Evaluating Homo naledi
Lee Berger’s remarkable cache of hominid bones found deep in a South African cave is generating a lot of news, but major questions remain.
At one level, it’s a great adventure story: squeezing through narrow cave passages and finding bones all over the floor, so hard to reach that a team of skinny female investigators had to be recruited to map and retrieve them. But at a scientific level, what these bones mean is not clear. Lee Berger (champion of Australopithecus sediba, 12/08/11) has given the bones a new species name within our genus: Homo naledi. He is almost as controversial, however, as the fossils themselves.
The bones appear to be from about 15 individuals. No other mammal bones were found there, leading to speculations it was an intentional burial site. The skeletons seem to be mosaics of human and australopith features; some think they fit within Homo erectus. But since no dates have been assigned to the fossils yet, even evolutionary paleoanthropologists are reluctant to draw conclusions.
It’s premature, therefore, to evaluate this find. What we can do is draw attention to the variety of opinions in the press.
Evolutionary Opinions
Homo naledi, a new species of the genus Homo from the Dinaledi Chamber, South Africa (eLife). This is the lead paper by Berger et al. announcing the find.
Geological and taphonomic context for the new hominin species Homo naledi from the Dinaledi Chamber, South Africa (eLife). This companion paper describes the conditions in which the bones were found.
Crowdsourcing digs up an early human species (Nature). This news article begins with a photo of Lee Berger smiling triumphantly outside Rising Star Cave where the bones were found. Ewen Callaway describes how Berger recruited cavers to excavate the room deep inside the cave, and gives some preliminary opinions of other paleoanthropologists.
New human species discovered (Science Magazine). Veteran hominid news reporter Ann Gibbons describes the process of finding the fossils, giving Lee Berger a chance to assure readers that his expedition”isn’t a media stunt.”
South Africa’s new human ancestor sparks racial row (PhysOrg). Some South Africans are taking offense at possible racial overtones to the evolutionary claims made about Homo naledi.
From the archives: The scientist behind those controversial new hominin fossils (Science Magazine). Michael Balter asks “Why is this enthusiastic paleontologist so controversial?” and points to a 2011 feature story about Lee Berger.
New Human Ancestor Elicits Awe—and Many Questions (National Geographic). Jamie Shreeve discusses frustration over not having dates for the bones, and perplexity of how they got there. The possibility of radiocarbon dating is discussed.
Mystery Lingers Over Ritual Behavior of New Human Ancestor (National Geographic). This entry begins with artwork of creatures with human-like bodies but ape-like facial features carrying their dead into the cave for burial. Writer Nadia Drake discusses whether ritual behavior over death of kin is unique to humans.
Human Evolution 101 (National Geographic). Nadia Drake takes advantage of the news about Homo naledi to ask leading questions like, “Why are scientists certain that human evolution happened?”
12 Theories of How We Became Human, and Why They’re All Wrong (National Geographic). Balancing out Drake’s positivism, Mark Strauss recounts the many ideas about human evolution that have fallen by the wayside over the years. He doesn’t mention Homo naledi.
Opinion: What about Homo naledi’s geologic age? (PhysOrg). Darren Curnoe laments over not having established a geological age for the fossils. “Its just the sort of thing that infuriates many scientists and detracts from an otherwise significant discovery; pity really.”
New species of extinct human found in cave may rewrite history (New Scientist). Colin Barras includes photos of the fossils, artwork of the presumed facial features, and a map of the cave chamber where they were found. “ONE thousand four hundred bones, 140 teeth, belonging to at least 15 individual skeletons – and that’s just what was recovered in a single short field session,” he begins.
Homo naledi: Unanswered questions about the newest human species (New Scientist). Rowan Hooper briefly discusses the main questions regarding the find. “We don’t even know how old H. naledi was. It could be millions of years old, making it one of the very earliest species of Homo, or only tens or hundreds of thousands of years old, making it a relict species of human that survived into modern times,” he says. “…The team say it may be possible to use isotope testing to age the remains, and that no attempt has yet been made to extract DNA.”
Researcher argues that there’s more to the genus Homo than we may think (PhysOrg). This is not specifically about Homo naledi. Joe Miksch discusses the views of Jeffrey Schwarz, who complains, “If we want to be objective, we shall almost certainly have to scrap the iconic list of (genus and species) names in which hominid fossil specimens have historically been trapped and start from the beginning.”
Non-Evolutionary Opinions
Homo naledi as Spin Detector (Evolution News & Views). Ann Gauger gives an intelligent-design perspective on the bones, taking issue with some of the initial interpretations, providing quotes that illustrate spin doctoring. Her earlier piece on ENV also concentrates on separating fact from interpretation. Gauger was co-author with Douglas Axe and Casey Luskin of the Discovery Institute book, Science and Human Origins.
Scientists dispute ‘new’ species discovery (World Magazine). Casey Luskin gets a quote in Daniel James Devine’s article on Homo naledi, a fairly straightforward account of the find. Luskin comments, “Whenever you hear the word ‘mosaic’ in evolutionary lingo, what that means is this species does not fit very well into our preferred phylogenic scheme.” In World, an ID-friendly Christian news magazine, Devine says that Berger admits “the fossils might be only tens of thousands of years old.” He also points out that “some scientists dispute Berger’s contention that all 1,500 bones came from the same species.”
