Wednesday, May 18, 2005

Chapter 4 – Osteometrics Today - Skeletons in the Closet


“Anybody what knows any moe ‘bout it dan dat has done gone”

-- Mattie Chandler in reference to an old slave graveyard in Gourdin South Carolina


Skeletons in the Closet

For the last three chapters this book has attempted to unwind the twisted mass of threads that has led us to our understanding of race. We have evaluated how items are pigeon holed, how science creates classifications and the guidance provided from the OMB regarding race declaration. At the end of the last chapter it seems that our unwinding has led us to what may be a simple answer providing tremendous clarity – Neandertal. We must be careful when we pull this thread as it may appear to unravel the ball, but I would argue it only makes for future tighter knots that are more complex than when we started. For that matter recent mitochondrial research in the topic area has twisted the mass beyond any simple discussion of the matter.

I will remind the reader that the first complete Neandertal finds occurred in the late 1850’s. It took almost 75 more years before the average scientist began accepting these bones as skeletal remains of an early form of human. Nearly 150 years later science is suggesting that Neandertal has no relation to present day human. So how can I suggest that Neandertal in any way relates to our discussion of origins? The simple answer is that the jury is still out on the validity of the mtDNA research conducted on the Neandertal bones. The pendulum has swung so many times associated with the support of Neandertal being of human ancestry, it is difficult to allow one set of research to convince the entire scientific community. Milford Wolpoff PhD. Of the University of Michigan remains perhaps the most ardent defender of Neandertal transition of modern day humans. Any reading of his material clearly cast some amount of skepticism on the Microbiological research that has only recently emerged. For the sake of the argument, let us at this time forget the fact that recent genetic research suggests a long separation of Neandertals from present day humans on the evolutionary tree. Let us look at the bone morphology that drives Wolpoff to heated and boisterous public debates with his peers.

How can I argue that we should forget recent DNA research on Neandertal? For three chapters I have discussed the importance of looking at race from a scientific perspective. How we review science is a difficult process in and of itself. The concepts of origins are quite complex. So it would seem that we would use the most recent and most advanced understanding available for our review. This is not always the correct method for science. The lessons of nature are difficult to extract. Often when nature reveals her information, it is usually a small path within a larger labyrinth that requires years of inspection before the exposure of the entire mosaic. I believe this is the case with Neandertal and recent DNA research. The details behind the DNA research will be reserved for the next chapter on Allele Difference, but for now let us place emphasis on the osteometrics.

Comparing any two modern humans is at a minimum no easy task. To many degrees Blumenbach was correct in that we can group broad measurements of anatomical components for the purpose of comparisons. Within the grouping there is a wide variation of bone density, bone shape, and overall compositions of the osteo-structures. I would further argue that phenotypic expression also allows us to examine the biochemical underpinnings of things such as personality and social behavior, but we will reserve that discussion for later in the text. Right now let us simply review what we know specifically about osteomorphology and how that may relate to our origins.

Cranial volume historically has been a main contributing factor associated with the definition of a modern human. Walker expends almost an entire chapter in his book, The Wisdom of the Bones, discussing the ramifications of cranial volume. In his work, Walker et al determine the humanness threshold to exist at a cranial volume exceeding 850 cc. He arrives at this discreet number through a complex discussion about birth canal, growth rate and biological mechanisms such as patraial and acoidtial growth of mammals. Assuming racial classification to be correct from a phenotypic understanding, we see that although races do demonstrate cranial volume differences on average, all races exceed the 850 cc. threshold. What’s more, is that we find both Homo sapien erectus and Homo sapien Neandertal also exceeded this threshold. But cranial volume alone is not the only determining characteristic. The shape and structures of the cranium provides significant insight into behavior. Consider for a moment the Broca’s spot located on the Erectus skull explicitly discussed in Walker's text. This small bump on the skull tends to suggest that Erectus had the ability for speech. However, as discussed in the last chapter the inner diameter of the vertebrae tell a much different picture. With no provision for intercostal muscle control, there is little hope that Erectus communicated like present-day humans. Not to mention the cranial volume of Erectus although in excess of 850 cc has been typically shown to be significantly less than modern day human averages. The Erectus cranial volume is 30 percent less than present day humans.

But, this is not true when considering Neandertal. The cranial volume of these skulls often exceeds 1700 cc. In many cases Neandertal skulls have been shown to have greater volume than present modern human skulls. So if cranial volume is directly correlated to intellect, could Neandertal communicate? From the period between 1856 and the 1980's it was widely accepted that Neandertal lacked the ability to communicate through vocalization. That was until a pivotal find of a tiny bone called the hyoid. In order to speak, modern day humans require this small bone located in the throat. This bone known as the hyoid is one of the smallest bones in the human body. Under the best fossilization conditions, the loss of the hyoid to time is not a difficult process. Discovering the hyoid after 30,000 years is a difficult task to say the least. As discussed before, nature provides just enough information to keep scientists employed and active. The lack of a hyoid bone made it easy to separate Neandertal from present day humans. But looking at the cranial volume and the fact that a hyoid bone was found in a Neandertal excavation, the comparison becomes more aligned than separate. Moreover, other finds indicate tool development, ritualistic burials, and the establishment of familial support structures for the elderly and sick. Evidence for present day humanness in Neandertal exists. The measurement of this humanness is the point of contention. Perhaps the cross over point of advanced abstraction and consciousness through speech occurred with Neandertal and not with Erectus after all.

