It’s been a long time, so let’s go spanning the globe for anatomy news and notes!
Can you walk and chew at the same time? Not chew gum—bamboo! That’s the key to being a giant panda. And some research on the giant panda’s false thumb posits a theory about their evolution and their diet, switching over time from eating meat to eating only bamboo. The panda never developed a truly opposable thumb. These bears only have a thumb-like digit from the radial sesamoid (a.k.a. the wrist).
But a fossil of a panda that lived 6 or 7 million years ago (give or take), shows that the earliest bamboo-eating panda did have this “thumb.” Surprisingly, reports SciTechDaily in this fascinating article, this thumb is no longer than its modern descendants. Blame, yes, all that walking. Worth reading!
Photo by Peter Burdon on Unsplash
Full credit to the research by the Natural History Museum of Los Angeles County’s Curator of Vertebrate Paleontology Xiaoming Wang and colleagues.
++
You have until October 30th to get yourself to Edinburgh and check out Anatomy: A Matter of Death and Life at the National Museum of Scotland.
“Charting 500 years of medical exploration, the exhibition considers the social and medical history surrounding the dissection of human bodies. Discover the role anatomy played in the Enlightenment, uncover the links between science and crime in the early 19th century, and consider approaches to anatomical study today.”
It's always good to look back and see how far we’ve come in understanding human anatomy—and it’s daunting to think what we’ll know in another 500 years, too.
The exhibit is upfront about some of dark past of the anatomical science, detailing how the cemeteries needed guard towers (!) and the fact that some of the cadavers brought to the university were poor people who had been murdered. Of course, that legacy cannot be defended in any way, shape, or form. It’s good that the exhibit doesn’t shy away, even as it shows how the endless fascination with human anatomy progressed even if that demand for knowledge outstripped the “legitimate supply.”
BTW, the mention of ‘death’ in the exhibit title is (we think) meant to be a bit of droll Scottish humor.
++
Listen up!
Well, if you have been around the `Anatomy in Clay® founder, you know how much he loves to talk about observing the fish in all of us. The gill-arch as today’s jaws. The tunicate, etc.
Now, scientists have discovered that our middle ears evolved from fish gills as well. The proof comes from a fossil fish brain that is 438 million years old. The fish is a Shuyu, with the skull the size of a fingernail.
The scientists, from the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences (according to the story as reported at Study Finds) focused on something called the spiracle. What’s the spiracle? It’s slits behind the eyes that lead to the mouth, which allows some species to breathe.
(Quick note: the word spiracle is from Latin and Middle English: spiraculum, spirare, ‘to breathe.’)
In sharks and rays, the spiracle intakes the water before being expelled from the gills.
Well, that spiracle is what evolved into the ear of a modern four-legged vertebrate, “eventually becoming the hearing canal used for transmitting sound to the brain via tiny inner ear bones,” said the article in Study Finds.
The scientists ran a total of seven virtual endocasts of the Shuyu braincase. (An endocast is a 3D representation of the space within a cavity.) The fossils were found to be the missing link from the gill to the middle ear.
.
.
.
.
Comments