Controversial study claims that Homo naledi, an extinct human cousin with a
brain one-third the size of ours, buried and maybe honored their dead.
The extinct human relative Homo naledi, whose brain was one-third the size
of ours, buried their dead and engraved cave walls around 300,000 years ago,
according to new research that is overturning long-held theories that only
modern humans and our Neanderthal cousins could do these complex
activities.
The data, according to some scientists, is insufficient to prove that H.
naledi buried or remembered their deceased.
"I can see where they are connecting the dots with this data and do think
it was worth reporting, but it should have been done with many more
caveats,"
Sheela Athreya, an anthropologist at Texas A&M University who was not engaged inside
the research, told Live Science in an email.
In South Africa's Rising Star Cave system, archaeologists made their
initial discovery of H. naledi's remains in 2013. Since then, the 2.5-mile
(4-kilometer) system has been home to more than 1,500 skeletal fragments
from various individuals. Due to the remarkable preservation of their
remains, H. naledi's anatomy is well known. They were bipedal creatures that
stood around 5 feet (1.5 meters) tall and weighed 100 pounds (45 kilograms),
had dexterous hands, a small but complex brain, and other characteristics
that have raised questions about the complexity of their behavior. In a 2017
research published in the journal
eLife, the Rising Star team hypothesized that H. naledi had purposely buried
their deceased in the cave system.
In a news conference on June 1, paleoanthropologist
Lee Berger, the Rising Star program lead, and his colleagues buttress that claim with
three new studies, published Monday (June 5) on the preprint server bioRxiv,
that together put forth the most substantial evidence so far that H. naledi
purposefully buried their dead
and created meaningful engravings on the rock above the burials. Peer review
of the results has not yet taken place.
According to the new research, two small, oval-shaped pits on the floor of
one cave chamber contained skeletal remains consistent with the burial of
fleshed bodies that were covered in sediment before they eventually
decomposed. These pits also contained skeletal remains. A solitary stone
item was discovered in close proximity to the hand and wrist bones,
suggesting that one of the graves may have possibly contained a grave
offering.
In the news briefing, Berger stated, "We feel that they've met the litmus
test of human burials or archaic human burials." The researchers' views, if
adopted, would move Homo sapiens' previous record for the oldest evidence of
intentional burial back 100,000 years.
The discovery of
abstract engravings on the rock walls of the Rising Star Cave system also signals that H. naledi had complex
behavior, the researchers suggest in another new preprint. It appears that
H. Naledi, who sanded the rock before using a stone tool to engrave it, made
these lines, shapes, and "hashtag"-like figures on specially prepared
surfaces. The line depth, composition and arrangement imply that they were
purposely produced rather than developed organically.
According to Berger, "There are burials of this species directly below
these [engravings]," indicating that this area was an H. naledi cultural
site. "They've intensely altered this space across kilometers of underground
cave systems."
In a different preprint, anthropologist
Agustin Fuentes
of Princeton University and colleagues investigate the rationale for H.
naledi's utilization of the cave network. "The shared and planned deposition
of several bodies in the Rising Star system" and "the engravings" are
indications that these people had a shared set of assumptions or beliefs
about death and may have memorialized the dead, "something one would
term'shared grief' in contemporary humans," they wrote. The new
interpretations, however, have not completely won over other
researchers.
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"Tick marks on rocks could have been made by humans. That doesn't add
anything to this discussion of abstract thought, according to Athreya.
There remain unanswered concerns regarding how H. naledi entered the Rising
Star Cave system; many of the researchers' interpretations of significant
behavior are predicated on the notion that it was challenging. Did they
enter by the same entrance as us, or might there have been another way in?
Jonathan Marks, a University of North Carolina at Charlotte anthropologist who was not
engaged in the study, made this observation to Live Science. "This is a job
for archaeology — lots of archaeology."
Read more about the findings from the
National Geographic Society, which funded the research.
