Bones of Contention: Cal Paleo Expert Doubts Homo Naledi Is New Species

By Glen Martin

The popular science press went bonkers last month with news that fossilized bones of a previously unknown hominid had been discovered in a cave system in South Africa. Dubbed Homo naledi by lead researcher and University of the Witwatersrand paleoanthropologist Lee Berger, these proto-humans appeared to have lived somewhere between 1 to 3 million years ago, used tools, walked upright, and may have buried their dead, a practice that has only been attributed to our own species, Homo sapiens, and Neanderthals.

So there was a lot of talk of a “missing link”—the biggest find in paleoanthropology since Lucy, the skeleton of a female Australopithecus, was excavated from a gully near Ethiopia’s Awash River in 1974. (Donald Johanson, the lead researcher in Lucy’s discovery team, founded the Institute of Human Origins, which later moved from Berkeley to Arizona State.)

Certainly, the discovery seemed destined to open a new chapter in the study of ancient hominids, kick the telegenic Berger into the firmament of paleo­an­thro­pological superstars, and likely pay off big time for the National Geographic Society, which funded Berger and made the diminutive H. naledi the cover story for the October issue of its magazine. Indeed, the find seems destined for the full Nat Geo multimedia treatment, including television specials.

Amid all the hoopla and confetti, however, a growing number of scientists are advising caution. They’re not denying the importance of the find; the fossils, they say, are invaluable. But they contend that the bones may not represent a new species. The evidence these skeptics point to suggests that the finds may actually be bones from Homo erectus, the earliest known hominid to manifest the general proportions, stance and gait of modern humans. H. erectus had a long tenure on the planet, living from about 2 million to 70,000 years ago. The species was widely distributed (from Africa to East Asia and possibly southern Europe), used tools and fire, and may have constructed rafts to cross wide bodies of water.

By virtue of his scholarly bona fides, Berkeley paleoanthropologist Tim White seems the default, if somewhat reluctant, lead spokesman for the H. naledi contrarians. White worked with Richard Leakey in Kenya and Mary Leakey in Tanzania. In 1994, as a co-director of the Middle Awash Project in Ethiopia, White and his fellow researchers unearthed a fossilized partial female skeleton of Ardipithecus ramidus; at 4.4 million years of age, “Ardi” is the oldest know human antecedent. Two years later, White and his fellow researchers discovered fossils from Australopithecus garhi, a 2.5-million-year-old hominid who was contemporaneous with the earliest known use of stone tools.

And to White’s eye, Berger’s findings are probably South African representatives of Homo erectus. The Homo naledi cranium is similar in conformation and size to the earliest and most primitive Homo erectus representatives, White said.

Berger maintains that 13 of the 83 characteristics he noted on H. naledi’s skull differ from characteristics on known H. erectus skulls. “But many of these 13 characteristics are also present in H. erectus, not absent [as Berger and his co-researchers] claim,” White said during a recent interview in his Berkeley lab. “I wrote a text on human osteology [the study of bones]. Also, I teach a class on [osteological] variation in humans. Many of the characteristics that [Berger and company] claim differentiate H. naledi from H. erectus vary within our own species.”

Further, said White, some of Berger’s conclusions about H. erectus’s cranial features are just plain wrong. Berger maintains that an external occipital protuberance—basically, a bump at the back of the skull—is present in H. naledi but absent in H. erectus. White disputed this assertion by opening a cabinet in his lab, picking up a replica of an H. erectus skull found in Kenya, and pointing to a blatant occipital protuberance.

“That feature was noted in H. erectus fossils found in both [the former Soviet republic] Georgia and Kenya,” said White. “So you look at that, and you realize these claims of a new species are a little sketchy.”


Berger brushed off the criticism at a press conference near the findings. “Could this be the body of Homo erectus? Absolutely not. It could not be erectus,” he said.

Since then, White has cited other elements of the H. naledi saga that he finds troubling. The fossils come not from a single specimen, but from as many as 15 different individuals; it is therefore difficult to identify which bone came from which individual, and even whether they lived in the same period. Nor has Berger’s team been able to definitively establish the age of the bones. Photos taken of the find demonstrate to White that many of the fossils were not found in situ in rocky matrix, but had been “very disturbed, perhaps by earlier cavers, in the geologically recent past.”

