Why Evolution is True is a blog written by Jerry Coyne, centered on evolution and biology but also dealing with diverse topics like politics, culture, and cats.
As I say repeatedly, I find it very difficult to listen to long videos (and long podcasts without visuals are even worse). But I happened to click on the one below, part of the biweekly Glenn Show dialogue between Glenn Loury and John McWhorter, and found it quite worthwhile, even though it’s a bit more than an hour long (Loury gives an advertisement between 11:12 and 13:14). It’s interesting because of the topics: wokeness, race, and their intersection, and McWhorter (with whom I’m on a panel in three weeks) is particularly interesting.
In short, I think they disapproved of my opposition to the Gaza War, my criticisms of Israel’s prosecution of that war, and my praise of Ta-Nehisi Coates’s meditations on the West Bank settlements.
Well, I knew that Loury was a stringent critic of Israel, but praising Ta-Nehisi Coates’s “meditations” on the West Bank, meditations that followed just 10 days visit in the Middle East and did not even mention Palestinian terrorism, isn’t something to praise. At any rate, since Loury retired from Brown, he’s contemplating his next move, and hints that the University of Austin (UATX) has been courting him.
That leads to a brief discussion of whether schools like UATX are the wave of the future: schools that can teach humanities courses without them being polluted by extreme “social justice” mentality. Both men ponder whether universities like that are the wave of the future, and whether regular universities will devolve into “STEM academies”. That, in turn, leads to a discussion, mostly by McWhorter, about music theory and how that, one of his areas of expertise, has been polluted by wokeness.
The biggest segment of the discussion involves McWhorter’s recent visit to Washington’s National Museum of African American History and Culture, and his thoughts about it (read his long NYT op-ed piece, which is very good, here). McWhorter characterizes it as not a dolorous place but a “happy place,” and one that gives a balanced view of black history—a view in which black people are more than simple oppressed people who serve to remind the rest of us of their guilt. It portrays as well, he avers, the dignity and positive accomplishment of African Americans. (McWhorter compares the dolorous view of black history with the narrative pushed by Nikole Hannah-Jones of the 1619 Project.) His description makes me want to visit that museum more than ever (I haven’t yet been but will, and I must also visit the United States Holocaust Memorial Museum).
Finally, they discuss the question of whether they were wrong to be so hard on DEI, given that some aspects of it (e.g., a call for equality) are positive. Here McWhorter is at his most eloquent, saying that, given the overreach of DEI, it was imperative for both of them to have criticized it. As McWhorter notes, the extreme construal of DEI did not “fight for the dignity of black people” and, he says, in the face of that extremist ideology, their silence would not have been appropriate. Loury agrees. At this point McWhorter brings up Claudine Gay, ex-President of Harvard, claiming that she was hired simply because she was a black woman, which was “wrong and objectifying.” (Only McWhorter could get away from saying something like that.) The elevation of Gay, says McWhorter, was the sort of thing they were pushing back against when they opposed DEI.
This is worth a listen, and I’ve put the video below.
It’s time for a Sunday Duck Report. Esther’s brood hatched on May 6, and so today they are 26 days old, coming on to four weeks. As we’ll see at the bottom, in the last week or so they’ve started growing their feathers.
Here are some videos and pictures of the brood, most taken around May 20 when they were two weeks old.
The brood (still six):
A swimming duckling. They are starting to look like big ducks, though they still have their baby down:
A diving duckling. It’s learning a skill that will help it not only forage, but also escape predators:
They get fed two or three times a day and are coming quite close to us. (I whistle for them, a call that they recognize as “feeding time,” but all I really have to do is show up at the pond with my bag ‘o duck food, and they coming swimming towards me rapidly.)
By the way, they get a good diet: Mazuri duck chow, which is a complete diet. Esther and big ducks get big pellets (I get this in 50 lb. bags), while the babies get the same thing, but in smaller pellets since their bills are too small to engulf the big ones (this “waterfowl starter chow” I get in 25-lb bags). As a special treat, they get freeze-dried mealworms, which are high in fats and protein. This is their favorite food, but it’s a dessert, not the main course.
