Genie's Tips on Teaching Evolution

Dr. Eugenie Scott directs the National Center for Science Education, a non-profit organization that defends the teaching of evolution in public schools. In a recent talk at PNU, Dr. Scott offered current and future biology faculty important tips on teaching evolution, especially to students who come in with misconceptions about what evolutionary theory is and whether it poses a threat to their religious faith. I will do my best to reproduce these tips here, with the caveats that 1) all credit is due to her and 2) any inaccuracies are my own fault.

Genie's Approximately Ten Top Ways to Teach Evolution Better

1. Convey the idea that evolution is a core scientific concept, repeatedly tested over many decades and found to be both reliable and fundamental. Its basic premise, that all living organisms are descended from a common ancestor, is universally accepted by biologists. The fine details, those persisting gaps in knowledge most commonly attacked by anti-evolutionists, belong properly to the frontiers of science, where models and explanations are actively being tested and are still subject to major changes.

2. Recognize that evolution can be discussed in terms of A) the major concept (organisms change through time and descend from common ancestors), B) pattern (ordering organisms in terms of how closely they are related, i.e., how long ago they last shared a common ancestor), or C) mechanism (the exact genetic changes responsible for observed differences over time). Opponents of evolution often conflate these, acting as though uncertainty as to mechanistic details of a specific case or the precise relationship between a particular set of organisms deals a huge blow to the basic concept.

3. Realize that scientists and laypersons use a number of common terms with very different connotations. A scientific fact is an observation, repeatedly confirmed and accepted as true. A body of these facts can be summarized as a law, a descriptive generalization of behavior under stated circumstances. A hypothesis is a tentative explanation of these generalized observations. Repeated testing of a hypothesis can confirm it as a scientific theory - a well-substantiated explanation of facts, laws, and so forth. So evolution is not "just" a theory - its status as a theory makes it superior in scientific parlance to any of the other terms defined above.

4. Don't conflate methodological materialism with philosophical materialism. Science is limited by definition to explaining the natural world via natural processes. We can only test material forces using scientific methods, and we do this by holding some factors constant and varying others. However, this does not necessarily mean that this material world is all there is. We are capable neither of constraining nor of manipulating supernatural forces. God *could* be involved in natural processes, but we cannot control Her actions, and therefore we have nothing to say about what role She might be playing.

5. Know that scientists and laypersons talk about causation in very different ways as well. We can generally agree on proximate (directly observable) causes - for example, that New Orleans was destroyed by a hurricane. However, while laypersons might proceed to deeper causes such as inadequate building codes, and finally to non-material ultimate causes, such as punishment of a city for its sins, scientists cannot. Our secondary causes are inferred explanations for observed phenomena, and our ultimate causes are still material. The possibility for non-material causation exists, but it lies outside the realm of science, see #4.

6. Be able to explain that evolution is not unique to biology. Its basic concept of change through time applies to all of science, from the birth and death of galaxies to continental drift to the radiation of Romance languages from common Latin roots. It is only opposed so violently in the area of biology because it threatens the comforting idea that humans are different from all other animals, specially created by God in His image.

7. Know what evolution is NOT.
A) It is not an explanation for the origin of life, the spontaneous self-organization of organic molecules into complex systems. This is a very interesting field, but quite distinct and still largely speculative.
B) It is not equivalent to "Darwinism", that bogeyman of anti-evolutionists who present it as an evil atheistic ideology (helped along by certain scientists who confuse their own lack of belief with conclusions capable of being drawn froms scientific observations and methods).
C) It is not "chance" or a completely random process with an infinitesimal probability of success. Evolutionary adaptation is due to the force of natural selection - that is, the differential success of random variation results in some characteristics becoming more prevalent in a population over time. Even complicated organs like the eye can be generated by incremental steps, each successive version an improvement over the last.

8. Be able to clarify the difference between the outmoded "great chain of being" and evolution. Although we commonly speak of modern day organisms as "primitive" or "advanced," they are all the SAME distance from their last common ancestor! All terrestrial vertebrates are descended from a fish-like ancestor that crawled onto land, so we should not expect to find evidence that, say, modern reptiles are intermediate between ourselves and fish.