“One tibia, for example, was white on one end, a clear indication it had been snapped off in the recent past,” said White. “This (region’s) complex is extensive and like Swiss cheese, and it’s a favorite with spelunkers. You find beer cans next to fossils that are 3.5 million years old. So it’s important not to jump to conclusions.”


Further, the excavation itself seems inadequate to justify Berger’s claims, White said. “It was about the size of a phone booth floor, roughly 80 x 80 cm and 20 cm deep,” White said. “That’s much smaller than you would expect for a discovery of this magnitude. Virtually all excavations related to important finds are much larger. With a typical excavation, you must establish a threshold that provides an understanding of the successive layers, that provides the means for comprehensive analysis and comparison with specimens from other sites.”

Finally, White observed, claims that the hominids might have buried their dead (because so many bones were found in the same chamber) were hyped heavily in publicity materials; but the scientific paper that Berger and his fellow researchers produced on the fossils is much more circumspect about such possibilities. “There is no evidence of burial rituals,” the Berkeley professor said. “The only evidence seems to be ‘We can’t think of anything else.’ This is not evidence.”

When California queried Berger on White’s comments on the discovery, he emailed the following response:

“I would really rather debate Tim’s ideas in a scientific journal where they belong rather than him attempting to debate this in the media. We have had almost 60 scientists working for two years on these refereed papers—Tim is shooting from the hip using characters that appear to largely concentrate on the head rather than the whole organism and well, the one thing I can assure you is the debate on Homo naledi being a ‘primitive Homo erectus,’ whatever that is, will not be settled in the media, either traditional or social. [Reporter’s note: The query was meant to imply an early representative of H. erectus, not a biologically ‘primitive’ form.] Tim continuing to use the media to argue whatever unsupported case he has for such assertions while protesting we are using media to ‘hype’ our fossils (although our ideas are in fact published in a well respected scientific journal) appears to be a way of just getting his name in the media rather than any form of scientific discourse. I would rather confine such discourse to where it belongs, a scientific paper published by Tim White in whatever journal he might be able to get such an argument in based on real numbers, real fossils and not just his opinion.”

The Academy can be a hothouse of discord and dissent, and some fields—paleoanthropology among them—seem particularly fertile ground for contention. But White is not alone in his uneasiness over H. naledi. Reviewers at top scientific journals also found the evidence for the new hominid species to be suspect. Berger and his team originally submitted multiple papers on H. naledi to the prestigious journal Nature, which rejected them.

“Tim continuing to use the media to argue whatever unsupported case he has for such assertions while protesting we are using media to ‘hype’ our fossils (although our ideas are in fact published in a well respected scientific journal) appears to be a way of just getting his name in the media rather than any form of scientific dis-course.”

Berger and his co-authors ultimately published their findings in eLife, an open-access, peer-reviewed, online journal edited by Cal biology professor and Nobel laureate Randy Schekman, the former editor-in-chief of the Proceedings of the National Academies of Science. Schekman assumed the editorship of eLife after declaring that he would no longer publish in closed-access journals such as Cell, Nature, and Science because the editors were more concerned with burnishing the reputations of their journals than publishing cutting-edge research. Like other open-access journals, eLife usually has a quicker peer-review process than long-established journals, and a much higher acceptance rate: around 25 percent, compared to the 7 percent acceptance rate of Science.

White said he agrees with Schekman that the peer-review process at the established journals is often flawed, but maintains that open-access journals such as eLife and PLOS One are not necessarily a panacea, in that research can be rushed to publication before being properly vetted by gimlet-eyed peers. “That’s clearly the case here [with H. naledi],” he said, noting the timeline between the discovery of the fossil site and the publication of the findings in the peer-reviewed and general press was only two years.

Indeed, the H. naledi announcement essentially was made simultaneously in the academic and popular media. During the press conference heralding the publication of Berger’s findings in eLife, a mock-up of National Geographic’s October magazine cover featuring the find was presented, and a television special sponsored by National Geographic and Pithecus was announced. By contrast, White and his colleagues took 15 years to publish their findings on “Ardi.” It took three years just to remove the fossils from the field. Years were spent carefully teasing the fossils from the matrix in the lab, obtaining moulds, photographs, and micro CT scans, compiling and analyzing the data, and comparing the fossils with all other known fossils and relevant living species.

