Evolution of Snake Venom

In related news, it seems that the evolution of snake venom is not so mysterious either:

This study analyzed the origin and evolution of snake venom proteome by means of phylogenetic analysis of the amino acid sequences of the toxins and related nonvenom proteins. The snake toxins were shown to have arisen from recruitment events of genes from within the following protein families: acetylcholinesterase, ADAM (disintegrin/metalloproteinase), AVIT, complement C3, crotasin/ defensin, cystatin, endothelin, factor V, factor X, kallikrein, kunitz-type proteinase inhibitor, LYNX/SLUR, L-amino oxidase, lectin, natriuretic peptide, nerve growth factor, phospholipase A2, SPla/Ryanodine, vascular endothelial growth factor, and whey acidic protein/secretory leukoproteinase inhibitor. Toxin recruitment events were found to have occurred at least 24 times in the evolution of snake venom. Two of these toxin derivations (CRISP and kallikrein toxins) appear to have been actually the result of modifications of existing salivary proteins rather than gene recruitment events. One snake toxin type, the waglerin peptides from Tropidolaemus wagleri (Wagler's Viper), did not have a match with known proteins and may be derived from a uniquely reptilian peptide. All of the snake toxin types still possess the bioactivity of the ancestral proteins in at least some of the toxin isoforms. However, this study revealed that the toxin types, where the ancestral protein was extensively cysteine cross-linked, were the ones that flourished into functionally diverse, novel toxin multigene families.

Sorry about the technical language. That's the abstract of a brief article by Bryan Fry, of the university of Melbourne, Australia. The more approachable version can be found in this article from The New York Times, by Carl Zimmer:

Ultimately, this rush is not what drives Dr. Fry, who is 34. His goal is to decipher the evolution of snake venoms over the past 60 million years. Reconstructing their history will help lead to medical breakthroughs, Dr. Fry believes. For the past 35 years, scientists have been turning snake venoms into drugs. Just this February, Dr. Fry and his colleagues filed a patent for a molecule found in the venom of the inland taipan that may help treat congestive heart failure.

Understanding the evolution of snake venoms will speed up these discoveries immensely, Dr. Fry predicted. “You need a good road map to get your research going,” he said.

And from later in the article:

Dr. Fry has constructed evolutionary trees of these venom genes, and his results indicate that venom actually evolved only once in snakes. It started out being produced at low levels, as illustrated today by garter snakes. Later some lineages evolved a more deadly bite.

“It's been the most important adaptation in the history of snakes,” Dr. Fry argued. The snakes that evolved venom no longer had to rely solely on constriction or other ways of physically subduing their prey. “It's freed them up from having to be big-muscled and slow-moving and killing their prey using constriction,” he said. “They can be light, agile, athletic, and they can occupy any niche from the bottom of the ocean to the top of the tallest tree.”

Dr. Fry's research has also shed light on the origin of venom molecules. A number of researchers have suggested that venom toxins are modified saliva proteins. They point out that ordinary saliva proteins are able to start breaking down food in the mouth. Perhaps some tinkering was all that was necessary to turn them into lethal poisons.

As Dr. Fry reports in the March issue of Genome Research, the DNA of venom genes goes against this idea. He constructed evolutionary trees of 24 venom genes, searching through online databases for their closest relatives among nonvenom genes. In only two cases did he find that venom genes evolved from saliva genes. In almost all the other cases, venom genes evolved from ones that were active outside the venom gland - in the blood, for example, as well as the brain and liver.

The evidence indicates that the evolution of a typical venom gene may begin with the accidental duplication of a gene that is active in another organ. In a process known as gene recruitment, one of these copies then mutates in such a way that it begins producing proteins in the venom gland.

In some cases, these borrowed proteins turn out to be harmful when injected into a snake's prey. Natural selection then favors mutations that make these proteins more lethal.

When I look at what actual biologists do I find them working their tails off to solve actual problems of potential importance to people's day-to-day lives. I find them using evolutionary theory as a tool for guiding them towards research projects that are likely to yield fruit.

When I look at what ID folks do, I see them desperately trying to make a virtue out of ignorance. I see people who make no attempt to do any sort of actual science based on ID, and who devote their lives to tearing down the work of others. They do this solely because their weak faith in God can only be maintained by finding scientific gaps for Him to fill. Pathetic.

