Last month research was published on a skull from the 1.7 million year old site of Dmanisi, Georgia. The fossil (known as skull 5) showed that a single population of Homo erectus was more variable than expected, suggesting that the definition of H. erectus be broadened to take this into account. However, this new, broader definition would include Homo ergaster, a species thought to be a regional variant of H. erectus, into the pot. It’s a fairly significant discovery that has major implications for how we view the diversity in the human family. But what if the discovery is a fraud?
That’s the question Brian Thomas (of the Institute for Creation Research) asks in his article New Human Fossil Borders on Fraud. Now, he’s not suggesting that this is a full-blown hoax akin to Piltdown man. Rather, he seems to be arguing that this is very clearly an ape that is (perhaps deliberately) being mislabelled as a human to prop up the theory of evolution.
An international team of paleoanthropologists reported discovering the earliest human fossils found outside Africa at a dig in the country of Georgia….[but] the seven observations below indicate this might be another case of evolutionist experts mistakenly associating ape fossils for those of humans
So lets examine his 7 observations and see if we’re actually dealing with an ape at Dmanisi.
But first, a quick aside. We’re dealing with evolutionary biology, specifically the subfield known as evolutionary anthropology. The people who know their stuff are called evolutionary experts, not “evolutionist experts”. It seems he doesn’t actually know the name of field he’s critiquing. Or maybe he’s so used to talking about those ‘pesky evolutionists’ that he’s forgotten how English works. Either way, it’s not a good start to the article.
1. It is anatomically quite different from known human skulls. The Science authors wrote, “The morphology of skull 5 stands apart from that of any other known fossil Homo specimen through its combination of a small braincase with a large prognathic face.” Maybe it “stands apart from” man because it was not a man. Could it actually be an ape’s skull?
Now, within evolutionary anthropology “human” is often used to refer to our genus Homo, whilst the phrase “modern human” is reserved for well…modern Homo, i.e. us, Homo sapiens. Is Brian trying to argue the Dmanisi finds are not modern humans (which his use of the word “man” implies) or that they should be stripped from our lineage entirely? If it’s the former then he’s right. Homo erectus is not Homo sapiens (as the fact they’ve been given different names suggests). In fact, the only people who seem to be arguing the Dmanisi fossils are modern humans are other creationists. Answers in Genesis, for example, wrote of the Dmanisi fossils
While there could be ape bones in the mix, these could also be humans suffering skeletal malformations and growth disorders due to pathological conditions stemming from disease or deprivation.
But given Brian is trying to lump the Dmanisi finds in with apes I’m going to assume he doesn’t fully understand the subtleties of the definition of “human” and is trying to remove them from our lineage entirely. So, do the unique characteristics of skull 5 justify removing it from the human family.
It is certainly true that the Dmanisi fossils are very different from all other known members of Homo. However, they are no more different from other (almost) universally accepted (non-modern) humans than two chimps are from each other. In fact, skull 5 is no more different from “classic” Homo erectus than two humans are from each other (see graph on the right). So either Brian is going to argue that some living modern humans are secretly apes, or is this argument falls flat on its face.
2. It is too loosely linked with human postcranial material. The study author’s phrase “probably associated” cannot substitute for solid scientific evidence.
The Dmanisi site has yielded 4 other skulls (hence why this one is called skull 5) and a few parts from the rest of the skeleton. These post-cranial remains were argued to come from the same guy as skull 5 given (a) both sets of fossils have similar levels of arthritis, (b) both sets were equally well preserved; suggesting they were buried around the same time under similar conditions and (c) the post-cranial remains were distributed along a north/south axis. Skull 5 was not found with its jaw, which were separated along a north south axis.
Whilst I think this makes a compelling case, there’s still a possibility they’re wrong. But I think Brian is over-exaggerating it and playing on the naturally cautious language of science to suggest their is no good reason to link the skull with the post-cranial remains. I hope the 3 arguments above convince you otherwise.
