No anthropophagy among spiders, yet. That we know of.

I thought you might want to know that Spiders feeding on vertebrates is more common and widespread than previously thought, geographically and taxonomically. Not that I want you to worry or anything, but you should know that vertebrates like you are prey to certain spiders. (Not you, personally, of course — just your smaller, weaker cousins.)

You might be wondering who the killer spiders are, and you’re in luck: here’s a table of the spider families that will kill your relatives.

Frequency distribution of 39 spider families engaged in vertebrate predation based on cummulative literature data (source: McCormick & Polis 1982; Brooks 2012; Nyffeler & Kno ̈rnschild 2013; Nyffeler & Pusey 2014; Nyffeler et al. 2017a, 2021; Nyffeler & Vetter 2018; Weisberger 2019; Nyffeler & Altig 2020; Reyes-Olivares et al. 2020; Fulgence et al. 2021; Nyffeler & Gibbons 2021, 2022; Google Scholar & Google Picture Survey for Sparassidae feeding on vertebrates 2021). The ten spider families Atracidae, Theridiidae, Pisauridae, Ctenidae, Theraphosidae, Nephilidae, Araneidae, Lycosidae, Sparassidae, and Trechaleidae are the most prominent vertebrate-eaters (combined 91% of a total of 966 recorded incidents). *The number of records for Atracidae (n 1⁄4 20) presented here is an underestimate [The atracid Hadronyche formidabilis must be considered to be a habitual frog-eater due to the fact that countless frog bones had been found in funnels of this species which not could be taken into account in this graph (McKeown 1952)].

See? No worries. You probably don’t even recognize most of those names.

I’m here to inform you that the number one culprit, the Theridiidae, also known as the tangle-web spiders or comb-footed spiders, are also among the most common house spiders. The spiders I raise in large numbers in the lab, the Steatodas and Parasteatodas and Latrodectus, all belong to this family, and I’ve long noted their ability to bring down animals much larger than themselves with their potent venom and most excellent cobwebs.

Not you, of course. You can continue to sleep well at night, knowing that the spiders living in your attic and basement are not going to eat you. Not unless they grow significantly larger, or form significant and numerous cooperative colonies.

My spiders do get along well with each other, so there are possibilities…

If you doubt me, here are some spiders eating birds, bats, frogs, fish, and snakes. Yum.

Examples of habitually vertebrate-eating spiders – A. Argiope aurantia Lucas, 1833 feeding on a female ruby throated hummingbird (Archilochus colubris) in front of a house in College Station, Texas (Photo by Donell S. Frank). B. Nephila pilipes (Fabricius, 1793) feeding on a small bat (superfamily Rhinolophoidea) entangled in the spider’s web; incident observed at the top of the Cockatoo Hill near Cape Tribulation, Queensland, Australia (Photo by Carmen Fabro). C. Megadolomedes australianus (L. Koch, 1865) (Pisauridae) feeding on a Graceful Tree Frog (Litoria gracilenta) in Barratt Creek, Queensland, Australia (Photo by Barbara Maslen ‘‘Wild Wings & Swampy Things Nature Refuge, Daintree’’). D. Adult male of Ancylometes sp.(possibly Ancylometes rufus (Walckenaer, 1837)) caught a characiform fish (Cyphocharax sp.) near Samona Lodge, Cuyabeno Wildlife Reserve, Ecuador (Photo by Ed Germain, Sydney). E. Adult female black widow (Latrodectus hesperus) feeding on a subadult coral snake Micruroides euryxanthus (Elapidae) near the Boyce Thompson Arboretum, Superior, Arizona, USA (Photo by Lawrence L. C. Jones).

But don’t worry, they aren’t eating people yet!

Nyffeler M, Gibbons JW (2022) Spiders feeding on vertebrates is more common and widespread than previously thought, geographically and taxonomically. Journal of Arachnology 50:121–134.

The tastiest part of a cockroach is its heart

I did not know this. Being a giant relative to cockroaches, I’d only imagined mashing the whole animal into a pulpy mass between my molars, but apparently, with a lesser size difference, one can be a connoisseur of the flavors of different meats in the prey animal, and appreciate the subtleties of the meal. As the emerald jewel wasp does.