Evolution of Swim Bladders

While the ID folks continue to wring their hands over the impossibility of explaining the origins of complex biological systems, real scientists are doing the hard work of unravelling their origin. Consider this article (only available by subscription, alas) from the March 18 issue of Science Magazine:

Scuba divers wear air-filled dive vests to move up and down in the water column. Researchers have now used the fish family tree to piece together how the piscine equivalent, an internal air sac called a swim bladder, evolved a complex capillary network and special hemoglobin molecule to inflate it with oxygen. Moreover, according to the proposal presented on page 1752 by Michael Berenbrink of the University of Liverpool, United Kingdom, and his colleagues, these innovations helped fish expand their species diversity. “The scenario developed presents a fascinating picture of the evolution and radiation of fish,” says Bernd Pelster, an animal physiologist at the University of Innsbruck, Austria.

Herring and other fish with primitive swim bladders must surface and gulp air to keep their bladders full and their bodies buoyant. The more sophisticated species use oxygen in the blood, an advance that freed them from their air tether and allowed for the expansion into the deep ocean. These species depend upon a network of blood vessels to concentrate oxygen in their swim bladder. However, high oxygen concentrations usually inhibit the release of oxygen from the blood. To get around this problem, these fish have a special Root-effect hemoglobin, a form of the protein that releases its oxygen cargo even when concentrations of the gas are high.

This new hemoglobin evolved before the swim bladder's capillary network, according to Berenbrink, a comparative animal physiologist. He and his Liverpool colleague Andrew Cossins reconstructed the history of the self-contained swim bladder by looking for its prerequisite components, such as the hemoglobin. The researchers studied species, ranging from sharks to dolphinfish, that represented the different stages of fish evolution.

According to the new study, the Root-effect hemoglobin evolved once in primitive fish. Although the molecules function at high oxygen concentrations in sharks, lungfishes, and even tetrapods, they are most efficient at releasing oxygen in those conditions in codfish and other modern fish. Next came a capillary network that supplied oxygen to fish eyes, allowing them to see better. This also evolved just once, about 250 million years ago, and depended upon the Root-effect hemoglobin. From that point, the hemoglobin was essential to fish.
About 100 million years later, a similar capillary network, this one supplying oxygen to the swim bladder, finally began showing up. This network arose four times in different fish groups, the researchers found.

“It's one of the few examples of our understanding of the evolution of a complex organ from simpler parts,” says Albert Bennett, an evolutionary physiologist at the University of California, Irvine. “They have done an excellent job of teasing apart what happened when.”

Of course, the accompanying technical article provides many of the details.

As a practical matter it is very difficult to unravel the precise evoutionary trajectory taken by the precursors to a modern, complex system. The individual steps of such a trajectory represent isolated events lost to deep time. We are constrained by our lack of evidence. Occasionally we have fossils to help guide us (as with the evolution of the mammalian inner ear from jaw bones in ancient reptiles), but most of the time we have only whatever inferences we can draw from modern species.

But that does not mean we must wallow in ignorance. As described in the excerpt above, what we can do is look for the individual parts of the system in closely related species. In other words, we mgiht try cataloging the parts of the system and investigating which modern species have which parts. If we find that the patterns of appearances and disappearances of the relevant parts are consistent with phylogenetic trees constructed from other data, we can assert with some confidence the sequence in which the parts of the system formed.

And that is what the researchers described in the excerpt did. As they write in their research article (subscription required):

By taking advantage of the wide divergence of fishes and by integrating data from all levels of organization, we reconstruct on a vertebrate phylogeny the likely sequence of evolutionary events leading to the ability to secrete O2. We support this analysis by identifying consistent patterns of secondary losses of several of these components in specific clades of advanced fishes, thereby characterizing factors that affect their maintenance.

In other words, they found that the patterns of appearances and disappearances of the parts of the swim bladder system was entirely consistent with the phylogenetic trees compiled from other data. If the swim bladder was not the product of evolution, there would be no reason to expect to find such patterns. Indeed, the only reason the researchers thought to look for the patterns they found was that they started from the hypothesis that the swim bladder had evolved gradually.

Of course, the ID folks will be quick to tear into this. They will blather about just-so stories and guess-work, they will claim that the parts of the sequence the researchers identified are themselves highly complex, and they will boast about their high evidentiary standards relative to those muddle-headed evolutionists. And they will be wrong on every count.

