finely ground crab nerve membranes. The ATP-degrading enzyme found in the preparation required the presence of magnesium ions and was stimulated with increasing quantities of sodium ions up to a certain limit. Above this Skou was able to obtain further stimulation if he added small quantities of potassium ions. An indication that the enzyme was coupled to the ion pump was that maximal stimulation was obtained at the concentrations of sodium and potassium that normally occur in the nerve. In his further studies of the enzyme mechanism Skou showed that sodium ions and potassium ions bind with high affinity to different places in the enzyme. In addition he showed that the phosphate group separated from ATP also binds to ATPase. This is described as a phosphorylation of the enzyme. The enzyme is dependent on sodium ions when it is phosphorylated and on potassium ions when it is dephosphorylated. Substances known to inhibit sodium/potassium transport are certain digitalis alkaloids, e.g. oubain, and Skou showed that oubain interferes in the enzyme's activation by sodium.

The picture that slowly emerged from Skou's and others' work is that the enzyme consists of two subunits, alpha and beta. The first carries the enzyme's activity and the other presumably stabilises the structure. The enzyme molecules are located in the cell membrane, often in twos, and expose surfaces to the outside as well as the inside. Three sodium ions and ATP bind to the interior surface. A phosphate is then transferred from ATP to an amino acid in the enzyme, aspartic acid, whereupon the ADP is liberated and the enzyme changes form so that the sodium ions are transported to the outside. Here they are released and two potassium ions attach instead. When the phosphorus that is bound to the enzyme is removed the potassium ions are transported into the cell and when new ATP binds to the enzyme they are rejected.

As a result of the action of the Na + , K + -ATPase, the cell keeps a high concentration of potassium in its inside. As the cell membrane is rather permeable for potassium ions, a few of these potassium ions leak out, leaving unpermeable, negative charges on the inside of the cell. Therefore, the inside of the cell membrane becomes electrically negatively charged, as compared to the outside.

This difference in potential across the membrane is necessary for a nerve stimulation to propagate along a nerve fibre or a muscle cell. This is why a shortage of nourishment or oxygen in the brain rapidly leads to unconsciousness since the ATP formation ceases and the ion pump stops. The pump is also important for maintaining cell volume. If the pump stops, the cell swells. The difference in sodium concentration between the interior and the exterior is the driving force in the uptake of important nutrients necessary to the cell, e.g. glucose and amino acids. It can also be used for transport of other ions through the cell membrane. Thus sodium ions that enter can be exchanged for calcium ions that exit.

Following the discovery of Na + , K + -ATPase other ion pumps have been discovered with similar structures and functions. Examples are Ca 2+ >-ATPase in skeletal muscle, which participates in the control of muscle contraction and H + , K + -ATPase which produces hydrochloric acid in the stomach. It is the latter enzyme that is specifically inhibited in modern treatment of stomach ulcers. Corresponding enzymes are also found in lower organisms, for example in yeast where an H + -ATPase secretes hydrogen ions formed during fermentation. As a common name these enzymes are nowadays termed P-type ATPases since they are phosphorylated during the course of the reaction.

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The images of the Nobel Prize medals are registered trademarks of the Nobel Foundation (© The Nobel Foundation). They are used here, with permission, for educational purposes only.

Time Tree: The Timescale of Life

 
Check out the Time Tree website. You can type in any two species and find out when they diverged.

This is a great learning tool. Try it with Homo sapiens (that's us) and ....

Gallus gallus (chicken)
Danio rerio (some kind of fishy thing)
Strongylocentrotus purpuratus (purple sea urchin)
Drosophila melanogaster (fruit fly)
Caenorhabditis elegans (nematode)
Saccharomyces cerevisiae (baker's yeast)
Arabidopsis thaliana (flowering plant)
Plasmodium falciparum (protozoan, causes malaria)
Escherichia coli (bacterium)

Keeping in mind that the Cambrian explosion happened about 550 million years ago, try and guess when the lineage leading to these species diverged from the lineage leading to humans. Check your guess on the website.

Where you right? Why, or why not?

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[Hat Tip: ERV]

Chiropractors Receive Warning

 
The McTimoney Chiropractic Association of Great Britain has issued a waring to all it members. You can read the entire thing on The Quackometer. The bottom line is that the members are supposed to remove all references to treatment of "whiplash, colic or other childhood problems."