What to make of Homo naledi? More pseudo-scientific claims of human ancestry (CMI). Marc Ambler discusses the flamboyant character of Lee Berger. He notes that all other fossils in the area had been australopiths. Central point is cautionary:
One will have to wait and see whether the evolutionary scientific community come down on the side of the remains being Homo, or just Australopithecus. But why label the remains Homo naledi if there is so much indication that these may have been ordinary humans with some unique anatomical variations just as there are variations today between different people groups but all descended from the first two people created by God—Adam and Eve? University of California’s Tim White, who holds a different interpretation of human evolution, believes the remains belong to the species H. erectus, named in the 19th century. He is reported as saying that “New species should not be created willy-nilly. In order to claim a new species one has to demonstrate that it’s different from anything that’s ever been known.”
Homo naledi, a New Human Ancestor? (ICR). Frank Sherwin gives his initial take on the fossils, ending with a suggestion that the individuals are more ape-like than human-like, pointing to doubts about the intentional burial interpretation. Incidentally, ICR is about to release its new 4-part DVD production on the human body, Made in His Image; click here for trailer and information.
Other Human-Evolution News
Almost buried in the news about Homo naledi was another major announcement about Homo bones in a cave in Spain. In Science Magazine, Ann Gibbons writes about the new dates assigned to Denisovans, ranging from 50,000 to as much as 170,000 years ago. Gibbons thinks “they help solidify our murky view of Denisovans,” but can such a vast range of dates be plausible for individuals with many of the capabilities of Neanderthals and modern humans? And how much can be learned from a tiny fragment of a pinky fingerbone? “Denisovans occupied Denisova Cave repeatedly over more than 100,000 years,” she claims in a related Science Magazine article without winking a skeptical eye. “Neandertals slipped in as well, and modern humans were the last to live there.”
Gibbons also claimed in a recent Science Magazine piece that Neanderthal DNA is shaking up the family tree. But that’s old news. She leaves science for the humanities in “Humanity’s Long, Lonely Road,” speculating this way and that about the relationships of Denisovans, Neanderthals and so-called modern humans (although the differences between all three are slight). Her speculations put modern humans on a long, lonely road as far back as 3/4 of a million years ago. “That would mean that the ancestors of humans were already wandering down a solitary path, apart from the other kinds of archaic humans on the planet, 100,000 to 400,000 years earlier than expected.” It sure took these lookalikes a long time to learn farming.
Most curious in the early-man news is Michael Balter’s suggestion in Science Magazine that the “world’s oldest oatmeal” may have been discovered in an Italian cave. Estimated 32,000 years old, that would make it 25,000 years before the invention of farming. One would think they would tire of the same breakfast cereal after two weeks, let alone 25,000 years.
New Scientist, meanwhile, drags in climate change to explain “key moments in human evolution.” Climate change becomes an all-purpose gimmick for explaining any evolutionary mystery, but it has a problem: why didn’t all the other species change accordingly? It explains opposite outcomes; therefore, it explains nothing.
Eskimos are human, aren’t they? Sure they are. But changes to their stature—genetic mutations and all—occurred rapidly (geologically speaking) due to their high fat diet, Julie Hussin writes in The Conversation. She attributes this to natural selection, but hey: the Inuit can marry Europeans or Chinese and have happy kids.
It’s an appropriate time to remember Ian Tattersal and Jeffrey Schwarz’s critical comments in Science Magazine about defining the genus Homo. These veteran paleoanthropologists think their colleagues have been going about it all wrong. There is no simple ancestor-descendent relationship to be found in human fossils. “If we want to be objective, we shall almost certainly have to scrap the iconic list of names in which hominin fossil specimens have historically been trapped, and start from the beginning by hypothesizing morphs, building testable theories of relatedness, and rethinking genera and species.” What does that imply for “Homo naledi“?
In conclusion, we remind readers that “the myth of the missing link does science no favors,” as Sean Nee argues in The Conversation. Depending on the traits one focuses on, or one’s starting metanarrative, any story of relationships can be concocted; “we must choose our metaphors wisely, lest we be misled,” he says. “The Great Chain of Being, strung through evolutionary space by Blind Watchmakers, with missing links waiting to be discovered, isn’t going to help us understand infectious disease” or anything else that matters to us. Fossils like those announced by Lee Berger need to be interpreted on their own terms.
Update 9/21/15: At Evolution News & Views, Casey Luskin provides a detailed look at four major controversies about these fossils, including their classification, whether they were buried or chase into the cave, whether they comprise multiple species, and more. He provides many quotes from the literature.
We provide these links as preliminary coverage regarding so-called Homo naledi. Obviously many questions are floating around, and without dates, even the evolutionists don’t know what to think. If original unfossilized tissue or radiocarbon is found, the evolutionary story will be moot; evolutionists would have to claim, like with Homo floresiensis (the “hobbit”) that the creatures were relicts of earlier evolution, caught in some kind of refugium away from evolving modern humans. That would seem hard to maintain. Rather than rely on the opinions of experts, go to the original papers and read them critically, asking the kinds of questions evolutionists don’t think about.
In a profound new peer-reviewed paper in Theoretical Biology and Medical Modelling, creation geneticist John Sanford and team have shown that human evolution is unworkable anyway. There is simply not enough time, using realistic models of fixation and population size, for the mutations needed to change an ape into a man to have occurred (this is similar to the argument against whale evolution in the new film Living Waters). And that’s only one of numerous falsifications of neo-Darwinism.
With unguided mechanisms off the table, the only rational alternative for interpreting the bones from Rising Star Cave will be to start with intelligent design or Genesis 1.