No one craves scentlessness

Friday, April 16th, 2021

In The Power of Habit Charles Duhigg tells the story of a chemist at P&G who was working with hydroxypropyl beta cyclodextrin, or HPBCD, at the lab, and when he came home, his wife asked if he’d stopped smoking, because his clothes didn’t smell like smoke at all. The new product they developed was a huge success — but only after they learned how to market it:

They spent millions perfecting the formula, finally producing a colorless, odorless liquid that could wipe out almost any foul odor.


They decided to call it Febreze, and asked Stimson, a thirty-one-year-old wunderkind with a background in math and psychology, to lead the marketing team.


The same pattern played out in dozens of other smelly homes the researchers visited. People couldn’t detect most of the bad smells in their lives. If you live with nine cats, you become desensitized to their scent. If you smoke cigarettes, it damages your olfactory capacities so much that you can’t smell smoke anymore. Scents are strange; even the strongest fade with constant exposure. That’s why no one was using Febreze, Stimson realized.


Television commercials were filmed of women spraying freshly made beds and spritzing just-laundered clothing. The tagline had been “Gets bad smells out of fabrics.” It was rewritten as “Cleans life’s smells.”

Each change was designed to appeal to a specific, daily cue: Cleaning a room. Making a bed. Vacuuming a rug. In each one, Febreze was positioned as the reward: the nice smell that occurs at the end of a cleaning routine. Most important, each ad was calibrated to elicit a craving: that things will smell as nice as they look when the cleaning ritual is done.

The irony is that a product manufactured to destroy odors was transformed into the opposite. Instead of eliminating scents on dirty fabrics, it became an air freshener used as the finishing touch, once things are already clean.

When the researchers went back into consumers’ homes after the new ads aired and the redesigned bottles were given away, they found that some housewives in the test market had started expecting — craving — the Febreze scent.

One woman said that when her bottle ran dry, she squirted diluted perfume on her laundry. “If I don’t smell something nice at the end, it doesn’t really seem clean now,” she told them.

“The park ranger with the skunk problem sent us in the wrong direction,” Stimson told me. “She made us think that Febreze would succeed by providing a solution to a problem. But who wants to admit their house stinks?

“We were looking at it all wrong. No one craves scentlessness. On the other hand, lots of people crave a nice smell after they’ve spent thirty minutes cleaning.”

New habits are created by putting together a cue, a routine, and a reward, and then cultivating a craving that drives the loop.

SARS-CoV-2 is a sort of zombie virus

Tuesday, April 13th, 2021

Athena Aktipis and Joe Alcock suggest that SARS-CoV-2 is a sort of zombie virus, turning people not into the undead but rather into the unsick:

People typically think of zombies as the stuff of science fiction. But in the biological world, zombies are all over the place, from the Ophiocordyceps fungus that perpetuates itself by zombifying ants; to Toxoplasma gondii, a single-celled parasite that completes its life cycle by leading rodents into the jaws of predators. Zombie viruses are also a real thing, influencing their host’s behavior in ways that enhance the viruses’ evolutionary fitness.


About 40% of those with SARS-CoV-2 are asymptomatic spreaders, never showing symptoms at all. And those who do show symptoms are most contagious in the two days before symptoms appear. Why people don’t feel sick earlier – or sick at all – might be part of the evolutionary strategy of SARS-CoV-2.

A look under the hood of the virus reveals more about that manipulative machinery. SARS-CoV-2 interferes with a person’s immune response; this is why people don’t necessarily feel sick and withdrawn as they would in a typical viral infection. Instead, SARS-CoV-2 silences the body’s alarm signals that otherwise would orchestrate anti-viral defenses. It blocks interferons, a set of molecules that help fight viruses. Interferon activity makes people feel more depressed and socially withdrawn – so when the novel coronanvirus impedes interferon activity, mood is lifted, sociality is increased and you feel less sick.