They love to enter the plastic tubs that used to be used as supports for the “plant cages”. I think of it as a duck spa:
About a week ago, the ducklings and Esther climbed up the southern “ramp” on the east side of the pond, where they’d sun themselve and then, going further into the brush, would all rest together. Here they are approaching the ramp that leads to their resting spot. Esther always leads the way, but sometimes the brood is reluctant to land as they still want to swim and play:
More recently, since the babies have gotten large enough to jump directly out of the pond onto its edge, they like to do that together and sun themselves on the cement. Esther, of course, is always nearby.
Having a good rest:
Sometimes they pile up a few feet away from mom, but she’s always nearby. The piling up keeps them warm, as it’s been a bit chilly lately.
A video showing their postprandial resting on the edge of the pond:
A pile o’ ducklings:
Finally, in the last eight days or so the babies have been sprouting their feathers. Feather appearance starts at the tail, in which a few tiny feathers make the tail look like a paintbrush:
. . . then the feathers start sprouting on their wings (arrow). Next stop: scruffy-looking “punk ducks” with a mixture of feathers and fluff. Stay tuned for that!
John Avise has started a new short series, damselflies of North America (he’s finished with dragonflies). John’s captions and IDs are indented, and you can enlarge his photos by clicking on them.
Damselflies in North America, Part 1
This week’s post begins a short series on Damselflies, which are in the taxonomic Order Odonata and can be thought of as svelte (slim and delicate) relatives of the Dragonflies. As usual, I show the state where each photo was taken.
Welcome to Sunday, the sabbath for goyische cats, and we’re now into June. It’s June 1, 2025. Here is the June illustration from the Très Riches Heures du Duc de Berry (ca. 1412-1416). It’s time to reap!
Limbourg brothers, Public domain, via Wikimedia Commons
Refresh yourself with this video about the Heimlich Maneuver, and don’t forget the back pounding:
There’s a Google Doodle today, celebrating “hyperpop” music, which, says the site, is “a genre/anti-genre of electronic music pioneered by LGBTQ+ artists.” Click below if you want to see where it goes (it’s Pride Month):
Readers are welcome to mark notable events, births, or deaths on this day by consulting the June 1 Wikipedia page.
Da Nooz:
*More tariffs in store: Trump is planning to double the tariff on foreign steel and aluminum. Just another stupid move in the endless tariff wars. The news last night (sans Lester Holt, my fave, who left) announced the European countries already pay less for these metals than we do. We’re only going to fall farther behind.
President Trump said on Friday that he would double the tariffs he had levied on foreign steel and aluminum to 50 percent, a move that he claimed would further protect the industry.
The announcement came as Mr. Trump traveled to a U.S. Steel factory outside Pittsburgh to hail a “planned partnership” that he helped broker between U.S. Steel and Nippon Steel, a corporate merger that he opposed last year as a presidential candidate. Although the details of the U.S. Steel deal are still murky — and Mr. Trump later admitted he had not yet seen or signed off on it — the president used the moment to cast himself as a champion of the embattled industry.
Speaking to a crowd of steel workers, Mr. Trump claimed that foreign countries had been able to circumvent the 25 percent tariff he put in place this year. The higher tariffs would “even further secure the steel industry in the United States,” Mr. Trump said.
It is not clear how much doubling the tariff rate would actually bolster the domestic steel sector, but the move gave Mr. Trump the opportunity to wield tariffs at a time when his other import taxes have proved vulnerable to legal challenges.
In a post on Truth Social, Mr. Trump said that the tariffs would take effect on June 4 and that they would provide a “big jolt” to American steel and aluminum workers.
A big, big, BIGLY jolt. In fact, the highest jolt in the history of the WORLD! But while it may boost American metal production, we all know that it will also boost the prices of goods made with steel and aluminum, and the net effect on the American economy would be negative. I could have written about many other maladaptive things our “President” is doing, including issuing pardons to bad people (see below), trying to block or rescind visas for foreign students, cutting grants, and so on. But I don’t want to turn this site into a Trump-bashing venue, for there are many other places you can go to see that.
