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Tuesday, March 10, 2009

Salmon with Peas on Toast

 
When my kids were growing up I used to make them one of my favorite meals—Mom's Creamed Salmon on Toast. We usually enjoyed it when Ms. Sandwalk was away from home.

Now that they are adults, my children never lose an opportunity to make fun of Dad's cooking and how they were forced to eat salmon when Mom was away.

Now the joke's on them ... or at least on my son, because ...

Teenage boys who eat fish at least once a week achieve higher intelligence scores. Looks like boys get smart by eating salmon. It explains why my son is so smart. It also explains why my daughter never appreciated salmon and peas on toast. It doesn't work on girls.1


1. I don't believe the study. It's ridiculous to think that eating fish is all it takes to make you smarter. If that were true then Newfoundlanders would be smarter than cowboys or vegetarians ... hmmmmm, come to think of it ....

P.S. Just in case there is someone out there who doesn't get my sense of humor, here's a link to a posting about my daughter [Another Dr. Moran]. And just so he doesn't feel left out, here's a link to my son's website [Gordon Moran].

Richard Dawkins on "Purpose"

One of the most astonishing discoveries of modern science is that the universe does not exhibit any signs of "purpose" or "goals." This single conclusion is probably more responsible for the profound conflict between science and religion than any other. The attractiveness of religion was that it seemed to answer the "why" questions that science, presumably, could not answer. Now, modern science tells us that the question was meaningless.

That evolution is a blind, purposeless process is difficult to grasp, yet it is a fundamental part of understanding biology. The concept is explicitly mentioned in college level textbooks, although some introductory biology textbooks place less emphasis on it than you will find in more advanced courses.

Here's how Douglas Futuyma describes purpose in Evolution (2005) (p. 12).
Above all, Darwin's theory of random, purposeless variation acted on by blind, purposeless natural selection provided a revolutionary new kind of answer to almost all questions that begin with "Why?" Before Darwin, both philosophers and people in general answered "Why?" questions by citing purpose. Since only an intelligent mind, with the capacity for forethought, can have purpose, questions such as "Why do plants have flowers?" or "Why are there apple trees?"—or diseases, or earthquakes—were answered by imagining the possible purpose that God could have had in creating them. This kind of explanation was made completely superfluous by Darwin's theory of natural selection. The adaptations of organisms—long cited as the most conspicuous evidence of intelligent design in the universe—could be explained by purely mechanistic causes. For evolutionary biologists, the flower of the magnolia has a function but not a purpose. It was not designed in order to propagate the species, much less to delight us with its beauty, but instead came into existence because magnolias with brightly colored flowers reproduced more prolifically than magnolias with less brightly colored flowers. The unsettling implication of this purely material explanation is that, except in the case of human behavior, we need not invoke, nor can we find any evidence for, any design, goal, or purpose anywhere in the natural world.

It must be emphasized that all of science has come to adopt the way of thought that Darwin applied to biology. Astronomers do not seek the purpose of comets or supernovas, not chemists the purpose of hydrogen bonds. The concept of purpose plays no part in scientific explanations.
Richard Dawkins made the same point in his book River Out of Eden (1995) (pp. 96-98). Here he is reading those pages.


The concept of purposeless, or accidental, evolution comes naturally to those evolutionary biologists who are used to thinking about random genetic drift. Those biologists tend to be comfortable with the idea that the tape of life will never be replayed.

But, as Richard Dawkins notes at the end of his reading, there are other biologists for whom "the illusion of purpose is so powerful that [they] use the assumption of good design as a working tool." Many of these biologists are not completely comfortable with the idea that the tape of life may not play out the same. They tend to see convergence, and other things, as evidence of some sort of inevitable purpose (design) in the history of life. This is, of course, materialistic design, not supernatural design.

This point of view crops up in terms such as "the evolution of evolvability," "facilitated variation," and even "self-organization."

In addition to this subtle form of "purpose" we see clear evidence of true purpose in animals with sophisticated brains. Those animals clearly develop goal-oriented behaviors.

Dawkins addresses these points in his current lecture tour by making a distinction between different definitions of purpose.
The Purpose of Purpose

"We humans are obsessed with purpose. The question, “What is it for?” comes naturally to a species surrounded by tools, utensils and machines. For such artifacts it is appropriate, but then we go too far. We apply the “What is it for?” question to rocks, mountains, stars or the universe, where it has no place.

How about living things? Unlike rocks and mountains, animals and plants, wings and eyes, webbed feet and leaves, all present a powerful illusion of design. Since Darwin, we have understood that this, too, is an illusion. Nevertheless, it is such a powerful illusion that the language of purpose is almost irresistible. Huge numbers of people are seriously misled by it, and biologists in practice use it as a shorthand.I shall develop two meanings of “purpose”. Archi-purpose is the ancient illusion of purpose, a pseudo-purpose fashioned by natural selection over billions of years. Neo-purpose is true, deliberate, intentional purpose, which is a product of brains. My thesis is that neo-purpose, or the capacity to set up deliberate purposes or goals, is itself a Darwinian adaptation with an archi-purpose.