And so, in another attempt to win his students’ attention, the scientist set out to film an emerald jewel wasp larva as it feasted on the cockroach from within.

“That’s the way science often unfolds for me,” said Dr. Catania, the author of “Great Adaptations.” “I’m looking at something out of curiosity, or art.”

This is how he ended up capturing the larva’s taste for cockroach heart. But he made an unexpected discovery: After eating the heart of the cockroach, the wasp larva started gnawing at its quarry’s trachea, the insect equivalent of lungs. This caused air to leak out of the cockroach’s respiratory system and into its body cavity, air that the wasp larva then eagerly slurped up.

In other words, the emerald jewel wasp both eats the cockroach’s heart out and takes its breath away.

After performing the experiment two dozen times, Dr. Catania was able to show that not only do the air bubbles allow the larva to breathe while fully inside the cockroach’s body, but they also give the little hell-raiser a metabolic boost. Once the air bubbles appear, the larvae start to chew faster, which Dr. Catania documented this year in a study published in the journal Current Biology.

Now that’s an interesting twist. When you’re head first in the gooey, slimy, liquid interior of the victim you’re eating, respiration becomes a problem — so you suck air out of its respiratory system. Brilliant! I’ll remember that next time I dive into the body of an animal 50 times my size.

There’s a video if you’d like to see a living cockroach heart get eaten by a wasp. It’s cute and heartwarming.

Learn to love your spiders!

Well, this is discouraging.

Scientists asked almost 1,800 people to rate 25 species of animals according to how much fear and disgust a photo of each one elicited. The spider got equally high rankings for both fear and disgust from more people than any other animal. The spider was also deemed the scariest and nearly the grossest as well.

I find myself snuggled up in the top right corner of that chart. No wonder nobody likes me.

But there are some words of hope.

Ecologist and self-proclaimed spider ambassador Bria Marty tested whether learning about spiders can change how people feel about them for her master’s thesis project at Texas State University in San Marcos. She recruited college students to find and identify spiders using an illustrated guide and then upload photos to iNaturalist. Marty, currently a PhD student at Texas A&M University-Corpus Christi, surveyed participants before and after the activity, and one thing jumped out: Afterwards, people reported being far less likely to react negatively to a spider. “Doing an activity like this really does help a lot around fear,” she says.

This kind of change has been known to happen to iNaturalist users, says Tony Iwane, the platform’s outreach and support coordinator and a self-described spider lover. He pointed me to a thread on the site’s discussion forum about how contributing to iNaturalist helped people overcome their fear of spiders, with users sharing the “gateway spider” species that changed how they felt. For @mira_l_b, it was the particularly tiny Salticid (jumping spider) species Talavera minuta. “If I am finding myself confronting life-long fears and cooing sweetly to tiny Salticidae,” she wrote, “then there’s hope for us all!”

The author is advocating a big spider counting exercise for everyone, which sounds like a good idea to me. Except this is not the best time of year for it — spiders are making themselves scarce right now, hiding from the winter onslaught, but you can still find lots of spiders in your houses.

So go find them and say hello!

The neuroendocrinologists strike back

I keep seeing these naive pop culture simplifications of sex and gender — it’s all about gametes, or Y chromosomes, or hormone titers. It’s all about finding the one magic criterion that defines the unambiguous binary that certain people want. It’s the opposite of good science. You should be looking at the evidence to see that sex is messy and complicated and defies reduction to the state of a single variable.

It’s a relief, then, to look at the actual scientific literature and see that scientists working in the field all pretty much agree — it’s not a simple binary. So here’s an article by real, genuine, qualified neuroendocrinologists declaring that they’re fed up with the notion of a simple binary. It’s titled Deconstructing sex: Strategies for undoing binary thinking in neuroendocrinology and behavior by Massa, Aghi, and Hill. It’s also behind a paywall, goddamn it, but at least I have access. Here’s the introduction, which is pretty strong.