Ultimately, findings on “Ardi” were published in both the journal Science and in National Geographic; but White made sure the material appeared first in the peer-reviewed publication.

“We held the popular press off for 10 years,” says White, “for the simple reason that you can’t do good science when those guys are in the room. So when you actually invite them into the room—as Berger did, when they’re in the (tent) filming while excavation is going on, that has a very high impact on the work.”

Also, said White, Berger’s team was negligent in the handling and care of their find. He produced a photo of a member of Berger’s team scraping some of the bones; a small pile of shavings is clearly visible. “Those are bone scrapings, and that’s a terrible thing to see. You lose valuable information when you remove bone like that, information you’ll never be able to recover.”

“This find is remarkable enough for what it is—a huge injection of new data important for understanding early hominid evolution. There was no need to turn it into something more than that.”

Both Berger and National Geographic have run into hominid-associated controversy before. In 2008, Berger was the lead author of a paper in PLOS One on the discovery of the remains of dwarfish, Hobbit-like hominids in the Palau archipelago. They were reported to be similar to bones found earlier on the Indonesian island of Flores 2,000 kilometers to the south. The Flores find was tentatively identified as a new species, H. floresiensis, a designation that has since become highly controversial. Berger suggested that the Palau discovery indicated the Flores hominids may not constitute a separate species, but are rather a manifestation of the dwarfism that sometimes occurs among mammals isolated on islands.

But Berger’s hypothesis for a troupe of island-bound dwarves was quickly disparaged by many of his academic peers, who maintain the bones were more likely those of juvenile normal-sized humans. Michael Pietrusewsky, a University of Hawaii at Manoa anthropologist widely considered the preeminent authority on ancient South Pacific human remains, stated: “The more I read the paper, the more I am convinced it is complete nonsense and cannot be accepted as serious science.”

In a Nature piece on the Palauan discovery, reporter Rex Dalton described the controversy and Berger’s claims as a “crossfire between entertainment and science,” with entertainment winning. Dalton noted that Berger appears often on television, and that he and the National Geographic Society collaborated with a London production company, Parthenon Entertainment, to make a film of the Palauan finds.

Though National Geographic provides seed grants to scientists in an array of fields, many of whom produce valuable research, Dalton writes that “National Geographic is also a nonprofit media empire…. Its editors work to get featured discoveries by its funded researchers into both its flagship magazine and peer-reviewed journals at the same time. This arrangement can sometimes backfire, as it did in 2000 when the magazine featured a report of a flying dinosaur fossil that later turned out to be a cleverly faked composite. Berger’s project in Palau provides a behind-the-scenes view of when entertainment and science meet….” (Last month, National Geographic magazine’s nonprofit parent organization effectively sold it to a for-profit operation whose chief shareholder is one of Rupert Murdoch’s global media companies.)

Berger, for his part, remains largely undaunted by the controversy his work has engendered. In response to misgivings over his Palau project, he emailed Nature’s editors: “Might it be that such critics have not read our manuscript as carefully as is required of a sophisticated debate on human variation before commenting?”

H. naledi—or whatever it is—certainly isn’t a modern-day Piltdown Man. White emphasizes that the discovery constitutes a major event in paleoanthropology. To illustrate his point during his recent interview with California, he produced another photo of one of Berger’s fossils. Even to an untrained eye, it was clear that it included digit bones.

“That’s a complete hand,” White said, calling these the first fossils ever found of a probable Homo erectus hand. “This find is remarkable enough for what it is—a huge injection of new data important for understanding early hominid evolution. There was no need to turn it into something more than that. Speculations about mortuary ritual or the need for a new metaphor to describe evolutionary process are both unnecessary and unwarranted.”