The association is worried about lawyers and citizens who are on the lookout for false claims by chiropractors.

The target of the campaigners is now any claims for treatment that cannot be substantiated with chiropractic research. The safest thing for everyone to do is as follows.

1. If you have a website, take it down NOW.

Sort of makes you wonder what they're afraid of, no?

I'm interested in another warning ...

If you use business cards or other stationery using the ‘doctor’ title and it does not clearly state that you are a doctor of chiropractic or that you are not a registered medical practitioner, STOP USING THEM immediately.

On a completely unrelated note, one of the MPs in our area is Ruby Dhalla a Liberal¹ from Brampton-Springdale.

Here's something from her website.

Dr. Dhalla brings extraordinary experience, passion, and perspective to her role as the Member of Parliament for Brampton Springdale in Canada’s Parliament. As a community activist, doctor, and entrepreneur she is one of the leading progressive voices in parliament and works tirelessly in Parliament on behalf of those that struggle to be heard. Dr. Dhalla made history in 2004 as the first South Asian Women to be elected to federal parliament in the western world and was subsequently re-elected on January 23, 2006 and again on October 14th 2008 by the support of her constituents. She is one of the youngest women in Canadian Parliament.

Her experience in politics started at a young age, beginning as a volunteer with her local MP, to knocking on doors in numerous liberal campaigns at the age of 12, to writing a letter advocating for peace to the late Prime Minister of India, Indira Ghandi, at the age of 10.

Born and raised in Winnipeg, Manitoba, and graduating with her Doctor of Chiropractic in 1999 in Toronto, Dr. Dhalla has had the fortunate opportunity of listening, learning, connecting and working with people from various socio-economic and cultural backgrounds. Her journey and experiences have served as her own inspiration in advocating for women, fighting for youth and promoting Canada’s role in the international arena.

As a doctor and an owner of multidisciplinary health care clinics prior to seeking public office, Dr. Dhalla has witnessed first hand the complexities and the challenges of Canada’s health system, especially those faced by patients and front-line health care providers. It is with this firsthand knowledge and insight that Dr. Dhalla has been able to contribute to her former role as the Critic for Health for the Official Opposition and as Vice- Chair for the Standing Committee on Health.

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1. I know she's a Liberal. I know some of her Liberal supporters. I originally typed "Conservative" just to see if anyone was paying attention! :-) (Not.)

[Hat Tip: Pharyngula]

The Most Famous Speech in Medical History

 
Robert Koch and Tuberculosis.

Koch's Famous Lecture

Robert Koch, a German physician and scientist, presented his discovery of Mycobacterium tuberculosis, the bacterium that causes tuberculosis (TB), on the evening of March 24, 1882. He began by reminding the audience of terrifying statistics: "If the importance of a disease for mankind is measured by the number of fatalities it causes, then tuberculosis must be considered much more important than those most feared infectious diseases, plague, cholera and the like. One in seven of all human beings dies from tuberculosis. If one only considers the productive middle-age groups, tuberculosis carries away one-third, and often more."

Koch's lecture, considered by many to be the most important in medical history, was so innovative, inspirational and thorough that it set the stage for the scientific procedures of the twentieth century....

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Monday's Molecule #125: Winner

 
Only one person guessed the molecule and that person was Bill Chaney from the University of Nebraska. Nebraska is very much like one of the provinces in western Canada so I count him as a honorary Canadian!

Naturally Bill also got the correct Nobel Laureate.

The molecule is lipoarabinomannan, also known as LAM. It's a complex derivative of phosphatidylinositol characterized by the presence of numerous mannose residues and branching arabinose chains. LAM is part of the cell wall of mycobacteria, including Mycobacterium tuberculosis, the bacteria that causes tuberculosis.

LAM is one of the major antigens in tuberculin, a complex that is easily isolated from cultures of M. tuberculosis. The complex antigen was used in skin tests for tuberculosis. Robert Koch was the first scientist to isolate tuberculin and he received the Nobel Prize in 1905 for his contributions to understanding how bacteria cause disease.

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This is the tentative structure of a very important molecule. It's "tentative" because the exact structure hasn't been fully worked out and because the "molecule" is heterogeneous—it's actually a mixture of several similar molecules.

Identify this molecule by giving its common name and the organism(s) from which it is derived. This particular molecule is part of a much larger complex that was first identified over 100 years ago. The person who discovered that large complex received a Nobel Prize. Identify the Nobel Laureate.

