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.”

Dozens of Cat Mummies, Plus 100 Cat Statues, Discovered in 4500-Year-Old Egyptian Tomb

iStock.com/Murat İnan
iStock.com/Murat İnan

The mummification of cats was a common practice in ancient Egypt, but it’s always a pleasant surprise when the felines are found thousands of years later. As NPR reports, dozens of mummified cats and 100 wooden cat statues were recently discovered in a 4500-year-old tomb near Cairo.

These items were uncovered by Egyptian archaeologists while excavating a newly discovered tomb in Saqqara, whose necropolis served the ancient city of Memphis. Another nearby tomb remains sealed, and it’s possible that it may have evaded looters and remained untouched for millennia.

In addition to the wooden statues, one bronze cat statue was found. It was dedicated to Bastet, goddess of cats, who was said to be the daughter of Re, god of the Sun. While cats were revered by ancient Egyptians, they weren’t directly worshipped. Rather, gods like Bastet were often depicted with the physical characteristics of an animal that was considered divine.

Even rarer than the mummified cats were a couple collections of mummified scarab beetles that were found in the tomb—the first of their kind to be unearthed in this particular necropolis, Egypt's Ministry of Antiquities announced in a Facebook post. The scarabs were still in “very good condition” because they had been wrapped in linen and placed inside two limestone sarcophagi, whose lids had black scarabs painted on top.

"The (mummified) scarab is something really unique. It is something really a bit rare," Mostafa Waziri, secretary general of Egypt's Supreme Council of Antiquities, told Reuters and other media. "A couple of days ago, when we discovered those coffins, they were sealed coffins with drawings of scarabs. I never heard about them before."

The beetles were an important religious symbol in ancient Egypt, representing renewal and rebirth. The Ministry of Antiquities said archaeologists also found wooden statues of a lion, a cow, and a falcon, as well as painted wooden sarcophagi of cobras (with mummies inside) and wooden sarcophagi of crocodiles.

[h/t NPR]

12 Doomed Facts About the S.S. Edmund Fitzgerald

The wind in the wires made a tattle-tale sound
When the wave broke over the railing
And every man knew, as the captain did too
'Twas the witch of November come stealin'
-Gordon Lightfoot, "The Wreck of the Edmund Fitzgerald" (1976) 

On November 10, 1975, two ships made their way in tandem across the stormy waters of Lake Superior. One was the Arthur M. Anderson, led by Captain Jesse Cooper. The other, captained by Ernest McSorley, was the S.S. Edmund Fitzgerald.

The ship was last seen on radar around 7:15 p.m. All 29 men on board were lost with it, and today, more than four decades after the most famous shipwreck in Great Lakes history, the cause is still a mystery.

Here's what we do know about the S.S. Edmund Fitzgerald, and what happened to it that fateful day:

1. IT WAS THE LARGEST SHIP ON THE GREAT LAKES.

The large cargo vessels that roamed the five Great Lakes were known as lakers, and the S.S. Edmund Fitzgerald was, at the time, the biggest ever built. It was constructed as a “maximum sized” bulk carrier and spanned 729 feet—the first laker to reach that length—sat 39 feet high with a width of 75 feet, and weighed more than 13,000 tons without cargo. It was christened on June 8, 1958, and made its first voyage on September 24 the same year. 

2. THE SHIP WAS OWNED BY AN INSURANCE COMPANY.


Wikimedia Commons // Public Domain

Great Lakes Engineering Works of Ecorse, Michigan, was contracted to build the ship in 1957 by Northwestern Mutual Insurance Company, which had invested heavily in the iron and minerals industries. With the commissioning of the Fitzgerald, Northwestern Mutual became the first American insurance company to build its own ship—at a cost of $8.4 million, the most expensive price tag for a freighter at the time, according to Michael Schumacher’s The Mighty Fitz.

3. IT WAS NAMED AFTER THE HEAD OF THE COMPANY.

The chairman of Northwestern Mutual had a long history with the Great Lakes shipping industry. Edmund Fitzgerald’s grandfather captained a ship on the lakes, his father owned a shipyard, and they both had ships named after them. After construction of the Fitzgerald was complete, Northwestern Mutual placed its charter with the Columbia Transportation Division of Oglebay Norton Company, based in Cleveland. 

4. THE SHIP'S MAIN JOB WAS HAULING IRON ORE. 


Wikimedia Commons // Public Domain

Most lakers traversing the Great Lakes and the connecting waterways carry massive amounts of raw materials such as rock, salt, and grain. The Edmund Fitzgerald generally loaded taconite, low-grade iron ore, from mines on the shores of Minnesota and transported the pellets to steel mills near Detroit and Toledo, Ohio.

5. "THE FITZ" WAS WELL-KNOWN EVEN BEFORE IT SANK.

