Posted by Nicola Griffith
https://nicolagriffith.com/2025/08/25/anothe-screwfly-solution-and-other-snippets/
http://nicolagriffith.com/?p=86982
It’s been a while since I did a snippets post. So for this sunny August Monday here in Seattle, some fun facts.
Flying flesh-eating maggots
First, for those who are familiar with the work of Alice Sheldon (aka James tiptree, Jr, aka Raccoona Sheldon), specifically “The Screwfly Solution,” I woke to a little frisson, a shiver down the spine at the news that the New World Screwfly is advancing rapidly towards the US. (Okay, it’s not exactly new news, but I’m just catching up.) Think flying, flesh-eating maggots, except of course it’s the flies that fly, and the maggots that scarf down the flesh, and you get the general idea. They can infect people—and the resulting wounds can be life-threatening, requiring surgery—though that’s rare. Best not to let it happen. The real worry is that, if these nasties reach the herds of Texas and California, the price of beef and diary products will sky-rocket. The USDA’s latest figures suggest the economic losses in Texas alone would be over $1.8 bn ($1,828,293,838 to be precise).
How do we know? Because it’s happened before. Officially eradicated in the 60s, but with occasional outbreaks, such as one in 1976. How did the USDA beat it then? Well, you could go read the USDA’s latest plan, or you could scare the spit out of yourself on several different levels by reading Sheldon’s story. You’re welcome.
Our squirrel-like ancestors of the frozen north
What is actually much more interesting, and certainly more pleasant to contemplate over lunch, is the recent suggestion that primates—y’know, the order we belong to—didn’t evolve in a warm climate like Africa but in a much harsher environment, one with temperature swings of nearly 40 degrees Celsius (over 70 degrees Fahrenheit), such as North America.
Here’s the abstract from the original paper:
One of the most influential hypotheses about primate evolution postulates that their origin, radiation, and major dispersals were associated with exceptionally warm conditions in tropical forests at northern latitudes (henceforth the warm tropical forest hypothesis). However, this notion has proven difficult to test given the overall uncertainty about both geographic locations and paleoclimates of ancestral species. By the resolution of both challenges, we reveal that early primates dispersed and radiated in higher latitudes, through diverse climates, including cold, arid, and temperate conditions. Contrary to expectations of the warm tropical forest hypothesis, warmer global temperatures had no effect on dispersal distances or the speciation rate. Rather, the amount of change in local temperature and precipitation substantially predicted geographic and species diversity. Our results suggest that nontropical, changeable environments exerted strong selective pressures on primates with higher dispersal ability – promoting the primate radiation and their subsequent colonization of tropical climates millions of years after their origin.
J. Avaria-Llautureo, T.A. Püschel, A. Meade, J. Baker, S.L. Nicholson, & C. Venditti, The radiation and geographic expansion of primates through diverse climates, Proc. Natl. Acad. Sci. U.S.A. 122 (32) e2423833122, https://doi.org/10.1073/pnas.2423833122 (2025).
But if, like me, you prefer your Monday afternoon reading to be a bit more digestible, there’s a better-than-average write-up on Earth.com. Basically, fossil evidence and statistical models using the Köppen-Geiger climate system that sorts environments by average heat and rain, point to a “70% chance that the first crown primates lived in what is now North America, with 30% pointing to Western Europe – territories then sitting near 45° N before plate motion.” So there you have it: we come from little squirrel-sized beasties roaming the northern forests 66 million years ago. At least they wouldn’t have had to worry about screwflies because unlike our tough little ancestors, they couldn’t have survived that climate.
Brid flu and Covid
I don’t really have anything new to say—things are just trundling along as they usually do.
Bird flu is both everywhere and in decline. There are several reasons, most prominently that it’s summer: flu doesn’t do well in summer, and migratory birds are not currently migrating. There’s also the fact that there’s not a lot of testing going on. But don’t be fooled—no news is not good news; it’s still out there, still circulating in the wild. It’s very possible it will come surging back at some point with a roar and a bag of dangerous reassortants, and if it does it could be fast, but right now, nothing to worry about. As always, though, keep an eye on your cats, don’t let them kill and/or eat birds, and never feed them unpasteurised raw food of any kind, especially dairy.
Covid-19 continues to evolve. We’re in the middle of the expected summer wave—with those most affected being the old, those with co-morbidities, and the under-4s. If you aren’t already, please start masking in crowded places, and very definitely when travelling, whether on municipal mass transit or planes. Rules for vaccination are changing all the time—but do remember, even if official recommendations imply you can’t get vaccinated if you’re under 65 without a comorbidity, doctors are often will to prescribe shots off-label. Just ask your healthcare provider. I had a Moderna booster shot before the Nebulas, and assuming I can find a Novavax shot in autumn I’ll get the next in November. (Novavax for two reasons: fewer side-effects for those who are sensitive to such things, and longer-lasting immunity.) There’s more and more data on Long Covid, and every single new study while adding to our understanding of its aetiology also confirms what we all know if we’re willing to admit it to ourselves: Long Covid is devastating; it lasts a very long time, often forever; and the odds of developing it increase with every infection. Wear that mask.
https://nicolagriffith.com/2025/08/25/anothe-screwfly-solution-and-other-snippets/
http://nicolagriffith.com/?p=86982