BioLogos, Ken Ham and David Menton—A Response, Part III

This is the third part of my response to David Menton's post on human origins, cited by Ken Ham in his swipe at BioLogos.  Part One his here, Part two is here.We have been proceeding, point by point.

Point 6.  Menton writes:

Evolutionists are particularly interested in the angle at which the femur and the tibia meet at the knee (called the carrying angle). Humans are able to keep their weight over their feet while walking because their femurs converge toward the knees, forming a carrying angle of approximately nine degrees with the tibia (in other words, we’re sort of knock-kneed). In contrast, chimps and gorillas have widely separated, straight legs with a carrying angle of essentially zero degrees. These animals manage to keep their weight over their feet when walking by swinging their body from side to side in the familiar “ape walk.”

Evolutionists assume that fossil apes with a high carrying angle (humanlike) were bipedal and thus evolved into man. Certain australopithecines (apelike creatures) are considered to have walked like us and thus to be our ancestors largely because they had a high carrying angle. But high carrying angles are not confined to humans—they are also found on some modern apes that walk gracefully on tree limbs and only clumsily on the ground. 

Living apes with a high carrying angle (values comparable to man) include such apes as the orangutan and spider monkey—both adept tree climbers and capable of only an apelike bipedal gait on the ground. The point is that there are living tree-dwelling apes and monkeys with some of the same anatomical features that evolutionists consider to be definitive evidence for bipedality, yet none of these animals walks like man and no one suggests they are our ancestors or descendants. 

Let's leave aside the fact that the spider monkey is not an ape, although it speaks to Menton's understanding of primate taxonomy.  Menton follows the above quoted passage with some of the differences between the human feet and hips and, largely, gets them right.  But that makes his comments about the carrying angle all the more peculiar.  In hominin biomechanics, the legs do not operate independently of the hip, or of the feet.  He comments that there are apes that seem to have similar carrying angles and yet can't walk bipedally to save their lives.  He even writes that, given the ape pelvis, there is no way to walk like a human.  He is right about their hips, they are long and narrow.  He is right about their feet, they have opposable halluxes and the toes are not straight and narrow.  These features, in combination would keep anyone from walking upright like a human, no matter what their carrying angle was.  Walking gracefully on tree limbs is not the same thing as walking gracefully on the ground.  He isolates the carrying angle and seems to think that, because it might be similar in apes and humans, our analyses of the gait differences between the two are suspect.  That is absurd. 

And this brings up another problem.  He states that australopithecines were considered bipeds because of their carrying angle.  What he doesn't mention is that we have many fossil finds that indicate that not only did they have high carrying angles, they had all of the other adaptations for bipedalism.  They had human-like hips, and feet that are mostly human-like and, unmentioned by Menton, STS-14, an almost complete australopithecine vertebral column, shows that they had the double-s curve of the spine that we have and that are critical to bipedal locomotion.

Further, in his discussion of the skull, he ignores the placement of the foramen magnum, which is critical to understanding primate morphology.  The foramen magnum is the hole in the skull through which the spinal cord descends into the body.  In non-human primates (all non-human primates!) the hole is at the back of the skull, to facilitate quadrupedal locomotion.  In all hominins, fossil or otherwise, the hole is at the bottom of the skull, reflecting a bipedal gait.  This is yet another thing that raised a red flag with Raymond Dart on the Taung skull—the hole was at the bottom of the skull, as in humans, not the back, as in baboons—and he noted it accordingly.  This is a critical difference between apes and humans and Menton fails to mention it. 

Point 7: The second major section of Menton's article is “Only Three Ways to Make an Ape-Man.” He writes:

Knowing from Scripture that God didn’t create any apemen, there are only three ways for the evolutionist to create one:

1. Combine ape fossil bones with human fossil bones and declare the two to be one individual—a real “apeman.”
2. Emphasize certain humanlike qualities of fossilized ape bones, and with imagination upgrade apes to be more humanlike.
3. Emphasize certain apelike qualities of fossilized human bones, and with imagination downgrade humans to be more apelike.

