Common vampire bat (Desmodus rotundus)

In an era of emerging infectious diseases, rabies is a uniformly lethal virus that has been with us for over two thousand years. It’s more lethal than West Nile, SARS, and Ebola. HIV, like rabies, is essentially 100% lethal but the course of infection is glacial compared to rabies. Moreover, we understand what HIV does to you and your immune system while our understanding of what rabies does do your nervous system remains somewhat hazy. It’s even less clear what rabies does in nonhuman animals but if you’ve ever seen or heard a description of a rabid dog or raccoon you wouldn’t think that rabies goes any easier on its reservoir hosts.

The lethality and speed of the virus that makes rabies deeply fascinating (and terrifying) on one level also makes it almost uninteresting on another level. As an evolutionary biologist, I’m drawn to variation and with rabies, it seems like there is no variation. It just kills you, quickly, and it has done so for a long, long time.

It turns out, however, that this might not be entirely true. A study published in Am J Trop Med Hyg last year reports serological data from two communities in the Peruvian Amazon. Seven adults of the 63 people sampled were positive for rabies virus neutralizing antibodies, 6 of those 7 people reported having been bitten by bats, and only one of them reported prior vaccination. In combination, these results suggest that people in an area of high risk for rabies transmission are being exposed to rabies, developing antibodies to the virus, and not getting sick. Whether this is because of selection for immunity in people living close to rabid vampire bats or whether it is a feature of the rabies strain itself it not clear, but it is certainly a novel aspect of what we thought was an old and familiar pathogen.

Relevant links:

The paper reporting the results of the Peruvian study.

An editorial on the Peruvian study by the doctor who treated the first case of an unvaccinated rabies survivor; creator of the Milwaukee protocol for treating rabies victims.

A Radiolab podcast on the Milwaukee Protocol. Also discusses the Peruvian study.

I put in the silver dollar, and pulled the lever.  The lights flashed, the reels spun; cherry. cherry. cherry.  Jackpot, I just won $10,000!

That never happened to me and it never will, because I don’t see the appeal of slot machines.  People tend to think I’m a gambler when I tell them that I played a lot of poker in college.  But actually, good poker players aren’t gamblers.  A good poker player has the exact opposite mindset to that of a rational gambler.  Gamblers want to maximize variation, poker players want to minimize it.

Casinos make money because the odds are stacked in their favor.  Any individual gambler may win or lose money, but if enough people play enough games, the law of large numbers kicks in and the casino makes a profit.  So the goal of any casino owner is to bring people in and keep people gambling.  Most casino visitors don’t think about gambling rationally, but if they did, they would realize that the house-edge (the amount that the odds are in the casino’s favor) is actually a fee that they are paying to gamble.  This fee pays for stochasticity, or variation in outcomes.  A rational gambler would consider how much he would like to win, and then bet exactly once on a game where he could win that amount.  Exactly once, because if he splits the bet and spreads it out over a lot of plays, the law of large numbers kicks in again, and he ends up with less variation in the outcome.  The odds favor the casino, and so less variation means a smaller chance of winning.

Good poker players take the opposite approach.  A good poker player has a limited amount of money, but the odds are in his favor.  Essentially, he is the casino owner, and the less skilled people he plays against are the casino gamblers.  His goal is to play as much as possible, to play enough hands to make the variation go away.  But he can only keep playing while he has money, and so even though the odds are in his favor, he needs to minimize variation as he plays to ensure that he doesn’t run out of money.  If he can play enough hands, the law of large numbers says that he will win.

Rational gamblers and good poker players both hope to have made money at the end of the day, but that’s where the similarities end.  The mindset of a gambler is completely different from that of a poker player.  Gambling just doesn’t appeal to me, and that’s why I’ll never win the jackpot on a slot machine.

I had an interaction with an older man who was ringing me up at the grocery store. Maybe it was my nose ring or my tattoos, but he asked me “are you an artist? I bet you’re an artist. Or a musician. You look like one.” I told him I was a research scientist at the university; his answer: “but you don’t LOOK like a scientist.”

