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Antibiotics, Pain Meds, and a Vegetarian Diet Found in Neanderthal Teeth

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The upper jaw of a Neanderthal found at El Sidrón, Spain, with dental plaque. Image Credit: Paleoanthropology Group MNCN-CSIC

 
As any dental hygienist will warn you, plaque is durable stuff. It traps bits of food, bacteria, and pathogens on your teeth, and if you don’t brush or floss regularly, it sticks there—for good.

That might be bad news for you, but it’s good news for archaeologists. Fossilized plaque, also known as dental calculus, has been found on corpses that are tens of thousands of years old. Now that scientists have the tools to analyze old plaque for pieces of ancient DNA, they can reconstruct the diet, health, and lifestyle of the dead.

One team recently looked at the fossilized plaque on the teeth of four Neanderthals found at two cave sites: Spy in Belgium and El Sidrón in Spain. As our closest known relatives, Neanderthals had a lot in common with modern humans before they went extinct. They built tools and lit campfires. They may have decorated their bodies and buried their dead. And, according to a new study published today in Nature, they took medicine for pain and natural antibiotics for infections, and at least some of them had a plant-heavy diet.

At 42,000 to 50,000 years old, these samples represent the oldest dental plaque ever to be genetically analyzed. One of the individuals found at El Sidrón suffered from a dental abscess visible on the jawbone. He also had an intestinal parasite. That may be why he was consuming poplar—which contains pain-killing salicylic acid, the active ingredient of aspirin—as well as a natural antibiotic mold, Penicillium. Previous research had shown that Sidrón Neanderthals may have used yarrow, an astringent, and camomile, a natural anti-inflammatory, as medicinal plants.

“Apparently, Neanderthals possessed a good knowledge of medicinal plants and their various anti-inflammatory and pain-relieving properties, and seem to be self-medicating,” Alan Cooper, director of the University of Adelaide’s Australian Centre for Ancient DNA (ACAD), said in a statement. “The use of antibiotics would be very surprising, as this is more than 40,000 years before we developed penicillin. Certainly our findings contrast markedly with the rather simplistic view of our ancient relatives in popular imagination.”

Archaeologists working in El Sidrón's Tunnel of Bones cave, where 12 Neanderthal specimens dating around 49,000 years ago have been recovered. Image Credit: Antonio Rosas, Paleoanthropology Group MNCN-CSIC

 
In addition to new insights on the medical regimen of Neanderthals, the study revealed regional differences in Neanderthal eating habits. As ACAD research fellow and lead author Laura Weyrich and her colleagues found, the menu at El Sidrón consisted largely of plant-based foods, like mushrooms, pine nuts, and moss. Meanwhile, at Spy cave, Neanderthals ate a lot of meat, including woolly rhinoceros and wild sheep.

This difference in diet also seemed linked to a difference in oral bacteria between these two Neanderthal populations, which implies that meat consumption contributed to changes within the microbiome for Neanderthals.

"The differences in the oral microbiome are important, because they tell us something about how the human microbiome began to change," Weyrich tells mental_floss. "We know today that historic changes in the human microbiome have likely resulted in the issues we now have with modern human health and altered microbiomes. We need to understand these changes in the past in order to understand how we obtained the bacteria that we now have with us today."

Christina Warinner, an expert on ancient DNA at the Max Planck Institute for the Science of Human History in Germany, tells mental_floss that the most important aspect of the study is the recovery of ancient microbial DNA.

“This provides our first direct evidence of oral microbial ecology in an archaic human,” says Warinner, who wasn't involved in the new study. Indeed, the researchers were able to reconstruct nearly the complete genome of the mouth-dwelling microbe they found, Methanobrevibacter oralis. At 48,000 years old, it is the oldest draft microbial genome created to date.

Warinner says she has consistently found members of this genus to be more common in the past than today. Hundreds of thousands of microbes live in or on the human body, and scientists are just starting to understand how these organisms affect everything from mood to allergies. Warinner suspects Methanobrevibacter microbes once played a much larger role in the human oral ecosystem than they do today, but scientists know little about the past and present function of these organisms.