9. Understand how evolutionary history determines future as well as present. Terrestrial vertebrates have four legs because we descended from fish-like marine ancestors with two pairs of fins. We will never sprout a pair of wings from our backs like Pegasus - we can only convert one pair of limbs to wings as birds and bats did independently.

Well, that was only nine, but Dr. Scott didn't have time for more because she had to dash to the airport right after the Q & A. If I could sum up her message in one phrase, it would be, "Information - not indoctrination." Given a few more words, I would add that our goal should be to produce a scientifically literate populace as well as future scientists. We should recognize the need to set standards for basic science education over individuals' objections - but also to find ways to teach controversial topics without making kids from different belief systems feel excluded or belittled.

Running on Empty

What does it take for the world's largest oil consumer to rethink its gas-guzzling ways? Global warming? A war in Iraq? The perceived necessity of drilling in pristine Arctic wilderness or of maintaining good relations with tyrranical leaders who control the oil supply? Nope, only voter indignation at the price we're currently being asked to pay at the pump. Suddenly the Republicans are falling all over themselves trying to present us with short-term solutions like the now-infamous $100 gasoline rebate without doing much at all to address this problem in the long term.

And the Democrats have no reason for pride on this score either. Senator Richard Durbin (D-IL) introduced a bill called the Automobile Fuel Efficiency Improvements Act way back in September 2005. But thus far, only two Senators, Maria Cantwell (D-WA) and Charles Schumer (D-NY), have been willing to co-sponsor S.1648, which would mandate dramatic improvements in automobile fuel efficiency. This is a bill that the whole party should get behind while the issue has momentum and visibility.

And let's have no more talk of decreasing the gas tax, or distributing gas rebates, or increasing the domestic supply by drilling in the Arctic National Wildlife Refuge. If it takes high gas prices to get our attention - if only short-term financial pain can alert us to the less tangible costs of our oil addiction in climate change, health, and national security - then the current crisis could be the answer to our prayers. Let's use this opportunity to create real changes in U.S. energy policy that will better serve our nation and the world.


The substance of S.1648 is summarized on the Library of Congress' legislative information website THOMAS as follows:

Automobile Fuel Efficiency Improvements Act of 2005

Amends federal transportation law to phase in an increase in average fuel economy standards: (1) from 25 miles per gallon for passenger automobiles manufactured between model years 1984 and 2008 to 40 miles per gallon for those manufactured after model year 2016; and (2) from 17 miles per gallon for non-passenger automobiles manufactured between model years 1984 and 2008 to 27.5 miles per gallon for those manufactured after model year 2016. Requires the Secretary of Transportation to prescribe such standards for non-passenger automobiles at least 18 months before the beginning of each model year after model year 2017.

Revises the definitions of automobile and passenger automobile, increasing the weight standards and seating capacity.

Increases the civil penalties for violations of fuel economy standards.

Requires the Secretary of Transportation to: (1) report biennially to Congress on the quality of the automobile fuel economy testing for all currently available automobile technologies; and (2) provide for the John A. Volpe National Transportation Systems Center to study what practicable automobile fuel economy testing process provides the most accurate measures of actual automobile fuel economy in highway use, in urban use, and in combined highway and in urban use.

Directs the Secretary to prescribe: (1) a revised testing procedure for accurately measuring the actual automobile fuel economy of each automobile model, based on the latter study; and (2) amended average fuel economy standards taking into account improved accuracy in their calculation resulting from use of such procedure.

Revises requirements for the fleet average fuel economy standards for U.S. executive agency automobiles, both passenger and non-passenger.

Directs the President to prescribe regulations that require a specified minimum number of exceptionally fuel-efficient vehicles leased or bought by U.S. executive agencies.

Straight from the Gut

If you haven't yet heard or read Stephen Colbert's recent address at the White House Correspondents Association annual dinner, go to Democracy Now. I mean right now.

Paying Our Dues

I finally filed my income tax returns and coughed up an additional $75 to the IRS, having learned that a single person living alone with a cat does not qualify as "head of household." At least my humble income still allows me to take advantage of the free tax preparation software linked to the IRS website - I tried H&R Block this year and found it very user-friendly.

In honor of the looming deadline, I highly recommend the following book: David Cay Johnston's Perfectly Legal, subtitled "The Covert Campaign to Rig Our Tax System to Benefit the Super Rich - and Cheat Everyone Else." In fact, Amazon currently offers it at a bargain price of under $5, so there's no excuse, even if you're not getting a refund.