The virus also decreases pain perception. Normally, pain motivates us to hunker down when we need to heal. But SARS-CoV-2 blocks this response by preventing the transmission of pain signals. This is why people feel fine even when they are teeming with virus before the onset of symptoms.

At the same time, SARS-CoV-2 dampens the body’s response to infection. It hinders pro-inflammatory cytokines, molecules that help spur the immune response. This too makes hosts feel better than they should. Typically, feeling sick helps our bodies prioritize healing by making us reduce our energy expenditure. With SARS-CoV-2, unsick hosts have the energy to do as much as they used to, maybe more.

Habits never really disappear

Monday, April 12th, 2021

One of the central ideas that Charles Duhigg explains in The Power of Habit is the habit loop:

To deal with this uncertainty, the brain spends a lot of effort at the beginning of a habit looking for something — a cue — that offers a hint as to which pattern to use.


And at the end of the activity, when the reward appears, the brain shakes itself awake and makes sure everything unfolded as expected.


First, there is a cue, a trigger that tells your brain to go into automatic mode and which habit to use. Then there is the routine, which can be physical or mental or emotional. Finally, there is a reward, which helps your brain figure out if this particular loop is worth remembering for the future:


The cue and reward become intertwined until a powerful sense of anticipation and craving emerges.

Habit Loop

Habits never really disappear.


In one set of experiments, for example, researchers affiliated with the National Institute on Alcohol Abuse and Alcoholism trained mice to press levers in response to certain cues until the behavior became a habit. The mice were always rewarded with food.

Then, the scientists poisoned the food so that it made the animals violently ill, or electrified the floor, so that when the mice walked toward their reward they received a shock. The mice knew the food and cage were dangerous — when they were offered the poisoned pellets in a bowl or saw the electrified floor panels, they stayed away.

When they saw their old cues, however, they unthinkingly pressed the lever and ate the food, or they walked across the floor, even as they vomited or jumped from the electricity. The habit was so ingrained the mice couldn’t stop themselves.

Although ice might seem simple, it is complicated stuff

Sunday, April 11th, 2021

Regular six-sided crystals of ice are actually just one of ice’s many forms, or polymorphs, the form known as ice 1. Now ice 19 has been discovered:

Although ice might seem simple, it is complicated stuff. For instance, only the oxygen atoms in the water molecules of six-sided ice crystals form a hexagonal shape, while their hydrogen atoms are randomly oriented around them. This makes ice I a “disordered” or “frustrated” ice in the terminology of ices. One of the properties of such disordered ices is that they can deform under pressure: “This is the reason why glaciers flow,” Loerting said.

In contrast, the hydrogen atoms in several of the other polymorphs of ice also have their own crystal patterns, and they are called “hydrogen-ordered” or “H-ordered” as a result. Unlike disordered ices, H-ordered ices are very brittle and will shatter, rather than deform, he said.

In those terms, the newly identified 19th form of ice is an H-ordered ice; in fact, it’s an H-ordered form of a disordered ice, called ice VI, which has a random pattern of hydrogen atoms. And ice VI also has yet another H-ordered polymorph, ice XV, in which the hydrogen atoms are aligned in an entirely different pattern.

“Ice VI, ice XV and ice XIX are all very similar in terms of density [because] they share the same kind of network of oxygen atoms,” Loerting said. “But they differ in terms of the positions of hydrogen atoms.” It’s the first time that such a relationship between ice polymorphs has been discovered, and it could allow experiments to study transitions between one form and another, he said.

Naturally this reminded me of ice-nine, from Kurt Vonnegut’s Cat’s Cradle:

Ice-nine is an alternative structure of water that is solid at room temperature and acts as a seed crystal upon contact with ordinary liquid water, causing that liquid water to instantly transform into more ice-nine.