Its impressive size made the ship popular with boat-watchers, and over the years it garnered many nicknames, including “The Queen of the Great Lakes,” “The Toledo Express,” and the unfortunate “Titanic of the Great Lakes.” Crowds would watch as the massive freighter moved through the locks at Sault Ste. Marie in Michigan’s Upper Peninsula. The “Soo” Locks, which connect Lake Superior to Lake Huron, allowed the Fitz to reach ports on the lower Great Lakes.

6. THE SHIP RAN INTO A DEADLY STORM ON LAKE SUPERIOR.

November is a brutal month on the Great Lakes. Frequent storms and hurricane-force winds can batter even the toughest-built freighters. On November 9, the Fitz was loaded with 26,116 tons of iron ore pellets at the Burlington Northern Railroad Dock in Superior, Wisconsin. It left at 2:30 p.m. A second ship, the Arthur M. Anderson, sailed 10-15 miles behind the Fitzgerald as a precaution, and the two ships remained in radio contact until just after 7 p.m. on November 10.

Gale warnings had been issued by the National Weather Service the previous day, and by the morning of the 10th, the advisories had been upgraded to an official storm warning. 

As swells reached 35 feet and winds raged at nearly 100 mph, the ship contacted Coast Guard officials in Sault Ste. Marie and said they were taking on water. Later, a blizzard obscured the Fitz on the Anderson’s radar, but Captain Ernest McSorley, who was on his final voyage before retirement, assured a crew member on the Anderson at 7:10 p.m. that, “We are holding our own.” It was the last anyone heard from McSorley or the Fitzgerald.

7. NO DISTRESS SIGNAL WAS SENT.

After that, there was nothing on the radar. No radio contact. The ship was approximately 15 miles north of Whitefish Point when it seemingly vanished. Captain Cooper, on the Anderson, was in contact with the Coast Guard and made it to Whitefish Point sometime after 8 p.m. with no sign or word from the Fitzgerald. Later, the Anderson made its way back into the storm to search for the ship, but found only a pair of lifeboats and debris. 

8. ALL 29 CREW MEMBERS DIED. 

Along with the captain, the other crew members of the Fitzgerald included porters, oilers, engineers, maintenance workers, cooks, watchmen, deck hands, and wheelsmen. Most crew members were from Wisconsin, Michigan, Ohio, and Minnesota.

9. THERE IS STILL NO DEFINITIVE EXPLANATION FOR THE SINKING.

The treacherous weather conditions are an obvious factor, but experts differ on what they think specifically caused the accident. Following the wreck, the U.S. Coast Guard and National Transportation Safety Board agreed that the tragedy was likely due to faulty cargo hatches, which led to flooding. Predictably, there are still those who harbor other theories, including unsecured hatches, maintenance troubles, massive waves, structural issues, and yes, even aliens. Author and Great Lakes historian Frederick Stonehouse posited that the ship likely hit a shoal and took on too much water before plunging into Lake Superior.

10. THE TRAGEDY WAS IMMORTALIZED BY A CANADIAN FOLK SINGER.

Gordon Lightfoot, who had released 10 albums from 1966 to 1975, was inspired to write the ballad “The Wreck of the Edmund Fitzgerald” after reading an article about the tragedy in Newsweek. He included the song on his 1976 album Summertime Dream, and the nearly six-minute single reached #2 on the Billboard Hot 100 charts that year and became Lightfoot’s second-most successful hit.

11. FAMILY MEMBERS REQUESTED A SYMBOLIC MEMORIAL FROM THE SHIP.

The U.S. Navy and Coast Guard deployed planes and cutters with magnetic anomaly detectors, sidescan sonar, and sonar survey to find the wreckage. In May, a Navy underwater recovery vehicle was sent to the site, and on May 20, 1976, the ship was spotted 535 below the surface of the lake.

In the decades since, only a handful of people have been able to see the wreck, which lies in two pieces. A pair of divers made their way down in 1995, the same year a crew—with help from the Canadian Navy, the National Geographic Society, Sony, and the Sault Ste. Marie Tribe of Chippewa Indians—retrieved the ship's bell at the behest of the families of those who were lost. The Canadian government has since prohibited access to the site. 

In eerie archival tapes below, you can hear Anderson skipper Jesse Cooper correspond with the Coast Guard, and see video of the wreck.

12. THERE'S AN ANNUAL REMEMBRANCE DAY.

The annual Edmund Fitzgerald memorial ceremony takes place on November 10th at the Great Lakes Shipwreck Museum at Whitefish Point. The recovered and restored bell will toll 29 times for each member of the Fitzgerald's crew, and a 30th for the estimated 30,000 mariners lost on the Great Lakes.

For more on the story and the ship, visit S.S. Edmund Fitzgerald Online

This article originally appeared in 2015.

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