My friend Ken Samples tells me it is one of the greatest stories ever told.
It’s the tale of Plato’s Cave. In this allegory, Plato describes a group of prisoners chained to a wall deep within a cave. The only thing they can see is the cave wall in front of them. Occasionally, shadows are projected on the wall as people and animals walk past the cave opening. These shadows are all that the prisoners know of reality. But the shadows provide only a limited—and, at times, inaccurate—understanding of the real world. Only when the prisoners break free and escape the cave do they gain true knowledge about the world as it is.
While Plato would have each of us climb out of our own cave and ascend into the real world to gain access to the truth, some paleoanthropologists think that the only way we can know the truth about our origins is to descend into the cave—in this case the Rising Star cave system located in South Africa. This cave system is in an area called the Cradle of Humankind, a UNESCO World Heritage site.
The Rising Star cave system houses the remains of a highly enigmatic hominin called Homo naledi. Recently, a team of paleoanthropologists headed by Lee Berger of the University of Witwatersrand in South Africa made a splash when they announced that H. naledi buried their dead ritualistically, mastered fire, and made art.1 These claims are shocking to many scientists because H. naledi had a brain size comparable to a chimpanzee. Most paleoanthropologists have long held the view that a large brain size was necessary for advanced cognition. But if these claims stand, they will upend the prevailing thinking among evolutionary biologists about what makes us human and prompt questions about why our brain evolved to be so large. Paleoanthropologist Christopher Stringer (who wasn’t affiliated with the research) said, “These are challenging finds, and they certainly make us think about what it is to be human.”2
A Theological Challenge These claims also threaten to undermine the notion of human exceptionalism. Many paleoanthropologists have thought that ritualistic burials and art were possible only for modern humans. But if H. naledi was also engaged in these behaviors, perhaps modern humans aren’t unique at all. If so, such behavior would challenge the biblical claim that human beings uniquely bear God’s image.
As Berger states, “We are facing a remarkable discovery here of hominids, nonhumans with brains a third of the size of [modern] humans . . . burying their dead, using symbols, and engaging in meaning-making activities.” “Not only are [modern] humans not unique in their development of symbolic practices, but [we] may not have even invented such behaviors.”3
So, are Berger’s claims credible? Do these new insights undermine the concept of human exceptionalism and the theological view that humans uniquely bear God’s image? How should Christians make sense of hominins such as H. naledi?
Before I offer my perspective on the finds and these questions, a bit of background on H. naledi may be helpful.
Homo naledi’s Recent Discovery The remains of Homo naledi were unearthed in 2013 and the first scientific reports on this hominin surfaced in 2015. Berger’s team recovered about 1,550 fossils from the Dinaledi Chamber of the Rising Star cave system. These fossils corresponded to about 730 skeletal elements from 15 individuals that spanned from infancy to old age at the time of death.
H. naledi had an unusual anatomy that appears to blend Homo and australopithecine features. This creature was about 4 feet in height, weighed about 90 pounds, and had a brain size that approximated a chimpanzee’s. Its lower limbs resembled those of an early member of Homo, indicating that this creature had a human-like gait. Its arms and torso were reminiscent of an australopithecine, indicating that this hominin could also move through the trees using arboreal locomotion. No tools were recovered in the Dinaledi chamber, but the hand structure indicates that H. naledi had the dexterity to manufacture and handle tools. Based on the tooth wear, this creature appeared to consume gritty foods, perhaps dirt-covered tubers and roots.
H. naledi’s position in the human evolutionary tree is uncertain. When originally recovered, its remains were undated. But based on the hominin’s blended anatomical features, Berger and his collaborators speculated that H. naledi lived about 2 million years ago and may well have been the key transitional form that gave rise to early H. erectus and the Homo genus.
However, to everyone’s surprise, when the H. naledi site was dated, the hominin was discovered to have lived around 330,000 to 250,000 years ago. This much more recent date would make it a contemporary with Neanderthals, Denisovans, archaic Homo sapiens, and perhaps modern humans.
Homo naledi Funerals? Even more startling than H. naledi’s unusual anatomy was the claim from Berger’s team that this hominin buried its dead and by doing so engaged in funerary practices. This behavior connotes a sense of the afterlife and implies the capacity for symbolism.