No one wondered how a man who couldn’t draw a map of his home was able to find the bathroom without hesitation

Saturday, April 10th, 2021

In The Power of Habit, Charles Duhigg tells the story of a man who lost his ability to form new memories:

The scans indicated that almost all the damage within Eugene’s skull was limited to a five-centimeter area near the center of his head. The virus had almost entirely destroyed his medial temporal lobe, a sliver of cells which scientists suspected was responsible for all sorts of cognitive tasks such as recall of the past and the regulation of some emotions.


At the time, no one wondered how a man who couldn’t draw a map of his home was able to find the bathroom without hesitation.


She asked him to point out which doorway led to the kitchen. Eugene looked around the room. He didn’t know, he said. She asked Eugene what he would do if he were hungry. He stood up, walked into the kitchen, opened a cabinet, and took down a jar of nuts.


As they rounded the corner near his house, the visitor asked Eugene where he lived. “I don’t know, exactly,” he said. Then he walked up his sidewalk, opened his front door, went into the living room, and turned on the television.

He couldn’t form “real” memories, but he could form habits.

The average person processes three liters of water each day

Tuesday, March 30th, 2021

The human body uses 30% to 50% less water per day than other primates:

The study compared the water turnover of 309 people with a range of lifestyles, from farmers and hunter-gatherers to office workers, with that of 72 apes living in zoos and sanctuaries.


When they added up all the inputs and outputs, they found that the average person processes some three liters, or 12 cups, of water each day. A chimpanzee or gorilla living in a zoo goes through twice that much.

Pontzer says the researchers were surprised by the results because, among primates, humans have an amazing ability to sweat. Per square inch of skin, “humans have 10 times as many sweat glands as chimpanzees do,” Pontzer said.


But the researchers controlled for differences in climate, body size, and factors like activity level and calories burned per day. So they concluded the water-savings for humans were real, and not just a function of where individuals lived or how physically active they were.


One hypothesis, suggested by the data, is that our body’s thirst response was re-tuned so that, overall, we crave less water per calorie compared with our ape relatives. Even as babies, long before our first solid food, the water-to-calories ratio of human breast milk is 25% less than the milks of other great apes.

Another possibility lies in front of our face: Fossil evidence suggests that, about 1.6 million years ago, with the inception of Homo erectus, humans started developing a more prominent nose. Our cousins gorillas and chimpanzees have much flatter noses.

Our nasal passages help conserve water by cooling and condensing the water vapor from exhaled air, turning it back into liquid on the inside of our nose where it can be reabsorbed.

Having a nose that sticks out more may have helped early humans retain more moisture with each breath.

It’s hard to know how many infections resulted

Friday, March 19th, 2021

A junior doctor in the UK explains that the Covid pandemic didn’t feel real there in the first few months of 2020:

Then in early March it began to feel far more real. We’d had one confirmed Covid case in my hospital so far when I went to review a patient in Accident and Emergency. He’d had a fall here in England while on holiday from Milan — the epicentre of Europe’s outbreak — and needed an operation to fix a fracture.

I asked the A&E consultant if he had screened the man for any Covid symptoms and he laughed, admonishing me — semi-jokingly — for my “racism” against Italians. I suggested that we should isolate him until we had tested for the virus, to be on the safe side.

At this point I was told sharply “whatever next? We test everyone who walks through the doors for covid?” Looking back, that comment feels entirely absurd — today, of course, every patient has a rapid Covid swab before they are admitted to the hospital — but a year ago such an idea didn’t even occur to anyone.

While it was not within my powers to question a senior A&E doctor, I was able to suggest to my surgical consultant that the patient should be isolated “just in case”. We moved him from the open ward, alongside all of the other elderly patients with fractures, to a side room.

At the time tests were hard to get and results took 48hrs, although our hospital had developed a more informal 24-hour test which was “not yet clinically validated”. The result came back negative, although in block capitals underneath the result was written DO NOT DEISOLATE PATIENT UNTIL FORMAL 48h TEST. And so… we deisolated the patient immediately, because, so I was told, “He has a fracture that we need to fix. He’s got no symptoms anyway!”