Neuroendocrinologists have long known that “sex” is a specious category. Much of our research relies on identifying mechanisms that produce differences in brain morphologies and behaviors, including how factors like hormones, chromosomes, and life experiences differences across “the sexes.” This work makes evident that “sex” is not a biologically coherent concept (Karkazis, 2019; Roughgarden, 2013) but is instead a constructed category reliant on several biological criteria that do not always align (Ainsworth, 2015). However, research across the biomedical sciences regularly treats “sex” as a single, internally consistent variable. And even while recognizing that “sex” is multifaceted and dynamic, even neuroendocrinologists often collapse the multiplicity (Karkazis, 2019) by selecting a single trait to sort research subjects and specimens into sex categories – a practice that obscures relevant physiologies and precludes the possibility of more specific (and more accurate) analyses.

While its shortcomings are well-established, “sex” remains deeply entrenched in our field. Scientists seeking to adopt more nuanced frameworks must contend with the limitations of existing resources, methods, and practices, much of which rely on binary (or otherwise simplistic) sex categorization. To encourage support for this paradigm shift, we first delineate how reliance on gross “sex” categories damages scientific knowledge and leads to harm of marginalized communities. We then examine how current policies may exacerbate these problems before providing reflective questions to help scientists critically examine the use of “sex” across the scientific enterprise. These questions, supported by a litany of neuroendocrine research, encourage researchers to conceptualize and study sexed physiologies as multiple, interacting, and variable. Furthermore, as an extension of discussions held during the SBN 2022 Symposium on Hormones and Trans Health, our guidance challenges researchers to break free of gendered preconceptions and conduct research which centers the impact, direct or indirect, on marginalized groups. We believe this critical reflection and scientific reorientation is vital to improve our science, widen the applicability of our findings, and deter the (mis)use of our research against marginalized groups.

This is what I’ve been saying all along, so obviously I agree with it. The authors go on to point out that sex is a multi-dimension category, not a simple variable.

“Sex” is a constructed category, not a biological variable – and our science should reflect that. Deconstructing “sex” and moving away from reductive approaches requires immediate local changes to experimental design and methodology as well as a deeper understanding of social influences on and of the scientific enterprise (purple and green, respectively, in Fig. 1). What follows are guiding questions we offer to facilitate this much-needed shift. We hope that thinking through these questions will impact how science is conducted – whether that means using specific relevant physiologies to determine sex category; moving to a multivariate, interacting, and continuous conceptualization of sexed variables; or moving past sex categories all together – and lead to a more comprehensive, accurate, and responsible scientific enterprise.

I have to say, though, that I’m not a fan of those kinds of meaningless diagrams. I’ll let it slide out of appreciation for the context.

One of the few reasons to read Xitter: Lee Cronin’s whines

Crank meltdown in progress. Leroy Cronin, who published that ridiculous “assembly theory” article in Nature has been struggling for the last few ways to cope with the ridicule coming his way.


Make a theory at the intersection of evolutionary biology, theoretical physics, complexity theory, & prebiotic chemistry = x 4 the ‘normal’ trolling fun. I love the virtue signalling & the fact they clearly have not even read the paper which is no excuse as it is open access.😂

‘Everyone who disagrees with me is a troll!’ is not the triumphant comeback you think it is. Yes, it’s a theory that combines a lot of disciplines, I agree. But has he considered that maybe the reason he’s getting so much pushback is that people who actually know something about each of those disciplines is saying that the authors don’t understand how the discipline works? I can say that his paper didn’t get evolutionary biology at all right, so now I’m wondering if he also got theoretical physics, complexity theory, and prebiotic chemistry just as wrong.


Gosh first the complexity theorists, then prebiotic chemists followed by the theoretical physicists, & evolutionary biologists. Is that all? Now the creationists are trolling me also. 🤷

I haven’t seen the creationists responding to assembly theory, but now I want to. Not hard enough to actually go digging, unfortunately.


Paradigm shifts involve 1) confusion & anger followed by 2) pronouncements on how obvious it is with the final 3) it has already been done or they thought of it before & it was trivial.

Yikes. The kooks always claim to be leading a ‘paradigm shift’ and start quoting Kuhn.

Here’s another famous quote, this time from Carl Sagan.

“But the fact that some geniuses were laughed at does not imply that all who are laughed at are geniuses. They laughed at Columbus, they laughed at Fulton, they laughed at the Wright brothers. But they also laughed at Bozo the Clown.”