It's been a year since I read it, but I still get hot under the collar when recalling this book. Johnston describes in shocking detail exactly how the legal loopholes built into our supposedly progressive tax system allow the wealthiest Americans to shift their tax burden onto the middle and lower classes. Even worse, he explains how underfunding and political pressure force the IRS to expend their limited energy checking up on honest (if sometimes financially challenged) citizens while letting the big tax cheats go scot free. In fact, you have a far greater risk of being audited if you request the earned income tax credit (for low income families) than if you're a multi-millionaire.

So as you burn the midnight oil trying to determine whether you exceed the standard deduction, and whether the AMT is going to bite you in the ass, pat yourself on the back for paying your dues to your country. You're a patriot where it counts - your wallet.

Men, Women, and Ghosts in Science

A few months ago, this article in PLoS by Dr. Peter Lawrence caught my eye. Its thesis, essentially, is that we should not expect equal numbers of men and women to pursue successful scientific careers because the two genders are in fact, contrary to idealistic belief, different. But before we rise up in indignation to give old Dr. Lawrence the Summers treatment, let's look a little more closely at what he has to say.

The "ghosts" to which the title alludes are "wayward beliefs and delusions" such as "the dogma that all groups of people, such as men and women, are on average the same, and any genetic distinctions must not be countenanced." Dr. Lawrence dares to argue that "boys and girls are different and remain so," and he cites Dr. Simon Baron-Cohen's recent article interpreting autism as an excessively "male" brain - good at systematizing and focusing narrowly, poor at empathy and communication - as well as a number of earlier studies. Although the qualities Dr. Lawrence discusses apply to male and female populations on average, not to every individual within those populations, he is very clear in his views that women are generally less ruthless, competitive, and self-aggrandizing, and thus tend to fare worse in the struggle to survive in science today.

But far from asserting that these differences make women poorer scientists, Dr. Lawrence attacks the scientific establishment for selecting for "male" qualities that have nothing to do with good science and in fact are likely to hinder it. Gone are the days when a socially inept male commanding a subfield of arcane natural history knowledge could function as an ideal researcher. We are now in an age of "big science" in which leadership and teamwork have become critical for productivity, and it is high time that we gave greater appreciation in the selection process to "feminine" virtues like understanding others and helping them to develop their diverse abilities. According to Dr. Lawrence, this sea change in the current discriminatory scientific selection process would lead to more women in science and to better science.

While applauding the spirit of this rallying cry, I would like to point out a couple of concerns. First, I have no doubt that male and female brains, on average, are different at birth due to genetic differences and/or hormonal millieu. However, I do think that we need to be very cautious about predicting the extent to which those initial differences might determine gender-biased behaviors later in life. For example, even if, on average, little boys begin with better spatial skills and little girls with greater empathy and verbal skills, these initial differences could reinforced and amplified for any of a number of reasons: 1) they are more motivated to practice skills they are good at, 2) their primary playmates will probably be of the same gender and thus prefer to practice those same skills in play, and/or 3) even if their parents are vigilant about discouraging gender stereotypes in the home, they will be bombarded by media and societal messages informing them that boys are supposed to like computers and cars while girls like to play house and hairdresser.

Second, in my opinion, the main omission in Dr. Lawrence's analysis is that he fails to take seriously the socioeconomic biases against women pursuing any highly demanding career, particularly one involving the long hours and relatively poor pay of academic science. The fact is that many women, even highly intelligent and ambitious ones, would like to have families, and no matter how starry-eyed they are on beginning graduate school, they soon realize from observing the few senior women in their departments that very little support exists for that. They certainly can't afford to pay for childcare in their graduate or postdoctoral years unless they are independently wealthy or married to someone who can shoulder the large majority of the financial burden. They will be struggling to land an assistant professorship and/or achieve tenure - hardly the preferred time in their careers for sleepless nights and frequent illness - during their best child-bearing years. And although Dr. Lawrence blithely states that "after about six months or so, there is no reason, in principle, why the main carer of the children should not be the father," in practice this is extremely rare among even the most enlightened couples.

