Dr Mona coming to UMM

Hey, gang! Thursday evening at 7pm we have a guest speaker, Dr Mona Hanna-Attisha talking in Edson Auditorium about her work. She’s one of the first people to discover how the water in Flint, Michigan was poisoned with lead (which, by the way, it still is), and she’s going to grace our little college with knowledge that evening. You should come. Why aren’t you coming? Don’t give me that old excuse that it’s far away — you have Google Maps, you can find us.

Ignore this if you’re not an arachnophile

I put more spider photos on Patreon and Instagram. Today’s subjects are members of the tribe of Pholcus phalangioides who are dwelling in my basement. They seem to have undergone a population crash recently, though, probably because, while it’s warm enough in our house, they’re probably getting hungry at the lack of invertebrates to eat here in the depths of winter.

The spiders are hiding on Freethoughtblogs, but they’re still around

I said I’d stop flashing spider photos at you all, so really, it’s safe to come back here if you’re arachnophobic. I still occasionally indulge on the Patreon site, and I just added a few this morning (I’ll put them on Instagram shortly). My model was the lovely Danu, a Parasteatoda tepidariorum I caught at Skepticon in Missouri last August. My lighting setup was far short of ideal, though, so I’m going to have to work on that.

Yes, I still have those St Louis spiders in my lab, they’re doing fine, but in the absence of St Louis males, are not producing babies for me. I guess I’ll just have to go to Skepticon again this year and find some mates for them. Maybe if you go to Skepticon, I can draft you to help!

Who’s been chalking our sidewalks?

When I walked into work this morning, I noticed something odd: all the sidewalk tiles were outlined with ragged, chalky lines. It sure was a lot of work to go to to get such a minimal, if striking effect.

The explanation was obvious (look at the top right tiles), and was clearer a little later when I came home. Melting snow and ice filled the cracks first, and then there’s a race between slow diffusion of meltwater and evaporation due to the sun, leaving precipitated salts at the leading edge of the front.

It looked cool, anyway.

If you thought eugenics was only an abstract notion…

You might want to look up Geoffrey Miller, evolutionary psychologist and general bigot, who wrote a piece for John Brockman’s Edge site on Chinese eugenics in which he’s practically drooling at the prospect of manipulating the human germ plasm. No, really, the West is doomed if we allow the Chinese to race ahead of us in practical eugenics!

Chinese eugenics will quickly become even more effective, given its massive investment in genomic research on human mental and physical traits. BGI-Shenzhen employs more than 4,000 researchers. It has far more “next-generation” DNA sequencers that anywhere else in the world, and is sequencing more than 50,000 genomes per year. It recently acquired the California firm Complete Genomics to become a major rival to Illumina.

The BGI Cognitive Genomics Project is currently doing whole-genome sequencing of 1,000 very-high-IQ people around the world, hunting for sets of sets of IQ-predicting alleles. I know because I recently contributed my DNA to the project, not fully understanding the implications. These IQ gene-sets will be found eventually—but will probably be used mostly in China, for China. Potentially, the results would allow all Chinese couples to maximize the intelligence of their offspring by selecting among their own fertilized eggs for the one or two that include the highest likelihood of the highest intelligence. Given the Mendelian genetic lottery, the kids produced by any one couple typically differ by 5 to 15 IQ points. So this method of “preimplantation embryo selection” might allow IQ within every Chinese family to increase by 5 to 15 IQ points per generation. After a couple of generations, it would be game over for Western global competitiveness.

There is unusually close cooperation in China between government, academia, medicine, education, media, parents, and consumerism in promoting a utopian Han ethno-state. Given what I understand of evolutionary behavior genetics, I expect—and hope—that they will succeed. The welfare and happiness of the world’s most populous country depends upon it.

Oh god. The high-decoupling.

First, sequencing DNA is not eugenics. Telling me how many genomes they sequence per year is not the same as telling me they have a eugenics program in operation. The Chinese government’s crackdown on He Jiankui suggests that they are a bit more hesitant than Miller imagines.

Second, the whole idea that they can get a 5-15 IQ point per generation increase is ludicrous. He’s postulating that a) the observed variation is entirely genetic, and b) that a ruthless pattern of selection is desirable and would have no unforeseen consequences. You can get equal, more equitable, and less disruptive effects by investing in better education. Note that IQ scores have been going upwards for the last century without the state choosing to cull the undesirables.

Third, the idea that IQ scores are a proxy for “competitiveness”, rather than the ability to do well on IQ tests, is a fallacious leap.

Fourth, why would you think eugenics would increase welfare and happiness? It would do the opposite for the majority of the population that lacks the arbitrary genetic markers they use for selection.

Fifth, he is an evolutionary psychologist, which means his understanding of “evolutionary behavior genetics” is feeble at best.

But he does imagine a country that tightly regulates its families on the basis of poorly understood DNA sequences is a “utopian ethno-state” that will increase the welfare and happiness of its citizens, which makes him a kind of third-rate villain in a dystopian SF novel.