The following day the result of the clinically-validated second test came back — the patient had coronavirus. By this point he had already been intubated and ventilated in theatres, itself an aerosol-generating procedure, and on several separate open bays full of patients. It’s hard to know how many infections resulted; how many deaths.

It’s worth remembering at this stage that masks were strictly Not Allowed when reviewing patients, unless they had either tested positive or had symptoms, and had also recently returned from China, Italy or Iran. When we were assessing our Italian patient in A&E, we were told sternly to remove our masks, lest we “scare the patients and other staff”.

My colleague, who had reviewed the patient with me, developed a cough several days later. Initially she stayed at work, since she had neither shortness of breath nor fever; when she called in sick the next day, many of the consultants laughed at how she had clearly been scared by her Covid contact, and was being ridiculous to not work through her “mild cold”. She was later admitted to our hospital with moderate “Covid pneumonitis”, as we would now say, requiring oxygen to help her breathe.

One woman’s blink of light was another woman’s fully formed narrative

Wednesday, March 10th, 2021

Tests of simple reaction time had done astonishingly little to help explain expert sports performance, David Epstein notes (in The Sports Gene):

The reaction times of elite athletes always hovered around one fifth of a second, the same as the reaction times when random people were tested.


So, in 1975, as part of her graduate work at [the University of] Waterloo, [Janet] Starkes invented the modern sports “occlusion” test.

She gathered thousands of photographs of women’s volleyball games and made slides of pictures where the volleyball was in the frame and others where the ball had just left the frame. In many photos, the orientation and action of players’ bodies were nearly identical regardless of whether the ball was in the frame, since little had changed in the instant when the ball had just exited the picture.

Starkes then connected a scope to a slide projector and asked competitive volleyball players to look at the slides for a fraction of a second and decide whether the ball was or was not in the frame that had just flashed before their eyes. The brief glance was too quick for the viewer actually to see the ball, so the idea was to determine whether players were seeing the entire court and the body language of players in a different way from the average person that allowed them to figure out whether the ball was present.

The results of the first occlusion tests astounded Starkes. Unlike in the results of reaction time tests, the difference between top volleyball players and novices was enormous. For the elite players, a fraction of a second glance was all they needed to determine whether the ball was present. And the better the player, the more quickly she could extract pertinent information from each slide.

In one instance, Starkes tested members of the Canadian national volleyball team, which at the time included one of the best setters in the world. The setter was able to deduce whether the volleyball was present in a picture that was flashed before her eyes for sixteen thousandths of a second. “That’s a very difficult task,” Starkes told me. “For people who don’t know volleyball, in sixteen milliseconds all they see is a flash of light.”

Not only did the world-class setter detect the presence or absence of the ball in sixteen milliseconds, she gleaned enough visual information to know when and where the picture was taken. “After each slide she would say ‘yes’ or ‘no,’ whether the ball was there,” Starkes says, “and then sometimes she would say, ‘That was the Sherbrooke team after they got their new uniforms, so the picture must have been taken at such and such a time.’”

One woman’s blink of light was another woman’s fully formed narrative. It was a strong clue that one key difference between expert and novice athletes was in the way they had learned to perceive the game, rather than the raw ability to react quickly.

The maladaptive variety is what gives competitiveness its bad name

Tuesday, March 9th, 2021

Top Dog: The Science of Winning and Losing draws a distinction between adaptive competitiveness and maladaptive competitiveness:

Adaptive competitiveness is characterized by perseverance and determination to rise to the challenge, but it’s bounded by an abiding respect for the rules. It’s the ability to feel genuine satisfaction at having put in a worthy effort, even if you lose. People with adaptive competitiveness don’t have to be the best at everything—they only strive to be the best in the domain they train for. They might be perfectionists at work, but they don’t care if they’re the worst at tennis and shuffleboard. They are able to defer gratification, meaning they accept that it can take a long time to improve. Healthy competitiveness is marked by constant striving for excellence, but not desperate concerns over rank. It’s adaptive competitiveness that leads to the great, heroic performances that inspire us all.

