Sci-Ed Update 315

Science finally studies women's bodies, Clostridium is our friend, teeth as birth records, dismantling DNA, new podcast episode, catching up, daylight savings is not our friend, how we lost our tails

Apr 16, 2024

“Where’s my tail?”
Geneticist Bo Xia asked that question as a child and it was on his mind again a few years ago, while he was recovering from a tailbone injury during his PhD at New York University (NYU) in New York City.
Xia and his colleagues now have an answer. The researchers identified a genetic change shared by humans and other apes that might have contributed to their ancestors’ tail loss, some 25 million years ago.
Mice carrying similar alterations to their genomes had short or absent tails, the researchers found — but that insight was hard won. The work was published on 28 February¹: nearly 900 days after being submitted to Nature and posted as a preprint, because of extra work needed to develop several strains of gene-edited mice and demonstrate that the genetic changes had the predicted effect.
“Respect to the authors,” says Malte Spielmann, a human geneticist at Kiel University in Germany, who reviewed the paper for Nature. “I’m incredibly excited about the fact that they’ve really pulled it off.”

Kevin Patton comment→ When one of your A&P students asks why human don’t have tails, now you have a quick answer for them: “humans and other apes carry a DNA insertion in TBXT that other primates with tails, such as monkeys, don’t have.”

TAPP Update

If you pay attention to such things, you’ve noticed quite a gap between the last issue of this publication and this one. I apologize if that disrupted your flow, but it was unavoidable. I’m hoping to get back on track starting with this issue. I warn you: it will be a slow ramp back up to “normal.” There are a lot of things going on behind the scenes that are pulling at me right now, but I’m working hard to rebalance the aspects that I can control.

Sometimes it’s hard to catch up, right?

There was a gap in the TAPP podcast, too, but I did finally get an episode out last week. It’s a long one—two hours! Hopefully, that will make up for some of the lost time. There’s a link to that episode below, in case you missed it.

Why Daylight Saving Time Messes With Your Brain

*A World War I-era poster extolling the value of Daylight Saving Time—which may actually do more harm than good. PUBLIC DOMAIN/WIKIMEDIA*

About one-third of Americans say they don’t look forward to these twice-yearly time changes. And nearly two-thirds would like to eliminate them completely, compared with 17% who aren’t sure and 21% who would like to keep moving their clocks back and forth.
But the effects go beyond simple inconvenience. Researchers are discovering that “springing ahead” each March is connected with serious negative health effects, including an uptick in heart attacks and teen sleep deprivation. In contrast, the fall transition back to standard time is not associated with these health effects, as my coauthors and I explained in a 2020 commentary.
I’ve studied the pros and cons of these twice-annual rituals for more than five years as a professor of neurology and pediatrics and the director of Vanderbilt University Medical Center’s sleep division. It’s become clear to me and many of my colleagues that the transition to daylight saving time each spring affects health immediately after the clock change and also for the nearly eight months that Americans remain on daylight saving time.

Pulse of Progress: Looking Back, Moving Forward

In Episode 147, host Kevin Patton reviews the highlights and events of the previous year in the world of The A&P Professor. He then turns to last year’s predictions for teaching human anatomy and physiology to see if he was on the right track.

Finally, predictions for the coming year are revealed. And lots of other stuff—this episode is two hours long, after all!

To listen to this episode, click on the play button above ⏵ (if present) or this link→ theAPprofessor.org/podcast-episode-147.html

Tracking Higher Ed’s Dismantling of DEI

The Chronicle is tracking higher ed’s dismantling of diversity, equity, and inclusion efforts. As colleges make changes in response to anti-DEI legislation and mounting political pressure, an inconsistent and confusing landscape has emerged. This resource aims to document the changes and help readers better understand how the campaign against DEI has actually reshaped campuses.
This tracker collects changes that public colleges have made to offices, jobs, training, diversity statements, and other DEI-related activities as the result of bills, executive orders, system mandates, and other state-level actions since January 2023, when The Chronicle began reporting on anti-DEI legislation. The information comes from a Chronicle survey, media reports, and tips from readers.
The Chronicle has tracked changes at 116 college campuses.
View more details by state and individual institution ...

The Birth Certificate in Your Mouth

*Dental X-ray of child's mouth. Courtesy of Masrour Makaremi.*

Baby teeth begin calcifying when we are still in the uterus, as does our first permanent molar. These teeth preserve lines that indicate the temporary position of enamel- and dentine-forming cells during birth. Scientists discovered these neonatal lines by examining hundreds of baby teeth from human children, finding dark, accentuated lines in a similar position in most teeth. Dental researcher Isaac Schour was the first to suggest that this microscopic disruption is caused by the physiological transition of birth. Others have since counted subsequent daily growth lines in young individuals, finding close agreement with their age and confirming that this line is indeed formed at birth.

Meet Clostridium butyricum—the bacteria that helps keep us feeling our best

C butyricum is a microbe that lives in the soil as well as our gut. It's commonly found in vegetables and sour milk. This microbe prefers to grow in environments lacking oxygen and exists in a mutualistic relationship with the human host—meaning the human body helps it to grow and survive, and in return it provides our body with benefits.
C butyricum has been so named because of its ability to produce the short-chain fatty acid butyrate, which is a major source of energy for our intestinal cells. It produces butyrate in the gut by fermenting fiber from foods such as whole grains, fruits and vegetables.
This short-chain fatty acid has been linked to many health benefits—all thanks to the hard work of C butyricum.
It's been suggested that C butyricum helps change the gut microbiome's composition by increasing the numbers of beneficial microbes in the gut—such as Lactobacillus and Bifidobacterium, which aid digestion and protect against pathogens.

Scientists are finally studying women’s bodies. This is what we’re learning.

Going to the doctor can be frustrating when you’re a woman—and even more so if you’re a woman of color.
That’s because women are more likely to be underdiagnosed with conditions from endometriosis to schizophrenia to ADHD. In the United States, Black women are almost three times more likely to die from pregnancy-related complications than white or Hispanic women. And somehow scientists still don’t have a good handle on why so many women struggle to breastfeed.
None of this is new. We’ve long known that women’s health concerns are dismissed more frequently and studied less. But the good news is that researchers are starting to fill in those gaps. Their research is yielding new biological insights—leading to better diagnoses and more targeted treatments, from menstruation to menopause.
Here’s a look at just a handful of those developments that we’ve covered in recent years.

The A&P Professor Science & Education Updates

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