To understand the basis for the claim, it helps to have some understanding of the Dinaledi Chamber’s location in the Rising Star cave system (see figure 1). The cave entrance leads to a descent of approximately 150 feet that terminates in an extremely narrow passage called Superman’s Crawl. The only way through the passage is for the caver to hold one arm tightly against his/her body and extend the other one straight above the head—like Superman in flight. This narrow passage opens into a large chamber that contains a stair-like structure that extends upward about 50 feet toward the ceiling, called the Dragon’s Back. At the top of Dragon’s Back is a narrow opening that leads to a chute that drops to the floor of the Dinaledi Chamber.
Figure 1: Depiction of a Section of the Rising Star Cave System Showing Access to the Dinaledi Chamber Credit: Wikipedia
Dinaledi Chamber is the location of the H. naledi remains. These remains are well preserved and mostly articulated. They show no evidence of damage from predators, and do not appear to have been washed into the chamber by flooding. These features led Berger and his collaborators to conclude that H. naledi must have intentionally buried their dead in the chamber. Because it would have been so difficult to carry a dead body from the surface (cave entrance) to the chamber, where it would have been deposited, Berger argued that the burial must have been ritualistic in nature. If so, it means that H. naledi would have had symbolic capabilities.
A recent preprint on H. naledi presents apparent evidence for ritualistic burials.4 Berger and his team recovered the remains of a single individual consisting of 83 bones and teeth in an area of disturbed soil shaped like an oval. Elsewhere in the chamber they found bones and teeth from a single juvenile that had seemingly formed into a fetal position. This location also contains partial remains of three other juveniles. A crescent-shaped stone with striations was recovered near the hand of one of the juveniles. Berger and his team contend that the orientation of the bones and the disturbed soil indicate that these individuals were deliberately interred in pits that were dug out from the Dinaledi Chamber floor.
While Berger’s interpretation of the burial evidence is plausible, other interpretations are equally plausible—and perhaps more reasonable. Instead of performing a ritualistic burial, could H. naledi have been caching their dead? But if so, why choose a location that is so hard to get to? It could be that Superman’s Crawl was much wider in the past than today. If so, the chamber with the Dragon’s Back would have been more accessible.
If this hominin was caching its dead, is there evidence that H. naledi dropped the remains down the chute? Perhaps. Yet, the recovery of nearly intact H. naledi remains far from the bottom of the chute refutes this explanation. In some instances, the intact remains are buried underneath scattered remains of several different H. naledi individuals. If H. naledi was dropping its dead down the chute, then the most intact individuals should be near the chute and on top of remains that display greater skeletal disarticulation.5 Still, if this latter pattern is verified, does it indicate that H. nalediwas transporting the remains of their dead group members down the chute into the Dinaledi Chamber?
Not necessarily. Some geologists who have been in the Rising Star cave system believe that the Dragon’s Back resulted from a relatively recent ceiling collapse.6 If so, then when H. naledi occupied the cave, Dragon’s Back wouldn’t have existed. And the chute that drops into the chamber would have been about 50 feet from the cave floor and inaccessible to H. naledi.
Paleoanthropologist Aurore Val has argued that there may have been an alternative entrance to the Dinaledi Chamber that was easily accessible from the surface.7 She has also challenged the claim that the H. naledi remains from the chamber weren’t modified by predators. She maintains that the absence of the heads on the long bones is a sure indicator that the remains were processed by predators. She has also identified evidence that beetles and snails damaged the H. nalediremains and contributed to their decomposition. The chamber conditions aren’t ideal for snails and beetles and no snail remains were recovered there. These two observations imply that significant decomposition of the H. naledi remains took place on the surface before they were deposited in the chamber. These observations support the notion that H. naledi was caching its dead using an opening into the chamber that was easily accessed from the surface and that no longer exists.
What about the H. naledi remains associated with oval areas formed from disturbed soil? In a piece published at The Conversation website, four paleoanthropologists point out that none of the claimed H. naledi burials satisfy the standards used by paleoanthropologists to determine if hominin remains have been deliberately buried.8 They argue that these locations on the cave floor don’t appear to be deliberately excavated and may simply be shallow areas. They also note that the remains don’t appear to have been aligned, nor do they display the high degree of skeletal articulation expected if the remains were deliberately buried.