The fact that your ideas are laughed at is not evidence that you are correct.


I love critical feedback because it helps improve stuff & I also get excited when people get ‘triggered’ scientifically as it means something REALLY interesting is shifting. It ain’t pretty but it might accelerate science. #AssemblyTheory

Also, the fact that experts are triggered and reject your theory is not interesting, and doesn’t mean you’ve made a productive change in the world. Creationists trigger me too, that doesn’t validate creationism.


I’m happy to be wrong as I learn more. I like to be almost right occasionally so I can dig deeper. I also want to be bold & honest about it. Science is about taking risks, not beating people up that offend your world view.

No one is offended. No one is beating people up. Cronin is being told that his ideas are wrong, which is what we’re supposed to do.

He’s feeling resentful about being corrected, nothing more. Well, also there should be some shame at publishing such a crappy article in a prestigious journal.

Finally, he reposts something from a supporter:


Absolutely wild to open Twitter and learn that evolutionary biologists think the origin of life is either solved or a non-problem.

No one has said that. The origin of life is not solved and is most definitely a problem of interest. The catch is that assembly theory does not solve any of the problems anyone is wrestling with, and doesn’t seem to solve much of anything.

This is all reminding me of how Dr Wolfe-Simon reacted defensively to criticisms of her claim that life can substitute arsenic for phosphorus. Things got loud back in 2010, and she was insistent that she made a great discovery, but when was the last time you heard about arsenic life? The idea was dead within a year.

Let’s check back in Fall of 2024 and see how Cronin’s theory is holding up.

Keep working hard, maybe someone will notice you

While the site was down, The Nobel Prize in Physiology or Medicine was awarded to Katalin Karikó and Drew Weissman for their work on mRNA viruses. This is exactly the kind of thing that deserves a prestigious award, since it was a fundamental discovery that opened the door for all kinds of scientific developments. It’s the personification of Faraday’s statement, “What good is a newborn baby?” and it also represents a conundrum — lots of science is done that is not immediately of use to others, but has undiscovered potential. I’m kind of impressed with Karikó’s struggle — she languished for years trying to do this work, yet she persevered.

Karikó, the 13th woman to win the prize, languished for many long years without funding or a permanent academic position, keeping her research afloat only by latching onto more senior scientists at the University of Pennsylvania who let her work with them. Unable to get a grant, she said she was told she was “not faculty quality” and was forced to retire from the university a decade ago. She remains only an adjunct professor there while she pursues plans to start a company with her daughter, Susan Francia, who has an MBA and was a two-time Olympic gold medalist in rowing.

The mRNA work was especially frustrating, she said, because it was met with indifference and a lack of funds. She said she was motivated by more than not being called a quitter; as the work progressed, she saw small signs that her project could lead to better vaccines. “You don’t persevere and repeat and repeat just to say, ‘I am not giving up,'” she said.

Universities, pay your adjuncts. Also, I hope UPenn doesn’t try to do any fundraising off this work by a researcher they disrespected.

I also just want to mention that I lived near her in Pennsylvania — I didn’t know her at all, but maybe fame was brushed off by proximity. She described how she got the news.

I was sleeping, and actually my husband picked up the phone. I am at my home in a suburb of Philadelphia in Abington township. And I was away in a conference in Cold Spring Harbor, and just Saturday returned. We celebrated 50 years of recombinant DNA technology. I met all of those people there, 80s, 90s that did the basic work, and I just came back.

My kids went to school in Abington! Neato!

I should note that, while academia didn’t appreciate her work and neglected her, capitalism saw some virtue.

But two biotech companies soon took notice: Moderna, in the United States, and BioNTech, in Germany, where Karikó eventually became a senior vice president. The companies studied the use of mRNA vaccines for flu, cytomegalovirus and other illnesses. None moved out of clinical trials for years.

I don’t think most adjunct faculty can fall back on their position as a senior vice president of a pharmaceutical company.

I wonder how many adjuncts are slaving away, struggling to get their work out there, and will never get this kind of acknowledgment? Probably something close to all of them.