So if we want to increase the retention of women in science in order to take advantage of more feminine leadership skills, create more supportive working environments, and provide role models for future Frances Cricks, it will not be enough to select for originality and insight over aggression and self-promotion. We need to recognize that the same feminine qualities that would make particular women (and men) nurturing mentors are also likely to make them good parents - and that we can and should take concrete steps to support their desires to be both. More affordable childcare options (preferably on-site at universities and research institutions) and more flexible working hours and tenure clocks would be a huge step in the right direction.

Postdoctoral Affairs

Although I had planned to keep my personal life out of this blog for the most part, this morning I received the second of two unpleasant surprises fit for a post on the problem of postdocs.

I'll start at the beginning. When I began postdoctoral research at Pseudonymous Northwest University, my advisor's grant was paying my salary (at the NIH recommended minimum) and benefits. These included a pretty good healthcare plan as well as a nice employer-matched retirement program, both standard for faculty at PNU. However, like any good postdoc, I began applying for outside fellowships as soon as possible. Getting one would not only bring prestige to myself, my advisor, and PNU, it would also free up funds from my advisor's grant so that he could hire additional hands in the lab.

I was lucky enough to be awarded a coveted fellowship by a cancer research foundation, a feat apparently deserving of a brief congratulatory announcement in the PNU Weekly. This fellowship not only provided for a substantial raise in salary from the standard pittance received by starting postdocs, it also came with a $2000 annual allowance for educational expenses. Things were really looking up. I was hopeful that I might even be able to recoup my relocation expenses by the end of my first year.

A couple of months after beginning support on my new fellowship, I went to a conference on the East Coast to present my research in progress. My advisor encouraged me to go, saying that I could use my educational allowance to pay for my trip. Unfortunately, when I returned and sought reimbursement, the payroll office informed me that the money in question had already been put towards my benefits. To his dubious credit, my administratively challenged advisor was as surprised to be reminded of this as I was to learn of it. He instructed me to ask the department for travel funds, but on finding that none had been allocated for postdoctoral (as opposed to grad student or faculty) travel, he eventually agreed to cough up the funds himself.

That was Unpleasant Postdoc Surprise #1.

This morning I was talking to our lab manager about IRAs, having stayed up far too late the night before struggling with my income tax returns. At one point, she suggested that I check exactly what kind of employer-matched retirement fund I had so that we could compare. Imagine how I felt when I logged into my employee account and discovered that I NO LONGER HAD ONE.

It took an irate call to the PNU Benefits Office to ascertain that I had been reclassified from "research associate" to "research associate trainee" when my fellowship support commenced in August of last year. That made me immediately INELIGIBLE for my faculty retirement plan. Some great reward for my success in securing outside funding! Same person, same skills, same job, that blurb, and yet... less love. And no one had even bothered to inform me!

That was Unpleasant Postdoc Surprise #2.

Am I alone in my experiences? Hardly. At noon today I complained to a room of 15 postdocs from departments scattered throughout PNU and was informed that at least three others had suffered similar incidents. The fact is, it's all too easy for postdocs to fall between the cracks. Although we form a huge fraction of the experimental enterprise, especially at top tier research institutions like PNU, university administrators don't seem to know what to make of us. We're not exactly students, or staff, or faculty, or well-organized or represented. That results in extreme heterogeneity of title, salary, benefits, and access to resources. Until very recently, PNU didn't even know how many of us there were, much less how to contact us or assist us. We were left entirely to the mercy of our research mentors (and the extremely generous interpretation of Howard Hughes "graduate" training program funds by a sympathetic faculty member) for training and support.

Hopefully this situation will improve as recognition of postdocs' plight spreads. According to the National Postdoctoral Association, over 100 US universities and research institutions have established their own Postdoctoral Associations and/or Offices of Postdoctoral Affairs. Major areas of advocacy include equitable pay and benefits, funded opportunities for professional development, and tracking of training experiences and outcomes.

One major NPA recommendation, as it happens, is to "increase the percentage of postdoctoral researchers funded by independent fellowships compared with grants initiated by Principal Investigators."

Hmm. Thanks to diligent advocacy by a band of determined postdocs, PNU just established its own OPA on an 18-month trial basis. I wonder if they can get my retirement plan back.

Will Hormones HuRT You?

