According to reports by two Associated Press (AP) reportes, Lynsey Chutel and Malcom Ritter, in Magaliesburg, South Africa, scientists had discovered a new member of the human family tree, revealed by a huge trove of bones in a barely accessible, pitch-dark chamber of a cave in South Africa.
And the discovery presents some key mysteries: How
old are the bones? And how did they get into that chamber, reachable
only by a complicated pathway that includes squeezing through passages
as narrow as about 7½ inches (17.8 centimeters)?
The bones were
found by a spelunker, about 30 miles (48 kilometers) northwest of
Johannesburg. The site has yielded some 1,550 specimens since its
discovery in 2013. The fossils represent at least 15 individuals.
Researchers
named the creature Homo naledi (nah-LEH-dee). That reflects the "Homo"
evolutionary group, which includes modern people and our closest extinct
relatives, and the word for "star" in a local language. The find was
made in the Rising Star cave system.
The creature, which evidently
walked upright, represents a mix of traits. For example, the hands and
feet look like Homo, but the shoulders and the small brain recall Homo's
more ape-like ancestors, the researchers said.
At a news
conference Thursday in the Cradle of Humankind, a site near the town of
Magaliesburg where the discovery was made, bones were arranged in the
shape of skeleton in a glass-covered wooden case. Fragments of small
skulls, an almost complete jawbone with teeth, and pieces of limbs,
fingers and other bones were arrayed around the partial skeleton.
Berger
handed a skull reconstruction to Deputy President Cyril Ramaphosa, who
kissed it, as did other VIPs. Berger beamed throughout the unveiling.
The
researchers also announced the discovery in the journal eLife. They
said they were unable to determine an age for the fossils because of
unusual characteristics of the site, but that they are still trying.
Berger
said researchers are not claiming that neledi was a direct ancestor of
modern-day people, and experts unconnected to the project said they
believed it was not.
If the bones are
about as old as the Homo group, that would argue that naledi is "a
snapshot of ... the evolutionary experimentation that was going on right
around the origin" of Homo, he said. If they are significantly
younger, it either shows the naledi retained the primitive body
characteristics much longer than any other known creature, or that it
re-evolved them, he said.
Eric Delson of Lehman College in New
York, who also wasn't involved with the work, said his guess is that
naledi fits within a known group of early Homo creatures from around 2
million year ago.
Besides the age of the bones, another mystery is
how they got into the difficult-to-reach area of the cave. The
researchers said they suspect the naledi may have repeatedly deposited
their dead in the room, but alternatively it may have been a death trap
for individuals that found their own way in.
"This stuff is like a
Sherlock Holmes mystery," declared Bernard Wood of George Washington
University in Washington, D.C., who was not involved in the study.
Visitors to the cave must have created artificial light, as with a
torch, Wood said. The people who did cave drawings in Europe had such
technology, but nobody has suspected that mental ability in creatures
with such a small brain as naledi, he said.
Not everybody
agreed that the discovery revealed a new species. Tim White of the
University of California, Berkeley, called that claim questionable.
"From what is presented here, (the fossils) belong to a primitive Homo
erectus, a species named in the 1800s," he said in an email.
At the news conference in South Africa, Berger disputed that. "Could this be the body of homo erectus? Absolutely not. It could not be erectus," Berger said.
This piece was published by Associated Presss (AP) Malcolm Ritter reporting from New York.
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