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Two views of an adult Homo naledi cranium found in the Lesedi Chamber of the Rising Star cave system in South Africa, where the remains of 15 individuals were discovered in a different cave in 2013.
Two views of an adult Homo naledi cranium found in the Lesedi Chamber of the Rising Star cave system in South Africa, where the remains of 15 individuals were discovered in a different cave in 2013.
Hawks et al. in eLife, 2017

Puzzling Human Relative Homo Naledi May Have Lived at the Same Time as Our Ancestors

Two views of an adult Homo naledi cranium found in the Lesedi Chamber of the Rising Star cave system in South Africa, where the remains of 15 individuals were discovered in a different cave in 2013.
Two views of an adult Homo naledi cranium found in the Lesedi Chamber of the Rising Star cave system in South Africa, where the remains of 15 individuals were discovered in a different cave in 2013.
Hawks et al. in eLife, 2017

It's tempting to think that evolution works in a straight line, with clearly defined, graduated steps from primitive to modern. We humans are especially prone to telling our own evolutionary story in this manner. Evolution doesn't work that way, though, and we aren’t even the end point of human evolution, but works in progress. (Personally, I hope we are amphibious and have fins in 3 million years. That would be awesome.)

The latest evidence for that essential truth comes from the Rising Star cave system in South Africa, where scientists say Homo naledi, the unusual hominid species they discovered there in 2013, is surprisingly young, living as recently as 236,000 years ago. That means it was one of various hominids wandering the Earth at the same time as the Neanderthals in Europe; the Denisovans in western Asia; the ancestors of the “hobbit,” Homo floresiensis; and, in Africa, potentially alongside the earliest members of our own species, Homo sapiens.

Moreover, the researchers found three more individuals in another chamber in the cave system, one of them with the most complete H. naledi skull discovered yet. (You can see it above.) Today the large team of researchers published a trio of papers documenting their results in the open-access journal eLife.

In 2015, we reported on the initial discovery of 15 sets of hominid remains found in the Dinaledi cave by a team of researchers led by paleoanthropologist Lee Berger. It was an unprecedented bounty of bones. Often, paleoanthropologists are reconstructing human evolutionary history from scant remains—a fragment of skull or jaw bone here, a femur or a finger there. But in the Dinaledi cave, there are at least 1500 bones, and likely a lot more, since only a small fraction of the cave was excavated by a half-dozen archaeologists—all female, all cavers, all slim enough to squeeze through a series of cave tunnels that narrowed to just 7 inches in one spot—who worked in extraordinary conditions to excavate the bones from a pitch-black cave nearly 100 feet beneath the surface.

The ancient creatures were no bigger than the small but formidable women who unearthed them. Slender and about 5 feet tall as adults, they would’ve weighed just under 100 pounds. Their bodies are a fascinating mosaic of primitive and modern: tiny, orange-sized brains housed in skulls with jaws and teeth closer to early Homo; shoulders suited for climbing trees but feet and ankles made for walking; hands potentially capable of making tools, but with fingers well-curved for tightly gripping tree branches.

The discovery made headlines worldwide. Most of us—whether scientist or science nerd—fascinated by the find had one question: How old were they?

DATING THE REMAINS

When H. naledi was first discovered, the researchers deliberately didn’t attempt to answer that question. Determining where a species fits into the evolutionary record based on its morphology is not an unusual approach, but it can also be misleading. In the past 1.5 years, other scientists have proposed ages for H. naledi that range from 100,000 to 2 million years ago.

In one of the current studies, researchers led by James Cook University geologist Paul Dirks conducted six dating tests to narrow the age range, including the paleomagnetic dating of calcite left behind by running water and a chemical analysis of three fossil teeth discovered in the cave using a technique called combined U-series and electron spin resonance (US-ESR) dating. From all the tests, they came up with an age range: they're most likely between 236,000 and 335,000 years old.