I wasn’t offended, but I’m writing this because this isn’t the first time I’ve had this interaction, and I’m sure that some of you have had similar conversations before. Much like Jessi’s post about the stereotype of a “professor” that still seems to linger in our increasingly integrated society, the stereotype of “scientist” for many people still conjures an image of a white man with little social tact and no fashion sense. He prefers to be isolated, and is generally aloof in his communications with others. But, after meeting scientists at the Fermilab, you can see that seventh grade children have a very different perspective – scientists become “normal people” (according to their descriptions).

Do you think these stereotypes can be damaging? As in, do you think that children may be turned off from science because of being seen as a reclusive nerd who doesn’t have a life? I can’t say I was ever affected by these stereotypes, as I was always my own person, and didn’t really care if people thought I dressed strangely or was “geeky” or introverted. Additionally, I had the opportunity to get my bachelor’s degree at a college where half the biology faculty were women, and the majority of my classmates and labmates were women, despite the student body at large being pretty evenly split, so I never felt like I experienced very much sexism. But I imagine it can be quite difficult for a woman in a male-dominated faculty, as it seems is more common at large research universities, or as an ethnic minority in a mostly white cohort at a major American university, constantly being placed aside the general public’s view of what a “scientist” looks like and what a “scientist” is.

Clearly, WE know that scientists can have a fashion sense, and that they are not all anti-social, and that there are a LOT of women scientists. This post was inspired by visiting this website, where you can peruse pictures of scientists from the spectrum of STEM fields, from undergraduates to silverbacks, of different races and genders, showing their true selves. We love science, but we are also outdoors(wo)men, musicians, dancers, aspiring culinary artists, parents, etc. That’s what a scientist looks like!

Feeling a little more like a scientist today. First publication! This stems from work I contributed to as an undergraduate at Arizona State University in the lab of Ananias Escalante with another undergraduate at the time, Benjamin Rice.

Check it out in the latest articles section of the Malaria Journal. We bring up the usefulness and necessity of identifying the underlying evolutionary processes that contribute to the generation of genetic diversity of genes used as genetic markers for epidemiological purposes. Many studies choose epidemiological markers based on diversity alone. We show that it is important to understand how that diversity it generated and its patterns through space and time. Such knowledge will help determine which epidemiological studies are suited for using particular methods and loci for genotyping.

There is a precedent for this. Aging scientists trying to impart wisdom to young folk. Sounds like my day job. But some write it down. Medawar is very good. The latest to try is E.O. Wilson, renowned entomologist, ant specialist and sociobiologist. I was really looking forward to reading his attempt, partly because I like to think I am never too young to learn, and partly because his TedMed talk preceded mine and I could not focus on a word he said. (I took immense pleasure in realizing his had roughly the same number of views as mine until I saw he had also given a Ted talk on the same thing – and that generated an order of magnitude more views…). Actually, I found his book a bit disappointing on the advice front (maybe I am too old to learn), though it is very endearing on the E.O.Wilson-, ants-, and how cool is entomology-, natural history- and evolutionary biology- fronts.

Dan Simberloff has a great review of the book. His review is so good, you can just read it and save the price of the book (unless you really care for ants).

Two pieces of advice Wilson offers really struck me.  (1) Real scientists do not take vacations. (2) Run from the guns. The first is nonsense (despite what Simberloff says). The second is something I have heard from the Nobel prize winners (1, 2) I have had teaching on my course. They too have said find yourself an important problem where there is a community of scientists but not too much competition.

All very easy to see in hindsight.

to get cited?

Obviously do some good work. But on top of that there seem to be other things that matter. Sadly there are contradictory views on exactly what they are. Nicole is a master (mistress?) of the eye-catching title (Ahead of the Curve, The Vector as Protector). But apparently amusing (sexy?) titles aren’t good.

Short titles are.

