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.
Being back home, I can now begin catching up on the backlog of readers’ wildlife photos, but before I do I’ll put up some pictures that came in just a few days ago from the ever-diligent Stephen Barnard, who is moving on to new animals:
I’ve been taking a lot of hummingbird photos and getting a little bored with them. Here’s a Rufous (Selasphorus rufus) and a Black-chinned(Archilochus alexandri). I’m also including two new birds for Aubrey Spring Ranch: a pair of Wilson’s Phalaropes (Phalaropus tricolor) and a Western sandpiper (Calidris mauri):
Note: the range of the Western Sandpiper, as shown on the Cornell map, doesn’t include Idaho, so perhaps this one was migrating, or a stray:
When I visited Matt Dillahunty in Austin, he suggested that we do a one-on-one interview not only about Faith versus Fact, but also about science in general and evolution in particular. This video was one of his productions for his Patreon contributors (you can find it here), but is also posted on YouTube, and I embed it below. As always, I can’t bear to watch it, so I can’t say how it went. It’s fifty minutes long. I have no idea why that blasted photo is the video avatar; it looks as if I can’t stand my own book!
Matt is doing superb work lecturing and especially debating theists: as a former diehard Southern Baptist, he’s uniquely qualified to debate believers, does so regularly, and, so I hear, has a remarkable record of victory.As most of you know, he also is one of the hosts of The Atheist Experience on Austin cable t.v., perhaps the nation’s most famous television show for nonbelievers (see the archive here).
I was greatly impressed by his knowledge of religion and philosophy, and by his ability to counter the arguments of both garden-variety theists as well as Sophisticated Theologians™. These efforts, which largely constitute Matt’s work, deserve our support. And you can tender your support, at least in a pencuniary way, by making a donation on Matt’s Patreon page.
Professor Ceiling Cat is finally home, having put about 7200 miles on the car. It was a great trip, and I had a blast reconnecting with old friends and meeting some of the readers who were gracious enough to invite me into their home. I’ve documented most of the trip, and other photos will follow.
As for now, I’ll be back writing on this site, slowly at first, but hope to get it up to speed soon. Again, thanks a ton to Grania for helping hold down the shop—indeed, she didn’t just hold it down, but kept business going pretty muchas usual, despite holding down a day job, and I’m very grateful to her. She will continue to contribute here when she has time. Meanwhile in Dobrzyn, there was a bumper cherry harvest—I believe over 15 tons of fruit, although the buyers seem to be in collusion to keep prices low. This, however, does not concern Hili, who is scouring the orchard for leftover cherries, presumably because they attract a more meaty prey:
A: Where are you going?
Hili: Where the cherry-pickers haven’t got to yet.
In Polish:
Ja: Gdzie idziesz?
Hili: Tam gdzie jeszcze nie ma zbieraczy.
As the capstone to Snake Week, let’s take a closer look at how the squirrel-like mammal being eaten by Tetrapodophis in Julius Csotonyi’s striking reconstruction died. In my earlier post, I took note of the fact that the describers of the newly discovered four-legged fossil snake had inferred from its skeleton that it was a constrictor (and thus the earliest known constricting snake, implying that constriction is an ancestral characteristic of snakes), and included Csotonyi’s lovely reconstruction showing the four-legged Tetrapodophis doing in and beginning to swallow a squirrel-like mammal. Here’s a reprise of the picture.
A multituberculate (?) being eaten by Tetrapodophis. Reconstruction by Julius Csotonyi.
The snake killed the ‘squirrel’, so we know who killed it, but what killed the ‘squirrel’? In police procedural talk, we’ve got the murderer, but we want to know the cause of death for the coroner’s report. Coincidentally, a new paper in the Journal of Experimental Biology, appearing at almost the same time as the description of Tetrapodophis, asks exactly that question, and shows via straight-forward and well-done experiments, what, in fact, is the ‘squirrel’s’ cause of death.
It was long thought that constricted prey died of suffocation, but it had also been suggested that the prey died of cardiac arrest due to drop in blood pressure. This had been suggested, in part, by the rapidity with which prey died, seemingly more rapidly than they would suffocate. What Scott Boback and colleagues have shown, using anesthetized rats fed to boa constrictors, with a set of catheters and probes in them to record their heart rates and blood pressures, is that there is a sharp and sudden drop in peripheral arterial pressure, an increase in central venous pressure, and a slowing of the heart rate. They conclude:
[S]nake constriction induces rapid prey death due to circulatory arrest.
I’m not sure if their experiments quite exclude asphyxia as a contributing cause, but it certainly shows the importance of the circulatory crisis caused by constriction.
Some of the media coverage has overstated the novelty of this result. For example, National Geographic headlined “Why We Were Totally Wrong About How Boa Constrictors Kill”, while Science, somewhat less over the top, headlined “Surprise: Snakes don’t kill by suffocation“. However, as Boback et al. note, circulatory collapse was first suggested over 80 years ago, and has been a viable idea for quite a while. Harry Greene, our foremost student of snake natural history, taking an ecumenical approach to the cause of death, wrote in his fine Snakes, in 1997, that constriction acted by “interfering with breathing and blood circulation so that the victim is immobilized within a minute or so”, while in a later, standard, herpetology text, Laurie Vitt and Janalee Caldwell (2009) wrote, “The tightening continues, and ultimately, circulatory failure causes death.” So Boback and colleagues have done a fine and needed study, but don’t believe the (media) hype!