In 2002, a study was published which claimed that hormone replacement therapy (HRT) increased the risk of stroke for older women. And this was no piddling fly-by-night affair - this was a randomized, double blind, placebo-controlled Women's Health Initiative study of 20,000 post-menopausal subjects conducted by the NIH. Since the investigators had hoped to show that estrogen had a protective effect on women's health, this unexpected result generated a lot of publicity and caused many alarmed women and their physicians to back off hastily from widely used hormonal treatments of menopausal symptoms.

But not so fast. How relevant are the results of this study to women in the real world? In a recent lecture at the University of Washington, Seattle, Dr. Phyllis Wise clued me in to the considerable caveats.

First of all, the women in the experimental group did not receive the standard doses of hormones used in treating menopausal symptoms; instead they were given relatively high, continuous doses of CEE (conjugated equine estrogen) along with MPA (which mimics progesterone and androgen and could interfere with estrogen). This was so that the investigators would be more likely to observe an effect, but was not an accurate re-creation of usual medical treatments.

Second, because this was a double blind study (no one was supposed to be able to tell who received treatment and who received placebo), only women who exhibited no menopausal symptoms were selected for the study. In other words, the investigators deliberately gave hormones to a group of women who would NOT normally seek hormone replacement therapy. Therefore, there is every reason to believe that the experimental group was not representative of the population of women who undergo HRT, meaning that results from this study cannot safely be generalized to the patient population.

Most critically, the participants were women aged 50-79 (average 63) years at the beginning of the study, and many of them had never received hormone replacement therapy. Prior to the experimental treatment, these women had no estrogen circulating in their bodies for an average of TWELVE YEARS.

Why is this so important? Because, biologically speaking, as many lactose-intolerants and former high school athletes have realized, if you don't use it, you lose it. Estrogen, like other hormones, is a signal that has to be received in order to work. Only tissues that make a protein receptor for the estrogen molecule can be instructed by it. And guess what - if there hasn't been any estrogen around for years, the body stops wasting its resources on making estrogen receptors. After that, taking estrogen won't help a damned thing. It's like holding up a stop sign to a driver who has his eyes closed.

This idea is supported by a really cool series of studies by Dr. Wise's group in an animal model for stroke. Researchers removed the ovaries from rats to mimic menopause and later used a suture to block a cerebral artery, temporarily stopping bood flow to one side of the brain. If the rats were given estrogen treatments immediately after removal of their ovaries, they suffered much less tissue death upon blockage of blood flow. However, if estrogen treatment was delayed (for a time equivalent to the years human women spent between menopause and hormone treatment in the WIH study), there was no longer any health benefit. This was because the estrogen receptor (ER-alpha) that mediated the effect of estrogen on brain tissue damage, and would normally be produced at high levels in response to brain injury, was no longer present following prolonged estrogen deprivation.

So the authors of the famous WHI study can't conclude anything about the possible health risks or benefits of standard hormone replacement therapy for women who come to their doctors complaining of menopausal symptoms. No matter how large the study, if it can't accurately represent the relevant treatment method or patient population, then the results cannot reliably inform our medical decisions.


References

Writing Group for the Women’s Health Initiative Investigators, Risks and benefits of estrogen plus progestin in healthy postmenopausal women principal results from the Women’s Health Initiative randomized controlled trial, JAMA 288 (2002), pp. 321–333.

P.M. Wise (2006). Estrogen therapy: Does it help or hurt the adult and aging brain? Insights derived from animal models. Neuroscience 138(3):831-5.

Just the Fats, Ma'am

In a recent widely publicized Women's Health Initiative study, the NIH found no significant differences in the incidence of breast cancer, heart disease, or stroke for women following a low-fat diet. This pronouncement was met with surprise by many clinicians (and one suspects with glee by the National Restaurant Association). But should we really conclude that years of warnings about reducing fat intake were mistaken?

Too little?
The study was meant to compare one group of women who had reduced their total fat intake to 20% of dietary calories with a control group who got 35-37% of their calories from fat. Investigators expected that such a substantial difference in fat consumption would reveal any impact of fats on women's health. And it might have... except that the low-fat group never met the study's goal. The women managed to reduce their fat consumption to 24% of total calories in the first year, but by year six were up to 29%, a difference of only 8% of calories from the control group*. This might not have been enough to affect their chances of developing cancer, heart disease, or stroke, even if fat intake were an important factor. In fact, the subset of women who reduced their fat intake the most did seem to reduce their risk of breast cancer.