3. It has a very ape-like brain volume—far smaller than that of a human. It was estimated at 546cc, similar to that of gorillas and Australopiths, but only about half the average size of a human
Hang on…reason 1 for calling skull 5 an ape was “The morphology of skull 5 stands apart from that of any other known fossil Homo specimen through its combination of a small braincase with a large prognathic face.” Brian is just repeating himself here!
As I said the first time, the difference in brain size between Dmanisi and other “classic” members of Homo erectus is no greater than the variation found in modern humans.
4. It has a heavily built, ape-like jaw.Skull 5 “has the largest face, the most massively built jaw and teeth and the smallest brain within the Dmanisi group,” according to a news release from the University of Zurich where three of the Science authors work. But where is the evidence proving that all five Dmanisi skulls even belong to the human group?
Again, Brian is just repeating himself by re-using the large prognathic face and jaw.
5. It links to other material that is not clearly identified or dated. The Science authors reported, “Furthermore, the remarkably large and robust dentognathic remains of early H. erectus from Java (Trinil/ Sangiran) exhibit close affinities with skull 5.” But the abstract describing the Java remains reads, “Temporal changes, within-group variation, and phylogenetic positions of the Early Pleistocene Javanese hominids remain unclear.”
Brian’s article is all about the idea that this is so clearly an ape to call it human borders on fraud. Here is where he quotemines a paper so clearly that it borders on fraud.
The paper about the Java hominins opens with Brian’s quote. It’s setting up the issue which they’re investigating.
Temporal changes, within-group variation, and phylogenetic positions of the Early Pleistocene Javanese hominids remain unclear. Recent debate focused on the age of the oldest Javanese hominids, but the argument so far includes little morphological basis for the fossils. To approach these questions, we analyzed a comprehensive dentognathic sample from Sangiran
It’s basic science writing. “There is a problem, which we’re going to solve.” Brian has selectively quoted this to “there is a problem.” If he’d have actually read the paper, rather than just grabbing the first sentence of the abstract he would’ve noted that after 15 pages of analysis they eventually conclude
The fossil collection of the Early Pleistocene Javanese hominids is not homogeneous, and can be divided into two groups both in terms of chronology and dentognathic morphology.
In other words, they eventually clearly identify and date the fossils. And by date, I mean develop a chronology of change. There never was an issue over how old the fossils were, just how they changed over time. Which Brian also misquoted as meaning they were “not clearly dated”
6.The researchers’ approach to skull 5 may be similar to other fraudulent or dubious finds. Dutch physician Eugene Dubois, anxious to find proof of human evolution, uncovered the famous Java “man” fossils in 1891. It was not until 30 years later that Dubois revealed the truth behind the find and admitted he had been hiding fully human skulls from the same Javan site. Some later suggested that his Java man skull cap was actually that of a gibbon. Could today’s scientists be subject to the same eagerness to prove evolution, leading to skewed analyses?
Scientists can make mistakes. Dubois did with his retraction of the Java fossils. Peer review is there to catch scientists when they slip up, double checking their conclusions to make sure their analyses aren’t skewed. And it caught Dubois. Other researchers have noted that the skull cap he found, which he later claimed was actually a giant gibbon, almost perfectly matches the skull cap of Homo erectus.
In this case the data on skull 5 has been published, and if there is a mistake then critical examination will reveal it. However, all Brian has offered thus far is quotemines and repetition.
7. It is replete with ape features. Skull 5 has a U-shape dental arch, not the more parabolic shape humans present. Its chin slopes back like an ape without the forward-jutting bottom point of a human chin. There is no human nose bridge, and it has prominent attachment points for enormous jaw and neck muscles.
This fossil is not a fully modern human. It is what we call Homo erectus, which is very similar to modern humans but not quite all the way there yet. It has a tall body (like a us) with long legs (like a us) and short arms (like a us) with relatively short fingers (like a us). Yet as Brian so astutely notes, they also share many similarities with modern apes.
There’s a word creationists use to describe a fossil “part-way” between two creatures, but I forget. Whatever it is, Dmanisi (and Homo erectus) clearly are it. The new definition of Homo erectus based on the Dmanisi fossils clearly cements it as a species en-route to becoming human, but not quite all the way there yet.
And so it is actually a great piece of evidence in favour of human evolution.