Neo-purpose really comes into its own in the human brain, but brains capable of neo-purposes have been evolving for a long time. Rudiments of neo-purpose can even be seen in insects. In humans, the capacity to set up neo-purposes has evolved to such an extent that the original archi-purpose can be eclipsed and even reversed. The subversion of purpose can be a curse, but there is some reason to hope that it might become a blessing."
Wesley Elsberry was at the Dawkins lecture in Michigan on March 2nd and he has posted a lengthy summary on The Panda's Thumb: Richard Dawkins and “The Purpose of Purpose”. It's very helpful for those of us who couldn't attend one of these lectures.


Monday's Molecule #111: Winners

 
UPDATE: I guess the hint was too much of a giveaway. The molecule is insulin from pig (Sus scrofa). Pig pancreas was the major source of insulin for diabetics before recombinant DNA. It is very similar to human insulin.

The Nobel Laureate is Fred Sanger who won in 1958 for determining the sequence of insulin. It was his first of two Noble Prizes.

The winners are David Schuller of Cornell University by one minute over Dima Klenchin, and Adam Santoro of the University of Toronto.




Identify this molecule. Be as specific as possible, including the species. Explain why that species was chosen.

Here's a hint: 1b17.

There's are several possible Noble Prizes associated with this molecule. I'm looking for the prize that was awarded for determining the primary structure.

The first person to identify the molecule and the Nobel Laureate wins a free lunch at the Faculty Club. Previous winners are ineligible for one month from the time they first won the prize.

There are six ineligible candidates for this week's reward: Dima Klenchin of the University of Wisconsin. Alex Ling of the University of Toronto, James Fraser of the University of California, Berkeley, Guy Plunket III from the University of Wisconsin, Deb McKay of Toronto and Maria Altshuler of the University of Toronto.

Dima has offered to donate a 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 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. I reserve the right to select multiple winners if several people get it right.

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


A Letter from the President of CIHR

 

There's a crisis in science funding in Canada. The budgets of the main granting councils are being cut by $148 million over the next three years.

Laura Frost is the President of the Canadian Society of Biochemistry, Molecular & Cellular Biology (CSBMCB). She recently wrote to Prime Minister Harper to draw his attention to the seriousness of this decision.
Dear Mr. Harper;

On behalf of the Canadian Society of Biochemistry, Molecular & Cellular Biology (CSBMCB), I would like to congratulate the Government of Canada for a number of measures in the 2009 Budget, including the more than $1.5 billion investment in science and technology. The CSBMCB is pleased to see in the budget $750 million for the Canada Foundation for Innovation (CFI) in support of research infrastructure and $87.5 million for the temporary expansion of the Canada Graduate Scholarship Program as well as continued funding for Genome Canada.

However, the lack of additional new investment in Canada’s granting agencies Canadian Institutes of Health Research (CIHR), NSERC and SSHRC is of great concern. Without increased investments in operating funds to support doing research, Canada could lose the competitive edge that previous investments in students, scientists and infrastructure have achieved. Operating monies are the funds that allow our gifted students and other trainees to become competitive at an international level and leaders in the next generation of scientists. Without these crucial increases, fewer labs will be funded and fewer students, scholarships notwithstanding, will be trained in the diverse areas of science that define “interdisciplinary research”. Targeted research is one essential component of the funding process, but as a country, we need a strong background in basic research that feeds into technological development and planning for crises ranging from SARS to mountain pine beetles to environmental concerns in the oil sands.

Over the past several years, many leaders and national and provincial partners dedicated to advancing research in Canada have advocated for increased investments in discovery research through the granting councils to match the growth in infrastructure and research capacity through the CFI and the Canada Research Chairs Program respectively. Failure to align these funding streams at the federal level has created a serious imbalance in the supply and demand in health research and research generally, which will, in turn, increasingly affect our capacity to retain and recruit the best scientists.

The biotechnology sector is also suffering from a lack of investment capital. This industry serves as a primary receptor for much of Canadian research related to health, agriculture, manufacturing, environmental and resource-based emerging technologies. Fifty percent of Canadian companies indicate they will be closing or selling off their operations to international partners by the end of this year. Canada cannot afford to ignore the competitive environment other nationals will be adopting to help grow and stimulate their knowledge-based industries.

The economic impact of Canadian health research is significant. On an annual basis our industry generates $12 billion in economic activity and provides employment and training for over 10,000 people across Canada. The sector also supports more than 20,000 scientists, clinical investigators and other researchers and staff.

Canada has many of the right ingredients to succeed in the knowledge-based economy including a highly skilled workforce and some of the best research facilities in the world. The CSBMCB looks forward to working with the Government of Canada in laying the foundation for a stronger and more sustainable economy of the future in which research and development in the health and life sciences are a top national priority.

Sincerely,



Laura Frost, Ph.D.
President, CSBMCB
CSBMCB has also published a letter from the President of the Canadian Institutes of Health Research (CIHR). Read this letter ... comments below.
MESSAGE FROM THE PRESIDENT OF CIHR

Following the January 26, 2009 Speech from the Throne, the Government of Canada tabled its 2009 Budget, Canada’s Economic Action Plan in the House of Commons on January 27. The Budget outlined the Government’s economic stimulus package designed to bolster the Canadian economy and provide support for Canadians as the world’s economies work through the current economic crisis. The Budget 2009 speech and documents can be found on the Finance Canada website at: http://www.fin.gc.ca.