H. naledi Fires? Berger also contends that these creatures must have mastered fire because they would have needed to illuminate the cave so that they could make their way from the surface deep into the cave to the Dinaledi Chamber while transporting dead bodies. Berger recently announced at a lecture at the Carnegie Institution of Science that he had evidence that H. naledidid, indeed, master fire. It is important to point out that at the time of this writing, Berger and his collaborators have yet to publish their evidence.9 As such, it is an unsubstantiated claim.
Nevertheless, in support of his claim, Berger points to blackened areas on the ceiling of the Dinaledi Chamber and soot particles on some of the rocks. He also notes that stone hearths containing burnt antelope bones have been found in other areas of the Rising Star cave system.
Some researchers interpret this evidence differently. It could well be that the blackened areas on the cave ceiling come from mineral discoloration, not burning activity. Without dates for the soot particles and the burnt antelope remains, it’s impossible to connect the hearth construction and the presumed burning activity with H. naledi. It’s possible that the hearths were constructed and used by cave dwellers other than H. naledi (such as archaic or modern humans).
The team of four paleoanthropologists mentioned earlier questions the fire mastery claims. They write, “Yet none of the scientific research needed to confirm the use of fire has been carried out. Or if it has, it hasn’t been published. Previously acquired radiocarbon dates obtained by the site investigators on the apparent hearth material provided very late dates that distanced the hearths from the remains of Homo naledi by several hundred thousand years.”10
H. naledi Art? In another preprint, Berger and his collaborators claim that they have evidence of H. naledi artwork in the Dinaledi Chamber.11 This putative art takes the form of hatch marks that were impressed into a pillar in the chamber. The hatch marks appear to form several patterns including Xs, crosses, triangles, and squares that the Berger team interprets as geometric shapes. Presumably, the hatch marks were made using a tool like the one found near one of the juveniles in the oval area of disturbed soil on the chamber floor.
I question whether these hatch marks legitimately constitute art or some type of symbol. I had a dog who scratched furniture. When he did, he left behind markings that formed geometric patterns. So, is it possible that H. naledi simply marked on the cave wall without any artistic intent whatsoever?
Even if the hatch marks are art, there’s no evidence that they were produced by H. naledi. It could be that this “art” was made more recently by another hominin occupying the cave site. The hatch marks haven’t been dated. Until they are, there’s no way to know who the “artist” might have been.
The Mystery Continues Without question, H. naledi is a fascinating, enigmatic hominin. Berger and his co-investigators deserve much credit for the work they’ve done to unearth and characterize H. naledi. Scientific mystery and intrigue surround this creature. Yet, at this juncture, one would be hard-pressed to conclude that this small-brained hominin buried its dead ritualistically, mastered fire, and produced art. The evidence presented to support these claims is scant and their interpretations are rife with speculation. In fact, given H. naledi’s brain size, we wouldn’t expect this hominin to have these capabilities at all.
Alternative scenarios readily account for the archaeological evidence associated with H. naledi—scenarios that seem more likely given the brain size of this creature. A more sober-minded approach understands H. naledi to be a fascinating creature with intelligence and emotional capacity but, unlike modern humans, it lacked the cognitive capacity to engage in symbolic behaviors. In short, H. naledi poses little threat to the idea of human exceptionalism.
Lee R. Berger et al., “241,000 to 335,000 Years Old Rock Engravings Made by Homo naledi in the Rising Star Cave System, South Africa,” BioRxiv (June 5, 2023), doi:10.1101/2023.06.01.543133; Lee R. Berger et al., “Evidence for Deliberate Burial of the Dead by Homo naledi,” BioRxiv (June 5, 2023), doi:10.1101/2023.06.01.543127; Agustin Fuentes et al., “Burials and Engravings in a Small-Brained Hominin, Homo naledi, from the Late Pleistocene: Contexts and Evolutionary Implications,” BioRxiv (June 5, 2023), doi:10.1101/2023.06.01.543135.
Private email correspondence with Sue Dykes, a paleoanthropologist who had been in the Rising Star cave system, September 11, 2015.
Aurore Val, “Deliberate Body Disposal by Hominins in the Dinaledi Chamber, Cradle of Humankind, South Africa? Journal of Human Evolution 96 (July 2016): 145–148, doi:10.1016/j.jhevol.2016.02.004.
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