The first person to identify the molecule and the Nobel Laureate, wins a free lunch at the Faculty Club. Previous winners are ineligible for six weeks from the time they first won the prize. Please note the change in the length of time you are ineligible. The idea is to give more more people a chance to win.

There are nine ineligible candidates for this week's reward: Laura Gerth of the University of Notre Dame, Stefan Tarnawsky of the University of Toronto, Dima Klenchin of the University of Wisconsin, Madison, Adam Santoro of the University of Toronto., Michael Clarkson of Waltham MA (USA), Òscar Reig of Barcelona, Maria Altshuler of the University of Toronto, Mike Fraser of the University of Toronto, and Jaseon Oakley of the University of Toronto.

Mike has saved Canadians from embarrassment.

I still have one extra free lunch donated by a previous winner to a deserving undergraduate so I'm going to continue to award an additional free lunch to the first undergraduate student who can accept it. Please indicate in your email message whether you are an undergraduate and whether you can make it for lunch.

THEME:

Nobel Laureates
Send your guess to Sandwalk (sandwalk (at) bioinfo.med.utoronto.ca) 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 Prizes so you might want to check the list of previous Sandwalk postings by clicking on the link in the theme box.

Correct responses will be posted tomorrow.

Comments will be blocked for 24 hours.

---

[Image Credit: The structure of Mycobacterium tuberculosis lipoarabinomannan (LAM) by Achim Treumann and Steve Homans.]

10 scientific objects that changed the world

 
New Scientist, which used to be a decent science magazine, has a list of 10 scientific objects that changed the world. You are invited to vote for your favourite on the Science Museum site.

To mark its centenary, the Science Museum in London had its curators select the ten objects in its collection that made the biggest mark on history. Explore them in this gallery, and cast your vote in the public poll to decide the most significant of all.

In fairness, the Science Museum picked ten objects that had a big impact on history. It appears to be New Scientist that labeled these "scientific objects."

Here's a preview.

1. Apollo 10 capsule: engineering, not science
2. Thompson’s Atmospheric Engine: engineering, not science
3. The electric telegraph: engineering, not science
4. Model T Ford: definitely not science
5. Pilot ACE Computer: engineering, but used in science
6. V2 rocket engine: military, not science
7. Penicillin: science as applied to medicine
8. DNA double helix: the only pure science choice
9. X-ray machine: a scientific instrument
10. Stephenson's Rocket: definitely not science

That's quite a list. I really don't like that fact that science and technology are hopelessly confused in the minds of the general public. And I loathe the idea that a so-called "Science Museum" and a so-called "science" magazine can't tell the difference.

The Science Museum in London is a wonderful place but the displays do nothing to teach the difference between real science and its applications.

Here's are some objects that are missing: The Beagle or Darwin's notebooks, Galileo's telescope, the ultracentrifuge, Lucy, the microscope, the electron microscope, William Smith's map, model of an atom, COBE, an early DNA sequencing apparatus, Newton's Principia Mathematica, Lyell's Principles of Geology, a camera, a bottle of oxygen, Pasteur's bell jar, Einstein's 1905 paper "On the Electrodynamics of Moving Bodies" ....

I'm sure there are many more I haven't thought of.

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Vaccine refuseniks are free-riders

 
There are some really interesting ethical issues associated with vaccinations. The advantages of vaccination benefit the entire community (the "herd") but not necessarily the individual. If everyone is vaccinated then one person can opt out without a great deal of risk. They get the benefit but don't pay the cost. They get a free ride.

Janet Stemwedel is interested in these ethical problems. Read what she has to say about those who refuse to vaccinate their children at Vaccine refuseniks are free-riders.

I wonder if there's a cultural difference when it comes to these kinds of problems? Are there some cultures who value the society more than the individual and others who value the individual more? If so, do they differ in the number of people who refuse to be vaccinated?

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What Is Natural Selection?

 
If you ever thought that the concept of natural selection was easy then you must read Understanding Natural Selection: Essential Concepts and Common Misconceptions by T. Ryan Gregory. The article appears in the latest issue of Evolution: Education and Outreach and it contains many references to studies of how students perceive evolution.

