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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.
Guy de la Bedoyere, Wikimedia Commons // CC BY-SA 4.0
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Stones, Bones, and Wrecks
Archaeologists Unearth the Victims of a Mysterious Massacre 400 Years Ago on an Australian Island
Beacon Island
Beacon Island
Guy de la Bedoyere, Wikimedia Commons // CC BY-SA 4.0

The cargo ship Batavia set out from the Netherlands in October 1628, bound for the Dutch colony at present-day Jakarta, Indonesia, with more than 300 crew and passengers. For some still-unknown reason, the ship veered off course to the south and smashed into a coral atoll about 50 miles west of the Australian coast.

What happened over the next few months—culminating in a mysterious and brutal massacre that left at least 125 people dead—is Australia's oldest cold case.

In a story that aired on 60 Minutes Australia, correspondent Liam Bartlett traveled to this "island of horror" where a team of Australian and Dutch scientists is uncovering the nearly 400-year-old skeletons, well preserved in the sand of what is now Beacon Island. They hope to discover what led to the sudden mass slaughter of adults and children.

"We're dealing with a psychopath and some pretty horrible events," Alistair Paterson, an archaeologist at the University of Western Australia and the leader of the research team, tells Bartlett. "There's nothing like it in Dutch history or Australian history."

A screenshot of the Beacon Island dig site from 60 Minutes Australia
A scene from the 60 Minutes Australia report
Kat Long

The Batavia, the flagship of the Dutch East India Company, was on its maiden voyage. The commander, Francisco Pelsaert, and the captain, Ariaen Jacobsz, detested each other. Jacobsz conspired with Pelsaert's deputy, Jeronimus Cornelisz, to take control of the ship and its load of silver and valuable paintings. But before the mutiny could unfold, the ship crashed into the reef in the early morning of June 4, 1629.

About 100 people died in the wreck, while almost 200 made it to a cluster of islands in the Abrolhos chain—treeless, desert-like stretches of sand without water or food. Pelsaert and Jacobsz sailed for help, hoping to reach their original destination nearly 2000 miles away by boat.

The events of the next three months continue to puzzle and horrify modern researchers. Initially, Jeronimus Cornelisz organized food rations and shelter for the survivors on Beacon Island as a way to cement his leadership. But then, he hoarded the weapons and boats for his own use. He ordered his followers to execute the strong, able-bodied men who could pose a threat to his control over the group. Most of the women and children who would be a drain on supplies were also killed, though some women were kept alive as sexual slaves, Bartlett reports.

"Totally Lord of the Flies," Paterson says.

The Batavia massacre
An image from Pelsaert's journal of the voyage
Wikimedia Commons // Public Domain

Cornelisz marooned several men on a nearby island to get them out of the way as the killing rampage continued. But those men, led by a sailor named Wiebbe Hayes, managed to find water and food, and made a primitive protective fort of stone slabs—which still exists as the first European-made structure on Australian soil. In early August, two months after the wreck, Cornelisz and his men attempted to storm Hayes' stronghold and eliminate his band of survivors.

At the last moment, a rescue ship helmed by Pelsaert and Jacobsz appeared on the horizon. Both Hayes and Cornelisz sent out boats to intercept the ship, hoping to establish their version of events as fact and save themselves from punishment. Fortunately, Hayes's men reached the ship first.

Only 80 to 90 survivors out of the Batavia's 300-plus passengers eventually arrived in present-day Jakarta. Cornelisz, who never showed a hint of remorse or offered an explanation for his brutality, was hanged along with his co-conspirators. The bones of his victims, preserved in the island's alkali coral sand for almost four centuries, are now revealing clues to the historical mystery. 

"Horrible things happened to these individuals. They clearly were victims," Paterson tells Bartlett. "But the archaeology allows us to get their story told." 

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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.
iStock
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Stones, Bones, and Wrecks
Archaeologists Find Traces of What Could Be the Oldest Wine in the World
iStock
iStock

Humankind has enjoyed wine for a long time—since the early Neolithic period, at least, judging from ancient residue on prehistoric pottery shards excavated from two sites in Georgia, in the South Caucasus. The fragments potentially date back to 6000 BCE, pushing back the earliest evidence of winemaking by about 600 to 1000 years, as The New York Times reports.

Published in the journal Proceedings of the National Academy of Sciences (PNAS), the findings pinpoint Georgia as one of the very first—if not the first—nations to have mastered winemaking. Before, Iran held the honor, although China can still lay claim to the world's oldest fermented beverage (a cocktail-like concoction of rice, honey, hawthorn fruit, and wild grapes that was enjoyed as early as 7000 BCE).

Leading the PNAS study was Patrick McGovern, a molecular archaeologist from the University of Pennsylvania Museum of Archaeology and Anthropology. He and his team excavated the remains of two Neolithic villages, located around 30 miles south of Georgia's capital city, Tbilisi. There, they found shards of clay jars—the likely remnants of large, rotund vats, which once could have accommodated as many as 400 bottles worth of today's wine.

Remains of ancient Georgian pottery vessels that may have once contained wine, photographed by Mindia Jalabadze.
(A) Representative early Neolithic jar from Khramis Didi-Gora (B) Jar base (C) Jar base (D) Jar base, interior
Mindia Jalabadze, courtesy of the National Museum of Georgia

These shards were collected for chemical analysis. Eight of them ended up containing tartaric, malic, succinic, and citric acids, all of which had leached into the clay long ago. The combination of these four acids is believed to be present only in grape wine. Researchers also noted traces of ancient grape pollen, starch from grape wine, and signs of prehistoric fruit flies.

Of course, there is the off chance that the jars might have been used to just make grape juice, but their decorations indicate that they weren't made to hold ordinary drinks, researchers argue.

Archaeological evidence dating back to the Bronze Age shows that Georgians have always held wine in great importance. But some experts thought this love of vino dated back even further—and now they believe they have pretty convincing proof.

[h/t The New York Times]

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