As eLife notes in a commentary on the study, “The estimated dates are much more recent than many had predicted, and mean that H. naledi was alive at the same time as the earliest members of our own species—which most likely evolved between 300,000 and 200,000 years ago. These new findings demonstrate why it can be unwise to try to predict the age of a fossil based only on its appearance, and emphasize the importance of dating specimens via independent tests.”

American Museum of Natural History paleoanthropologist Ian Tattersall echoed that sentiment to Mental Floss. “This is an object lesson in trying to date anything by what it looks like,” he says. While he doesn't find the age estimate surprising, he’s less convinced that H. naledi belongs in our Homo genus: “Anything as odd as this is always going to be tough to fit into both a phylogeny and a timescale,” he notes.

Did our ancestors interact with this oddball? We have no idea. But we do know that the picture of human evolution continues to expand in detail and complexity with every discovery like H. naledi.

Bioarchaeologist (and regular Mental Floss contributor) Kristina Killgrove, who teaches biological anthropology, human origins, and evolutionary theory at the University of West Florida, tells us that the long wait for H. naledi dates was “worth it.”

She says, “These dates reveal a much more complicated story of hominin evolution than ever before. We used to think of human evolution as a single lineage—the classic image of the progression from apes to humans. But H. naledi shows that palaeoanthropologists are onto something far more complex—and far more interesting! While these new dates won't make it into textbooks in time for the fall semester, I will certainly be updating my human evolution lectures this summer."

ONE NEW CAVE, THREE NEW BODIES

Whatever we have to learn about this cousin of humanity can only be helped by the other discovery reported today in eLife: 133 bones from three likely H. naledi individuals—two adults and one child—found in another cave in the Rising Star system. First spotted in 2013 by cavers, the bones were unearthed in three locations in a cave the researchers coined Lesedi. The two caves are found at the same depth, but they’re not directly connected.

As with the first expedition into the Dinaledi cave, the working conditions for the researchers weren’t easy: Wits University archaeologist Marina Elliott, who led the intrepid team of “underground astronauts” who excavated both sites, told National Geographic that while the Lesedi cave was slightly easier to reach than Dinaledi, she still had to excavate one set of remains from a 2-foot-wide alcove while laying on her chest, her shoulders pinned between rocks. “It’s extremely physically difficult,” she said. “I’ve tried to do a lot of yoga to get myself to be able to do it.”

Elliott would probably say it was worth it, though; the remains she excavated in that location yielded the most complete H. naledi skull so far discovered. Dubbed Neo (after the Setswana word for "a gift," not the The Matrix character), this adult has a larger skull—and therefore a larger brain capacity—than the other specimens so far discovered, but it falls within an expected range.

ARE THESE BURIALS OF A SORT?

One of the most contentious theories Berger and the team proposed when the first H. naledi fossils were discovered was that these bodies had been intentionally placed in the cave in some sort of death ritual. Berger and John Hawks, a paleoanthropologist at the University of Wisconsin, revisit that theory in the third paper published in eLife. They point out that the caves are difficult to access and aren’t obvious “death traps” that individuals could’ve accidentally fallen into. Nor did the remains show any signs of mass death, having been fed upon by carnivores or scavengers, or of having been flushed into the caves by a water system.

So how did they get there?

The researchers write, “We propose that funerary caching by H. naledi is a reasonable explanation for the presence of remains in the Dinaledi and Lesedi Chambers. Mortuary behaviors, while culturally diverse, are universal among modern human cultural groups. Such behaviors are not seen in living non-human primates or in other social mammals, but many social mammals exhibit signs of grief, distress, or other emotional response when other individuals within their social group die.”

They say that while there’s no evidence of symbolic thinking among H. naledi, such sophisticated thought isn’t necessarily a requirement for a death ritual. The “physical and social effects of the deaths of group members” could have been motivation enough.