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I doubt many scientists would view the National Geographic magazine as a scholarly peer-reviewed publication. But, it does bring interesting articles to the general public and serves to generate interest in topics that might otherwise go unnoticed in scientific journals. People who are stimulated by the NG article and want to learn more about H. naledi will go online and look for more scholarly articles. The comments in your article provide a different perspective of some of the findings of Berger and his colleagues, which is needed. I suspect that paleoanthropology will get a boost from such a discovery as it did following Johanson’s discovery of Lucy. Let’s hope so.
Biological species concept is still blurry, especially about fossils of H. sapiens. In my theory, the solution is dependent on whether the Macroevolution in Levant 150kya is true: If true, Naledi seems a new species and perhaps a new genus as neither Homo nor Australopithecus.
This is an embarrassment for White and shows why he advised others to not say things without doing a little checking first. Some of the surface bones had been broken when cave explorers visited the site decades ago. This was obvious in video. Anybody who wants to download and print a copy of the main finds is free to do so. White is setting on his last find like a dragon guarding it’s hoard and the only person that brought up the missing link statement was a member of the press and was immediately told the term was not in vogue.
Soooo, that makes it ok to put out sloppy so-called scientific conclusions to the general public? This is not only disrespectful to the very group of people who are funding this type of research, but also sows the seeds of confusion and misinformation. How is it ok for scientists to do that? If paleoanthropology needs “boost” from this type of shenanigans, it really makes me wonder.
This fossil had a small brain capacity so it’s not a new species. It’s an ancestor of today’s liberals.
I find fascinating the Egos at loggerheads in this field. What is apparent here is the “old boy network” of the peer review system and the “new” system of open forum journals. The establishment in science would have all believe that it is the one human endeavor free from self-interest, self-promotion, the desire for fame and fortune… all in the search for truth. the drama does not make the field less interesting; it clearly adds to the popular interest of sometimes mundane work, but it also reveals the very human push and pull that is needed in the authentic search for the truth.
I was under the impression that alumni magazines are supposed to showcase actual accomplishments of faculty, staff, and students at their institutions, not just rebuttals to the work of other scholars. While White does have a noteworthy career and he does bring up a couple valid critiques and points of discussion about the important Homo naledi discovery, “California Magazine” seems like a very odd and inappropriate outlet for his views (as opposed to the scientific literature, or Dr. White’s personal blog, if he has one). This article appears to be a cheap attempt by Berkeley to themselves profit from the media coverage this new species is receiving, in spite of the fact that no one from Berkeley, or indeed, the UC system, was directly involved in the initial investigation of the Homo naledi fossil material.
Berger apparently made a point of collecting a bunch of fresh faces willing to work for little or nothing in return for the opportunity to do important research and get their name on an important paper they could use as a foundation for their resume. It was a good deal for all parties. However I’ve seen evidence that some of the old timers were at the least in the loop because they knew what was coming. Not really clear why White seems to have been left out. He doesn’t seem to have been networking effectively because he has ties with South Africa and did research there at one time. Berger noted White hasn’t been to South Africa in 10 yrs.
I watched the NatGeo doc on this “discovery”. As a layman I was really turned off out how much camera mugging and self flagellation this scientist was doing. He declared this a new species while ON SITE! I called BS and knew this would come back to haunt him.
I can categorically state that if my father, F. Clark Howell, were alive, he would strong dispute any suggestion that Tim White would ever personally pander for UC Berkeley, nor would he allow himself or his views to be exploited for such a purpose. My father regarded Tim as one of the most careful, cautious, and conscientious scientists he knew, and a paleoanthropologist of unimpeachable stature. Those are just some of the reasons he and Tim worked closely together for over thirty years. Brian Howell
With respect preventing yourself and your views from being exploited by others is very hard to do and exploiting the notoriety about your find and views or getting a little air time by commenting on the finds of others is how people get funding in this branch of science. For most funding is painfully hard to obtain if it can be obtained at all.
