Crunchies vs. Squishies: ask the pterosaurs

I’m not a taxonomist; early in my career I settled on the model systems approach, which meant all the nuances of systematics disappeared for me. “That’s a zebrafish” and “that’s not a zebrafish” were all the distinctions I had to make, and zebrafish were non-native and highly inbred so I didn’t have to think much about subtle variations. There was one taxonomic boundary one of my instructors forced me to recognize: Graham Hoyle had nothing but contempt for “squishies”, as he called vertebrates like fish or mice or people, and was much more focused on the “crunchies”, insects and crustaceans and molluscs. These seemed like odd ad hoc taxonomic categories to me, I and could think of lots of exceptions where “crunchies” were pretty squishy (see witchetty grubs or slugs), and “squishies” were armored and crunchy (armadillos, any one?), and besides, as a developmental biologist, they were all squishy if you caught them young enough. But OK, if you like dividing everything into two and only two categories, go ahead.

Then today I read this paper, “Dietary diversity and evolution of the earliest flying vertebrates revealed by dental microwear texture analysis”, and saw that there was at least one practical use for the distinction. What you eat affects wear patterns on your teeth, that if you eat lots of crunchy things vs. lots of squishy gooey things, you’ll have a different pattern of dental scratches, and since teeth fossilize — unlike guts — you can get an idea of what long dead animals had for dinner. Furthermore, you can compare fossil microwear textures to the textures in extant animals, where you do know what kinds of things they eat.

This is cool — so you can estimate the range of things ancient pterosaurs ate from how their teeth were worn, whether they ate lots of soft-bodied bugs like flies, or hard-shelled crustaceans, or soft-fleshed fish, by making a fine-grained inspection of their fossilized teeth and comparing them to modern reptiles.

a–c Reptile dietary guilds; a piscivore (Gavialis gangeticus; gharial), b ‘harder’ invertebrate consumer (Crocodylus acutus; American crocodile) and c omnivore (Varanus olivaceus; Grey’s monitor lizard). d–f Pterosaurs; d Istiodactylus, e Coloborhynchus (PCA number 5) and f Austriadactylus (PCA number 2). Measured areas 146 × 110 µm in size. Topographic scale in micrometres. Skull diagrams of extant reptiles and pterosaurs not to scale.

But they’re not done! Knowing the phylogenetic relationships of those pterosaurs, you can then infer evolutionary trajectories, getting an idea of how dietary preferences in species of pterosaurs shifted over time.

a Phylo-texture-dietary space of pterosaur microwear from projecting a time-calibrated, pruned tree from Lü et al.33 onto the first two PC axes of the extant reptile texture-dietary space. b Ancestral character-state reconstruction of pterosaur dietary evolution from mapping pterosaur PC 1 values onto a time-calibrated, pruned tree from Lü et al.33. To account for ontogenetic changes in diet, only the largest specimen of respective pterosaur taxa, identified by lower jaw length, were included. Pterosaur symbols same as Fig. 2. Skull diagrams of well-preserved pterosaurs not to scale (see ‘Methods’ for sources).

These results provide quantitative evidence that pterosaurs initially evolved as invertebrate consumers before expanding into piscivorous and carnivorous niches. The causes of this shift towards vertebrate-dominated diets require further investigation, but might reflect ecological interactions with other taxa that radiated through the Mesozoic. Specifically, competition with birds, which first appeared in the Upper Jurassic and diversified in the Lower Cretaceous, has been invoked to explain the decline of small-bodied pterosaurs, but this hypothesis is controversial. DMTA provides an opportunity for testing hypotheses of competitive interaction upon which resolution of this ongoing debate will depend.