The maladaptive variety is what gives competitiveness its bad name. Maladaptive competitiveness is characterized by psychological insecurity and displaced urges. It’s the individual who can’t accept that losing is part of competing; it’s the person who competes when others around him are not competing. He has to be the best at everything, and he can’t stop comparing himself to others even when the competition is over. He doesn’t stop when the whistle blows. He drags others into competitions they don’t want to be in, by provoking them. And he will resort to cheating when he can’t win.

The advice to “keep your eye on the ball” is literally impossible

Monday, March 8th, 2021

When David Epstein’s The Sports Gene: Inside the Science of Extraordinary Athletic Performance came out, I bought it in hardcover and enjoyed it immensely — but physical books don’t lend themselves to blogging. So, when I saw that the Kindle edition was on sale for $1.99, I “picked up” a copy and reread it.

The opening chapter explains how the Pepsi All-Star Softball Game was contested by Major League Baseball players — until one year, when they brought in a true softball pitcher from Team USA, Jennie Fitch:

As part of the pregame festivities, a raft of major league stars had tested their skill against Finch’s underhand rockets. Thrown from a mound forty-three feet away, and traveling at speeds in the upper-60-mph range, Finch’s pitches take about the same time to reach home plate as a 95-mph fastball does from the standard baseball mound, sixty feet and six inches away. A 95-mph pitch is fast, certainly, but routine for pro baseball players. Plus, the softball is larger, which should make for easier contact.

Nonetheless, with each windmill arc of her arm, Finch blew pitches by the bemused men.

For four decades, scientists have been constructing a picture of how elite athletes intercept speeding objects.

The intuitive explanation is that the Albert Pujolses and Roger Federers of the world simply have the genetic gift of quicker reflexes that provide them with more time to react to the ball. Except, that isn’t true.


A typical major league fastball travels around ten feet in just the 75 milliseconds that it takes for sensory cells in the retina simply to confirm that a baseball is in view and for information about the flight path and velocity of the ball to be relayed to the brain. The entire flight of the baseball from the pitcher’s hand to the plate takes just 400 milliseconds. And because it takes half that time merely to initiate muscular action, a major league batter has to know where he is swinging shortly after the ball has left the pitcher’s hand, well before it’s even halfway to the plate.

The window for actually making contact with the ball, when it is in reach of the bat, is 5 milliseconds, and because the angular position of the ball relative to the hitter’s eye changes so rapidly as it gets closer to the plate, the advice to “keep your eye on the ball” is literally impossible. Humans don’t have a visual system fast enough to track the ball all the way in.


So why are [All-Star batters] transmogrified into Little Leaguers when faced with 68-mph softballs? It’s because the only way to hit a ball traveling at high speed is to be able to see into the future, and when a baseball player faces a softball pitcher, he is stripped of his crystal ball.

Hurtling to the earth in a free fall is something you can get acclimated to

Sunday, March 7th, 2021

Top Dog: The Science of Winning and Losing opens with a study of first-time skydivers:

Analyzing the jumpers’ saliva samples, Deinzer wasn’t surprised to learn that they had a huge rush response to the first jump. But with each subsequent jump, the rush was reduced by about a quarter. By just the third jump, there was still a pronounced rush of stress, but (on average) it was now only half the first jump’s intensity. It was more akin to the stress you get from driving in slow traffic that’s making you late.

Apparently, hurtling to the earth in a free fall is something you can get acclimated to, rather quickly.


Stephen Lyng is a scholar who studies edgework, a term borrowed from Hunter S. Thompson’s description of anarchic human experiences. During the 1980s, Lyng was a jump-pilot at a local skydiving center. He contrasted what he learned there from skydivers with what he learned later by studying car racers, downhill skiers, combat soldiers, and business entrepreneurs. Lyng eventually concluded that the true “high” of skydiving, and other edgework, stems from the way skilled performance brings control to a situation most people would regard as uncontrollable.