A marvellous find & great work, but unfortunately, the discoverers’ interpretations are anthropocentrically biased. This find is not unexpected (google aquarboreal): comparative anatomy suggests that Homo or Australopithecus naledi was no savanna runner as prof. Berger thinks, but a bonobo-like wetland wader, who fossilised in mudstone. The curved hand bones suggest vertical climbing in the branches above forest swamps, and the flat humanlike feet look more flamingo- (plantigrade wader) than ostrich-like (digitigrade runner). Lowland gorillas regularly & bonobos occasionally wade bipedally in swamp forests for sedges, waterlilies etc. (google bonobo wading), but naledi apparently habitually exploited this special niche (google gorilla bai). When they died, their bones sank in the mud, and when later the underground eroded, the mudstone got in the caves (google researchGate marc verhaegen).
I believe in science not science fiction. On December 9, 2010 in The New York Times science writer Nicolas Wade wrote: “Anthropologists have been thrown into turmoil about the nature and future of their profession after a decision by the American Anthropological Association at its recent annual meeting to strip the word ‘science’ from a statement of its long-range plan.” Pro-evolutionist, Bill Bryson in his best-seller “A Short History of Nearly Everything” wrote “If you correlate [fossil] tool discovery with the species of creature most found nearby, you would have to conclude that early hand tools were mostly made by antelopes…” He alsowrote of the ultimate arrogance of The American Museum of Natural History life-sized African diorama with two small, hairy homonid—based on a set of footprints! In China in 1999 National Geographic hailed the discovery of Archaeoraptor as “a great discovery of significant importance.” It was called “a true missing link in the complex chain that connects dinosaurs to birds.” It was discovered that this “missing link” was glued together from 88 fragments of mortar and bits of fossil and stone. National Geographic eventually conceded that the fossil was a fraud. (I have been a National Geographic member for over 15 years) Sometimes it seems that many anthropologists are still trying to make monkeys out of us. This is chicanery not science. This is weird imagination not science. This is absolute fraud. This is pure bunk.
I compared the flat humanlike feet of naledi to the plantigrade feet of flamingoes as opposed to the digitigrade feet of ostriches, but I was wrong: flamingoes are digitigrade, although their feet are much flatter than those of (also digitigrade) ostriches. In any case, comparative evidence shows that naledi were wetland waders, like bonobos or lowland gorillas collecting aquatic herbs in wetlands but much more frequently: that’s why they abundantly fossilised in mudstone, had curved hand-bones (for climbing vertically in the branches above the swamp like bonobos do) and had flat & more humanlike feet (for wading/swimming), google “aquarboreal”.
It is simply pathetic, and an indictment of the intellect of our species that there are minds such as Thom Mccann’s among us. This is not ad hominem, but recognition of how dogmatic and foolish a species we are that so many are so willfully ignorant. No wonder we’re doing nothing about global climate change. No wonder so many of us kill others to please the ONE TRUE GOD — several of them. I hope one day a uniformly intelligent, skeptical, and open-minded species is here in our place, or that we we’re gone and our giant brains and imaginations can no longer be misused for such inane drivel. Calculus, the laws of gravity, evolution, relativity, yes, but also such stupidity. On average, dolphins may be right there with us…
I realized after posting that not everyone would understand my sarcasm. I support Thom Mccann and his efforts to challenge the pro-evolutionist, pro-gravitation, and pro-heliocentrist movements. When will you fools realize that we know God’s (there’s just one) thoughts and plans, and he is working through us? Duh.
there says NOTHING about the feet!!!!!!!!!
You mean naledi’s feet, Wolfette? The flat humanlike forefeet are probably the prime reason why Berger placed naledi into Homo, and why he believed that naledi were distance runners: he thought: since naledi had adducted big toes like humans (who walk on the ground) as opposed to chimps, they walked like us. This is a logical mistake (called ‘post hoc ergo propter hoc’). According to comparative & ontological data, the early hominids (sensu Pan-Homo-Gorilla+fossils) were already parttime bipedal waders in forest swamps (like bonobos still are parttime, google: bonobo wading) with flat forefeet more flamingo- than ostriche-like. Chimpanzees (re)evolved abducted big toes when they left the swamp and climbed more. OTOH, human ancestors had to use their flat feet for walking, although toe- & hoof-walking (digiti- & unguligrady) are more suited to running than our plantigrady (sole-walking). IOW, naledi (except its feet generally remarkably bonobo-like) is more likely a fossil relative of bonobos (Pan) than of us (Homo).