In summary, our analyses provide quantitative evidence of pterosaur diets, revealing that dietary preferences ranged across consumption of invertebrates, carnivory and piscivory. This has allowed us to explicitly constrain diets for some pterosaurs, enabling more precise characterisations of pterosaurs’ roles within Mesozoic food webs and providing insight into pterosaur niche partitioning and life-histories. Our study sets a benchmark for robust interpretation of extinct reptile diets through DMTA of non-occlusal tooth surfaces and highlights the potential of the approach to enhance our understanding of ancient ecosystems.

So pterosaurs started as small bug-eaters and diversified into niches where they were consuming bigger, more diverse prey over time, which certainly sounds like a reasonable path. I don’t know that you can really assume this was a product of competition with birds — I’d want to see more info about the distribution of pterosaur species’ sizes, because expanding the morphological range doesn’t necessarily mean that you’re losing at one end of that range, but I’ll always welcome more ideas about how Mesozoic animals interacted.

Adam Savage on hearing loss

He gives a good answer to a common question.

My hearing is fine, thank you very much, except for an obnoxious tinnitus that isn’t yet affecting my life much. My wife, however, is losing her hearing in an unusual way, with the lower registers progressively dropping out (usually it’s the other way around, losing the higher frequencies first). Savage mentions the high cost of hearing aids, and we have some experience with that — there’s a reason for it. Modern hearing aids aren’t just amplifiers that make all sounds louder, they have to be more sophisticated than that. For instance, my wife has an app on her phone that lets her tweak the amplification, it’s like a built-in equalizer so she can boost the volume at specifically the frequencies that are affected. The technology is cool, but Savage is right — it’s also awkward and clumsy and expensive.

At least her condition means my voice is becoming gradually more inaudible, while she can hear the grandkids just fine, which is probably for the best. It still ought to be a right for everyone to have this kind of necessary support. You never know, maybe someday I’ll say something worth listening to!

Don’t be fooled by the Barrington Declaration

Even as COVID-19 infection rates are rising, there are people out there lobbying for decreased diligence. Open all the businesses! Party on! If everyone gets the disease, we’ll acquire herd immunity! That latter is from people who previously pooh-poohed the concept in order to defend anti-vaxxers, who now don’t give a damn if a few million people die in order to reach the unreachable goal. Worst of all, the right-wing think tanks are backing the nonsense. A small group of conservative shills have formulated something they call the Barrington Declaration.

The declaration, which calls for an immediate resumption of “life as normal” for everyone except the “vulnerable”, is written by three science professors from Harvard, Oxford and Stanford, giving it the sheen of academic respectability. But there is much to set alarm bells ringing. It makes claims about herd immunity – the idea that letting the virus rip among less vulnerable groups will allow a degree of population-level immunity to build up which will eventually protect the more vulnerable – that are unsupported by existing scientific evidence. The professors do not define who is “vulnerable”, nor do they set out a workable plan for shielding them. The declaration sets itself up against a straw proposal that nobody is arguing for – a full-scale national lockdown until a vaccine is made available. There is no acknowledgement of the massive scientific uncertainty that exists with a new disease.

It’s coming out of an organization called the American Institute for Economic Research (AIER), which, as you might guess from the name, is not a medical or scientific institution, but one focused on making money for its sponsors or throwing out noise to prevent sensible initiatives that might save lives, but reduce profits. It’s fake.

The statement claims to have been signed by more than 6,000 medical scientists, but anyone can sign up claiming to be one (there are a number of fake medical signatories on the list, including a Dr Harold Shipman). When Sky News pressed one of the co-authors on this, he said: “We do not have the resources to audit each signature.” Consider what this approach would mean for scientific endeavour were it applied more broadly. And what are scientists doing fronting a campaign whose back office is run by a thinktank that flirts with climate change denial?

(The Shipman name is fake, I hope, since Dr Harold Shipman was a serial killer who committed suicide.)

This phony declaration business is a familiar tactic used by cranks, quacks, and profiteers, and I’ve run into it many times. There are a lot of gullible people who fall for it, though — false authority is a useful tool to sway the suckers, I guess. But today I first learned that there is a handy, succinct name for it from David Gorski.