I was deeply affected by time I spent in a teaching hospital a few months back, watching doctors struggling to save patients with infections. I wondered if it had always been thus. Evidently not.

I have just returned from my first Society for Invertebrate Pathology meeting, which overall was really great.  I had the opportunity to talk to a bunch of really fun folks and listen to many talks that often had a very different perspective on insect-pathogen interactions.  So it was really good for getting the brain juices flowing in a different direction.

However, I did come home with one really important take home message from this meeting.  Never turn into an old fart.  Why is it that the younger crowd often presents the interesting science (exceptions are Matt and Andrew of course)?  When I become old and gray I promise to do the following: I promise to never pontificate about my personal history in the field, which inevitably often involved climbing uphill in the snow both ways. Instead, get to the science.

I promise to never pat my back for past successes explicitly in my talk, but instead let my research stand on its own merit.I also will promise to obey talk time limits and not drag over. When I turn into an old fart I will endeavor to not suck the living soul out of my audience by talking in a monotone with zero emotion.

Finally, I promise to never use age as an excuse to grab someone’s butt on the dance floor.  It’s not cute or charming just because you are old.  So please, let us all age gracefully in academics or wherever we end up.

A cow gave birth on the Bromley dairy farm in Vermont at 5:30am this past Saturday. This idyllic place is where my husband grew up and his family is still. People often come and go on the farm. They help out, stop by to visit, often stay for a meal, and sometimes strangers get lost up there after mistaking the mile long driveway for a public road.

A maternity ward nurse had visited the day before and was disappointed to learn she had missed the birth by just a few hours. She had really wanted to know what a cow placenta looked like and particularly how much it weighed. It was time to gather some data on the farm in the name of comparative anatomy!

The placenta was saved, strung up with some old twine from a hay bale, and then photo documented. (The photographer, and good friend of the nurse, cracked, “Does it have a good side?” as this hideous gelatinous collection of sacs was turned back and forth on the twine).  This was followed by discussion about what all of the parts were, what they connected to and how, and whether the amniotic sac should be counted as part of it when it was weighed.

An old metal basket scale was used. A cow placenta weighs approximately 13 pounds in case you were wondering. There was some debate about whether all of the fluid should have been drained to count just the tissue, but since no one really wanted to deal with emptying all of those sacs of gush, it was decided a 13 pound estimate was good enough. I suppose more replicates can be added with further births.

Everyone who visited the farm that day checked out the placenta, including my cousin, who happened to be in town. He made a huge show of disgust upon hearing there was a cow placenta strung up in the barn and remembered one I had shown him more than a decade or two ago when one of our family’s cows had given birth. Apparently it had made quite an impression on him. He couldn’t help checking this one out and quizzing us on how many placentas there would be for a twin birth. (The farmers knew the answer: two for fraternal twins, one for identical twins).

This trip home was a reminder to me that you don’t need formal training or a lab coat to do science, particularly on a farm where life happens 24/7. Also it was a refresher course on how fun biology is! There was enthusiasm for anatomy, data acquisition, and discussion without any formal “outreach” type prompting. I think that curiosity is the most powerful motivator for getting people interested in science, and outreach efforts just make the interesting stuff more readily available.

In high school, I was the drum major of our marching band. The drum major, for those of you who may not have gone the “band geek” to “science geek” route, is the person who marches or stands in front of everyone, decides the tempo of the music, and shouts and/or whistles to get the band to march. I could say a lot of things about this as, like, an ironic juxtaposition of skill (i.e., an innate sense of rhythm and unexpectedly loud shouting voice) and personality (i.e., someone who would rather lead by example or suggestion than by, like, literal leading), but I bring this up now because I recently recalled something that happened to me as a drum major that felt abstractly quite related to how I’m feeling now, as a person who just finished her PhD.