Sacrifices made in the name of lust

Some spiders have a serious problem: runaway evolution sometimes produces maladaptive conditions. Here’s a spider, Tidarren sisyphoides, that exhibits extreme sexual dimorphism — males have about 1% of the mass of the females.

Male and female T. sisyphoides in copula. The minute male (indicated by the arrow) on the female’s ventrum is ≈1% of the female’s mass. (The scale bar represents 1 mm.)

That’s not the problem, though. The problem is that the males maintain a massive pair of palps. Really gigantic. They probably clang when they walk. Look at these two big boys, and the monster intromittent organs dangling from the front of their faces.

You may notice that the top spider has the normal two palps, which are so large that they’re interfering with each other. The bottom spider has only one palp. The surprise is that this is a product of self-mutilation.

During copulation, males generally use both pedipalps in an alternating fashion to inseminate the paired spermathecae in the female. In Tidarren, however, one pedipalp is removed (either left or right pedipalp, seemingly at random) before sexual maturation which has also been described for another spider of similar size and closely related to Tidarren (Echinotheridion). Just after molting to the penultimate instar, the male secures one of its pedipalps to a silk scaffold and then twists it off by turning in circles and pushing the bulb with the third and fourth pairs of legs.

Ouch. There’s a reason for their partial emasculation, though.

We found that, for male Tidarren sisyphoides, maximum speed increased (44%) significantly and endurance increased (63%) significantly after pedipalp removal. Furthermore, spiders with one pedipalp moved approximately 300% greater distances before exhaustion and had a higher survival after exertion than those with two pedipalps. Removal of the pedipalp may have evolved in male Tidarren because of enhanced abilities to search for females (higher endurance and survival after exertion) and to out-compete rival males on the female’s web (higher maximum speed). Our data also highlight how the evolution of conflicts can result in the evolution of a novel behavior.

Not recommended for humans, unless your testicles are the size of basketballs.

Ramos M, Irschick DJ, Christenson TE (2004) Overcoming an evolutionary conflict: removal of a reproductive organ greatly increases locomotor performance. Proc Natl Acad Sci U S A 101(14):4883-7.

Summer research presentation time!

My students talked about their work today — this picture was taken before the crowds put them to work.

Violet took full advantage of the medium, a big screen connected to a laptop, and instead of a static display, the ‘poster’ rotated through a big collection of images. They had the prettiest poster of the group, as long as spiders are considered to belong to the category “pretty”.

Synchronicity is just another word for coincidence

Lately, I’ve been having these odd dreams in which I’m traveling to Quito, where I’m expected to take a ride in the space elevator. I’m oddly anxious about it, and I don’t know why, and I don’t board the silly thing. The End.

Anyway, this morning I discover that Angela Collier has a video about space elevators, and she dismantles the concept with math and engineering, which was very satisfying.

Very convenient. Next time this dream pops up in my subconscious playlist, I’ll just dismiss it and say it’s not possible, go away, and get back to that nice dream where I can talk to spiders.

A horror scenario

Could a disease arise that killed half the human population? And that inflicted horrifying neurological effects as the victims slowly died? Sure could. It’s happened in other animals. It’s happening right now in moose.

Minnesota saw a 58% decline of the moose population in the northeastern part of the state between 2006 and 2017.

If you’ve ever seen a moose, you know they’re huge and intimidating — you don’t want to tangle with one. The bulls are temperamental and cranky, the cows are fiercely protective, and you really don’t want to have to deal with a 700kg angry beast. But here’s what’s bringing them low.

A primary driver of the decline is brainworm, a parasite that affects the animal’s nervous system ultimately leading to paralysis and death. Researchers from the University of Minnesota and the Grand Portage Band of Lake Superior Chippewa recently discovered evidence that moose in Minnesota consume species of gastropods —slugs and snails—which are known hosts for the brainworm parasite (Parelaphostrongylus tenuis).

This massive die-off is a consequence of climate change: the worm is moving north as the weather warms, migrating with resistant deer populations whose range is overlapping with that of moose. When people talk about new diseases accompanying climate shifts, this is the kind of thing we’re talking about.

It can happen to us, you know.

I do sometimes wonder if Republicans have been eating snails.