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M. Haslam
M. Haslam

Brazilian Monkeys Make Stone Hammers That Look a Lot Like Early Human Tools

M. Haslam
M. Haslam

Animals are adorable when they do people things. It’s a scientific fact. But the list of “people things” just keeps on shrinking. Other animals can hold grudges, name their babies, read our expressions, and even read our mammogram results. The latest ding in our dominance comes courtesy of Brazilian capuchin monkeys, who, as it turns out, have been sharpening stones into human-style hammers for a long, long time. A report on the findings was published in the journal Nature.

Researchers in Brazil have had their eye on the bearded capuchin (Sapajus libidinosus) for some time now and have found that despite a varied diet, the little monkeys expend a lot of energy acquiring one particular food: cashews. To access the sweet meat inside the cashew’s tough shell, capuchins developed their own specialized tools, which they’ve been using now for at least 700 years.

The team now reports that those same monkeys may have been inadvertently messing with the timeline of human events. In addition to their cashew bashing, the researchers say, the capuchins will also pound one rock against another. This stone-on-stone percussion (as the researchers call it) chips away pieces of both rocks, sharpening them in the process—and producing results that look an awful lot like early human cutting tools.

The researchers couldn’t tell why the monkeys were smashing rocks. They did use some of the newly broken stones as hammers, but they didn’t use the sharpened parts. About half of the time after breaking a rock, a monkey mason would lick or sniff it, which suggests that they might be after essential minerals they can’t get any other way.

These findings have pretty substantial implications for both primate evolution and archaeological research. Before this, hominins (the group of primates that includes humans and our human-like ancestors) were the only known animals to make this type of tool.

“Our understanding of the new technologies adopted by our early ancestors helps shape our view of human evolution,” co-author Michael Haslam of the University of Oxford said in a statement. “The emergence of sharp-edged stone tools that were fashioned and hammered to create a cutting tool was a big part of that story. The fact that we have discovered monkeys can produce the same result does throw a bit of a spanner in the works.”

It also makes scientists wonder about certain caches of tools allegedly made by early humans. In an accompanying commentary in the same issue of Nature, paleontologist Hélène Roche called the research a “shattering discovery.” She noted that we have plenty of corroborating evidence showing that artifacts from the Early African Stone Age were indeed made by people. But there have been some questions about the origin of tools from the Late Pleistocene epoch (between 40,000 and 20,000 years ago), and the answer might well be “monkeys.”
 
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Slow Motion Is the Only Way to Appreciate a Chameleon’s Lightning-Fast Tongue
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From the unusual way they walk, to their ability to change color, the evolutionary adaptations of chameleons are pretty bizarre, and some of them remain mysterious even to scientists. Their super-powered tongues, for instance, can dart out so quickly that the movement can barely be seen with the naked eye. But modern high-speed cameras have enabled researchers at the University of South Dakota to observe this appendage at work like never before. The video below, shared over at The Kid Should See This, includes some of that groundbreaking footage, and it's pretty amazing to watch.

Shooting at 3000 frames per second, the camera was able to capture every split-second aspect of the chameleon's tongue strike. Slowed down, the video allows you to see how every component of the process works in harmony: First, muscles in the lizard’s tongue contract like the string of a bow. Then, when that tension is released, the bony base of the tongue shoots forward, pushing the sticky, elastic part toward the chameleon’s prey.

According to Christopher Anderson, one of the scientists who conducted the high-speed camera research, larger chameleons can catapult their tongues forward at distances of one to two times their body length. For smaller chameleons, this distance can reach up to two and a half times their body length. “Small chameleons need to be able to eat more food for their body size than large chameleons,” he tells bioGraphic in the video, “and so by being able to project their tongues proportionately further than these large species, they basically are opening up additional feeding opportunities to themselves that they wouldn’t have if they had a shorter tongue.”

To see one of nature’s greatest hunting tools in action, check out the full video below.

[h/t The Kid Should See This]

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There May Be an Ancient Reason Why Your Dog Eats Poop
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Dogs aren't known for their picky taste in food, but some pups go beyond the normal trash hunting and start rooting around in poop, whether it be their own or a friend's. Just why dogs exhibit this behavior is a scientific mystery. Only some dogs do it, and researchers aren't quite sure where the impulse comes from. But if your dog is a poop eater, it's nearly impossible to steer them away from their favorite feces.

A new study in the journal Veterinary Medicine and Science, spotted by The Washington Post, presents a new theory for what scientists call "canine conspecific coprophagy," or dogs eating dog poop.

In online surveys about domestic dogs' poop-eating habits completed by thousands of pet owners, the researchers found no link between eating poop and a dog's sex, house training, compulsive behavior, or the style of mothering they received as puppies. However, they did find one common link between the poop eaters. Most tended to eat only poop that was less than two days old. According to their data, 85 percent of poop-eaters only go for the fresh stuff.

That timeline is important because it tracks with the lifespan of parasites. And this led the researchers to the following hypothesis: that eating poop is a holdover behavior from domestic dogs' ancestors, who may have had a decent reason to tuck into their friends' poop.

Since their poop has a high chance of containing intestinal parasites, wolves poop far from their dens. But if a sick wolf doesn't quite make it out of the den in time, they might do their business too close to home. A healthier wolf might eat this poop, but the parasite eggs wouldn't have hatched within the first day or two of the feces being dropped. Thus, the healthy wolf would carry the risk of infection away from the den, depositing the eggs they had consumed away in their own, subsequent bowel movements at an appropriate distance before the eggs had the chance to hatch into larvae and transmit the parasite to the pack.

Domestic dogs may just be enacting this behavior instinctively—only for them, there isn't as much danger of them picking up a parasite at home. However, the theory isn't foolproof. The surveys also found that so-called "greedy eaters" were more likely to eat feces than dogs who aren't quite so intense about food. So yes, it could still be about a poop-loving palate.

But really, it's much more pleasant to think about the behavior as a parasite-protection measure than our best pals foraging for a delicious fecal snack. 

[h/t The Washington Post]

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