As the drum major, as I said, I stood at the very front of the band. During field shows- those musical, formation-y things that happen, for example, at half-time during non-professional American football games- I stood at the front of the band atop a platform that was, to me, about eyeball height when my feet were on the ground. During the show I’m thinking of, it was very windy. (And cold, as it seems to most often be at American football games, but the wind is what is important to the story.)

So, it was very windy.

I was standing up on this platform, flailing my arms about- on the beat, though, because that was my job- and the wind was blowing at me so hard that I had to lean into it, lest it whisk me off the platform, onto the xylophones and suspended cymbals (Xylophones are very expensive, and suspended cymbals are very pointy on top, so, beyond the threat of mortification in front of a stadium-full of people, there are plenty of reasons to resist a rapid, uncontrolled approach at them from above).

So, I was flailing my arms about and leaning, hard, into the wind.

When, suddenly, the wind let up. Suddenly, there was nothing to push against! I stumbled a half-step forward- all I had between me and open space- as, suddenly, the effort that I was putting forth wasn’t doing anything helpful at all.

There was a half-beat of terror, my toes at the edge…But then I regained my footing, and the show went on.

I share this with you because I feel like the wind has suddenly stopped, and I’m afraid of being impaled by cymbals and breaking expensive things with my face. I want to thank all of you who convinced me to lean into the wind, even when I felt rather like just stepping off of the podium to where the wind was less harsh, but I’d also like to ask… how many beats does the terror last?

I tend to avoid lab work. It’s not my forte, and I love working on theory-type stuff. I also worry a lot about messing up experiments (my own & others’) via cross-contamination, etc. Once when I was an undergrad, I had to redo a fungal growth experiment when I realized that I had been measuring fungal growth incorrectly, and henceforth I always worried about realizing at some future date that my methods had biased the results so much that I couldn’t draw any conclusions. I suspect most experimentalists worry about this a lot, but I sidestepped the problem by focusing on theory.

Photographic evidence that I did lab work.

This week, I faced my fears and visited the Ferdig lab at Notre Dame to get some data on malaria cultures. Fortunately they didn’t just turn me loose in the lab, and Lindsey Turnbull did the heavy lifting for the experiments. However, I did relearn the joys of pipetting, made one blood smear slide I’m not ashamed of (as Jessi can attest, it’s not easy), labeled 180 slides, and took over 3000 pictures of malaria parasites. Much of our understanding of malaria biology relies on accurate counts of red blood cells and parasites, as well as consistent identification of parasite life stages, and I hope to be able to use the pictures to automate that process, or at least make it less error-prone. It will take time to analyze the images and see what we’ve got, but I’m glad I got the opportunity for a week of intensive lab work, to put the theory in perspective.

Young parasites look like rings. (It's the strain I mentally refer to as Mary Poppins, in case your were curious.)

Next stop: Edinburgh.

Figure 1: Schematic graph describing how a drinker's success in bar-based sports changes with the consumption of alcoholic drinks. Note the steep decline in performance after reaching the OBL. This can be soul-crushing.

Last Friday, Monica found out something that every friend of mine discovers eventually – I am terrible at bowling. My lack of gaming abilities aren’t restricted to bowling, though. No, I am also terrible at pool, darts, pinball and probably other bar-based entertainments. But this doesn’t stop me from playing. I plough on, inspired by the memories of glorious strikes and games won upon reaching ‘The Optimum Beer Level’ (OBL).

The OBL is the amount of alcohol that confers a previously unattainable level of talent on the drinker. These newfound abilities persist for a period long enough for a round or two of pool, when the stuff of memories occurs, and then evaporate miserably (Figure 1).  While I’m a proponent of the idea, I can’t take the credit for recognizing the phenomenon or coining the phrase – that goes to two high school friends of mine.

It seems they were in good company. Microsoft CEO Steve Ballmer is credited with noting a similar effect, now known as the Ballmer Peak, that may be of interest to anybody out there struggling with R. Defined by urbandictionary.com as ‘The theory that computer programmers obtain quasi-magical, superhuman coding ability when they have a blood alcohol concentration percentage between 0.129% and 0.138%’, it appears to be well known among programmers. So well known in fact that there’s a ballmerpeakathon, which sees Silicone Valley’s geeks come together to drink beer and create apps.