*The Times of Israel, quoting a reliable international organization, says what anybody with brains already knows: Iran has been sneakily trying to build a bomb while hiding its activities from the rest of the world:
Iran carried out secret nuclear activities with material not declared to the UN nuclear watchdog at three locations that have long been under investigation, the watchdog said in a wide-ranging, confidential report to member states seen by Reuters.
The findings in the “comprehensive” International Atomic Energy Agency report requested by the agency’s 35-nation Board of Governors in November pave the way for a push by the United States, Britain, France and Germany for the board to declare Iran in violation of its non-proliferation obligations.
A resolution would infuriate Iran and could further complicate nuclear talks between Tehran and Washington.
VIENNA — Iran carried out secret nuclear activities with material not declared to the UN nuclear watchdog at three locations that have long been under investigation, the watchdog said in a wide-ranging, confidential report to member states seen by Reuters.
The findings in the “comprehensive” International Atomic Energy Agency report requested by the agency’s 35-nation Board of Governors in November pave the way for a push by the United States, Britain, France and Germany for the board to declare Iran in violation of its non-proliferation obligations.
A resolution would infuriate Iran and could further complicate nuclear talks between Tehran and Washington.
While many of the findings relate to activities dating back decades and have been made before, the IAEA report’s conclusions were more definitive. It summarized developments in recent years and pointed more clearly towards coordinated, secret activities, some of which were relevant to producing nuclear weapons.
It also spelled out that Iran’s cooperation with IAEA continues to be “less than satisfactory” in “a number of respects.” The IAEA is still seeking explanations for uranium traces found years ago at two of four sites it has been investigating. Three hosted secret experiments, it found.
The IAEA has concluded that “these three locations, and other possible related locations, were part of an undeclared structured nuclear program carried out by Iran until the early 2000s” and that “some activities used undeclared nuclear material,” the report said.
Whatever made U.S. and world leaders think the Iran was enriching uranium for “peaceful” purposes? Blindness, stupidity, or both, I guess. This should be a wake-up call to Trump to stop trying to strike a “stop-the-nukes” deal with Iran in return for loosening sanctions. Iran is lying, it’s always lied about this, and Trump should just go ahead and let Israel try to take out the bomb-making facilities-. In fact, the U.S. and Israel should do that jointly,
I suppose you can say that at least Trump is not a hypocrite. Fathomlessly corrupt himself, he has been particularly assiduous in pardoning his fellow white-collar criminals.
Just in the past month, he gave a pardon to a former Connecticut governor who pled guilty to honest services fraud, mail fraud, and tax fraud; to a nursing home exec who pled guilty to tax crimes; to reality TV stars Todd and Julie Chrisley, for bank fraud, wire fraud, and tax dodging; to a former Staten Island congressman, for tax fraud; to a former Detroit mayor, for fraud and racketeering; to a labor union leader who took gifts up to $315,000 and didn’t report them; to a federal judge in Missouri, for Medicaid fraud; to a former member of the Cincinnati City Council, for bribery; and to a Nevada pol who embezzled the money raised for a statue honoring a murdered police officer and spent it on plastic surgery. Then there’s the infamous former governor of Illinois, Rod Blagojevich, who tried to sell a Senate seat.
. . . . Trump can empathize, of course. His own company was convicted of tax fraud, and he tried to steal an election. There is nothing in the presidency he wouldn’t monetize — as his latest $1 million-a-plate crypto dinner and the Qatari 747 prove beyond any doubt. He and hisfamily are now, and always have been, emphatically for sale; and he regards any other approach to life as stupid. But it’s also striking how the huge majority of his pardons have been for Trump-supporting Republicans. Even Blagojevich calls himself a Trumpocrat. Fraud is fine and pardonable — if you like and support Trump. It’s the only criterion that matters.