What this work shows is that yet another complex system reveals clear indications not of being a pristine creation from nothing, but of being the end result of a gradual evolutionary process. If the data had been slightly different from what it it is, the researcher's theory would not be tenable. Surely even the ID folks would have to concede that this data makes the hypothesis that the swim bladder evolved more likely than it was before this work.

One final thing. Creationists of all sorts have always been schizophrenic on this point. When they are trying to make the case for the direct action of an intelligent agent in natural history they claim that no one has the faintest idea how this or that complex system could have evolved naturally. But when a scientist comes along and says the clear evidence idicates the system went through phases X, Y and Z during its evolution, the creo's turn around and say it's easy to tell a story about how something evolved.

But the fact is, it's not easy at all. Hypotheses about how complex systems evolved are hard to test directly, but they still must be consistent with the large amount of data that's available from modern species. It seems that time after time the data comes out just the way it ought for evolution to be a viable hypothesis.

The ID folks will doubtless continue to fold their arms and shake their heads. With each passing day the sterility of their enterprise becomes a little more obvious. Meanwhile, evolution continues to be a reliable guide for scientists who actually care about understanding the natural world.

God Bless Paul Krugman

Paul Krugman's column from Tuesday's New York Times was even more excellent than usual:

Claims that liberal bias keeps conservatives off college faculties almost always focus on the humanities and social sciences, where judgments about what constitutes good scholarship can seem subjective to an outsider. But studies that find registered Republicans in the minority at elite universities show that Republicans are almost as rare in hard sciences like physics and in engineering departments as in softer fields. Why?

One answer is self-selection - the same sort of self-selection that leads Republicans to outnumber Democrats four to one in the military. The sort of person who prefers an academic career to the private sector is likely to be somewhat more liberal than average, even in engineering.

But there's also, crucially, a values issue. In the 1970's, even Democrats like Daniel Patrick Moynihan conceded that the Republican Party was the “party of ideas.” Today, even Republicans like Representative Chris Shays concede that it has become the “party of theocracy.”

Consider the statements of Dennis Baxley, a Florida legislator who has sponsored a bill that - like similar bills introduced in almost a dozen states - would give students who think that their conservative views aren't respected the right to sue their professors. Mr. Baxley says that he is taking on “leftists” struggling against “mainstream society,” professors who act as “dictators” and turn the classroom into a “totalitarian niche.” His prime example of academic totalitarianism? When professors say that evolution is a fact.

In its April Fools' Day issue, Scientific American published a spoof editorial in which it apologized for endorsing the theory of evolution just because it's “the unifying concept for all of biology and one of the greatest scientific ideas of all time,” saying that “as editors, we had no business being persuaded by mountains of evidence.” And it conceded that it had succumbed “to the easy mistake of thinking that scientists understand their fields better than, say, U.S. senators or best-selling novelists do.”

The editorial was titled “O.K., We Give Up.” But it could just as well have been called “Why So Few Scientists Are Republicans These Days.” Thirty years ago, attacks on science came mostly from the left; these days, they come overwhelmingly from the right, and have the backing of leading Republicans.

Krugman is right on both counts. Obtaining a job as a math or science professor requires obtaining a PhD in something. That means spending many years wroking very hard first to learn a lot of very esoteric material, and then making some original contribution to your subject. During this time you will be making very little money, and you can look forward to a career in which you are very unlikely to obtain any great measure of fame or fortune. I suspect that the sort of person who finds that life appealing (me, for example) also tend to be left-leaning in their politics.

But the bigger cause by far is the fact that, as things are now, the Republican Party is very hostile to both science and education. Administrations that use the term “Reality-Based Community” as an epithet are never going to be popular among scientists. A President who believes the jury is still out on global warming or evolution is not someone a scientist is likely to support.

Meanwhile, the Republicans seem to think that it's the teacher's unions that are responsible for the decline of public education. As anyone who actually works in education knows, the only reason teachers get the crumbs that they do in terms of salary and benefits is because their unions fight tooth and nail to get them. Instead of giving the public schools sufficient funding to do their job, Republicans seem more interested in giving huge tax breaks to wealthy people.

And then there's the fact that the Repbulican Party is currently at the mercy of the Religious Right. I know a great many scientists who hold perfectly orthodox religious views, but after devoting your life to an enterprise that values logic and evidence above all else you're not likely to find fundamentalism appealing. A belief that the Bible is the beginning and end of all wisdom is contrary to everything science is supposed to stand for.