The declaration of new species should be subject to peer review as opposed to how it is done today. It should not be left to the judgment of the “discoverer.”
Indeed, John: fossil-hunters often believe “their” fossil is a human ancestor (anthropocentric fallacy). Prof.Berger is no exception: Homo or Australopithecus naledi was no ancestor of ours, they didn’t run over the savanna (endurance running fantasy), they didn’t make tools more than chimps do, and of course they didn’t bury their dead in caves: naledi’s accumulation was a completely natural process of swamp-living bonobo-like fossil apes (google: bonobo wading): their curved finger-bones indicate vertical climbing, their flat forefeet (flamingo- rather than ostrich-like) indicate wading-swimming, not running, they fossilised in mud-stone = stagant water. The comparative data are clear, but no, prof.Berger produces far-fetched “explanations” to make naledi a human ancestor. But is peer review the solution? Paleo-anthropologists have found more than 1000 fossils of “human ancestors”, but virtually no bonobo, common chimp & gorilla ancestors, although the ancestors of the African apes did live in Africa at least the last 5 Ma. Isn’t that remarkable: 1 species with say 1000 fossils, 3 species with 0 or 1 fossils… This is statistically impossible, even if human ancestors fossilised remarkably 1000 times more likely than African ape ancestors. And this incredibly anthropocentrism is repeated over & over in all textbooks of human evolution & even in Nature & Science & other peer-reviewed journals without questioning: “born to run”, “Man the Hunter”, “le singe coureur”, “Savannahstan” & more anthropocentric fantasies. The (non-anthropocentric) solution is simple: australopiths are fossil relatives not only of Homo, but also of Pan & Gorilla (google: verhaegen human evolution). Gorilla & chimp ancestors were more bipedal than living African apes: they waded vertically in the wetlands where their fossils were found, like lowland gorillas today but much more frequently (google: gorilla bai).
The theory, that the cave should be a burial ground, sounds unlikely. It might as well being a dump to prevent the stench of dead bodies attracting carnivores.
Thanks, Jan. IMO there’s no need for supposing burials (nor dumping dead bodies), AFAICS it was a completely natural accumulation of fossils (in fact, years ago we predicted naledi-like ancestors of Pan-Homo-Gorilla: vertical wetland dwellers with flat humanlike feet & curved hand-bones, google “aquarboreal”). Fossil-hunters see everywhere “human ancestors”: there are some 7 extant African hominoid species (1 bonobo, 3 common chimp, 1 human & 2 gorilla species), but fossils hunters find 1000s of “human” fossils & 0 or 1 fossils of the other 6 species. Isn’t that remarkable? Are they fooling themselves? They don’t do this consciously IMO (you get more funds & attention when you discover a human ancestor than when you discover an ape ancestor), they argue: apes live in forests, humans on the ground, hence we got humanlike feet to walk/run bipedally on the ground, naledi had humanlike feet, hence they were “already” bipedal. They can’t imagine that the LCA (last common ancestor) of Homo & Pan (& Gorilla) might have had more humanlike feet. In fact, prenatal chimps have feet resembling ours, with forward pointing big-toes: “only as it approaches its birth does its foot acquire the appearance of a hand” (S.C.Coon 1954). Naledi fossilised in mudstone = stagnant water. Bonobos & lowland gorillas still wade sometimes in stagnant waters for aquatic herbaceous vegetation (AHV: forgbit, papyrus, waterlilies…). Naledi lived in a much wetter & hotter climate, where forest swamps were probably a lot more abundant: naledi’s flat feet (more flamingo- than ostrich-like) suggest frequent wading-swimming, their curved hand-bones suggest vertical branch-climbing: they were ideally adapted to such wetlands (google illustrations at “bonobo wading”). They flat feet were not for running over the plains as prof.Berger believes, but for bipedal wading and/or for surface-swimming. Their long thumbs were not for tool-making as prof.Berger assumes, but simply for surface-swimming and/or for scooping AHV. When they died, their bodies sank in the mud, and when much later the underground eroded away (cave system), the mudstone sank, slid or fell into the caves. In short: we don’t need far-fetched “explanations”: there were no burials, naledi might swell have been Pan (bonobo?) rather than Homo ancestors, they were no distance-runners, and they didn’t make tools more than chimps do.
“This is not ad hominem…” Really? You have not answered the statements condemning anthropologist cases of outright lies Bill Bryson and I have presented. Similarly you weasel out of the arguments and try to present them as a religious issue. “Tu quoque” is not an answer or repudiation by an erudite person. You may try again but this time you failed to ring the bell and get no cigar.

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