If DNA data were as powerful as he imagines it is, though, don’t worry about the Chinese supermen overwhelming us. Comrade Geoffrey has done his part to sabotage the program by donating his DNA, corrupting the database with his genome rich mainly in ignorance and arrogance.

The fall of the mayfly empire?

I’m only a 21st century Minnesotan, by which I mean I grew up on the West coast, lived on the East coast, and only made the trek to the Midwest when I was in my 40s, in the summer of 2000. One feature of the trip across Ohio and Illinois, up through Wisconsin along Lake Michigan, and across to Minnesota and the Mississippi that grossed out my kids was the bugs — the windshield splatter, and worst of all, the black cake of insect carcasses matting the grille of our truck at the end. In the years after we arrived, there were many times our car imitated a filter feeder on summer drives, sucking in a pathetic mass of dead mosquitos and mayflies, requiring a thorough hosing out to be presentable once again. We’d also see the weather radar on the TV, showing vast clouds of insect hatches rising from the rivers and lakes.

In recent years, though, almost imperceptibly, the population of insects has declined to the point where it’s unusual and noticeable when we splatter a few bugs on a drive across the state. Apparently, we also missed the genuinely remarkable swarms that sporadically blanketed the Midwest in the 1950s.

Through the middle of the 20th century, enormous summertime swarms of Hexagenia mayflies were a common sight across many of North America’s largest waterways. The immense scale of mayfly emergences made them a natural spectacle, and reports of the aquatic insects blanketing waterfront cities regularly filled newspaper headlines. Deep drifts of mayflies rendered streets impassable until snowplows could clear and grit roadways, and the dense swarms reduced visibility and inhibited water navigation, temporarily halting river transportation.

I regret not ever seeing that spectacle, although the locals don’t seem to — while I’ve heard many stories of fierce blizzards and massive snowfalls in the “old days”, no one has regaled me with tales of deep deposits of mayfly corpses. It’s a shame, I’d like to hear about it.

These stories do at least make an anecdotal impression that there has been a steep decline in the aquatic insect population. From a time when insect swarms could shut down travel in the mid-century, to my personal experience of running into major bug densities when I first arrived in Minnesota, to now only rarely hearing about scattered clouds of mayflies rising off the lakes, it’s hard to avoid the conclusion that we have a problem here. The problem is…us.

…by 1970, these mass emergences had largely disappeared. The combination of increasing eutrophication from agricultural runoff, chronic hypoxia, hydrologic engineering, and environmental toxicity resulted in the disappearance of Hexagenia from many prominent midwestern waterways, with complete extirpation from the Western Lake Erie Basin and large segments of the Illinois, Ohio, and Mississippi Rivers. After two decades of absence, targeted efforts in conservation and environmental protection led to the eventual recovery of Hexagenia populations and recolonization of major habitats in the early 1990s.

So there was a window of time where the numbers were even lower, and what I saw in 2000 was a resurgence? I’d say, from my subjective observations, that they’re in decline again, and what we need is more hard data on insect numbers over time. That’s what we’re getting from Stepanian and others, who recently published quantitative data on the emergence of mayflies across Lake Erie and the Upper Mississippi river, making calibrated measurements using weather radar. For instance, here’s a single emergence event smothering the entire western end of Lake Erie in a single night in June of 2018.

Macroscale phenomenology of a mayfly emergence over Lake Erie on the night of June 27, 2018 as observed by weather surveillance radar. (A) Radar snapshot at 01:56 Coordinated Universal Time (UTC) depicting the initial ascent of mayflies from the lake surface surrounding the shorelines of Point Pelee, Pelee Island, and Kelleys Island. At this time, a total of 2.1 million mayflies are detected in the airspace. (B) Radar snapshot at 02:50 UTC showing the continuing ascent and downwind drift of mayflies across the lake to the southeast. Additional emerging mayfly plumes develop surrounding North, Middle, and South Bass Islands. Mayflies reaching the southern lakeshore rapidly descend out of the airspace. At this time, a total of 394 million mayflies are detected in the airspace. (C) Radar snapshot at 03:32 UTC. Emergence and ascent have largely terminated as mayflies continue to fly downwind toward the southern lakeshore. At this time, the aerial abundance reaches a maximum, with a total of 2.0 billion mayflies detected in the airspace. (D) Radar snapshot at 04:32 UTC. Most mayflies have already descended from the airspace as the trailing edge of the mayfly plume approaches the southern lakeshore. At this time, a total of 81 million mayflies are detected in the airspace. (Lower) The time series of aerial mayfly abundance during the emergence event. The mayfly numbers given in A–D are annotated as well as the time of local sunset.

Over two billion insects surging out of the water over the span of a few hours! That isn’t even the most impressive event: they report that a single event in Lake Erie can spawn 88 billion mayflies with a mass of over 3,000 tons; the upper reaches of the Mississippi might produce 3.25 billion insects weighing a total of 114 tons. These events represent a huge transfer of organic matter from the bottoms of lakes and streams to terrestrial environments. That’s a significant transfer of nutrients like phosphorus and sulfur to the land, and is clearly an important food source for many animals. The authors do an entertaining calculation of how many calories are in flux here.