Research plays a key role in improving the health of Canadians. That’s why, over the past three years, the Government has increased the annual base budget of the Canadian Institutes of Health Research (CIHR) by over $142 million. This year CIHR plans to spend approximately $917 million on peer-reviewed health research projects conducted at universities, hospitals and research centres across Canada.

I have summarized below the details of Budget 2009 as it relates to CIHR.

First, CIHR will receive $35M over the next three years for Canada Graduate Scholarships (CGS) to fund an additional 200 doctoral scholarships, valued at $35, 000 each per year for three years beginning in 2009-10, and an additional 400 master’s scholarships, valued at $17, 500 each for one year, in both 2009-10 and 2010-11.

Second, Budget 2009 also provided the results of the Government’s Strategic Review process. CIHR was one of the 21 Government Departments and Agencies that undertook a Strategic Review of its programs and services. The objective of the process was to assess whether programs:

• are effective and efficient;

• meet the priorities of Canadians; and

• are aligned with federal responsibilities.

The results of the process are as follows:

• CIHR funding of the Open Team Grant program will be discontinued. To respect current commitments, reductions will be phased in over the next three years with $1.5M in 2009-10, $5.5M in 2010-11, and $27.6M in 2011-12 and thereafter; and

• Funding for the Intellectual Property Mobilization (IPM) program will be discontinued. To respect CIHR’s current commitments, the annual reductions of $2M will commence in 2010-11 and end in 2011-12.

In addition, funding under the Indirect Costs Program will be reduced in proportion to reductions in the above direct cost programs. The relative ratio of funding for the direct and indirect costs will therefore remain essentially the same as prior to the Strategic Review.

In summary, taking into account the new investments for the Canada Graduate Scholarships and the strategic reallocations, CIHR’s budget for 2009-10 will increase by $12.5M, bringing our total budget to $978.8M.


Sincerely,



Alain Beaudet, MD, PhD
President
Canadian Institutes of Health Research
This is unacceptable. It sounds like a letter from a political lackey and not from someone who is really concerned about scientific research in Canada. Why can't Alain Beaudet mention that he is fighting on behalf of all Canadian scientists to increase CIHR funding in order to better support basic research? Is it because he isn't fighting?

We need someone who will stand up and oppose government underfunding, not someone who will make excuses for it. If the current President does not have the confidence of the scientists who are supported by CIHR then perhaps we should find a new CIHR President who does have their confidence.


Monday, March 09, 2009

Happy Birthday PZ!

 
Today is PZ Meirirz birthday.

So far he's not having a good one [No More Birthday] so don't bother to send him an email message.

Wait until tomorrow.


Monday's Molecule #111

 
Identify this molecule. Be as specific as possible, including the species. Explain why that species was chosen.

Here's a hint: 1b17.

There's are several possible Noble Prizes associated with this molecule. I'm looking for the prize that was awarded for determining the primary structure.

The first person to identify the molecule and the Nobel Laureate wins a free lunch at the Faculty Club. Previous winners are ineligible for one month from the time they first won the prize.

There are six ineligible candidates for this week's reward: Dima Klenchin of the University of Wisconsin. Alex Ling of the University of Toronto, James Fraser of the University of California, Berkeley, Guy Plunket III from the University of Wisconsin, Deb McKay of Toronto and Maria Altshuler of the University of Toronto.

Dima has offered to donate a 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 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. I reserve the right to select multiple winners if several people get it right.

Comments will be blocked for 24 hours.


Good Quality Journalism Sells Newspapers

 
On Saturday night we celebrated my nephew's birthday at Pic Nic on Queen St. East. I won't tell you how many years we were celebrating ... let's just say that I remember babysitting Mark when I was 18 years old. He's old enough to fend for himself (on most days).

We got to discussing science journalism—he reads my blog. Mark was defending (poorly ) the idea that newspapers, TV, etc. are profit-making companies and, consequently, it is unreasonable to expect them to be truthful and accurate. Sensationalism sells. I was defending the idea that telling the truth about science isn't necessarily going to hurt profits. Accurate science can be just as exciting as gross distortions of the truth. Maybe even more exciting.

We had a really fun time discussing the topic, aided, perhaps, by the excellent wine list at the restaurant. I wish I could remember all the points I made. I think some of them were brilliant.

Along comes André Picard of The Globe and Mail to back up my case better than I was able to do on Saturday night. (You lose again, Mark! ) Here's his bio.
André Picard is the public health reporter at The Globe and Mail, where he has been a staff writer since 1987.

He has received much acclaim for his writing, including the Michener Award for Meritorious Public Service Journalism, the Canadian Policy Research Award, the Atkinson Fellowship for Public Policy Research and the Award for Excellence in Women’s Health Reporting. In 2002, he received the Centennial Prize of the Pan-American Health Organization as the top public health reporter in the Americas.
I think we can assume he's an expert on health journalism in the same way that we have experts in science writing.