The foulest by far was his pardon of all the participants who tried to stop the peaceful transfer of power by mob violence. This mega-pardon of more than 1,500 people, at the very beginning of his second term, was not a validation of fraud, but an actual presidential endorsement of political violence. The pardon process used to be painstaking, methodical, and careful. Trump made the J6 decision with the words: “Fuck it: Release ’em all!” His open mulling over whether to pardon the conspirators to assassinate governor Gretchen Whitmer adds a touch of specific menace.
The concept of a pardon, of course, is extremely hard for Trump to understand. Traditionally, a pardon is due to someone who has completed (or nearly completed) their sentence, expressed remorse, and turned their life around — and thereby been the recipient of mercy. But remorse is a concept unknown to a pathological narcissist. Mercy is even stranger. After all, who wins and who loses in an act of mercy? It’s one of those acts defined by grace — another literally meaningless concept for Trump. For him, all human conduct is built on a zero-sum, winner-vs-loser foundation. So a pardon is always instrumental — a way to reward allies, win credits, and enlarge his power by announcing to the world that he alone is the ultimate rule of law, and can intervene at any point to ensure his version of justice is the dispositive one. A monarch, in other words.
. . . .So of course, he is using the pardon power all the time, rather than waiting till the end of his term. It replaces the rule of law with monarchical discretion. That’s why he could not tolerate Jeff Sessions all those years ago. Because Sessions, for all his passionate partisanship, still understood the system he was operating in and still believed that the appearance of impartial justice was integral to liberal democracy’s survival. Sessions was an American.
The core reason Trump is an existential threat to liberal democracy is because he literally cannot understand this. I don’t even think he is that cynical about it. He honestly believes that people on his side can only be prosecuted out of political malice, and that people on the other side are always guilty. A judge who rules in his favor is wise; a judge who rules against him is ipso facto corrupt. And his wily capacity to wriggle free of the many impeachable offenses he committed in office, and legal accountability thereafter, has only deepened this belief.
Yes, we all know now that Trump behaves like a petulant child, lashing out at perceived enemies and rewarding his toadies. I thought it was bad to live through the Nixon era, but Trump beats all. And if the Democrats don’t get their act together, we’ll have President Vance in 2028—and eight more years or Republican rule.
*At Richard Dawkins’s Substack, he reproduces his new foreword to George Williams’s classic book on evolution, Adaptation and Natural Selection. Richard’s intro is called “Foxes in the snow.”
On opening it I have the feeling of being ushered into the presence of a penetrating and outstanding mind, the same feeling I get, indeed, from reading The Genetical Theory of Natural Selection, although Williams, unlike Fisher, was no mathematician. In George Williams we have an author of immense learning and incisive critical intelligence, who thought deeply about every aspect of evolution and ecology. Williams not only enlarged the synthesis, he exposed with great clarity where many of its followers had gone astray, even in some cases the original authors themselves. ‘is is a book that every serious student of biology must read, a book that irrevocably changes the way we look at life. Throughout my career as an Oxford tutor, I obviously recommended many books to my students. But I think this was the only one I insisted that all should read. Here’s a list of major mistakes a student is likely to make before reading this book, but will not make afterwards.
You can read the mistakes for yourself, but it really is a great book, and must be one of the first books that a beginning student in evolutionary biology reads. Here’s a bit about “spandels”: things that look like direct adaptations but are adaptive byproducts of other features installed by natural selection (“spandrels” comes from Gould and Lewontin’s 1978 paper, a mixed effort):
A ‘spandrel’ is a non-adaptive by-product. The name comes from the gaps between gothic arches which are a necessary but non-functional by-product of the functionally important arches themselves. Long before the word was introduced into biology, Williams, a leading advocate of adaptation as a proper subject for scientific study, gave an incisive critique of what would later be called spandrels. His vivid example, which regularly grabbed the attention of my Oxford students, was a fox repeatedly running along its own tracks in the snow. Its paws increasingly flattened the snow, which made each successive journey easier and faster. But it would be wrong to say the fox’s paws were adapted to flattened snow. They can’t help flattening snow. This particular beneficial effect is a by-product. Williams summed up the message pithily: adaptation is an ‘onerous concept’.