So, what’s going on here?

Plugging in ‘performance’ and ‘alcohol’ into Google Scholar yields the inevitable slew of papers that demonstrate alcohol’s suppression of motor skills, cognitive ability etc. The only article that discusses a beneficial impact of alcohol in the context of sports is a piece of conjecture published in a Vegas magazine by two psychology PhDs (legitimate PhD’s – I found their theses on the University of Florida’s website).  In it they propose the ‘Optimum Altered State’ (OAS) and hypothesize that unexceptional competitors benefit from the OAS/OBL because it promotes ‘automaticity’, whereby your ‘mind gets out of the way’, and confidence. A review of studies that address the relationship between moderate alcohol intake and psychological state, cites evidence to back their hypothesis: reductions in stress & self-consciousness; increases in confidence and problem-solving ability. The latter may result from a boost in creativity according to a recent study. These authors suggest that alcohol inhibits our normal tendency to exclude ‘distracting’ information when solving a specific task, information that is often useful in the process of finding inventive solutions to a problem.

Not being one for curve balls, bank shots, chips and tricks I doubt an increase in creativity is behind my OBL gaming abilities but it could well be behind the Ballmer Peak. Or any genius that comes out of post-lab meeting drinks at The Skellar, for that matter!

Last weekend one of our graduate students asked me what animal behavior was and why we study it. Seeing as I was recently at the annual meeting of the Animal Behavior Society, I should be able to answer this question.

An animal behaviorist watches animals, observes and describes behaviors of those animals, and attempts to determine the function of those behaviors. Some examples of behaviors from this year’s conference talks; the tail straddling walk of plethodontis salamanders, wrestling in male horn beetles, nest construction in rock wrens, cuddling in bats (you read that correctly), victory dances in crickets, mate guarding in spiders, home shopping in ants, social behavior in black widows, and dancing in honey bees. In most cases, we also endeavor to contextualize those behaviors in the interactions than animal has with other organisms and its environment.

Scientists working on these animals are tackling the above questions at a variety of levels and using many different methods, ethology, biochemistry, molecular biology, experimental manipulation in the laboratory and the field, transcriptomics, and many more. As a field we are moving to incorporate techniques to investigate behavioral interactions with eco-immunology, development, and epigenetics.

As for the question of why we need to study animal behavior, we are animals. Throughout the conference there were clear examples of how better understanding animal behavior has improved our understanding of human biology. Fernando Nettebohm is a man obsessed with learning and bird song. He is credited with discovering neurogensis and among other things is using birds as a model for better understanding human conditions such as Huntington’s disease. Animal behavior was one of the leading fields in establishing that environment effect gene expression. Most recently, there has been a push to determine the role of social context in determining gene expression. The implications of Gene Robinson’s studies on honey bees are so universal that they even offer insights into the metabolic pathways in some cancers. In other words, understanding social interactions in bees and their effect on the bee genome could contribute to curing cancer. Additionally, a new field of human social genomics is emerging from work on bees, chiclids, and baboons. I think the society’s outgoing president Robert Seyfarth explained the importance of animal behavior best, “Our field is an engine for new ideas and we are translational”.

I often focus on the biology of my study organisms (disease controlling mosquitoes) from a control perspective. These animals are important and even if my finding only applies to them I believe it has value from that perspective. I left the meeting inspired to broaden my framework and see if maybe these mosquitoes can teach me a thing or two about myself.

A couple weeks ago I made a visit to Toronto for a spontaneous mini-holiday. Part of the reason for this decision was that Jay-Z and my parents were going to be in town (independently, as far as I know), and part of the reason was that Nicole has recently relocated to Toronto for a faculty position. During my visit, we spent most of our time eating or wandering around the city on foot, and in between sharing a donut and a platter of Ethiopian food, Nicole and I talked a lot about science and how to do science. Not surprisingly given Nicole’s move, one of the issues we touched on is the difficulty of being science buddies with someone when you live and work in different places.

