Beating the allegory of the cave

When Beatriz Flamini spoke with reporters on April 14, she knew nothing of the previous 18 months. The Russian invasion of Ukraine? Nope. The death of Queen Elizabeth? Also no. But before you make fun of her, she has an excuse. She’s been living under a rock.

As part of an experiment to test how social isolation and disorientation affect a person’s mind, sense of time, and sleeping patterns, Ms. Flamini lived in a 70-meter-deep cave in southern Spain for 500 days, starting in November 2021. Alone. No outside communication with the outside world in any way, though she was constantly monitored by a team of researchers. She also had multiple cameras filming her for an upcoming documentary.

This is a massive step up from the previous record for time spent underground for science: A team of 15 spent 50 days underground in 2021 to similar study of isolation and how it affected circadian rhythms. It’s also almost certainly a world record for time spent underground.

All that time alone certainly sounds like some sort of medieval torture, but Ms. Flamini had access to food, water, and a library of books. Which she made liberal use of, reading at least 60 books during her stay. She also had a panic button in case the isolation became too much or an emergency developed, but she never considered using it.

She lost track of time after 2 months, flies invaded the cave on occasion, and maintaining coherence was occasionally a struggle, but she kept things together very well. In fact, she didn’t even want to leave when her team came for her. She wasn’t even finished with her 61st book.

When she spoke with gathered reporters after the ordeal, words were obviously difficult to come by for her, having not spoken in nearly 18 months, but her mind was clearly still sharp and she had a very important question for everyone gathered around her.

Who’s buying the beer?

We approve of this request.

Staphylococcus and the speed of evolution

Bacteria, we know, are tough little buggers that are hard to see and even harder to get rid of. So hard, actually, that human bodies eventually gave up on the task and decided to just incorporate them into our organ systems. But why are bacteria so hard to eliminate?

Two words: rapid evolution. How rapid? For the first time, scientists have directly observed adaptive evolution by Staphylococcus aureus in a single person’s skin microbiome. That’s how rapid.

For their study, the researchers collected samples from the nostrils, backs of knees, insides of elbows, and forearms of 23 children with eczema. They eventually cultured almost 1,500 unique colonies of S. aureus cells from those samples and sequenced the cells’ genomes.

All that sampling and culturing and sequencing showed that it was rare for a new S. aureus strain to come in and replace the existing strain. “Despite the stability at the lineage level, we see a lot of dynamics at the whole genome level, where new mutations are constantly arising in these bacteria and then spreading throughout the entire body,” Tami D. Lieberman, PhD, of the Massachusetts Institute of Technology, Cambridge, said in a written statement from MIT.

One frequent mutation involved a gene called capD, which encodes an enzyme necessary for synthesizing the capsular polysaccharide — a coating that protects S. aureus from recognition by immune cells. In one patient, four different mutations of capD arose independently in different samples before one variant became dominant and spread over the entire microbiome, MIT reported.

The mutation, which actually results in the loss of the polysaccharide capsule, may allow cells to grow faster than those without the mutation because they have more fuel to power their own growth, the researchers suggested. It’s also possible that loss of the capsule allows S. aureus cells to stick to the skin better because proteins that allow them to adhere to the skin are more exposed.

Dr. Lieberman and her associates hope that these variant-containing cells could be a new target for eczema treatments, but we’re never optimistic when it comes to bacteria. That’s because some of us are old enough to remember evolutionary biologist Stephen Jay Gould, who wrote in his book “Full House”: “Our planet has always been in the ‘Age of Bacteria,’ ever since the first fossils — bacteria, of course — were entombed in rocks more than 3 billion years ago. On any possible, reasonable or fair criterion, bacteria are — and always have been — the dominant forms of life on Earth.”

In the distant future, long after humans have left the scene, the bacteria will be laughing at the last rats and cockroaches scurrying across the landscape. Wanna bet?

The height of genetic prediction

Genetics are practically a DNA Scrabble bag. Traits like eye color and hair texture are chosen in the same fashion, based on what gets pulled from our own genetic bag of letters, but what about height? Researchers may now have a way to predict adult height and make it more than just an educated guess.

How? By looking at the genes in our growth plates. The cartilage on the ends of our bones hardens as we age, eventually deciding an individual’s stature. In a recently published study, a research team looked at 600 million cartilage cells linked to maturation and cell growth in mice. Because everything starts with rodents.

After that search identified 145 genes linked to growth plate maturation and formation of the bones, they compared the mouse genes with data from genome-wide association studies (GWAS) of human height to look for hotspots where the height genes exist in human DNA.

The results showed which genes play a role in deciding height, and the GWAS data also suggested that genetic changes affecting cartilage cell maturation may strongly influence adult height, said the investigators, who hope that earlier interventions can improve outcomes in patients with conditions such as skeletal dysplasia.

So, yeah, you may want to be a little taller or shorter, but the outcome of that particular Scrabble game was determined when your parents, you know, dropped the letters in the bag.

This article originally appeared on MDedge.com, part of the Medscape Professional Network.

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