If I might paraphrase the Anglican marriage service in a way that Williams might not, any attribution of adaptation should not be entered into unadvisedly or lightly; but reverently, discreetly, advisedly, soberly and in the fear of Occam’s Razor. You must first assure yourself that you could, if called upon to do so, translate your adaptation theory back into the rigorous terms of neo-Darwinism. The ‘adaptation’ you postulate must not just be ‘beneficial’ in some vague, panglossian sense. You must clearly set out, and be prepared to defend, a strictly Darwinian pathway to the evolution of the alleged adaptation. The ‘benefit’ must accrue at the proper level in the hierarchy of life, which is the unit of Darwinian natural selection. And the proper level, for Williams as for me, is that of the individual genes responsible for the putative adaptation.
. . .Return for a moment to Williams’ picturesque example of the fox in the snow. I think he’d have accepted the following reservation to his ‘spandrel’ or by-product lesson. Natural selection actually could favour an adaptive broadening of fox paws for the function of flattening snow.
But only if the resulting path benefited the fox itself (and its family) alone, rather than foxes in general. It might, for example, be connected to the individual fox’s own territory. This brings me to the central core of the book, which is Williams’ critique of ‘group selection’. This is as needed today as it was in 1966, for group selectionism won’t lie down. With its magnetic allure, perhaps politically or even aesthetically motivated, group selectionism keeps coming back for more, in ways that, I can’t resist confessing, remind me of Monty Python’s Black Knight.* Williams admits that natural selection could theoretically choose among groups.
For another prescient attack on group selection, which indeed won’t lie down, see Steve Pinker’s 2012 essay at Edge. But all beginning grad students in evolutionary biology should read Williams’ book. Seriously.
*I’m an Everest fan (I’ve trekked to the mountain, without climbing it, twice), and so was fascinated by this Wall Street Journal article about four Brits who set a record: flying from London and summiting Everest within five days. It usually takes weeks, but they ameliorated the climb by pre-adapting by inhaling xenon gas:
. . . the four British army veterans prepared for the world’s highest peak using a new pre-acclimatization regime involving inhaling xenon gas—once used as an anesthetic but now more commonly found in rocket propellant.
Their ascent is rocking the mountaineering community and Nepali authorities, with their use of a substance banned from competitive sport by the World Anti-Doping Agency provoking the criticism this amounts to cheating.
Nepal’s mountaineering authorities are studying the climb and its implications.
On May 29, when the country marks the first recognized summit of the mountain in 1953 as Everest Day, Nepal’s prime minister lamented the use of xenon.
“Dishonesty even with Mount Everest?” he said. “If it did happen, it should be stopped.”
Well, is it more dishonest than using supplemental oxygen? A bit more:
After hearing [Austrian mountaineer Lukas] Furtenbach speak on the radio in 2018 about his efforts to help climbers pre-acclimatize, Fries said he contacted him to propose his idea: breathe in xenon gas before a challenging climb. The gas, said Fries, appears to have neuroprotective properties and prompts the production of a hormone that triggers red blood cell production, improving the blood’s ability to carry oxygen.
Furtenbach had the four British climbers prepare for weeks at their homes in the U.K. by sleeping for a total of over 500 hours each in tents that simulate the low-oxygen conditions on Everest. That has long been part of Furtenbach’s expeditions offering a “flash” ascent of Everest in about three weeks. The men also worked out using masks that simulated thin mountain air.
Their regime included a new feature—a roughly 20-minute, one-time hit of a mix of xenon and oxygen some weeks before the men began their climb in Nepal. The formulation was developed and administered to the men in Germany by Dr. Michael Fries, head of anesthesia and intensive-care medicine at St. Vincenz Hospital in the German town of Limburg an der Lahn.
. . . . The International Climbing and Mountaineering Federation said in January that scientific literature didn’t support the idea that breathing in xenon improves performance in the mountains.
Given how swiftly it can work—putting people to sleep in a minute—highly experienced medical supervision is vital, said Fries.