These three approaches account for all of the attempts by evolutionists to fill the unbridgeable gap between apes and men with fossil apemen.

This is the hallmark of modern young earth creationism: to jettison all of modern science in favor of a particular and peculiar hermeneutic involving biology and its evolutionary history.  He reasons that since God would not have ever created a transitional form like an “ape-man,” humans must have fabricated them. How exactly does he know that God didn't create “ape-men?”  It is difficult to be charitable toward Menton regarding this section because he is, at once, so pompous, so insulting and engages in so much obfuscation that one is left wondering if he displays any intellectual integrity whatever. For his first point, he dredges up the Piltdown hoax, writing: 

The whole thing turned out to be an elaborate hoax. The skull was indeed human (about 500 years old), while the jaw was that of a modern female orangutan whose teeth had been obviously filed to crudely resemble the human wear pattern. Indeed, the long ape canine tooth was filed down so far that it exposed the pulp chamber, which was then filled in to hide the mischief. It would seem that any competent scientist examining this tooth would have concluded that it was either a hoax or the world’s first root canal! The success of this hoax for over 50 years, in spite of the careful scrutiny of the best authorities in the world, led the human evolutionist Sir Solly Zuckerman to declare: “It is doubtful if there is any science at all in the search for man’s fossil ancestry.”1

The Piltdown hoax celebrated its one hundredth anniversary two years ago, in 2012.  Far and away (in my opinion) is Frank Spencer's account of the hoax, called Piltdown: A Scientific Forgery. Here are details that Menton conveniently leaves out of the account.  When the Piltdown remains were found, there were no dating methods and very few fossil human remains of any kind.  Nonetheless, it sparked controversy when it was discovered by Charles Dawson and, as initially reconstructed by Grafton Elliot Smith, looked remarkably modern in appearance.  It was not until the jaw was found, conveniently missing the ascending ramus, and incorporated into the find that it took on a more ape-like morphology.  Once Piltdown was described, however, it was locked away in a vault and access was very limited. That is where the problems began.  At this point, a critical thing happened.  Dawson died, in 1915.  Common consensus is that Dawson was the perpetrator and took  this information with him to the grave.

As I noted here, as time went by, more and more human ancestor remains were discovered in Africa, Asia and continental Europe.  As this happened, two things became clear: Nothing even remotely resembling Piltdown was found elsewhere and nothing remotely resembling Piltdown was found in England.  As human lineage trees were constructed throughout the 1930s and 1940s, Piltdown's peculiarity grew and researchers struggled to place it within any context.  Franz Weidenreich, in his excellent monograph on the Homo erectus remains from Zhoukoudian, questioned the dating of the find and had mused, even since the 1920s,  that it might be a combination of human and ape parts.  Ales Hrdlicka, the head of the American Museum of Natural History, actually uttered the dreaded word “fake.”

Owing to all of these concerns, in 1949, Kenneth Oakley, then in possession of the ability to use a brand-new dating method, fluorine analysis, was successful in getting access to the skull on the condition that he not damage it in any way.   This analysis suggested that the bones were less than 50,000 years old.  On the strength of this, and since nobody could believe that a fossil ape had roamed the English countryside at this time, further, more in-depth analyses were undertaken.  In addition to using fluorine, he and Wilfred Le Gros Clark were able, for the first time, to use a powerful electron microscope, which had been invented in 1926 but was not in widespread use until around 1939.  It was only then that they could discern what Menton seems to think anyone could have seen: that the teeth had been filed down and the jaw stained and fractured.

Was this embarrassing?  Yup, sure was.  But Menton also fails to mention that the hoax was uncovered by scientists using the scientific method and that the primary reason it was uncovered in the first place is that we knew, even then, enough about human evolution, based on the fossil record, to tell that there was something wrong with Piltdown.  He also fails to mention that the quote by Solly Zuckerman is 44 years old (!) and that Zuckerman even admits that his view was soon in the minority.  Zuckerman, additionally, is remarking on why Piltdown escaped notice, and it is quite clear from his other writings that he accepted human evolution without question.  Menton, once again, fails to include these facts in his post. 

Part IV here.

BioLogos, Ken Ham and David Menton—A Response, Part II

Point 3:

Because of the rarity of fossil hominids, even many of those who specialize in the evolution of man have never actually seen an original hominid fossil, and far fewer have ever had the opportunity to handle or study one. Most scientific papers on human evolution are based on casts of original specimens (or even on published photos, measurements, and descriptions of them).

So?  Menton seems to think that there is a problem with performing analyses based on measurements that other people have taken.  That is nonsense.  A few years back, I was at a conference where a paper was given in which the author was attempting to show the differences between subtle details on various fossil crania.   The striking criticism of the study was that it was based on casts, not on original fossils and, because of this, the analysis was questionable.  When I did my dissertation on the origins of modern human crania, I had measurements of almost all of the original crania that had been taken either by my advisor or by other researchers in the field, who had then published them.  Almost every paper done on human evolution is based on measurements from the original fossils.  The only examples where this is not happening is where the original skulls are missing, as with the Homo erectus remains from Zhoukoudian, which vanished during the run-up to the second world war, or the European Mladec remains, which were destroyed when the allies bombed the castle in which they were housed.  Even in those cases, copious measurements were taken of the originals and, in the case of the Zhoukoudian remains, comprehensive photos were taken. There is absolutely nothing wrong with doing analyses based on measurements from the original fossils, especially where the photos are clear and detailed. Bill Howells took detailed measurements of the Near Eastern Qafzeh 6 cranium and then kindly sent me the measurements for it.

All of science is built on what came before and the observations of the those scientists are absolutely invaluable.

Point 4:

Since there is much more prestige in finding an ancestor of man than an ancestor of living apes (or worse yet, merely an extinct ape), there is immense pressure on paleoanthropologists to declare almost any ape fossil to be a “hominid.” As a result, the living apes have pretty much been left to find their own ancestors. 

More nonsense.   There are palaeoprimatologists that spend their entire lives researching the prehistory of non-human primates.  A check of Google Scholar revealed over forty-nine thousand papers dealing with non-human fossil primates.  One of the most productive and exciting aspects of fossil primate studies is the search for the last common ancestor (LCA).  This involves an in-depth study of Miocene apes.  Another area of important study is the origin of the large-bodied primates and the split between the Old World and New World monkeys.  When Menton states that the living apes have been left to find their own ancestors, he forgets the media circus that surrounded the find of the fossil primate Ida, which shed light on the origin of primates as a group. 

Point 5:

In contrast to man, apes tend to have incisor and canine teeth that are relatively larger than their molars. Ape teeth usually have thin enamel (the hardest surface layer of the tooth), while humans generally have thicker enamel. Finally, the jaws tend to be more U-shaped in apes and more parabolic in man.

The problem in declaring a fossil ape to be a human ancestor (i.e., a hominid) on the basis of certain humanlike features of the teeth is that some living apes have these same features and they are not considered to be ancestors of man. Some species of modern baboons, for example, have relatively small canines and incisors and relatively large molars. While most apes do have thin enamel, some apes, such as the orangutans, have relatively thick enamel. Clearly, teeth tell us more about an animal’s diet and feeding habits than its supposed evolution. Nonetheless, thick enamel is one of the most commonly cited criteria for declaring an ape fossil to be a hominid. 

Menton may be correct in his statements about enamel thickness.  Enamel thickness may be a better indicator of dietary adaptations than of morphology, but, where primates are concerned, that is only true of enamel thickness.  It is not true of tooth morphology.  Primatologists have no trouble telling baboons from humans.  They do not have the same features.  Fossil and modern baboons are quite different from humans, even human ancestors.

In 1924, when the well-trained anatomist Raymond Dart was given the deposits that had the Taung child in them, he knew immediately that the teeth did not belong to any fossil baboon.  It wasn't the thickness of the enamel that tipped him off.  The dimensions were similar to those of an infant human and the morphology of the canine and the premolars was like that of humans. Remember, at this time, there were very few other prehuman ancestors with which to compare it, and no australopithecines.

Teeth are, actually, one of the most conservative features on a skeleton and change very little over time.  For example, the Y-5 molar pattern that we have in our mouths is first found in Aegyptopithecus, from the Oligocene epoch, some 30 million years ago. Furthermore, one of the ways we can tell the new world primates from the Old World primates is the number of teeth they have.  New World monkeys have two incisors, one canine, three premolars and three molars in each quarter of the mouth.  All Old World monkeys and apes are lacking the extra premolar (bicuspid, if you are a dentist).  We have this same pattern. 

These differences are either glossed over or not mentioned by Menton, who simply declares, based on enamel thickness, that the teeth are similar and completely disregards information that doesn't fit his narrative. 

Part III here.  

Science Daily: "Anthropologists Confirm Link Between Cranial Anatomy and Two-Legged Walking"

This sort of fits under the category of "gee, who knew" but it is nice to finally have confirmation of something that has been tacitly understood for almost ninety years.  Science Daily writes:

The study, published in a forthcoming issue of the Journal of Human Evolution, confirms a controversial finding made by anatomist Raymond Dart, who discovered the first known two-legged walking (bipedal) human ancestor, Australopithecus africanus. Since Dart's discovery in 1925, physical anthropologists have continued to debate whether this feature of the cranial base can serve as a direct link to bipedal fossil species.

Okay, first, the controversial nature of this is being massively overstated. There is very little doubt, based on comparative anatomical studies, that the placement of the foramen magnum is directly indicative of the kind of locomotor pattern that a given animal employs. That is what clued Dart in to the whole idea that the Taung child represented a biped in the first place. Its foramen magnum was not in the place that you would have expected it to be if the individual had been either a quadrupedal baboon or extinct ape (of which there were none in South Africa). It was, however, located in the same place as in bipedal humans. Further studies demonstrated that if you placed the Taung skull on a quadrupedal animal, it didn't work. The animal would have its face pointed down all of the time, instead of out, like your average quadruped. Put simply, the Taung child was an early biped and there was no reason to think anything differently.

Once again, comparative anatomical studies to the rescue!

As part of the study, the researchers measured the position of the foramen magnum in 71 species from three mammalian groups: marsupials, rodents and primates. By comparing foramen magnum position broadly across mammals, the researchers were able to rule out other potential explanations for a forward-shifted foramen magnum, such as differences in brain size.

According to the findings, a foramen magnum positioned toward the base of the skull is found not only in humans, but in other habitually bipedal mammals as well. Kangaroos, kangaroo rats and jerboas all have a more forward-shifted foramen magnum compared with their quadrupedal (four-legged walking) close relatives.

Well, now we know for sure...sort of.   

New Explanation for Brain Evolution in Australopithecines

Science Daily is reporting on new examinations of the famous Taung brain endocast that provides insights into human evolution. They write:

"These findings are significant because they provide a highly plausible explanation as to why the hominin brain might grow larger and more complex," Falk said.

The first feature is a "persistent metopic suture," or unfused seam, in the frontal bone, which allows a baby's skull to be pliable during childbirth as it squeezes through the birth canal. In great apes -- gorillas, orangutans and chimpanzees -- the metopic suture closes shortly after birth. In humans, it does not fuse until around 2 years of age to accommodate rapid brain growth.

The second feature is the fossil's endocast, or imprint of the outside surface of the brain transferred to the inside of the skull. The endocast allows researchers to examine the brain's form and structure.

The argument is that the metopic suture stays open in hominins longer to allow the brain to grow more postnatally, something we have known for some time. It is the new imaging techniques that have allowed us to get a better handle on this. The endocast has been around for almost ninety years and has been subject to all kinds of studies, some of which have led to riotous disagreements between researchers. More pieces of the puzzle.

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