I’ll discuss why that’s the case in a moment, but first I’d like to take a trip down memory lane to revisit various examples of science denialists using similar “declarations,” “petitions,” and “open letters” to give the false appearance of strong scientific support for their positions. Why? Because declarations like this, although they can be used for good (such as when US climate scientists recently signed an open letter to Congress reaffirming the overwhelming scientific consensus that human activity is the primary driver of climate change and the overall warming of the climate), more frequently such letters are propaganda for pseudoscience. Indeed, such “declarations,” “open letters,” and “petitions” signed by physicians and scientists represent a technique that goes back at least to the tobacco companies lining up lists of doctors to testify to the safety of cigarettes. (One particularly ludicrous example from R.J. Reynolds in the 1940s claimed that 113,597 doctors preferred their cigarettes.) The idea was (and is) to give the false impression of a scientific controversy where none exists and to appeal to the authority of scientists and doctors to support their claims. It’s a technique that John Cook has referred to as the “magnified minority”:

Nice, “magnified minority”. I’ll remember that.

As usual, Gorski is thorough in describing past “magnified minority” operations, and documents the phony signatures on this one, as well as the absurdity of their proposal and AIER’s shady history as a climate change denialist outfit funded by the Koch brothers. Really, why anyone listens to anything by them is beyond me at this point: “funded by the Koch brothers” ought to be the kiss of death for any organization.

I’m working on corrupting my granddaughter, too

An inspiring story for us all.

Although, to be honest, Iliana seems to be building her own interests without my help, and is more excited about owls than spiders. And that’s fine. We’ve just got to grow that interest in the world around us.

Nature indicts Trump

Good morning! Nature has a long article titled “How Trump damaged science — and why it could take decades to recover”, and everyone should read it.

The US president’s actions have exacerbated the pandemic that has killed more than 200,000 people in the United States, rolled back environmental and public-health regulations and undermined science and scientific institutions. Some of the harm could be permanent.

It goes through some of the areas Trump has damaged: climate science has been deeply compromised, the environment has been thrown open to destruction, the pandemic is ravaging the country, and he’s been closing the doors to international collaboration and has been dismantling our international reputation. It doesn’t even touch on the fact that he’s packing the judiciary with science deniers, or his dangerous enabling of racists.

Yet here we are, seriously considering re-electing this corrupt vandal back into office where he can do even more damage. Some of his terrible decisions are going to take decades to repair if they’re reparable at all, if he gets four more years we can just forget about any delusion of leadership in science, or of having any kind of technological edge. It’ll all just be…gone.

The arrogance of TERFs

The Royal Society of Biology is celebrating Biology Week 2020, and some random TERFy twit saw it as an opportunity to declare that sex is determined at conception, observed at or before birth and is immutable, none of which is universally true. I’m particularly annoyed at the claim that sex is determined at conception. To a real biologist, “determination” is a specific term with a specific definition — “The normal process by which a less specialized cell develops or matures to become more distinct in form and function” — and sex is most definitely not determined at conception, but emerges progressively over time, requiring many genes and many cellular interactions to reach its final state. In humans, the process isn’t even complete at adolescence!

So take note of how the Royal Society of Biology responds to that TERFy intrusion.

“Please take your transphobia out of our hashtag please. BYE”. Hah.

You know, you can disagree with the consensus of biologists. You can disagree with the major scientific societies. You can disagree with the big name biology journals. But when you do that, you can no longer assert that biology, as a generic institution, supports your claims. To be honest, you have to admit to dissenting from biology, and then you’re likely to make gross errors of fact, as @TriciaFasman did with her claim that sex is determined at conception.

Yet they persist, and there’s Ms Fasman lecturing the Royal Society of Biology on biology to defend a fantasy author’s misconceptions about biology. Sweet. I’m used to TERFs hectoring me about their bogus understanding of biology, but wow, here’s one self-righteously wagging a finger at a whole scientific society. The arrogance is impressive.