All of the safety rituals used to minimize the danger (in situations of extreme risk) engender this sense of control, but edgeworkers’ fundamental skills are the ability to avoid being paralyzed by fear and the capacity to focus their attention on the actions necessary for survival. The feeling of self-determination they get from conquering the risks is the real payoff. It’s not pure thrill they seek, but the ability to control the environment within a thrilling context.

How does this compare to ballroom dancing — in the Nordrhein-Westfalen Regional Ballroom Dance Competition?

The pressure of ballroom dancing induced a stress rush just as strong as someone’s second parachute jump. Many of the ballroom dancers’ stress response was every bit as high as a first parachute jump.

Don’t forget — this was not the dancers’ first competition, or second. On average, the competitors had been in 131 competitions, and they had been going to dance contests for eight years. Yet even with all that experience competing, plus thousands of hours of practice, ballroom dancing was still enormously stressful.


According to what science tells us, dancing at that point in their lives should have required very little cognitive control. All the muscle memory should have been driven down into the cerebellum region of their brains, where it was automated. There should have been no worry over forgetting to vary the inside and outside of their feet to create style and line.


The cutthroat world of the ballroom remained terrifying no matter how long they’d been at it. The contestants did not habituate.


How is it that someone can immediately get used to skydiving but can never get used to ballroom dancing?


The real difference was the psychological environment. The expert dancers were in a competition, and the novice parachutists were not. To be more precise, it wasn’t the dancing that was stress-inducing. It was being judged. It was winning and losing.


Ten years of practice may make you an expert. But even then, it just gets you in the door. You’ll still have to dance against other experts — most of whom have put in their ten years, too.


The same fundamental skills that matter in edgework turn out to matter in any competitive situation: the ability to avoid being paralyzed by fear, and the capacity to focus attention.

(I bought the Kindle edition on sale for $1.99, and it’s still on sale.)

Social outcomes are substantially determined at birth

Tuesday, March 2nd, 2021

Gregory Clark’s latest (pre-print) paper, For Whom the Bell Curve Tolls, argues that a lineage of 400,000 English individuals 1750-2020 shows genetics determines most social outcomes:

It is generally assumed that the elements that define social status — occupational status, educational attainment, wealth, and even health — are transmitted across generations in important ways by the family environment. Above we show that the patterns of correlation of social status attributes in an extended lineage of 402,000 people in England are mainly those that would be predicted by simple additive genetic inheritance of social status in the presence of highly assortative mating around status genetics. Parent-child correlations for a trait equal those of siblings, and the patterns of correlation of relatives of different degrees of genetic affinity is mainly consistent with that predicted by additive genetics. Further family size and birth order, elements that would significantly affect the family environment for children, have modest effects on adult outcomes. The underlying persistence of traits is such that people who have likely never interacted socially, such as second to fifth cousins, remain surprisingly strongly correlated in terms of occupational status and wealth. The patterns observed imply that marital sorting must be strong in terms of the underlying genetics.

If this interpretation is correct then aspirations that by appropriate social design, rates of social mobility can be substantially increased will prove futile. We have to be resigned to living in a world where social outcomes are substantially determined at birth. Personally I would argue that this should push us towards compressing differences in income and wealth that are the product of such inherited characteristics. The Nordic model of the good society looks a lot more attractive than the Texan one.

We’ve gotten so good at preventing so many diseases, there’s been a loss of knowledge and a loss of experience

Saturday, February 27th, 2021

In our quest for perfect solutions to the current pandemic, we’d forgotten an extremely obvious and simple one — fresh air:

A colleague joked, at one point, that things would have gone better in the pandemic if we still believed in miasma theory.

Miasma theory — discredited, of course, by the rise of germ theory — held that disease came from “bad air” emanating from decomposing matter and filth. This idea peaked in the 19th century, when doctors, architects, and one particularly influential nurse, Florence Nightingale, became fixated on ventilation’s importance for health. It manifested in the physical layout of buildings: windows, many of them, but also towers erected for the sole purpose of ventilation and elaborate ductwork to move contaminated air outdoors. Historic buildings still bear the vestigial mark of these public-health strategies, long after the scientific thinking has moved on.