Does André Picard try and sell papers by sensationalizing topics like vaccination, prescription drugs, complementary medicines and "health" foods?

Let's check out his article in last Thursday's paper: The Internet has changed the nature of scientific debate.
If you read scientific literature and health research with an open mind and still conclude that vaccines are not poisons, that chelation therapy will not cure heart disease, that realigning someone's chakra is not going to clear up a bladder infection, or that strange concoctions of vitamins and minerals cannot cure bipolar disorder - all theories that have pretty broad followings on the Web - then you are dismissed as an agent of an evil empire.

Those who promote these bogus therapies - and often profit from them - will, paradoxically, dismiss you as a paid shill for Big Pharma, oppressive government or some other branch of the devilish military-industrial complex.

Doctors, nurses, pharmacists, pharmacologists, biochemists, immunologists, geneticists and journalists are not to be trusted. They are all on the take.

Medical journals that publish peer-reviews research: They are nothing but promotional tools for Big Pharma and researchers are their puppets and profiteers.

So who do you trust?

Well, you depend on chiropractors and Hollywood stars to give you advice about vaccinating your baby; you trust the guy at the health-food store to offer up a sure-fire cure for arthritis; and you take as gospel the e-mail that warns ominously that if new food safety rules are adopted by government, storm troopers will soon be busting down your front door to seize the chamomile tea.

In the world of cyberspace science, the best evidence is anecdote and the more fantastical the claims, the larger the following they seem to garner.
This is an example of honest, skeptical reporting and I think the general public will be just as interested in reading about the exposure of quacks as in reading articles that promote their claims.

In other words, accuracy and the truth can sell newspapers. And the public benefits.

Let's have more of it in the science section.


[Photo Credit: Dr. Louise Nadeau and Mr. André Picard as masters of ceremonies at the 2006 Fifth Annual Canadian Health Research Awards celebration.]

[Hat Tip: Propter hoc: The most sensible thing I’ve read in months and RichardDawkins.net]

Did biologists really think that human evolution stopped?

John Hawks has responded to my posting on the Discover article. In that posting [Are Humans Still Evolving?] I criticized Hawks and his colleagues for claiming that the consensus view among scientists is that human evolution is over.

Recall that the opening sentence of the article is ...
For decades the consensus view—among the public as well as the world’s preeminent biologists—has been that human evolution is over.
John replies with: Did biologists really think that human evolution stopped?.
Yet despite the abundant evidence that human biologists have opposed the idea of recent human evolution, I still think that McAuliffe's opening sentence does construct a "straw man" argument. Many prominent examples don't prove that there has been a decades-long consensus that human evolution stopped. And our research is not about human evolution merely continuing -- we think it actually accelerated. Evidence that some biologists thought that human evolution stopped is interesting. But the reality is that almost no one has thought that human evolution accelerated.
So, John and I agree that McAuliffe's article was misleading when she suggested that the consensus view was that human evolution had stopped. It was misleading in spite of the fact that one can find quotations from some prominent scientists who might have held this view.

My position is that the consensus view is often that found in the leading textbooks. The textbooks on evolution always discuss recent examples of human evolution; such as lactose tolerance, skin color, and shifts in the frequency of blood type alleles. Most of them spend time discussing races and diversity—usually with the goal of dispelling false concepts of race, but always with the assumption that humans have, and are, evolving.

Take Evolution by Barton et al. (2007), for example. They have sections on the evolution of humans by random genetic drift and natural selection. One section on page 775 is headed: Natural Selection Has Shaped, and Is Shaping, Human Evolution. The standard examples are explained.

Barton et al. discuss what happens when negative selection is relaxed due to medical advances and they point out, correctly, that this will lead to the accumulation of formerly deleterious alleles by drift. They even address the very issue that Hawks writes about (p. 775).
It is unclear how effective natural selection has been in our recent history. On the one hand, our relatively low effective population size (Ne ~ 104) makes it impossible for us to avoid accumulating mildly deleterious mutations, and there is evidence that more such mutations have accumulated along our lineage than along that of our sister species, the chimpanzee. However, it could be that our low effective population size actually reflects the effects of a large number of selective sweeps, and therefore the success of natural selection. (Recall that Ne is really a measure of the inverse rate of genetic drift. It can be reduced by both low population size and selective sweeps.) When a favorable mutation is swept to fixation, it may carry with it more weakly deleterious alleles that happen to be tightly linked to the original mutation. Thus, we can make two radically different interpretations of the observed low genetic diversity within our species: on the one hand, that it reflects a low population size in the past, implying inefficient selection, or on the other, that it is a side effect of intense adaptive selection.
Since this is what evolutionary biologists are teaching undergraduates, I think it's fair to say that the consensus among evolutionary biologists is that humans are evolving. Indeed, most evolutionary biologists know that it is impossible to stop evolution.

I guess we can conclude that the author of the Discover article didn't get her straw man version of human evolution from John Hawks. Where, then, did she get it? Maybe it was from Henry Harpending, John's former postdoc advisor and collaborator.