But hey, if you really think fantasy authors have more authority in biology than, you know, biologists, you can always find that Neil Gaiman and Stephen King are saying the words “trans rights”, and they’re both far better writers than Rowling.

(Seriously, TERFs, if you try to comment here that you’ve got the backing of biology supporting your claims, I’m going to laugh at you and swing the banhammer, just as I do with racists and creationists who pretend that biology supports their fuckwittery. It doesn’t.)

[random attribute] + [subjective, complex phenomenon] → BAD STUDY

You’d think reviewers and journals would figure this formula out. It’s practically a guaranteed recipe for a bad paper. Pick some random feature, like, say, carrying a guitar case. Then correlate it with some messy, subjective and almost impossible to measure property, like sexual attractiveness. Bingo! You are guaranteed to generate statistics, whether positive or negative, and can find an undiscriminating journal somewhere that will publish it. Then, even better, some tabloid will pick up the story and give you publicity with headlines like, “CARRY A GUITAR TO ATTRACT THE LADIES!”

I didn’t pick my examples at random. There actually was a paper titled “Men’s music ability and attractiveness to women in a real-life courtship context”, now retracted, that tried to make that claim with crappy (and probably faked) statistics.

The same author, Nicholas Guéguen, also had a paper retracted previously that claimed that high heels make women sexier. Oh, I should have mentioned — another important element of the recipe is to make sure one of the elements has something to do with sexual stereotypes.

Apparently, Nicholas Guéguen has published about 340 papers using the magic formula. Publishers still haven’t caught on. Or they have, and they don’t care, they just want more garbage to churn.

It’s depressing.

Baby spiders are voracious

As long as I was up early, I darted into the lab and fed my horde of baby spiders. I think I may need to increase their feeding frequency because whoa, they were eager. The tubes they are living in are a dense maze of silk, so you drop a fly in and they are instantly trapped and flailing about, and the babies just home in right away. They’re currently still a little smaller than a fruit fly (but they’re fattening up nicely), making for a nice little battle with a juicy reward at the end.

The adults, on the other hand, are experiencing a bit of seasonal malaise, I think, and are a bit sluggish. I’m going to have to do a major cleanup of their cages and maybe that’ll brighten them up a bit…but that’ll have to wait until after Thanksgiving. I just have too much to dooooooooo…

Sometimes, the Nobel Committee does the right thing

There has been an ongoing and ugly legal battle over rights to the CRISPR/Cas technology for gene editing, which has swiftly become an important tool in the molecular biology toolbox. I think most of us agree that the people most responsible for the discovery are Jennifer Doudna and Emmanuelle Charpentier, but then the Broad Institute under Eric Lander saw a hot topic, threw bodies at the problem, and rushed to get their fingers in the pie, including, as a sneaky tactic, publishing a review article that downplayed the role of Doudna/Charpentier. It was a nasty, greedy game they were playing, and I’d hoped people would see through it.

Apparently they did, because now Doudna and Charpentier have been awarded the Nobel Prize in Chemistry. Justice served!

It’s clear now that history has stamped Doudna and Charpentier with the credit for this scientific discovery, which is nice. I doubt that that will matter much to the legal system which determines who gets stamped with all the money from the patents, but it is a step forward.

Gladiatorial games, now open to the public

I’ve got a research student, Ade Atolani, and we’ve been in the lab recently, learning the basics…which mainly involves learning how to configure and aim a camera at a spider, throwing in a few flies, and talking about what’s going on during the bloodthirsty gladiatorial games. Then we do a few things to figure out how to transfer files and upload them to YouTube. Here are a couple of examples, nothing too exciting, but just the ordinary routine of getting a student comfortable with observing spider behavior.

This one is an adult:

This is a month-old juvenile:

Maybe we should start selling tickets to the spectacle? We can’t do betting, though, because the spider always wins.