If I had a bucket-list dream that I know won’t be fulfilled, it would be to stand atop Everest. I’m too old now to perch on the Earth’s highest spot, but I have been at the lowest. It’s not the same, though. . .
Meanwhile in Dobrzyn, the Editor-in-Chief claims her rights:
Finally men won’t be allowed to smash women in the face live on TV and win medals for it. Well done, World Boxing
Shame on the IOC (who allowed it in Paris) & male sports writers who cared more about a man’s feelings than the safety of women & their right to fair sport 🥊 pic.twitter.com/vAOFetaSP0
You really need to be more careful with those Freudian slips. Khelif isn’t trans, but by casually equating him to a trans women you admit that you know the latter, too, are men. According to the rules of your favourite game, you’ve just been extremely transphobic. pic.twitter.com/d9wtBqnbnT
Two posts from Dr. Cobb. The first compares the cuts in American science funding with two other political alterations of the direction of science, although they aren’t precise parallels:
There are 2 previous historical cases of countries destroying their science and universities, crippling them for decades: Lysenkoism in the USSR and Nazi Germany. The Trump administration will be the 3rd.It's not just budgets but research, institutions, expertise, and training the next generation.
Here’s the latest comedy/news stint from Bill Maher’s “Real Time” show, a “New Rule” segment called “Freak-end update”, referring of course to Diddy’s “Freak offs,” his drug-fueled sex orgies often involving prostitutes. Diddy is very likely to be convicted (you’ve seen the tape, right?), and it will be a huge come-down from his status as music king to living in a cell sans sex and drugs.
Maher’s new rule is this: “If you’ve being abused, you gotta leave right away.” He understands why abused women and loath to report it, and will even send affectionate messages to their abusers, but Maher adds that we must understand these dynamics and not let them soften our attitudes towards abuse. He then recounts how laws and attitudes are changing to punish abusers more seriously, and advises abused women to go to the police immediately rather than just telling a few friends or writing about it in a journal.
This is far more serious than most of Maher’s other bits, but he feels strongly about it. Yet he still manages to eke out a few laughs.
This article from the NYT recounts a new study from PLOS One in which researchers tried to understand whether cats knew the scent of their staff as opposed to other cat owners and other people who didn’t own cats (click on screenshot to read, or find the original article archived here). The results are straightforward, and I’ll quote the NYT summary:
An excerpt:
Through referrals from friends and colleagues, the researchers recruited 30 cats and their owners to participate in the study. The cats’ owners captured their own scents by rubbing cotton swabs behind their ears, between their toes and under their armpits. Eight additional people who don’t own pets and didn’t know the cats’ owners were recruited to be “odor donors.”
Each of the study cats, in the comfort of its own home, was then presented with an array of test tubes containing the smelly cotton swabs from its owner, a stranger and a blank control. A camera mounted to the experimental setup recorded the cats’ reactions to the test tubes.
The cats spent more time sniffing the samples from the strangers than from their owners — an indication that the cats could recognize their owners’ scents and devoted more time to exploring the ones they’d never smelled before.
While this finding might seem like common sense, it’s “a very important piece of information,” said Dr. Carlo Siracusa, an associate professor of animal behavior at the University of Pennsylvania School of Veterinary Medicine who was not involved with the study. “This is how science works. You need to prove everything.”
Dr. Uchiyama and his colleagues further analyzed video recordings of the cats sniffing the test tubes and observed the cats predominantly using their right nostrils to smell the strangers’ test tubes, regardless of where the tube was placed within the array. These findings seemed to corroborate previous studies of other animals, including dogs, which also led with their right nostrils when exploring strange scents.
“The left nostril is used for familiar odors, and the right nostril is used for new and alarming odors, suggesting that scenting may be related to how the brain functions,” Dr. Uchiyama said. “It is likely that the right brain is preferred for processing emotionally alarming odors.”
. . .[Dr. Uchiyama] also remarked on the logistical feat of designing a study protocol deemed acceptable by its feline participants.