Harpending has just published a book with Gregory Cochran, another collaborator on the "acceleration" paper. The opening chapter of The 10,000 Year Explosion is Overview: Conventional Wisdom.
Scientists have long believed that the "great leap forward," some 40,000 t0 50,000 years ago in Europe, marked the advent of cultural evolution and the end of significant biological evolution in humans. At this time, the theory goes, humans developed culture, as shown by the sophisticated new tools, art, and forms of personal decoration that emerged in the Upper Paleolithic. Culture then freed the human race from the pressures of natural selection: We made clothes rather than growing fur and built better weapons rather than becoming stronger.

The argument that the advent of behavioral modernity somehow froze human evolution is dependent on the notion of a static environment. In other words, if a population—of humans, wolves, crabgrass, you name it—experiences a stable environment for a long time, it will eventually become genetically well matched to that environment. Simple genetic changes then do little to improve individual fitness, because the species is close to an optimum.
I assume John Hawks will agree that this "conventional wisdom" is a straw man. Perhaps Gregory Cochran and Henry Harpending are referring to a subset of scientists when they talk about arrested human evolution. Perhaps they are only referring to adaptationists, or maybe just adaptationist anthropologists?

My own view is that humans are evolving (duh!) and that the evidence for accelerated evolution is unconvincing at this time, but intriguing. I think this is the consensus view among evolutionary biologists. If I were trying to educate the general public that's what I would tell them.

I would not tell them that a revolution in our thinking about human evolution is in progress.


Epigenetics, Lamarck, and Darwin.

 
Ryan Gregory at Genomicron educates us about Jean-Baptiste Pierre Antoine de Monet, Chevalier de la Marck and Charles Darwin [Lamarck didn't say it, Darwin did.
What people insist on dubbing "Lamarckian inheritance" in the context of epigenetics is actually closer to the view held by Darwin than by Lamarck....


International Women's Day

 
Yesterday (Sunday) was International Women's Day.

Ms. Sandwalk and I celebrated by buying a new monitor for her computer. The monitor was designed and marketed by an American company and assembled in Asia (probably by women) using parts that were produced in five or six other countries.

Hey, don't knock it! What did you do to celebrate international women yesterday?

Apparently men in Russia celebrate a little differently.


The Value of Science in Canada

 
Canadian Girl Postdoc in America writes about The Value of Science in Canada. Here's a teaser ... read it all.
Stephen Harper (the Prime Minister of Canada) is, as far as I'm concerned, has an underlying ideology that he weasels into every policy. While I may be a granola eating birkie-wearing tree hugger, Harper is a neo-con who lives and dies by the market. He won't listen to hard-done-by stories of the 'little people' and his natural inclination is toward rigid conservative policies. Stephen Harper's closest advisor (Tom Flanagan) believes in the teachings of Leo Strauss, a man who taught that people "are too stupid to make informed decisions about their political affairs. Elite philosophers must decide on affairs of state for us." Strauss also believed that the ruling elite should hide the truth from the public -- Strauss's "noble lie" -- in order to protect the citizens from themselves.

The comparison between Harper and Bush is stark and explains why Canadian scientists are fearful about the future of science.



[Hat Tip: Canadian Cynic: Chicks with brains]

Saturday, March 07, 2009

The Streetcar We Desire

 
Last night we rode the atheist streetcar for about an hour and a half through downtown Toronto. Nobody reacted to the sign. That's probably a good thing.

Thanks to Chris, the Freethought Association of Canada, and The Centre for Inquiry for organizing the event and the bus campaign.




The Untenability of Theistic Evolution

 
A reader has alerted me to an essay by Bart Klink, a Dutch atheist [The Untenability of Theistic Evolution].
I think that from all the arguments mentioned above, the believer, and especially the Christian, is on the horns of a dilemma. The one horn is that he takes his religion, including its holy book, seriously, which leads to scientific conflicts. The other horn is that he avoids all conflict with science, which reduces his creation story to myth and leads to deism or atheism. Conservative Christians often choose the first horn, with scientific untenability as consequence. Proponents of theistic evolution are forced to choose the latter horn, with philosophical and theological untenability as consequence. Besides this, the theistic conception of an omnipotent, omniscient, and perfectly good God is hardly compatible with the process of evolution.
I agree with the main points of the article. Most versions of theistic evolution still conflict with science in one way or another and the only way to avoid conflict entirely is to adopt some form of deism.


Friday, March 06, 2009

Are Humans Still Evolving?

This is a follow-up to my earlier posting about the latest issue of Discover magazine [Ascent of Darwinism]. I want to discuss another article in that issue: "Are We Still Evolving" by Kathleen McAuliffe. The title of the web version is: They Don't Make Homo Sapiens Like They Used To.

In a minute we'll look at the quality of science journalism in this article, but first a little background.

The point of the article is that human evolution may have accelerated enormously in the past 40,000 years. The idea is based almost entirely on a few papers by John Hawks and his colleagues. What they did was to look at various polymorphisms in the human genome. The most common variants are single nucleotide mutations (single nucleotide polymorphism = SNP = "Snips"). Some people will have one tpe of variant while other people will have another. Almost all of these variants are neutral—they have no visible or functional effect—but some of them will affect fitness.