“Such behavior may have many different motivations, from the removal of decaying bodies from habitation areas, to the prevention of scavenger activity, to social bonding, which are not mutually exclusive,” they note. “We suggest only that such cultural behavior may have been within the capabilities of a species that otherwise presents every appearance of technical and subsistence strategies that were common across the genus Homo.”

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Two views of an adult Homo naledi cranium found in the Lesedi Chamber of the Rising Star cave system in South Africa, where the remains of 15 individuals were discovered in a different cave in 2013.
Penn Vet Working Dog Center
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Stones, Bones, and Wrecks
New Program Trains Dogs to Sniff Out Art Smugglers
Penn Vet Working Dog Center
Penn Vet Working Dog Center

Soon, the dogs you see sniffing out contraband at airports may not be searching for drugs or smuggled Spanish ham. They might be looking for stolen treasures.

K-9 Artifact Finders, a new collaboration between New Hampshire-based cultural heritage law firm Red Arch and the University of Pennsylvania, is training dogs to root out stolen antiquities looted from archaeological sites and museums. The dogs would be stopping them at borders before the items can be sold elsewhere on the black market.

The illegal antiquities trade nets more than $3 billion per year around the world, and trafficking hits countries dealing with ongoing conflict, like Syria and Iraq today, particularly hard. By one estimate, around half a million artifacts were stolen from museums and archaeological sites throughout Iraq between 2003 and 2005 alone. (Famously, the craft-supply chain Hobby Lobby was fined $3 million in 2017 for buying thousands of ancient artifacts looted from Iraq.) In Syria, the Islamic State has been known to loot and sell ancient artifacts including statues, jewelry, and art to fund its operations.

But the problem spans across the world. Between 2007 and 2016, U.S. Customs and Border Control discovered more than 7800 cultural artifacts in the U.S. looted from 30 different countries.

A yellow Lab sniffs a metal cage designed to train dogs on scent detection.
Penn Vet Working Dog Center

K-9 Artifact Finders is the brainchild of Rick St. Hilaire, the executive director of Red Arch. His non-profit firm researches cultural heritage property law and preservation policy, including studying archaeological site looting and antiquities trafficking. Back in 2015, St. Hilaire was reading an article about a working dog trained to sniff out electronics that was able to find USB drives, SD cards, and other data storage devices. He wondered, if dogs could be trained to identify the scents of inorganic materials that make up electronics, could they be trained to sniff out ancient pottery?

To find out, St. Hilaire tells Mental Floss, he contacted the Penn Vet Working Dog Center, a research and training center for detection dogs. In December 2017, Red Arch, the Working Dog Center, and the Penn Museum (which is providing the artifacts to train the dogs) launched K-9 Artifact Finders, and in late January 2018, the five dogs selected for the project began their training, starting with learning the distinct smell of ancient pottery.

“Our theory is, it is a porous material that’s going to have a lot more odor than, say, a metal,” says Cindy Otto, the executive director of the Penn Vet Working Dog Center and the project’s principal investigator.

As you might imagine, museum curators may not be keen on exposing fragile ancient materials to four Labrador retrievers and a German shepherd, and the Working Dog Center didn’t want to take any risks with the Penn Museum’s priceless artifacts. So instead of letting the dogs have free rein to sniff the materials themselves, the project is using cotton balls. The researchers seal the artifacts (broken shards of Syrian pottery) in airtight bags with a cotton ball for 72 hours, then ask the dogs to find the cotton balls in the lab. They’re being trained to disregard the smell of the cotton ball itself, the smell of the bag it was stored in, and ideally, the smell of modern-day pottery, eventually being able to zero in on the smell that distinguishes ancient pottery specifically.

A dog looks out over the metal "pinhweel" training mechanism.
Penn Vet Working Dog Center

“The dogs are responding well,” Otto tells Mental Floss, explaining that the training program is at the stage of "exposing them to the odor and having them recognize it.”