“It is an important reminder of how we've really just scratched the surface of the human microbiome, and how much work there is to do to understand the evolution and ecology of this fundamental part of our human biology,” Warinner says.

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iStock // Ekaterina Minaeva
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Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning
May 21, 2017
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iStock // Ekaterina Minaeva

Jacques Mattheij made a small, but awesome, mistake. He went on eBay one evening and bid on a bunch of bulk LEGO brick auctions, then went to sleep. Upon waking, he discovered that he was the high bidder on many, and was now the proud owner of two tons of LEGO bricks. (This is about 4400 pounds.) He wrote, "[L]esson 1: if you win almost all bids you are bidding too high."

Mattheij had noticed that bulk, unsorted bricks sell for something like €10/kilogram, whereas sets are roughly €40/kg and rare parts go for up to €100/kg. Much of the value of the bricks is in their sorting. If he could reduce the entropy of these bins of unsorted bricks, he could make a tidy profit. While many people do this work by hand, the problem is enormous—just the kind of challenge for a computer. Mattheij writes:

There are 38000+ shapes and there are 100+ possible shades of color (you can roughly tell how old someone is by asking them what lego colors they remember from their youth).

In the following months, Mattheij built a proof-of-concept sorting system using, of course, LEGO. He broke the problem down into a series of sub-problems (including "feeding LEGO reliably from a hopper is surprisingly hard," one of those facts of nature that will stymie even the best system design). After tinkering with the prototype at length, he expanded the system to a surprisingly complex system of conveyer belts (powered by a home treadmill), various pieces of cabinetry, and "copious quantities of crazy glue."

Here's a video showing the current system running at low speed:

The key part of the system was running the bricks past a camera paired with a computer running a neural net-based image classifier. That allows the computer (when sufficiently trained on brick images) to recognize bricks and thus categorize them by color, shape, or other parameters. Remember that as bricks pass by, they can be in any orientation, can be dirty, can even be stuck to other pieces. So having a flexible software system is key to recognizing—in a fraction of a second—what a given brick is, in order to sort it out. When a match is found, a jet of compressed air pops the piece off the conveyer belt and into a waiting bin.

After much experimentation, Mattheij rewrote the software (several times in fact) to accomplish a variety of basic tasks. At its core, the system takes images from a webcam and feeds them to a neural network to do the classification. Of course, the neural net needs to be "trained" by showing it lots of images, and telling it what those images represent. Mattheij's breakthrough was allowing the machine to effectively train itself, with guidance: Running pieces through allows the system to take its own photos, make a guess, and build on that guess. As long as Mattheij corrects the incorrect guesses, he ends up with a decent (and self-reinforcing) corpus of training data. As the machine continues running, it can rack up more training, allowing it to recognize a broad variety of pieces on the fly.

Here's another video, focusing on how the pieces move on conveyer belts (running at slow speed so puny humans can follow). You can also see the air jets in action:

In an email interview, Mattheij told Mental Floss that the system currently sorts LEGO bricks into more than 50 categories. It can also be run in a color-sorting mode to bin the parts across 12 color groups. (Thus at present you'd likely do a two-pass sort on the bricks: once for shape, then a separate pass for color.) He continues to refine the system, with a focus on making its recognition abilities faster. At some point down the line, he plans to make the software portion open source. You're on your own as far as building conveyer belts, bins, and so forth.

Check out Mattheij's writeup in two parts for more information. It starts with an overview of the story, followed up with a deep dive on the software. He's also tweeting about the project (among other things). And if you look around a bit, you'll find bulk LEGO brick auctions online—it's definitely a thing!

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8 Common Dog Behaviors, Decoded
May 25, 2017
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Dogs are a lot more complicated than we give them credit for. As a result, sometimes things get lost in translation. We’ve yet to invent a dog-to-English translator, but there are certain behaviors you can learn to read in order to better understand what your dog is trying to tell you. The more tuned-in you are to your dog’s emotions, the better you’ll be able to respond—whether that means giving her some space or welcoming a wet, slobbery kiss. 