It's a very good article. Ryan has thought of many misconceptions that I would have missed and he has documented the existence of those misconceptions in the classroom—among students and teachers alike!. He also does a really good job of explaining natural selection, with one important omission.

One thing that the article didn't mention is that natural selection is a stochastic process. A given allele may be demonstrably beneficial to survival but that doesn't mean it will sweep to fixation.

One of the misconceptions that we most frequently encounter in the blogosphere is the idea that whenever a beneficial effect is demonstrated, or conceived, it will automatically take over. The reality is that the probability of fixation is related to the population size and the coefficient of selection. Imagine that a new mutation gives rise to an allele conferring an advantage of 1% on the individual carrying it. The probability of fixation in the population is approximately 2%—in other words, the allele is lost 98% of the time.

Most people think that beneficial alleles will always become fixed in a population. That's one of the most important misconceptions about natural selection and it's a shame that it was left out of the article.

This misconception is behind much of adaptationist thinking. To them it seems to be sufficient to postulate a benefit, no matter how small, and it automatically follows that the entire population/species will acquire it. The reality is that such adaptionist thinking requires two separate components: (1) the existence of a possible beneficial allele and, (2) the demonstration that the postulated benefit is of sufficient potency to lead to fixation with a high probability.¹

There's one other misconception that's missing. Many people think that natural selection only occurs when the environment changes. This is formally equivalent to a belief that, in a stable environment, all species become perfectly adapted so that no further adaptation can take place. There's no evidence to support this concept. It requires that most species are sitting at the top of an adaptive peak.

In order to become perfectly adapted, all possible beneficial mutations would have had to arise and be fixed in the population. I believe that this hasn't happened in most cases so that all species are still capable of further adaption even if the environment has been stable for a million years.

The corollary to this misconception is that species that haven't changed much in outward appearance over a long period of time (e.g. living fossils) have not evolved because their environment didn't change. In fact, we see plenty of change at the molecular level in these so-called "living fossils" and some of that change is almost certainly adaptation.

If you combine Ryan's article with the ideas that natural selection has a stochastic component and that perfect adaptation is rarely achieved, then you will understand natural selection better than most people.

If, in addition, you learn that there's more to evolution than natural selection then will truly be able to say you understand evolution.

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1. For example, it's possible to imagine that there might be an allele conferring a particular behavior that's beneficial. Say, females not communicating with male relatives when they are ovulating. But that's not sufficient. Evolutionary psychologists must also explain why the adaptive benefit is sufficient to lead to fixation and preservation in the population. Is it a 0.001% benefit or a 25% benefit?

Monday's Molecule #125

 
This is the tentative structure of a very important molecule. It's "tentative" because the exact structure hasn't been fully worked out and because the "molecule" is heterogeneous—it's actually a mixture of several similar molecules.

Identify this molecule by giving its common name and the organism(s) from which it is derived. This particular molecule is part of a much larger complex that was first identified over 100 years ago. The person who discovered that large complex received a Nobel Prize. Identify the Nobel Laureate.

The first person to identify the molecule and the Nobel Laureate, wins a free lunch at the Faculty Club. Previous winners are ineligible for six weeks from the time they first won the prize. Please note the change in the length of time you are ineligible. The idea is to give more more people a chance to win.

There are nine ineligible candidates for this week's reward: Laura Gerth of the University of Notre Dame, Stefan Tarnawsky of the University of Toronto, Dima Klenchin of the University of Wisconsin, Madison, Adam Santoro of the University of Toronto., Michael Clarkson of Waltham MA (USA), Òscar Reig of Barcelona, Maria Altshuler of the University of Toronto, Mike Fraser of the University of Toronto, and Jaseon Oakley of the University of Toronto.

Mike has saved Canadians from embarrassment.

I still have one extra free lunch donated by a previous winner to a deserving undergraduate so I'm going to continue to award an additional free lunch to the first undergraduate student who can accept it. Please indicate in your email message whether you are an undergraduate and whether you can make it for lunch.

THEME:

Nobel Laureates
Send your guess to Sandwalk (sandwalk (at) bioinfo.med.utoronto.ca) 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 Prizes so you might want to check the list of previous Sandwalk postings by clicking on the link in the theme box.

Correct responses will be posted tomorrow.

Comments will be blocked for 24 hours.

---

[Image Credit: The structure of Mycobacterium tuberculosis lipoarabinomannan (LAM) by Achim Treumann and Steve Homans.]