Too late?
The participating women were aged 50-79 years at the start of the study and followed for about 8 years. This means that they were already old enough to be at fairly high risk for various cancers as well as heart disease before the changes in diet. These illnesses develop over time, and it is still quite possible that a low-fat diet earlier in life could help to prevent them.

Good fat, bad fat
Most troubling was the failure of this study to distinguish between the various types of fat that make up total fat intake. Saturated fats (mainly from animal products like red meat and dairy), and especially trans fats (from hydrogenated oils), have long been linked to increased risk for heart disease. But unsaturated fats, from fish, nuts, and vegetable oils, are considered "good fats" that lower risk for heart disease. So instructing the participants specifically to reduce their trans and saturated fat intake (and maybe even increase unsaturated fat) could have produced very different results.

All in all, just the kind of situation that confuses everyone and makes me crazy. No wonder people lose faith in the ever-fluctuating recommendations of scientists and clinicians. Even studies like this - huge, well-funded, controlled studies that should be setting the standards - have built-in design flaws that finally allow us to conclude... absolutely nothing.


*This made me grateful that I study the effects of diet in fruit flies and not human beings. If I want to look at brain development on a protein-free diet, my experimental subjects will stick to sucrose, and dammit, they'll like it.

Dealing with India

On March 7, the New York Times ran an editorial that lamented President Bush's recent trip to India and Pakistan. The authors contend that, while a similar offer should not have been made to our ally Gen. Musharraf, who pardoned the Pakistani scientist that helped transfer nuclear technology to leading rogue states, "Granting India a loophole that damages a vital treaty and lets New Delhi accelerate production of nuclear bombs makes no sense either."

The treaty in question is, of course, the Nuclear Non-Proliferation Treaty, signed by the five nations possessing nuclear weapons in 1968 as well as the vast majority of the remaining sovereign states, including both Iran and North Korea (which has since withdrawn). It was not signed by India, Pakistan, or Israel, all three of which have since developed nuclear technology and are believed to possesss more than 60 missiles apiece. Although the US signed the treaty, we were engaged in secret weapons sharing agreements with non-nuclear members of NATO, and still provide nuclear bombs to Belgium, Germany, Italy, the Netherlands, and Turkey, thus violating Articles I and II. (This fine example of global leadership fits right in with our refusal to sign the Comprehensive Nuclear Test Ban, along with China, Israel, India, and Pakistan.)

So the US is hardly in a position to take the moral high ground when it comes to nuclear non-proliferation. Clearly we are willing to operate by a double standard in our own interests - or, let's say, in the interest of global stability - by providing trusted democratic allies with weapons of mass destruction.

And the new deal with India doesn't even go that far. The proposed agreement 1) does not introduce nuclear technology to a non-nuclear power, 2) provides nuclear materials for civilian energy use, not military purposes, and 3) encourages India to reclassify many existing nuclear plants as "civilian" and subject them to monitoring by the IAEA.

In fact, my main question is, why has it taken so long for the US to create official agreements like this with the world's largest democracy? Apparently we're still suffering the after-effects of the cold war strategy that involved support of military coups (especially in Central/South America) in opposition to those left-leaning legitimately elected leaders who might turn out to be (cue ominous music)... COMMIE SYMPATHIZERS!!! And India, which chose to pursue many socialist policies as a fledgling nation to keep itself from being economically overrun by more powerful nations, has been regarded with similar suspicion... in contrast to neighboring Pakistan, currently ruled by the military dictator who usurped their democratically elected leader.

And let's face it, having Musharraf on our side really hasn't accomplished very much in the fight against Al-Qaeda. Although, as our President said recently, finding Bin Laden isn't really that important anyway.

Because clearly it's much more critical to eliminate a sovereign government with no links to 9/11 or Al-Qaeda - a secular regime, however abhorrent, that had been providing a critical balance against fundamentalist Iran. And to maintain good relations with the Sauds and Emirati who supplied 17 of the 19 identified 9/11 hijackers.

***
Declaration of competing interests: I am currently dating an Indian national, discussions with whom provided the basis for this post.