1. What you’ll see: Your dog is standing with his legs and body relaxed and tail low. His ears are up, but not pointed forward. His mouth is slightly open, he’s panting lightly, and his tongue is loose. His eyes? Soft or maybe slightly squinty from getting his smile on.

What it means: “Hey there, friend!” Your pup is in a calm, relaxed state. He’s open to mingling, which means you can feel comfortable letting friends say hi.

2. What you’ll see: Your dog is standing with her body leaning forward. Her ears are erect and angled forward—or have at least perked up if they’re floppy—and her mouth is closed. Her tail might be sticking out horizontally or sticking straight up and wagging slightly.

What it means: “Hark! Who goes there?!” Something caught your pup’s attention and now she’s on high alert, trying to discern whether or not the person, animal, or situation is a threat. She’ll likely stay on guard until she feels safe or becomes distracted.

3. What you’ll see: Your dog is standing, leaning slightly forward. His body and legs are tense, and his hackles—those hairs along his back and neck—are raised. His tail is stiff and twitching, not swooping playfully. His mouth is open, teeth are exposed, and he may be snarling, snapping, or barking excessively.

What it means: “Don’t mess with me!” This dog is asserting his social dominance and letting others know that he might attack if they don’t defer accordingly. A dog in this stance could be either offensively aggressive or defensively aggressive. If you encounter a dog in this state, play it safe and back away slowly without making eye contact.

4. What you’ll see: As another dog approaches, your dog lies down on his back with his tail tucked in between his legs. His paws are tucked in too, his ears are flat, and he isn’t making direct eye contact with the other dog standing over him.

What it means: “I come in peace!” Your pooch is displaying signs of submission to a more dominant dog, conveying total surrender to avoid physical confrontation. Other, less obvious, signs of submission include ears that are flattened back against the head, an avoidance of eye contact, a tongue flick, and bared teeth. Yup—a dog might bare his teeth while still being submissive, but they’ll likely be clenched together, the lips opened horizontally rather than curled up to show the front canines. A submissive dog will also slink backward or inward rather than forward, which would indicate more aggressive behavior.

5. What you’ll see: Your dog is crouching with her back hunched, tail tucked, and the corner of her mouth pulled back with lips slightly curled. Her shoulders, or hackles, are raised and her ears are flattened. She’s avoiding eye contact.

What it means: “I’m scared, but will fight you if I have to.” This dog’s fight or flight instincts have been activated. It’s best to keep your distance from a dog in this emotional state because she could attack if she feels cornered.

6. What you’ll see: You’re staring at your dog, holding eye contact. Your dog looks away from you, tentatively looks back, then looks away again. After some time, he licks his chops and yawns.

What it means: “I don’t know what’s going on and it’s weirding me out.” Your dog doesn’t know what to make of the situation, but rather than nipping or barking, he’ll stick to behaviors he knows are OK, like yawning, licking his chops, or shaking as if he’s wet. You’ll want to intervene by removing whatever it is causing him discomfort—such as an overly grabby child—and giving him some space to relax.

7. What you’ll see: Your dog has her front paws bent and lowered onto the ground with her rear in the air. Her body is relaxed, loose, and wiggly, and her tail is up and wagging from side to side. She might also let out a high-pitched or impatient bark.

What it means: “What’s the hold up? Let’s play!” This classic stance, known to dog trainers and behaviorists as “the play bow,” is a sign she’s ready to let the good times roll. Get ready for a round of fetch or tug of war, or for a good long outing at the dog park.

8. What you’ll see: You’ve just gotten home from work and your dog rushes over. He can’t stop wiggling his backside, and he may even lower himself into a giant stretch, like he’s doing yoga.

What it means: “OhmygoshImsohappytoseeyou I love you so much you’re my best friend foreverandeverandever!!!!” This one’s easy: Your pup is overjoyed his BFF is back. That big stretch is something dogs don’t pull out for just anyone; they save that for the people they truly love. Show him you feel the same way with a good belly rub and a handful of his favorite treats.

The best way to say “I love you” in dog? A monthly subscription to BarkBox. Your favorite pup will get a package filled with treats, toys, and other good stuff (and in return, you’ll probably get lots of sloppy kisses). Visit BarkBox to learn more.

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