In writing this post, I wondered what to call the prey in Csotonyi’s reconstruction. It could not be a rat, as in Boback’s study, as there were no rats, or rodents of any kind, in the Cretaceous. On the other hand, it does look like a squirrel (a rodent as well, again not possible for the Cretaceous), so I settled on ‘squirrel’, with scare quotes. A likely mammal for Tetrapodophis to have eaten is some sort of multituberculate, an extinct type of mammal found in the Cretaceous, and convergent on rodents in their dentition (gnawing incisors with a diastema before the molariforms). And, some of them showed arboreal adaptations, as do tree squirrels, but even more so, having prehensile tails. In the reconstruction below, accompanying a paper by Farish Jenkins and David Krause, the multiberculate Ptilodusis shown to be quite squirrel-like, except for its opossum-like prehensile tail.
Cover illustration from Science by L.L. Sadler accompanying Jenkins and Krause (1983).
Boback, S.M., K.J. McCann, K.A. Wood, P.M. McNeal, E.L. Blankenship and C. F. Zwemee. 2015. Snake constriction rapidly induces circulatory arrest in rats. Journal of Experimental Biology 218:2279-2288. abstract
Greene, H.W. 1997. Snakes: The Evolution of Mystery in Nature. University of California Press, Berkeley.
Jenkins, F.A. and D.W. Krause. 1983. Adaptations for climbing in North American multituberculates (Mammalia). Science 220:712-715. abstract (pdf of JEB commentary)
Samantha Cristoforetti is back from her 199 day mission on the International Space Station and spoke to CNN’s Christiane Amanpour about her experience there and being back on our planet. Long story short: gravity is a nasty welcome back to earth and we are all crew members on Spaceship Earth.
She talks about the experience of being able to fly in zero gravity (“I was like Superman!”) and the future of manned space travel, and getting children into science and technology.
The research on astronaut’s skin is a new investigation and was started because many astronauts had complained about skin problems; so Cristoforetti’s team had their skin scanned before and after the mission to help with this.
“We use femtosecond laser pulses. We scan the skin and we get signals from the skin, particularly fluorescence, as well as another signal called second harmonic generation,” he explained. “So with these two signals we can build up images and get a precise look into the skin with a high resolution. The resolution is a factor of one thousand times better than ultrasound.”
The article also shows many of her favorite photographs that she took while on her ISS mission. I love this one of Carribean.
Here’s a dramatic set taken of noctilucent clouds, not an angle we often get to see.
Biologist and naturalist Lou Jost, who lives and works in Ecuador who regularly sends WEIT examples of his amazing photography and art has sent in some more photographs of hummingbirds, this time with a difference. Here’s what he wrote to Jerry.
In case people think that all hummingbirds are like the little buzzy things we have in the US, here is a hummingbird I saw last week that was almost as big as a swift or swallow. It’s called the Great Sapphirewing (Pterophanes cyanopterus). It is a very high elevation Ecuadorian and Colombian hummingbird, living around timberline at 3400-4000m. These huge hummingbirds have a more stately flight than the little guys, and they glide a lot. This is one of the largest hummingbirds in the world.
I watched it feeding on the turquoise-blue flowers of a giant terrestrial bromeliad (Puya sp.) whose wooly flower stalk was about 3-4m tall. This was a strange paramo (tropical high-elevation alpine grassland) studded all the way to the horizon with white-leaved Espeletia plants, in the aster family. These Espeletia are only found in very wet paramos and have a limited distribution in Ecuador. WEIT readers with good memories might recall reading about this genus of plants in relation to the recently-rediscovered Oxypogon hummingbird in Colombia. We were looking for Oxypogon hummingbirds here, but we didn’t find any, and none have ever been seen in Ecuador. But we have Espeletia in some spots, so maybe some day we’ll find one. (If one is ever found here, it will surely be a different species from the rediscovered one.)
In the shrubby transition zone just below this paramo, my group saw another iridescent blue bird, the Golden-crowned Tanager (Iridisornis rufivertex). This is one of my favorite birds for its subtle but beautiful colors, and I was really happy to finally get pictures of it. We lured it in with recordings of its own song and the songs of small owls (which little birds love to mob).
It’s Caturday again, and it is time to examine feline proclivities.
I’m not sure whether this falls under Cruel and Unusual or whether the cats even noticed, but this was to test whether cats liked listening to music: DEVO Cat Listening Party, you can watch 50 minutes of it at the link.
Verdict: I’m not sure the cats cared.
Our literate ancestors liked cats and they certainly made their way into medieval manuscripts in a variety of delightful poses, but there are also several images preserved for posterity of cats at their least elegant.
Maccabean revolt against the Seleucid Empire: Cat licks butt.
This is all due to an intensive conservation campaign, however they are not out of the woods yet as they are still endangered not only by humans but also by disease that is killing off rabbits which is their main source of food.
Something that cats may or may not care about is homage from humans. They probably feel it is their due, and so approve of it on general principles.
Here’s an extract, you can read the rest over on The New Yorker:
For I will consider my Cat Cherie
for she is the very apotheosis of Cat-Beauty
which is to say, nothing extraordinary
for in the Cat, beauty is ordinary
like the bliss
conferred
upon us
in the hypnosis
of purr-
ing.
She has been known
to knead her claws
upon a sleeve.
And on a knee.
And on bare skin,
sharp claws sinking in— just a warning. For she is of the tribe of Tyger and eyes burning bright though cuddling
at night
until you wake to discover—
where is she? Cher-ie? Don’t inquire.
In Polish:
