The fierce debate over whether Homo sapiens was the first species to bury its dead is far from over.
After a decade of back-and-forth with skeptics, paleoanthropologist Lee Berger and his team are not going to let their hypothesis die: that a small-brained species called Homo naledi was culturally burying their dead long before modern humans were.
Their latest peer-reviewed paper presents a reexamination of a contentious hominin ‘burial ground’, addressing previous criticisms to argue once again that the ‘cradle of humankind’ in South Africa is home to some of the earliest evidence of funerary practices.
Related: Did This Ancient Species Really Bury Its Dead Before Modern Humans?
The team lays out why they think this is the simplest explanation for how the bones of numerous H. naledi ended up deep in a cave system near Johannesburg.
These hominins lived more than 240,000 years ago, while early Homo sapiens and our Neanderthal cousins are only thought to have begun burying their dead some 120,000 years ago.
The claim that H. naledi had cultural burial practices more than 120,000 years before our own kind is a monumental one, so it’s natural that other scientists want the evidence to be ironclad.
The hypothesis was first put forward by Berger and his team in 2015, when they announced that they had found the fossilized remains of at least 15 individuals of a previously unknown hominin, deep underground in a cave in South Africa.
Carvings on the walls and charcoal fragments had the scientists thinking this was an intentional burial site. But evidence was circumstantial at best, and it caused an eruption of debate over what defined a cultural burial, and how best to prove the existence of one.
In 2023, Berger and his colleagues published a series of preprints on their latest excavations. Still, many scientists were unconvinced, arguing that the charcoal wasn’t properly dated, that the burial pits weren’t clearly defined, and that the engravings on the wall may not even be human-made.
A painstaking review of the preprint papers, published in 2024, added that Berger’s and his team’s analysis fell far short of providing sufficient evidence that H. naledi had deliberate funerary practices.
Not to be discouraged, Berger and his team persisted, responding to the revisions.
Their latest publication explains that in at least three locations, the bodies were encased in sediment shortly after they arrived in the cave system. This refutes the idea that the bodies fell into the cave and were gradually covered by sediment.
“The work we report here illustrates that neither gravity and resulting sediment slumping, nor downslope movement of bodies on a talus, nor slow, gradual sedimentation, nor any other ‘natural’ process previously hypothesized can account for the position and context of the H. naledi features,” the authors write.
“Here for the first time, we have considered the hypothesis that Homo naledi was directly involved in the burial process of bodies.”
Earlier this year, co-author and anthropologist John Hawks addressed critics and explained why the team had openly published their results before peer review. As part of eLife’s process, all reviews are made public and transparent, which Hawks sees as a benefit, not a downside.
“I’ve been in paleoanthropology for a long time,” he wrote on his blog. “You can’t do anything interesting without facing some challenging reviews. What we need to support as scientists is for the work to be as transparent as possible, from observation to interpretation. If we can eliminate the culture of fear around releasing new research and data, that would go a long way toward making research more reliable.”
No doubt there will be plenty of responses to their newest argument.
The preprint is available in eLife.