“I really commend this group of scientists for being successful in engaging 30 cats in doing this stuff,” Dr. Siracusa said. “Most cats want nothing to do with your research.”
The nostril difference is interesting; I know of know other species with two nostrils in which the nasal volutes have different functions. Could something like this be true in humans, too?
Click below to see the original article:
There’s one figure showing a cat (there should have been more!); here it is with caption from the paper:
Fig 6. Photographs of cats. a) Sniffing the tube on the left and right side with a tilted head. b) Rubbing the same side of the face as the nostril that was used immediately prior to this. https://doi.org/10.1371/journal.pone.0324016.g006
ScienceAlert tells us why we shouldn’t give milk to cats. Click below to read; I’ll add an excerpt:
An excerpt:
Farmers began to employ them as pest controllers. It was through this arrangement that cats and milk first became acquainted.
Before the commercialisation of pet food, cats were mostly fed scraps from the family table. Not much was known about their nutritional needs. In his 1877 book on cats, Scottish doctor Gordon Stables insisted cats need two bowls – “one for water and the other for milk” – and suggested porridge and milk as an excellent feline breakfast.
From these origins, cats and milk became further embedded in the collective zeitgeist through depictions of milk-loving cats in art, books, movies and cartoons. There’s even the classic trope of the scruffy street cat being rescued from the rain to enjoy a saucer of milk from a kindly stranger.
. . . . While it’s not surprising that cats and milk have persisted as an unquestioned combination, research now tells us cats shouldn’t be drinking milk at all.
Like all mammals, cats begin life drinking milk from their mother. But past kittenhood, milk is a completely unnecessary part of a cat’s diet.
After weaning (around 6–12 weeks of age), kittens stop producing the enzyme lactase, required to digest lactose in milk. For the vast majority of cats, this means they are lactose intolerant.
However, just like in humans, the level of intolerance varies for each individual based on how much of the enzyme their body naturally produces.
Don’t rush to give your kitten milk, though. Just because kittens can digest lactose doesn’t mean they should be drinking cow’s milk. Cats are much smaller animals than cows and, fittingly, the amount of lactose in the milk of mother cats is much lower than in cow’s milk. It’s best to let them drink from their mother or to get them a kitten-appropriate cat formula.
Lactose intolerance isn’t the only reason not to give your cats milk. Though rare, cats can also develop an allergy to milk or dairy.
. . . And if you’re thinking your cat is one of the lucky few that isn’t lactose intolerant, think again. Cats are very good at hiding discomfort because, in the wild, showing weakness would make them a target for predators.
If you absolutely must, opt for lactose-free milk or milk formulated specifically for cats, and keep it as a very occasional treat.
While it won’t upset their stomachs in the same way as regular cow’s milk, it still won’t offer your cat any nutritional benefit.
As for milk alternatives like oat, soy or almond milk? Any unusual additions to your cat’s diet are likely to cause digestive upset, so it’s best to avoid these as well.
Today we have a historical/natural history post by reader Lou Jost, who works as a naturalist and evolutionary biologist at a field station in Ecuador.
A diatom sample from the HMS Challenger expedition of 1872-76
The Challenger in 1873, painting by Swine
The HMS Challenger was a British naval ship equipped with both sail and steam power. At the urging of scientists, and riding the wave of popular curiosity about our then-poorly-known planet, the ship was converted by the Royal Society of London to become the world’s first specialized oceanographic vessel. It went on a mission from 1872 to 1876 to systematically explore the world’s oceans, especially the scientifically almost completely unknown Southern Ocean near Antarctica. This mission was the 19th century equivalent of a trip to the moon or to Mars (except that this HMS Challenger mission had a much more interesting and diverse subject region!).
One of the navigators, Herbert Swine, made contemporaneous drawings and paintings on site, including the two HMS Challenger images I have shared here (though these were probably polished somewhat for publication). He also published his lively diaries of his time on the expedition, in two volumes, just before he died of old age. He was the last survivor of the crew.