Starting with the 104.49 calories contained in a single Hexagenia limbata, we multiply by the Lake Erie emergence (115 billion individuals) to get annual caloric content (12.016 trillion calories). We took the tree swallow (Tachycineta bicolor) as a model aerial insectivore that has been shown to rely on aquatic insect emergence for feeding fledglings during the nesting season. Dividing the total annual caloric content of the emergence (12.016 billion kcal) by the required 224 kcal to raise a nestling over the 15-d development period, we arrive at the total number of nestlings that can be supported by this food resource (53.6 million birds).

That matters! While I vaguely had the impression that mayfly numbers have declined in the 20 years I’ve lived here, that kind of loss has effects that ripple upwards through the populations of animals that live here. It’s too easy to obliviously trundle along, relieved that I’m not having to go to the car wash as often, and then at some point we notice that we’re not hearing as many songbirds, and the bats seem to be dying off, and the fishing isn’t quite as good anymore, and we finally wonder what’s going on…and it’s too late, because we didn’t stop to think that maybe life in the Midwest has been missing the tons of flying biomass that had been periodically deluging the environment with manna.

That’s one of the messages of this paper — that we have lost about half the mayfly biomass in recent decades, lost to poor management of fertilizers and excessive toxic chemicals in our most productive agricultural lands and just general neglect of wetlands. They’re measuring the disappearance of billions of insects.

Ongoing declines in Hexagenia mayfly abundance (individuals ×109) and biomass (tons ×103) on the Upper Mississippi River. Surveys of Hexagenia abundance over the Upper Mississippi River (black) as well as contributions from the northern (La Crosse, WI; red) and southern (Davenport, IA; blue) subdomains as measured by benthic sampling (crosses) and radar surveillance (circles).

It’s a slow, quiet catastrophe. We’re in the depths of winter right now, no mayflies in sight, but just yesterday I was out by our local river, the Pomme de Terre, where this is a typical view. It’s frozen over, with a foot or two of ice frosted with snow, but beneath all that is a busy ecosystem, with fish feeding on the aquatic insect larvae, and billions of mayfly larvae consuming algae and detritus, growing strong for the spring thaw and the summer breeding season, when they should leap into the air in eager swarms, filling the air with life.

But will they?

The Pomme de Terre river, near Morris, Minnesota, on 15 February 2020. There are mayflies there, you just can’t see them…yet.

Stepanian PM, Entrekin SA, Wainwright CE, Mirkovic D, Tank JL, Kelly JF (2020) Declines in an abundant aquatic insect, the burrowing mayfly, across major North American waterways. Proc Natl Acad Sci U S A. 2020 Feb 11;117(6):2987-2992. doi: 10.1073/pnas.1913598117.

Is it surprising that dissecting human cadavers is the ethical thing to do?

For prospective pre-med students looking for an undergrad institution: the UMM biology discipline just approved a change to our anatomy class. No more cats to dissect, no more mink, no more fetal pigs. Instead, we’re going to have two human cadavers for all anatomy instruction. I know, that sounds strange, but it means we won’t be killing a large number of small mammals to teach the course anymore, and instead will use voluntary donations of individual large mammals that died of natural causes. So it’s actually more ethical, and it means our pre-health profession students will get a more thorough grounding in human anatomy.

I’m mentioning this because I’m predicting it might increase our pre-med enrollment, so I’m trying to influence the outcome. No, I don’t have any money riding on it. I wish we could teach more comparative anatomy, but at least with this approach we won’t be killing any animals in this course.

Don’t you love seeing how science is done?

I have a few fossil molluscs from the Devonian — they’re fairly common orthocerids, these cone-shaped shells that once housed mighty ancient cephalopods. Mine are small, but some of these shells get to be 5 or more meters long. We have to imagine big eyes and swarms of arms writhing out of the broad end of the cone, because those squishy bits don’t fossilize well. Well, not just imagine, because we do have data that lets us reasonably infer what the animal looked like. Here’s an excellent post that describes how this kind of reconstruction of Endoceras was done.

That’s not guesswork. Using trace fossils and phylogenetic bracketing and assembling bits of evidence from multiple specimens, you can make an informed estimation of the main features of the animal.

And it is awesome. Bring ’em back.

Mayflies on Patreon

This feels mildly peculiar, to put posts up behind a paywall, but that’s what I’ve done because I’m anxious to build up a revenue stream to cover certain ugly circumstances. There is now a 1500-word post on the science of mayfly population declines available for my patrons, at any level, to read.

I’m in the business of science communication, so it’s an awkward compromise on just flinging tasty science freely about, but if you can’t afford it, that’s fine — I’ll be posting an openly accessible copy of the article right here in about a week. Check back in!

Also, there’s more coming — I’ve also got a cool article on mayflies as experimental organisms, in addition to being significant as populations ecologically. That’ll appear there later this week.