Being scientific collaborators isn’t as difficult, since you can use e-mail and Skype to discuss any issues at hand. But when you’re buddies, the science talk is interwoven with non-science talk and it’s much harder to generate that kind of free form conversation over e-mail or Skype. Even on a smaller geographic scale, I struggle with the distance between the MSC and Merkle buildings. It’s not that I don’t talk to people in MSC but the interactions tend to be more scheduled and more structured. I’ve tried to distribute my time between buildings more equally, but I have yet to find a happy balance.

Things like coffee hours help for the between buildings issue, but we can still probably do more to foster blended work/personal relationships. I obviously don’t have an answer for how to maintain science friendships across buildings and across boarders, but as science becomes more interdisciplinary I think this is an issue that people are going to have to put more thought into.

Katey Glunt, my first US PhD student, had her PhD defense last week, and is now Dr Katey. I just love this picture. It says it all.

”If you’re going to be crazy, you have to be paid for it, or else you’re going to be locked up.”

July 18th was Hunter S. Thompson‘s would-be 72nd birthday. I started re-reading “Kingdom of Fear“, and with it rekindled my appreciation for the ideals surrounding gonzo journalism: the throwing of objectivity out the window, speaking from a very personal platform, and of course, no shortage of profanity.

But, what if there were someone who advocated gonzo medicine? I think he’d be loath to use that term, but Dr. Vinay Prasad at the National Cancer Institute at the NIH in Bethesda has been advocating what many would consider some pretty radical reforms in premedical and medical education. Chiefly, that basic science education (he specifically mentions physics, calculus, and organic chemistry multiple times) isn’t necessary to be a good physician, and that the core of nearly all US premedical programs and the testing battery of the MCAT is completely invalid.

In his words, “reflecting on medical education from the vantage of caring for patients, I am tempted to conclude that nearly every step is irrelevant for the next one.”

Counterintuitively, he argues that a primary focus on basic science de-emphasizes intuition, quick thinking, and decision making in rare or unencountered circumstances. He advocates that medicine be taught with a more Hippocratic end, with the core focus on patient care. This seems obvious, but the more I ponder it, I’m not sure I think that our medical education focuses primarily on patient care. I’ve never been to med school, so this is also speculation on my part, but from my peers going through the process now, I hear far more about the difficulty in memorizing hundreds of flashcards for a physiology course than I do about being tested on bioethics, statistics and decision-making, and real-world doctor-patient communication skills.

He poses a question to many advocates of the status quo who state that rigorous basic science backgrounds elevates physicians to a status of “professional” and not “technician”: does it really? Prasad argues that possessing a mental database of facts may “make one feel more comfortable deciding when to generalize data, but it does not guarantee that one is in fact more often correct in those generalizations.” In short, medical students are not being taught to think.

Prasad is not arguing that medicine take a complete overhaul and become a solely touchy-feely empathy-based field built only on listening to the patient, with no background in the basic sciences and statistical logic. He is advocating what he calls “encounter-based medicine“. He argues that a mechanistic understanding of the underpinnings of medicine is vital, but that a core focus on such details often results in reversals of adopted medical procedures that are based solely on the mechanistic reasoning (here, he audaciously uses the word “belief”) they would work.

For the general practitioner, I think that an encounter-based curriculum may be more useful, and that such a curriculum will result in more competent and efficient physicians at the general care level. However, for physicians interested in researching for innovative treatment regimes and possible cures, I maintain that a solid background in the basic sciences – even physics and calculus – is invaluable.

Whether you agree with Dr. Prasad or not, I suggest you read all of his opinion pieces, as he writes on subjects from unethical practice in pharmaceutical research to modeling how habits like taking food from a talk you didn’t attend will result in you being statistically more likely to be called into question by an ethics board later on in life. And whether you agree with Dr. Prasad or not, I don’t think he cares.

