In case you missed it, I wrote a magazine article!
Here’s how it happened. I was following the arguments between Tim White and Lee Berger playing out in the press, with White insisting Homo naledi was actually just H. erectus and Berger defending his work, with both trading pointed barbs. However, the words of Ian Tattersall’s latest book were ringing in my ears and it occurred to me that the fight between Berger and White was actually over something much deeper. I decided to try on my journalist hat and make a few phone calls.
Berger and White don’t just have disagreements about Homo naledi, open-access publishing, the pace and rigor of publishing new fossils, or the thresholds for naming new species. While those disagreements are real, they are minor compared to their disconnect on the biggest question in paleoanthropology: what is the nature of the human fossil record?
Is our history more or less a linear progression of one species gradually evolving into the next until we reach the pinnacle, Homo sapiens? Or did the hominin lineage experience extensive adaptive radiation, spreading out into a bushy family tree, culled to a few branches by the harshness of natural selection?
Read the full story in next month’s Skeptic Magazine or in the electronic version, eSkeptic, available now.
One thought on “Lee Berger, Tim White, and Homo naledi: A New Fight, the Old Way, and the Future of Paleoanthropology”
This is a great discovery & excavation, but prof.Berger’s interpretations (human ancestor, deliberate burial, tool maker, distance runner) are anthropocentric. AFAWCS it was a completely natural accumulation of fossils. Years ago we predicted naledi-like ancestors of Pan-Homo-Gorilla: bipedally wading, rather bonobo-like, frequently dwelling in forest swamps, flat humanlike feet, curved hand-bones etc., google “aquarboreal”).
Fossil-hunters see everywhere “human ancestors”: there are 6 or 7 extant African hominoid species (1 bonobo, 2 or 3 common chimp, 1 human & 2 gorilla species), but fossils hunters find 1000s of “human” fossils, and at most 1 or 2 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 and/or might have been more bipedal (e.g. for wading). 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). The australopithecines were no bipedal savanna runners as often assumed in popular publications: their fossils are typically found in swamp forests, lagoons, wetlands etc., where they might have waded bipedally for wetlands foods (explaining their dento-gnathic anatomy, thick enamel, micro-wear etc., google “Puech Verhaegen”).
Naledi fossilised in mudstone = stagnant water. Bonobos & lowland gorillas still wade sometimes in stagnant waters for waterside & aquatic herbaceous vegetation (AHV: frogbit, papyrus, sedges, cattails, waterlilies…). Naledi lived in a much wetter & hotter climate (Pliocene), where forest swamps might have been more abundant: naledi’s flat feet (more penguin- or 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”). Their flat feet were not for running over the plains as prof.Berger believes, but for bipedal wading or for surface-swimming. Their long thumbs were not for tool-making as Berger anthropocentrically assumes, but simply for surface-swimming, collecting 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: natural accumulation.
In short: we don’t need far-fetched “explanations”: there were no burials (they had chimp-sized brains), naledi might well have been ancestors of Pan (cf.bonobo) rather than of us, they were no distance-runners, and they didn’t make tools more than chimps do.