If the Republicans started emphasizing the libertarian aspects of conservatism and left behind the fanatical religious nonsense, they would find much more support among academics. That does not seem likely to happen anytime soon. Until it does, it's simple common sense that explains the prevalence of liberals at universities.

P.Z. Myers has some additional thoughts here.

Sean Carroll also comments here.

Richards on Relativity

Here's ID proponent Jay Richards, lecturing us about relativity. The subject is this article, from The New Yorker about Godel and Einstein:

The February 28 issue of The New Yorker has an interesting article by Jim Holt on Einstein and Gödel. It bears a striking similarity to an article on Einstein and Gödel that David Berlinski published in Discover magazine in 2002. Similarities aside, Holt summarizes Einstein's argument on special relativity nicely, so nicely, in fact, that it reveals what I have long suspected is a mistake in Einstein's argument.

Holt tells us:

A century ago, in 1905, Einstein proved that time, as it had been understood by scientist and layman alike, was a fiction. And how did he do that? Simple: If the events in question are at some distance from one another, judgments of simultaneity can be made only by sending light signals back and forth.

Whoops. Stop right there. Maybe there's more to Einstein's argument than that (although this is just how I've seen it described many times before.) But assuming this is accurate, there's an obvious problem.

Determining that two events are simultaneous is not the same thing as two events being simultaneous. Right now, my wife is doing something at home. She's doing it right now even though I don't know what it is she's doing.

Einstein's argument seems to mistake epistemology for ontology. Holt's description of Einstein's argument, as it proceeds in this article, provides more evidence of this.

See the original article for links.

More to Einstein's argument than a two-sentence description in a popular-level account? Ya think?

What kind of mindset does it take to say “I've found what appears to be an error in a common, popular-level treatment of a major theory from physics. I guess Einstein and everyone after him has overlooked this, so I'm going to rush to point it out in a blog entry.”

This sort of arrogance is SOP for creationists. We're talking about people whose knowledge of evolution starts and ends with popular work of Stephen Jay Gould and Richard Dawkins. It is upon this basis that they feel qualified to attack the entire field.

Anyway, cosmologist Sean Carroll has the takedown here.

I'm reminded of something Richard Dawkins once wrote, responding to a vicious review of The Selfish Gene by philospher Mary Midgley: “Indeed, we are in danger of assuming that nobody would dare to be so rude without taking the elementary precaution of being right in what she said.”

Cranks All Read From the Same Playbook

Here's Slate's Dahlia Lithwick commenting on the book Men in Black: How the Supreme Court is Destroying America, by Mark Levin:

If a book lands on the best-seller list and nobody hears it, did it really happen? Mark R. Levin's Men in Black: How the Supreme Court Is Destroying America was ranked eighth on the New York Times list this week; it's been on that list for six weeks now, and seems to be leaping off the bookshelves, despite the fact that it concerns constitutional law and the U.S. Supreme Court. Yet it has been reviewed virtually no place and written up by almost no one. True, Charles Lane did a piece about it in the Washington Post a few days ago; he noted that absolutely nobody who writes, talks, or thinks about the high court has even read it. It's selling, it seems, almost entirely due to endorsements by Rush Limbaugh, Sean Hannity, and Fox News.

Men in Black was published by Regnery Publishing—the outfit that brought us Unfit for Command: Swift Boat Veterans Speak Out Against John Kerry last summer. Serious journalists spent serious time debunking the claims set forth in the Swift Boat book, but absolutely no one seems to be taking on Levin. This isn't too surprising: For one thing, there's no election on the line. And for another, no serious scholar of the court or the Constitution, on the ideological left or right, is going to waste their time engaging Levin's arguments once they've read this book.

I use the word “book” with some hesitation: Certainly it possesses chapters and words and other book-like accoutrements. But Men in Black is 208 large-print pages of mostly block quotes (from court decisions or other legal thinkers) padded with a forward by the eminent legal scholar Rush Limbaugh, and a blurry 10-page “Appendix” of internal memos to and from congressional Democrats—stolen during Memogate. The reason it may take you only slightly longer to read Men in Black than it took Levin to write it is that you'll experience an overwhelming urge to shower between chapters.

And later:

I can understand completely why the serious legal thinkers of this world have no interest in engaging with Levin on his legal scholarship. Jeff Rosen probably had to swallow hard—twice—before even referencing Men in Black in his op-ed on judge-bashing last weekend. But ignoring this book won't keep it from tearing up the best-seller list; and it's unwise to write off everyone who reads it as a Swift Boat lunatic.