A fungus had penicillin before us (humans).  A spider can spin silk that is stronger than steel.  A humpback whale’s fin may be more efficient than the airfoil of an airplane.  Observations like these make me wonder why we spend so much time trying to invent single products.  Each of the above products and many more were invented in nature using a single technique.  Wouldn’t it be easy to copy this technique to make new inventions?

Megan got me thinking about this when she brought the term “evolutionary machine” back from this year’s Evolution meeting.  I’m still not sure exactly what the term means, but my first thought (perhaps incorrectly) was that an evolutionary machine is a self-replicating machine, or alternatively, a computer in which a simulated entity can replicate.  Any amateur naturalist can tell you that organisms are generally well-adapted to their respective environments.  Descent with modification and natural selection is the reason.

I’m not an engineer or a physicist, but I was under the impression that we had equations to describe how fluids move over objects.  So then why are we studying humpback whale fins to improve airfoil design?  Wouldn’t it be easier to put those equations into a computer with the current airfoil design, and let evolutionary forces do the rest of the work?

I see two issues with taking this approach.  The first issue is that our understanding of air flow (or fill-in-the-blank pertaining to the invention of interest) may be imperfect.  This, however, would become obvious during prototype development and product testing, and so subsequent iterations of evolution could be improved by incorporating our newfound knowledge.  The second issue is that we may not know the objective function we are trying to optimize.  For the evolution of organisms, the objective function is a weighted combination of survival and reproduction, termed fitness.  For airfoil design, it is presumably some combination of efficiency, stability, and strength — but obviously some kind of objective function already exists because otherwise we wouldn’t know how great the humpback whale fin is.

I’ve been thinking a lot about sleep since Eleanore referenced a blog post on the profoundly disturbing topic of prion diseases (well-worth a read, though perhaps not before bedtime). In my opinion, the most terrifying disease mentioned (and the most terrifying disease period) is fatal insomnia. It comes in an inherited form (fatal familial insomnia) and a sporadic form (developing spontaneously), but I notice that no one argues about the fatal part. The disease takes away the ability to sleep—though it’s not clear how—and no medical intervention yet devised can restore it. Indeed, from the accounts in the book The Family That Couldn’t Sleep, medical advice ranges from fruitless to insulting. The book raised more questions than it answered, as did my subsequent searches on the Web of Science and Google Scholar. Why do humans and other animals afflicted with different prion diseases hold their heads in the same odd fashion?  Why should a misfolded protein cause such severe neurological damage? Why would we keep a gene around if it codes for a protein that is likely to misfold? And why do we even need sleep?

I’ve found no satisfying answers. While the misfolded proteins do aggregate to an alarming degree, causing conspicuous plaques in the brain tissues, they may not be the culprits behind the massive neurological damage. In a series of intriguing experiments (extensively reviewed here), mice lacking the prion gene don’t show nasty symptoms upon inoculation with prions—even when they have plaques in their brains! It takes a normal copy of the prion, attached to the surface of cells, to get the symptoms. The normal version of the prion gene is also implicated in other diseases, for example, helping cancer cells resist the body’s signals to die off. So why keep the gene around?

The answer may be partly (and ironically) to help us sleep. Mice without the prion gene don’t sleep as well, suggesting that fatal insomnia may come about not because of the misfolded protein, but because of the lack of the normally folded protein. But why do we need sleep? It’s not just humans (or mammals, or even vertebrates) that need sleep—even insects need some form of sleep. My guess is that any sort of complex processing unit needs downtime for routine maintenance (e.g., the computing cluster, my bank’s website, me). Sleep may be necessary for cognition and immunity, but I would regard a computing cluster as unforgivably flawed if it required routine maintenance for almost a third of every day. Still, selection hasn’t removed somniferous organisms just yet. I must conclude that sleep has huge (if uncharted) benefits and is therefore an activity I should spend more time and energy pursuing.