CLOSE
Artist unknown via Wikimedia Commons // Public Domain
Artist unknown via Wikimedia Commons // Public Domain

Injuries on Mammoth Skeleton Put Humans in the Arctic 45,000 Years Ago

Artist unknown via Wikimedia Commons // Public Domain
Artist unknown via Wikimedia Commons // Public Domain

There’s a lot of debate about what killed off the woolly mammoths. Some scientists believe climate change was to blame; some say bone disease. Others point to human hunters. The cause of the species' extinction remains unknown, but the cause of one mammoth’s death is plain as day. In a paper published today in the journal Science, archaeologists say the injuries they found on a woolly mammoth skeleton in Siberia suggest that humans were there 45,000 years ago.

If they're correct, they've moved the timeline of human habitation in the Eurasian Arctic back 10,000 years. Archaeologist Vladimir Pitulko, a lead author on the paper, has been in this situation before. In 2004, when scientists believed that humans had first entered the region 15,000 years ago, Pitulko and his team discovered a cache of hunting tools dating back 31,000 years. Speaking to National Geographic News, Pitulko said the find “demonstrates that humans were adapted to the harsh, unforgiving arctic environment much earlier than we might have thought."

That might be true all over again. In 2012, a team led by Alexei Tikhonov excavated the carcass of a male woolly mammoth from a cliff in the Siberian Arctic. The remains were unusually intact; the researchers were able to recover a near-complete skeleton as well as the soft remains of the mammoth’s hump and penis. Tikhonov brought the remains back to the laboratory, where he, Pitulko, and their colleagues took a closer look.

Pitulko et al., Science (2016)

There was no doubt about the mammoth’s cause of death. Its bones were peppered with injuries: three on the left shoulder, one on its skull, and two on its ribs, and part of one tusk had been broken off. The mammoth had clearly been hunted. X-ray scans of the bones showed that the outline of the wounds were the same shape as the point of a spear.

The beast didn’t go down easy, the researchers say. They paint a picture of an intense attack at close range, with hunters stabbing, slicing, and throwing their spears at the mammoth. 

After the animal died, the hunters appear to have broken its jaw and removed part of a tusk. The researchers speculate that the hunters broke the mammoth’s jaw to get at its massive tongue; previous studies have suggested that humans of that period regularly ate mammoth tongue.

The hunters then used their tools to break off the tip of one tusk, most likely so they could use it to make tools.

The researchers performed radiocarbon dating on the mammoth’s tibia and a sample of the cliff where it was found. The results of both tests indicated that the mammoth’s body had been there at least 45,000 years. “This is a rare case of unequivocal evidence for clear human involvement, even if there is no artifact association,” they conclude in their paper. “Apparently, humans’ ability to survive in the Arctic environment, and their spread within the region as early as [45,000 years ago], represents an important cultural and adaptational shift.”

nextArticle.image_alt|e
NUS Environmental Research Institute, Subnero
arrow
technology
Researchers in Singapore Deploy Robot Swans to Test Water Quality
NUS Environmental Research Institute, Subnero
NUS Environmental Research Institute, Subnero

There's something peculiar about the new swans floating around reservoirs in Singapore. They drift across the water like normal birds, but upon closer inspection, onlookers will find they're not birds at all: They're cleverly disguised robots designed to test the quality of the city's water.

As Dezeen reports, the high-tech waterfowl, dubbed NUSwan (New Smart Water Assessment Network), are the work of researchers at the National University of Singapore [PDF]. The team invented the devices as a way to tackle the challenges of maintaining an urban water source. "Water bodies are exposed to varying sources of pollutants from urban run-offs and industries," they write in a statement. "Several methods and protocols in monitoring pollutants are already in place. However, the boundaries of extensive assessment for the water bodies are limited by labor intensive and resource exhaustive methods."

By building water assessment technology into a plastic swan, they're able to analyze the quality of the reservoirs cheaply and discreetly. Sensors on the robots' undersides measure factors like dissolved oxygen and chlorophyll levels. The swans wirelessly transmit whatever data they collect to the command center on land, and based on what they send, human pilots can remotely tweak the robots' performance in real time. The hope is that the simple, adaptable technology will allow researchers to take smarter samples and better understand the impact of the reservoir's micro-ecosystem on water quality.

Man placing robotic swan in water.
NUS Environmental Research Institute, Subnero

This isn't the first time humans have used robots disguised as animals as tools for studying nature. Check out this clip from the BBC series Spy in the Wild for an idea of just how realistic these robots can get.

[h/t Dezeen]

nextArticle.image_alt|e
iStock
arrow
science
There May Be an Ancient Reason Why Your Dog Eats Poop
iStock
iStock

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]

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios