Wednesday, October 14, 2015

Elizabeth Mitchell, Homo naledi and the Straw Man

Elizabeth Mitchell, of Answers in Genesis, has written the rebuttal to the eLife Science paper on the new hominin find from South Africa, Homo naledi.  Sadly, her opening premise suffers from a fatal logical error, and all that follows proceeds from this premise. She writes:
Berger’s team believes the bones paint a mosaic picture of a species mixing human-like “Homo” and australopithecine ape features. Composites constructed from four partial skulls in the assemblage have small brain capacities—560 cc and 465 cc—that overlap the usual brain capacities of australopithecines. Such braincases are much smaller than those seen in most archaic humans1 and less than half the average for modern humans.
Hidden in this paragraph is a theme which runs throughout the post: that australopithecines were apes.  Compare, for example, these passages.  First, what Berger et al. write about the shoulder girdle:
The shoulders are configured largely like those of australopiths. The vertebrae are most similar to Pleistocene members of the genus Homo, whereas the ribcage is wide distally like Au. afarensis.
Now, what Mitchell writes:
Homo naledi’s shoulder joints and curved finger bones are typical of tree-swinging apes. Its flared hips are typical of australopithecine apes. The lower ribcage widens just like the ribcage of australopithecine apes.
When Raymond Dart discovered the first australopithecine specimen, in 1924, the first thing he noticed was that

it was not an ape.

As I wrote in more detailed fashion here, the find had several characteristics simply not found on any ape. First, the foramen magnum, the hole through which the spinal cord exits the head, was not at the back of the head, as in apes, but was on the bottom of the skull. Second, the teeth were not those of an ape, but had the dimensions of human teeth. In apes, even infant apes, the canines extend beyond the tooth row. In this skull, they did not. Third, the skull was simply too large to be that of an infant ape, based on the development. Fourth, there had never been found any apes in South Africa. Dart was a good anatomist and knew that what he had was not quite human—the skull was too small for that and the front of the face was too ape-like, but he also knew he did not have an ape.  That is why Dart gave it the name he did: Australopithecus africanus, “Southern Ape-Man from Africa.”   

Since this discovery some ninety one years ago,  the validity of this genus has only been reinforced, with the additional discoveries of more than ten different species of Australopithecus, all with variations on the same theme, and all with the following non-ape characteristics:
  • human-like teeth (although quite large in some species)
  • modern double-s shaped vertebral column
  • short, wide hips that resemble humans and not apes
  • a valgus knee, with the femoral-tibial articulation at an angle, instead of straight up, as in apes
  • a laterally-bending proximal femur to accomodate the wide hips and the connexion to the tibia and
  • a modern gait (reflected in preserved 3.6 million year old footprints at Laetoli)
There are countless other small anatomical characteristics that separate apes from these early hominins but the ones outlined above are enough to demonstrate that the initial premise of Dr. Mitchell is, simply, incorrect.

But there is something deeper at work here.  Pick up a paper on australopithecines, any paper, written in the last sixty years and you will find discussions of how these forms differed from each other and, more importantly, how they differ from apes.  Are they human?  Manifestly not.  In some early species, there are characteristics that are, indeed, intermediate between apes and early humans. But even that gives rise to the concept of transitional traits and forms in the fossil record.  That is where the problem lies.  If australopithecines can be painted as apes from the outset, then the task of showing that the new Homo naledi specimen is not different from australopithecines, and therefore, apes, becomes easier.

Then she writes something startling:
The question then is what is Homo naledi? Even the evolutionary anthropologists are not in agreement on that point, though most seem to have jumped on the Homo bandwagon. Yet while the fossil record contains many legitimate examples of extinct varieties of humans, such as Homo erectus and Homo neanderthalensis, after assessing the published reports, we beg to differ with Berger’s assessment of Homo naledi. We do not believe Homo naledi deserves its Homo designation. [Emphasis Mine]
When did they these fossil forms go extinct? There is no evidence of extinction in the accounts in the Bible. Other writers do not seem to think they went extinct during the flood.  David Menton is firm in his conviction that Homo erectus represents a post-Babel population:
Neanderthals buried their dead and may have worn jewelry. Homo erectus seems to have divvied up jobs to prepare food and sailed the high seas. Even with little to go on, we can be fairly certain the Denisovans wore jewelry, and the much-maligned “hobbits” left tools useful for dicing up lunch. All uniquely human traits—traits that show creatures made in the image of God.
Which one of the biblical patriarchs had an angular torus, large brow ridges, thick cranial bones and a cranial capacity of 900 cubic centimeters? All of these traits would have stood out in any population. The variation present that Menton squeezes into one happy family vastly exceeds that present in any other naturally-occurring genus on the planet, let alone species. 

She finishes her post with the same, time and time again rebutted argument that the reason that Homo naledi is not a human is similar to australopithecines and, therefore, is nothing more than an ape.  This is the vacuum chamber/wind tunnel that AiG operates within.  Despite clear, decisive anatomical evidence to the contrary, the writers keep telling themselves that australopithecines were nothing more than apes.  The argument still has no credibility.

1 comment:

  1. Just seen this post. You should have recently received this link earlier via email, reporting an interesting discussion I'm having with YEC David Bump - who has also suggested 'ape' at the second link: (I only skimmed this)

    AiG have their reasons for trying to persuade their supporters that Homo naledi must 'really' be an extinct 'ape. Basically this human had too many ape-like features - so they could not pretend it was really 'us' (YECs claim, based upon the Bible alone, that there has only even been one species of human - even if some of them were, ahem, 'archaic' and apparently went mysteriously extinct).