The dogs involved in the project were chosen for their calm-but-curious demeanors and sensitive noses (one also works as a drug-detection dog when she’s not training on pottery). They had to be motivated enough to want to hunt down the cotton balls, but not aggressive or easily distracted.

Right now, the dogs train three days a week, and will continue to work on their pottery-detection skills for the first stage of the project, which the researchers expect will last for the next nine months. Depending on how the first phase of the training goes, the researchers hope to be able to then take the dogs out into the field to see if they can find the odor of ancient pottery in real-life situations, like in suitcases, rather than in a laboratory setting. Eventually, they also hope to train the dogs on other types of objects, and perhaps even pinpoint the chemical signatures that make artifacts smell distinct.

Pottery-sniffing dogs won’t be showing up at airport customs or on shipping docks soon, but one day, they could be as common as drug-sniffing canines. If dogs can detect low blood sugar or find a tiny USB drive hidden in a house, surely they can figure out if you’re smuggling a sculpture made thousands of years ago in your suitcase.

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Two views of an adult Homo naledi cranium found in the Lesedi Chamber of the Rising Star cave system in South Africa, where the remains of 15 individuals were discovered in a different cave in 2013.
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Stones, Bones, and Wrecks
Archaeologists Say They May Have Found the Skeleton of the Pirate "Black Sam" Bellamy
iStock
iStock

The skeleton of a famous pirate dead for more than three centuries may have been discovered. This week, researchers in Massachusetts announced they'd found a human skeleton near the wreck of a ship that went down off the coast of Cape Cod in 1717—and they think it just might be the remains of New England's greatest pirate, Samuel "Black Sam" Bellamy.

Born to a poor English family in 1689, Bellamy joined the British navy at age 13. Following the War of Spanish Succession, Bellamy relocated to Massachusetts in 1715.

It's said that Bellamy fell in love with a local beauty named Maria Hallett, whose parents didn't want their daughter marrying a lowly sailor. This bit of folklore might be baseless—although historians do know that a young woman with that name did live in Eastham, Mass. at the time. But in any case, Bellamy soon left the colony to pursue a get-rich scheme.

He and a friend had learned that a treasure-laden Spanish fleet had recently sunk near the Florida Keys, so the duo promptly headed south. After failing to salvage any loot, Bellamy turned to a life of piracy, gathering a crew, acquiring a couple of sailing canoes, and heading out into the open seas. He had a real knack for the work: He captured more than 50 ships from 1716 to 1717. Forbes magazine has calculated that all the loot Bellamy seized would be worth $120 million in modern U.S. dollars.


Gold recovered from wreck of the Whydah.
Theodore Scott, Wikimedia Commons // CC BY 2.0

Despite the dark nickname bestowed by others—and his considerable net worth—Bellamy hated wealthy elites with a passion and liked to call himself the "Robin Hood of the Sea".

The flagship of Bellamy's fleet was the 300-ton Whydah, a former British slave vessel. In 1717, the pirate took the ship up to New England. Then, on April 26, 1717, a wicked storm sank the Whydah off the coast of Wellfleet. Most of the crew—including Bellamy—went down with it.

In 1984, marine explorer Barry Clifford and his diving team found the ship's wreckage. More than 200,000 artifacts from the site have since been taken ashore. To give them a proper home, Clifford established the Whydah Pirate Museum in West Yarmouth in 2016.

This past November, researchers at the museum found part of a human skeleton inside a hardened block of sediment they'd taken from the Whydah's general area a few years ago. The slab also contained a belt, some cufflinks, and—most interestingly—a pistol. According to an Associated Press report, this gun is believed to have been Bellamy's.

Forensic scientists at the University of New Haven plan to compare DNA from the bones against that of a living Bellamy descendant in England. Whether the skeleton turns out to be the famous captain's or somebody else's, though, it'll most likely be interred—eventually. On February 19, the bones will be on display during a press conference.

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