Some SNPs can linked to variants (alleles) that are under selection. If you assay for enough SNPs, you'll find several that just happen to be located near variants that are being selected. If selection is rapid then the nearby SNPs will be swept up along with the actual variant that improves fitness. A block of SNPs that forms a cluster found in many individuals is called a "haplotype." The presence of these haplotypes is evidence of a selective sweep (rapid increase in frequency due to selection).

As time goes on these clusters are broken up by recombination so using this technique you only see examples of recent adaptations.

Hawks and his colleagues claim to have found more than 11,000 examples of genes that are being selected in the human population. (Humans have about 20,000 genes.) They conclude that human evolution has accelerated in the past 40,000 years because our hunter-gatherer ancestors settled down to become farmers and this created a new environment. We have been adapting to that new environment ever since.

The important paper is Hawks et al. (2007). For more information read: Is Evolution Linked to Environmental Change?, Accelerated Human Evolution, Are Humans Evolving Faster? and Human Evolution Has Accelerated

The work is controversial. Many people are skeptical of both the result and the explanation. The general consensus among evolutionary biologists is "wait and see." They treat this as a preliminary result because they are well aware of the technical problems and how easy it is to score false positives. The technology is not foolproof.

Evolutionary biologists are not surprised by the claim that humans are evolving. The textbooks are full of examples of recent human evolution by both natural selection and random genetic drift. Besides, the evidence is all around us—you only have to look at the different appearance of people in Africa, Asia, and Europe to see the obvious. We also have the well-studied examples of human migration out of Africa and of coalescence to identify Mitochondria Eve. This is more evidence of recent human evolution.

So, evolutionary biologists aren't the least bit surprised by evidence of human evolution but they're skeptical of this particular study because it claims recent accelerated human evolution. The paper isn't that exciting to most people who know about evolution.

The popular press had a fit, aided and abetted by the PR departments at several universities and, more recently, by a newly published book: The 10,000 Year Explosion: How Civilization Accelerated Human Evolution.

This brings us to the article in Discover. The author, Kathleen McAuliffe, is a freelance writer who specializes in science and medicine. She has an M.A. in natural science. She just won an Alicia Patterson Journalism Fellowship "to continue her research into human evolution from the Stone Age to the present."

Here's how the article begins ....
For decades the consensus view—among the public as well as the world’s preeminent biologists—has been that human evolution is over. Since modern Homo sapiens emerged 50,000 years ago, “natural selection has almost become irrelevant” to us, the influential Harvard paleontologist Stephen Jay Gould proclaimed. “There have been no biological changes. Everything we’ve called culture and civilization we’ve built with the same body and brain.” This view has become so entrenched that it is practically doctrine. Even the founders of evolutionary psychology, Leda Cosmides and John Tooby, signed on to the notion that our brains were mostly sculpted during the long period when we were hunter-gatherers and have changed little since. “Our modern skulls house a Stone Age mind,” they wrote in a background piece on the Center for Evolutionary Psychology at the University of California at Santa Barbara.
I think this is wrong. I do not believe that the consensus among the world's preeminent evolutionary biologists1 is that human evolution is over.

I'm not familiar with the Gould quotation. It seems to have been uncovered by Cochran and Harpending, two of the authors on the Hawks et al. paper. They use it on the first page of their book The 10,000 Year Explosion: How Civilization Accelerated Human Evolution. Even if it's accurate, it does not represent the mainstream view of most evolutionary biologists.
So to suggest that humans have undergone an evolutionary makeover from Stone Age times to the present is nothing short of blasphemous. Yet a team of researchers has done just that. They find an abundance of recent adaptive mutations etched in the human genome; even more shocking, these mutations seem to be piling up faster and ever faster, like an avalanche. Over the past 10,000 years, their data show, human evolution has occurred a hundred times more quickly than in any other period in our species’ history.
There are two things wrong with this. First, the hype about blasphemy is a serious distortion of the truth. The scientific literature is full of examples of recent human evolution. Haven't you heard of the sickle cell gene, lactose intolerance, and blood types?

Second, while the Hawks et al. paper is interesting, it is extremely misleading to imply that their evidence is unchallenged. That's not good science journalism. (Incidentally, the peer-reviewed paper says that human evolution accelerated in the past 40,000 years, not 10,000.)

It's not until you get to the sixth paragraph that you find any sort of balance.
Not surprisingly, the new findings have raised hackles. Some scientists are alarmed by claims of ethnic differences in temperament and intelligence, fearing that they will inflame racial sensitivities. Other researchers point to limitations in the data. Yet even skeptics now admit that some human traits, at least, are evolving rapidly, challenging yesterday’s hallowed beliefs.
What kind of balance is that? Where's the sober description of the consensus view; namely, that humans are always evolving and the evidence of Hawks and his colleagues isn't convincing?