The obsession with ventilation — and miasma theory in general — was indeed wrong when it came to pathogens such as cholera and yellow fever that we now know spread through other means (water and mosquitoes, respectively). But it did make sense for the diseases that invisibly stalked people through 19th-century air: measles, tuberculosis, smallpox, influenza — all much diminished as threats in the 21st century. “We’ve gotten so good at preventing so many diseases, there’s been a loss of knowledge and a loss of experience,” Jeanne Kisacky, the author of Rise of the Modern Hospital, says. Science is not a simple linear march toward progress; it also forgets.

Today, amid a pandemic caused by a novel airborne virus, these old ideas about ventilation are returning. But getting enough schools and businesses on board has been difficult. Fixing the air inside modern buildings, where many windows don’t or barely open, means fighting against the very nature of hermetically sealed modern buildings. They were not built to deal with airborne threats. Nineteenth-century hospitals were.

That era saw the rise of well-ventilated “Nightingale pavilions,” named after Florence Nightingale, who popularized the design in her 1859 book, Notes on Hospitals. As a nurse in the Crimean War, she saw 10 times more soldiers die of disease than of battle wounds. Nightingale began a massive hygiene campaign in the overcrowded hospitals, and she collected statistics, which she presented in pioneering infographics. Chief among her concerns was air. Notes even laid out exact proportions for 20-patient pavilions that could allow 1,600 cubic feet of air per bed.

Each pavilion was a separate wing, radiating from a central corridor. And it had large windows that faced each other, which allowed a cross breeze to blow between the beds. The windows stayed open no matter the weather. There were stories, Kisacky told me, of hospitals in winter where “the patients are closing the windows, and the nurses are opening them. And the doctors come and knock the glass out to make sure they stay open.” In some pavilions, a central fireplace heated the room, so that contaminated air rose out of the ward via the chimney effect.

The world’s first successfully cloned Black-footed ferret has been born

Friday, February 19th, 2021

The world’s first successfully cloned Black-footed ferret has been born, marking the first time a U.S. endangered species has been cloned:

“Elizabeth Ann” was born on December 10, 2020, and is the clone of “Willa,” a wild-caught Black-footed ferret whose cell line was cryopreserved in 1988. A genomic study led, funded, and developed by Revive & Restore in 2014 helped determine that Willa’s genome possessed nearly three times more genetic diversity than the current Black-footed ferret population. This means that her clone Elizabeth Ann is now the most genetically valuable Black-footed ferret alive. This birth is the result of a long-standing genetic rescue effort for the Black-footed ferret species, the goal of which is to increase the genetic diversity and fitness of one of America’s most endangered species to help ensure its full recovery in the wild.

Much more than you wanted to know about COVID and Vitamin D

Wednesday, February 17th, 2021

Scott Alexander shares his beliefs after doing the research on COVID and Vitamin D:

Does Vitamin D significantly decrease the risk of getting COVID?: 25% chance this is true. The Biobank and Mendelian randomization studies are strong arguments against this; the latitude, seasonal, and racial differences are only weak evidence in favor.

Does Vitamin D use at a hospital significantly improve your chances?: 25% chance this is true. I trust the large Brazilian study more than the smaller Spanish one, but aside from size and a general bias towards skepticism I can’t justify this very well.

Do the benefits of taking a Vitamin D supplement at a normal dose equal or outweigh the costs for most people?: 75% chance this is true. The risks are pretty low, and it will probably bring you closer to rather than further from a natural range if you’re a modern indoor worker (side effects are few; the most serious is probably kidney stones, so don’t take it if you have any tendency towards that). And maybe some day, after countless false leads and stupid red herrings, one of the claims people make about this substance will actually pan out. Who knows?