See the original article for links.

Sound familiar? Not really a book at all? Two hundred eight large-print pages? Sells well but serious scholars don't want to touch it? Something that's obviously deranged to anyone knowledgeable in the field but persuasive to large numbers of people lacking such knowledge?

She could just as easily be talking about creationism. And that's because crankery always looks the same. The jacket title alone would tell a serious person that Levin is a crank. If the Supreme Court had as its explicitly stated goal the destruction of America they would be unable to accomplish the task. Separation of powers and all that. But over-the-top, mega-exaggerated claims are SOP among cranks.

Elsewhere in her artice Lithwick goes into detail about all the ridiculous oversimplifications and internal contradictions of Levin's book. But of course, Levin did not write the book in an attempt to make a serious contribution to legal scholarship. If you have ever seen him on one of his many television appearances, most notably on Fox's Hannity and Colmes, he is a bomb-thrower, not a scholar. This book exists to provide an excuse to have him on the show. Now he can be introduced as the author of the New York Times bestseller Men in Black, thereby giving him instant credibility.

Academics have a term for books like Men in Black: Quickie Books. It is an apt label for most of the books published by right-wing outfits like Regnery. The books of people like Ann Coulter, Mona Charon, William Bennett, Sean Hannity and Michael Savage are not there to be read and pondered. Most of the right-wing punditocracy would not be capable of writing such a book even if they wanted to. No, these books exist to provide phony credentials to their authors, and to persuade ignorant people that their baseless but deeply felt prejudices are justified.

But Lithwick is also right that ignorance must be confronted, and the confronting must be done by experts in the field. It's a thankless, boring job undertaken at the expense of more serious work, but it must be done nonetheless. Just as more legal scholars need to listen to Lithwick, so too do more scientists need to get down in the muck with the ID folks.

Evolution Books

P.Z. Myers has offered up this list of books to read about evolution. I recognize most of them, and am happy to concur with his assessment. Some of them I was unfamiliar with, and they have now been added to my personal “Books to Read” list.

However, there were a few books that I found especially useful when I was first learning about this subject that Myers does not mention:

• Finding Darwin's God by Kenneth R. Miller. I do not agree with Miller's theological ideas, but the book's first half is about as clear an explanation of why creationism and ID are a lot of nonsense as you could hope for. He also shows that thoughtful Christians have nothing to fear from evolution.
  
  
• Science on Trial by Douglas Futuyma. An excellent presentation of the evidence for evolution and a strong refutation of the common YEC arguments. This was written before ID replaced YEC as the dominant form of anti-evolution nonsense, but it's arguments are still useful and relevant.
  
  
• Ever Since Darwin, The Panda's Thumb, Hen's Teeth and Horse's Toes, The Flamingo's Smile, Bully for Brontosaurus by Stephen Jay Gould. These were the first five anthologies of Gould's Natural History essays. They provide fascinating commentary on many aspects of evolutionary theory. Gould's later essay collections were good as well, but they tended to move more towards history of science and away from science. Gould had his hang-ups about certain topics, like sociobiology and selfish genes, but his essays are essential reading nonetheless.
  
  
• Darwin's Ghost by Steve Jones. A chapter by chapter updating of The Origin of Species Spekaing of which:
  
  
• The Origin of Species by Charles Darwin. The one that started it all. Surprisingly still interesting and relevant.
  
  
• Abusing Science by Phillip Kitcher. A careful and thorough demolition of YEC written by a prominent philosopher.
  
  
• Climbing Mount Improbable by Richard Dawkins. I like this one even better than The Blind Watchmaker. Dawkins shows convincingly that complex biological systems show far more evidece of being the products of evolution than of being the products of divine intervention.
  

Anyway, I'm sure I'll think of others later. But those were a few I found especially interesting and helpful.

Do Science Classes Kill Curiosity?

I often tell people that math is easy; it's math classes that are hard. By this I mean that most of the mathematical ideas you encounter in high school and college mathematics courses are fairly common-sensical. Sadly, this fact tends to get lost in a sea of arcane rules for manipulating algebraic expressions and converting contrived word problems into actual equations you can manipulate. Courses inevitably tend to stress the latter aspect of mathematics because students have to receive grades at the end of the term, and these grades have to be based on something more concrete than “getting the idea.” On top of that, there are certain basic mathematical skills that must be mastered if you are going to move on in the subject. No one enjoys this aspect of learning a discipline, but the fact remains that you must walk before you can run.