John Hawks is featured prominently in this article.
These overriding trends are similar in many parts of the world, but other changes, especially over the past 10,000 years, are distinct to specific ethnic groups. “These variations are well known to forensic anthropologists,” Hawks says as he points them out: In Europeans, the cheekbones slant backward, the eye sockets are shaped like aviator glasses, and the nose bridge is high. Asians have cheekbones facing more forward, very round orbits, and a very low nose bridge. Australians have thicker skulls and the biggest teeth, on average, of any population today. “It beats me how leading biologists could look at the fossil record and conclude that human evolution came to a standstill 50,000 years ago,” Hawks says.
Beats me how John could possibly think that "leading biologists" have ignored the data.

McAuliffe also interviews Henry Harpending and Robert Moyzis, two other authors on the original paper. Not surprisingly, she gets a similar story from them about how their revolutionary ideas are overthrowing entrenched dogma.

McKauliffe is now on a role and she includes a number of just-so stories.
Paralleling the constant war against pathogens, human sperm may also be evolving at high speed, driven by the race to get to the egg before another man’s sperm. “It could be that cities create more sexual partners, which means fiercer competition among males,” Hawks says. Because sperm can fertilize an egg up to 24 hours after being ejaculated in the vagina, a woman who copulates with two or more partners in close succession is setting up the very conditions that pit one man’s sperm against another’s. Hawks infers that “sperm today is very different from sperm even 5,000 years ago.” Newly selected mutations in genes controlling sperm production show up in every ethnic group he and his team have studied; those genes may affect characteristics including abundance, motility, and viability. The selection for “super sperm,” Hawks says, provides further corroboration that our species is not particularly monogamous—a view widely shared by other anthropologists.
As agriculture became established and started creating a reliable food supply, Hawks says, more men and women would have begun living into their forties and beyond—jump-starting the selection pressure for increased life span. In support of that claim, Moyzis is currently performing a genetic analysis of men and women in their nineties who are of European ancestry. He has traced many early-onset forms of cancer, heart disease, and Alzheimer’s to older human gene variants. “The idea is that people with more modern variants tend to have greater resistance to these chronic illnesses of old age and should be overrepresented in the age 90-plus population,” Moyzis says.
Harpending and Cochran had previously—and controversially—marshaled similar evidence to explain why Ashkenazi Jews (those of northern European descent) are overrepresented among world chess masters, Nobel laureates, and those who score above 140 on IQ tests. In a 2005 article in the Journal of Biosocial Science, the scientists attributed Ashkenazis’ intellectual distinction to a religious and cultural environment that blocked them from working as farm laborers in central and northern Europe for almost a millennium, starting around A.D. 800. As a result, these Jews took jobs as moneylenders and financial administrators of estates. To make a profit, Harpending says, “they had to be good at evaluating properties and market risks, all the while dodging persecution.” Those who prospered in these mentally demanding and hostile environments, the researchers posit, would have left behind the most offspring.
The last one is accompanied by a passing reference to reality, "Critics note that the association between wealth and intelligence in this interpretation is circumstantial, however."

Six pages into the article we come to this ...
NOT SO FAST
Despite all these clues that human evolution has continued and accelerated into modern times, many evolutionary biologists remain deeply skeptical of the claims. Their resistance comes from several directions.

Some independent experts caution that the tools for studying the human genome remain in their infancy, and reliably detecting genomic regions that have been actively selected is a challenging problem. The hypothesis that human evolution is accelerating “all rests on being able to identify recent areas of the genome under natural selection fairly accurately,” says human geneticist Jonathan Pritchard of the University of Chicago. And that, he warns, is tricky, involving many different assumptions (about population sizes on different continents, for instance) in the poorly documented period before recorded history.

Given such uncertainties, researchers are more likely to be persuaded that a mutation has been recently selected if they understand its function and if its rise in prevalence meshes well with known human migratory routes. Genetic variants fitting that description include those coding for lighter skin coloring, resistance to diseases such as malaria, and metabolic changes related to the digestion of novel foods. There is broad consensus that these represent genuine examples of recent adaptations.
Hmmm ... there is "broad consensus" that humans have evolved recently.

How is that consistent with the outrageous claims in the opening paragraphs?

Do we blame science writer Kathleen McAuliffe or John Hawks and his colleagues for this misleading article?

Does the article contribute positively to educating the general public about human evolution or would we be better off if it had never been published?


1. I realize that McAuliffe said "biologist," not "evolutionary biologists" but surely the only biologists who count are the experts in the field? After all, you wouldn't ask ecologists their opinion about biochemistry, would you?

Hawks, J., Wang, J.T., Cochran, G., Harpending, H.C. and Moyzis, R.K. (2007) Recent acceleration of human adaptive evolution. Proc. Natl. Acad. Sci. (USA) 104:20753-20758 [doi: 10.1073/pnas.0707650104]

[Photo Credit: MSNBC]

Ribonucleic Acid (RNA)

 
There was a time in the not-to-distant past when RNA didn't get no respect. Most biochemists worked with proteins or DNA and RNA was relegated to minor status as just an intermediate in the information flow pathway.