A map of the expedition
The voyage of exploration went 80,000 miles, lasted 1250 days, and circumnavigated the globe. They made systematic chemical, temperature, and depth readings across the globe, taking biological specimens along the way. They discovered over 4000 new species, from vertebrates to phytoplankton, and lost several lives along the way. They were the first to systematically explore the mid-Atlantic Ridge, and by pure chance they also discovered the Marianas Trench, the deepest part of the Pacific Ocean. In 1950-1951 a modern vessel, again bearing the name Challenger in a homage to the original, found the deepest part of any ocean, the “Challenger Deep”, just 50 miles from the HMS Challenger’s deepest depth record.
The Challenger at work
The immense number of samples obtained by the crew of the Challenger took 19 years to analyze and publish, in 50 volumes. Specimens were sent to many scientists of the time, and some of these still circulate today. Among the most interesting organisms they sampled are diatoms. Diatoms are single-celled organisms that make up much of the oceans’ phytoplankton, and their most notable features are the finely sculpted glass cases called “frustules” that enclose them. These glass frustules are often preserved intact for tens of millions of years, sometimes forming enormous deposits of pure frustules known as “diatomaceous earth” on the beds of ancient lakes and oceans. Some of these deposits are so big that millions of tons of diatom frustules thousands of years old are whipped up by the wind in dry parts of Africa every year, and then cross the Atlantic by air and rain down on the Amazon basin in South America.
The expedition of the HMS Challenger launched the most systematic study of the 19th century on the diatoms of the Southern Ocean. They sampled at regular intervals during their voyage, and at multiple depths, including very deep water that had never before been studied, discovering new species of diatoms such as Asteromphalus challengerensis, named after the vessel (using bad Latin unfortunately). The samples were distributed to diatomists around the world, who carefully mounted them on microscope slides using special mountants of high-refractive-index liquid, designed to make the transparent diatom frustule more visible under standard microscopic illumination. Some of these Challenger diatom slides come up for sale periodically, and I could not resist buying one that appeared in eBay.
Increasing zooms of the diatoms on the slide:
This one slide, from 1873 during an Antarctic visit, has hundreds of individuals consisting of maybe a couple of dozen species. There are also many broken diatom fragments. Among the individuals, I was lucky enough to find several examples of what appear to be the aforementioned A. challengerensis. This is a rare species which is found only in water that is within 1 degree Centigrade of freezing. The taxonomy of this species and its relatives is in flux as we learn more about how the structures change with age.
Two slides of the species A. challengerensis:
Some of the taxonomic problems of these diatoms is caused by their weird way of replication. Diatoms can’t grow like a normal organism because they are in a glass case, so instead they shrink, each half of the frustule making a new matching half that is slightly smaller than the parent half-frustule, so that the two new halves each nest inside their parent half-frustule. Then they separate. Here is a nice illustration of this:
The population thus has a large spread of different sizes, and it appears that some frustule features may change as they get smaller, causing taxonomic confusions in the case of A. challengerensis and others. By the way, eventually the smallest ones go through a sexual reproductive phase that builds a new full-sized frustule, so that the cycle can start over. This is really weird. Later I hope to write long post about the utterly astounding, almost unbelievable biology of diatoms.
Darwin published his theory of evolution just 13 years before this expedition, and evolution was on everyone’s mind, and the commander of the ship was an “early adopter” of the theory. At the time there was still not much clarity about the predictions of the theory. It was widely believed that the cold dark oceans would preserve “living fossils” similar to the earliest forms of life on earth. The expedition did not find this to be true, and so it actually was a slight setback for evolutionary theory. They unfortunately missed the hydrothermal vents which do indeed shed light on the origins of life.
I wrote at the beginning of this post that the HMS Challenger expedition was the 19th Century analogue of space exploration. So it was fitting that NASA decided to name one of the space shuttles “Challenger”, after the two scientific ships which carried that name. The photo above shows Challenger orbiting over the ocean 110 years after the original HMS Challenger sailed that same ocean. Unfortunately, as in the original Challenger expedition, people died on that space shuttle in the name of science, a reminder that exploration on the margins of what is known will always be risky, and the participants are real heroes of their age.