I was thinking about this while reading this op-ed from the Harvard Crimson. The essay was written by Irene Sun, a Harvard undergraduate, and begins as follows:

“You’re concentrating in history and science and taking my class?” my molecular biology professor asked. “So that must mean you’re pre-med, right?”

“No,” I responded slowly. “Actually, I’m not.”

“Wow! I’m really impressed!” he exclaimed, with a genuinely surprised expression on his face. “You’re taking this class because you’re interested in the material!?”

At that moment, I honestly, truly wanted to cry. There I was, sitting in my professor’s office at the end of his weekly office hours, and I could hardly hold back my tears. I had a test the next day, but I couldn’t stop thinking about the fact that my own professor expects to teach to an audience whose primary goal is not to explore an interest, but to fulfill a requirement. I had never felt as disappointed in the meaning of a Harvard education.

After listing various science courses that she took, she writes:

In those classes, I encountered an incredibly driven pre-med population. They worked exceedingly hard in class, often forming study groups on Friday and Saturday nights. I was impressed by their diligence, but I was also continually frustrated by their unabated emphasis on grades. They memorized lectures and regurgitated textbooks in hopes of an extra two points on an exam, but I found that few of them were ever truly excited about the material they toiled over. And slowly, disturbingly, I found that my own interest in molecular biology was waning.

So here I am, beginning my fourth semester at Harvard by shopping zero science classes. I still love learning about how life works, but I can’t stomach the thought of continuing to learn it with the attitude that I’ve encountered here.

My conceptions of my peers, as well as of intellectual life at Harvard, have been thrown into turmoil. I now question the value of intellectual passion in a world that seems increasingly to be based on grades, course requirements and career prospects. I question the effectiveness and sensibility of our cutthroat GPA and exam-based academic structure. But I also question the mindset of science professors and of my fellow students. At what point did professors automatically expect that their students studied their subject matters because of career requirements rather than intellectual appeal? Why are so many of my fellow students so hell-bent on requirements instead of passion? What happened to that sense of academic adventure, excitement and curiosity?

Unfortunatly, Ms. Sun's questions have very simple answers.

Every math and science professor I know dreams about having a student like Ms. Sun. But the simple fact is that most students enrolled in introductory math and science courses are not there primarily out of a love for the subject. That is why Ms. Sun's molecular biology professor was surprised by her answer. When I teach first semester calculus I do so knowing that almost no one is there simply to learn about one of the supreme accomplishments of the human intellect. The reason I am so certain of this is that on the first day of class I have them write on an index card their reasons for taking the course. If two people in a class of thirty indicate an interest in the material as one of their reasons I consider it a good omen. In reality most of them are there to satisfy a requirement of one sort or another.

But Ms. Sun should also realize that the situation changes dramatically once you rise above the introductory classes. In mathematics, and I suspect in science as well, the upper-level courses are populated primarily by a small number of dedicated majors who really are there out of love for the subject. That is why professors generally prefer teaching those courses over introductory courses. It is not that professors dislike presenting beginner-level material. It is that the attitude of the students in such courses can be hard to take at times.

Concerning Ms. Sun's remaining questions, I think she is being a bit hard on her fellow students. The reason pre-med students care so much about grades is that the medical schools they will eventually be applying to care a great deal about them. But a desire to squeeze out every point they can on an exam does not imply that they don't also care about the subject. Caring about grades and caring about the material are not mutually exclusive.

As a college student I experienced some of the same frustration Ms. Sun describes. I recall one night being up until three in the morning desperately trying to solve the last problem in a homework assignment that was due the next morning. One of my well-meaning suitemates, concerned about my lack of sleep, informed me that I shouldn't worry about solving the problem since getting it wrong was not going to affect my grade very much. I was perfectly aware of that, of course, but it was not concern for my grade that was keeping me up. I hadn't gone to sleep because I really wanted to solve the problem! I think my friend found that idea amusingly eccentric.

I am sorry that Ms. Sun was discouraged by her science classes. It would probably help if more science departments offered courses intended for people who wanted a broad and serious overview of the subject, but were not intending to major in the field. Many math departments already offer such courses. Sadly, there are often practical reasons (not enough faculty to teach such courses, not enough students interested in taking them, not enough money in the budget to offer them) for not offering them.