We all knew that there were five main types of RNA:
  1. Messenger RNA (mRNA) and its precursors: The primary RNA transcripts are produced by copying the DNA of a protein-encoding gene.1 Subsequent processing steps include addition, removal, and modification of nucleotides as well as splicing events that excise internal segments.2 The mature mRNA is translated to produce a protein whose amino acid sequence is determined by the sequence of the coding region in the gene. The messenger RNA, as the name implies, is the molecule that carries the message from the gene to the protein synthesis machinery. (And from the nucleus to the cytoplam in eukaryotic cells.)

  2. Ribosomal RNA (rRNA): The ribosomes are the most important part of the translation machinery and it has long been known that much of the mass of ribosomes is due to the presence several types of ribosomal RNA. These are noncoding RNAs produced by transcription of ribosomal RNA genes.3 One of the key steps in translation—formation of the peptide bond—is catalyzed by the rRNA component of the ribosome. It is the major catalytic RNA in cells.

  3. Transfer RNA (tRNA): tRNAs are intermediates in protein synthesis. There are many different tRNA molecules in every cell and each one binds a specific amino acid, yielding an aminoacylated-tRNA (aa-tRNA). Each different aminoacylated tRNA interacts with a particular codon in mRNA thus delivering the correct amino acid to to the site of protein synthesis.4

  4. Small RNAs: The small RNAs represent a heterogeneous category of RNAs covering a wide ranges of functions. Some of them have catalytic functions—RNAse P is the classic example.4 Some of them are structural components of ribonucleoprotein complexes (e.g. signal recognition particle).5 Some of them are guide RNAs involved in various processing events. The best known examples of guide RNAs are the small RNAs of the spliceosome complexes that mediate the splicing of mRNA precursors.2 Other small RNAs were known to be involved in the regulation of gene expression.

  5. Genomic RNA: Some viruses, notably retroviruses, have an RNA genome instead of a DNA genome. In addition, the mobility of various transposons is due to an intermediate RNA copy of the transposon sequence (retrotransposons).
This was the state of knowledge 25 years ago. Since then, the study of RNA has made remarkable progress. Our knowledge of all the fundamental processes—transcription, processing, and catalysis—has expanded enormously.

The biggest change is in the area of small RNAs. Today there are several categories of small RNAs—siRNA, microRNA, piRNA—that were only discovered in the past 10-15 years. The functions of these small RNA molecules are still being worked out. There's little doubt that some of them have important biological roles but there's considerable controversy over what percentage might be artifacts of one sort or another.

This month's issue of Cell is devoted to RNA [Cell]. There are important reviews and essays on everything from micro RNAs to spliceosomes and transcriptional scaffolds. This is your chance to catch up on the latest work in the RNA field.

The Centrality of RNA
Phillip A. Sharp

RNA-Based Therapeutics: Ready for Delivery?
Laura Bonetta

MicroRNAs and Cancer: Short RNAs Go a Long Way
Andrea Ventura, Tyler Jacks

Viral RNAs: Lessons from the Enemy
Bryan R. Cullen

Crawling Out of the RNA World
Thomas R. Cech

The Dynamic Landscapes of RNA Architecture
José Almeida Cruz, Eric Westhof

Transcriptional Scaffolds for Heterochromatin Assembly
Hugh P. Cam, Ee Sin Chen, Shiv I.S. Grewal

Regulatory RNAs in Bacteria
Lauren S. Waters, Gisela Storz

Evolution and Functions of Long Noncoding RNAs
Chris P. Ponting, Peter L. Oliver, Wolf Reik

Origins and Mechanisms of miRNAs and siRNAs
Richard W. Carthew, Erik J. Sontheimer

Small RNAs as Guardians of the Genome
Colin D. Malone, Gregory J. Hannon

Origin, Biogenesis, and Activity of Plant MicroRNAs
Olivier Voinnet

Pre-mRNA Processing Reaches Back to Transcription and Ahead to Translation
Melissa J. Moore, Nick J. Proudfoot

The Spliceosome: Design Principles of a Dynamic RNP Machine
Markus C. Wahl, Cindy L. Will, Reinhard Lührmann

mRNA Localization: Gene Expression in the Spatial Dimension
Kelsey C. Martin, Anne Ephrussi

Regulation of Translation Initiation in Eukaryotes: Mechanisms and Biological Targets
Nahum Sonenberg, Alan G. Hinnebusch

Fidelity at the Molecular Level: Lessons from Protein Synthesis
Hani S. Zaher, Rachel Green

The Many Pathways of RNA Degradation
Jonathan Houseley, David Tollervey

RNA and Disease
Thomas A. Cooper, Lili Wan, Gideon Dreyfuss


  1. Theme: Transcription.

  2. RNA Splicing: Introns and Exons.

  3. Human Ribosomal RNA genes; Ribosomal RNA Genes in Eukaryotes; Ribosomal RNA Genes in Bacteria; The Composition of Ribosomes

  4. Transfer RNA: Structure; Transfer RNA: Synthesis; Transfer RNA Processing: RNase P.

  5. The Signal hypothesis; Signal Recognition Particle
[Hat Tip: Bayblab - CELL Website Gets Massive RNA Contamination]