It seems the mystery may be over. Present day humans evolved from Neandertal. Our origins began in Europe and Eastern Asia. If we reference back to Chapter 2 of this book we find the information we need. We know from the fossil record that Neandertal ranged from South West Europe to the Middle East. We also know that the OMB has provided classification of White to most of these areas. Is the answer that simple - we are all white? Are we all descendants of Neandertal? Furthermore, Wolpoff would lead you to believe that Neandertal facial features still exist in certain Australian and Oceanic populations. This idea suggests that Neandertal not only thrived in the region depicted in Chapter 2 but they migrated to other sections of the earth and now their direct descendants inhabit these areas as aborigines. If Wolpoff is correct, it is clear we have quite the conundrum in the socially accepted understanding of race - which I must remind the reader is a requirement by the OMB. I say with confidence that no one in my small southern town would at first or second blush consider an Australian Aborigine to be of the same origin as himself – be he black or white. Oddly enough, in the fairness to the scientific process, I must expose at this time that I believe Wolpoff is correct in his assessment. I must also state I believe there is a tremendous amount of osteometric data that indicates we are descendants of Neandertal. Furthermore I believe there is an explanation for the difference in conclusion presented from the DNA research.

I must be careful here in my explanation, less I provide too much confusion at this point. Descending from Erectus clearly places our origins within the continent of Africa based on our review of the information available. That African placement demands a black racial classification as required by the rules established by the OMB. Descending from Neandertal appears to drastically alter three chapters of discussion. But myself and many other anthropologists would argue that the descendants from Neandertal fail to change the ancestry tree. Confused? Lets explore this more by first considering the osteometric comparisons of Neandertal to present day humans, and then perhaps we can finally make sense of the mitochondrial DNA research.

Neandertal skulls are measured to be roughly the same size volumetrically as modern humans; but the shape is distinctly different. The Neandertal brow ridge is much thicker than moderns. The forehead of the Neandertal slopes back drastically, the nasal passage is enlarged, the eye sockets are more compressed in the vertical and perhaps the most obvious difference is the occipital bunt. The occipital bunt is the elongation of the cranium from the facial structure to the rear of the skull. Even with these differences it can sometimes be difficult to accurately group Neandertal, Erectus and Moderns. Each Neandertal skull has a degree of variation from another Neandertal skull. Likewise Neandertal skulls demonstrate even greater variations across geographic separations. To the formally and informally trained anthropologist the variation from modern to Neandertal skull is as evident as the separation of a cumulus nimbus cloud to a clear blue sky. To the formally trained anthropologist the variations on the edge of the separation are no clearer than the separations of ice and water at the molecular layer. One professional may claim the skull as modern in features while the next claims Neandertal yet a third may argue Erectus. Albeit these “edge point” variations are limited but none-the-less they do exists - specifically and most notably in osteoarchaic samples from the Middle East. But shouldn't this be suspected? Variations within the osteometric features perplex even the most educated in the study of human anatomy today. Specifically when the persons recent origin is of “mixed race”.

For the sake of the discussion at this point let us evaluate the information provided from the center presentations within the overall osteomorphology. The sloping forehead of the Neandertal phenotypically suggests a reduction in the frontal lobe of the brain. If mechanically the brain of the Neandertal worked the same as modern humans, this reduced frontal lobe may suggest a reduced ability in social control. It has long been known that the frontal lobe of the brain controls the social behavior of modern humans and thus frontal lobotomies were common on the clinically insane during the 1950s.

Can we assert this to be true based on cranial structure alone? What does this say about our origin? David Sloan Wilson's, Darwin's Cathedral, addresses the critical nature of the social behavior as an evolutionary adaptation and in his book. He addresses group size to religious processes. Communication skills are pivotal to the maintenance of the group. Was it more important for the group to be able to act with social control or to communicate through a better articulation of language? More importantly he asserts group size coincides with language. Subsequently we find baboons travel in 50 or less member packs. In either case we can suggest the reduction in the frontal lobe should have altered the behavior of Neandertal. But the question remains. Did his ability for speech overcome this potential lack of social control? This seems to be a fine nuance. Today our society is full of social misfits, but as our courts have demonstrated time and again we are still obliged to treat them as humans. Had Neandertal crossed over and thus defined our origin?

There is more to the skeletal review that provides insight into this question. The increased thickness of the brow ridge seems to provide little direct insight into the behavior of Neandertal, but it does perhaps explain the reason for the vertical reduction in eye sockets. More over does this thick brow ridge provide direct evidence to the reason for the extended occipital bunt? How could this information pertain directly to our understanding of race? To understand this concept actually lets us evaluate the argument against our transcendence from Neandertal. Consider a prime argument against Neandertal ancestry. Evaluation of animal bones located in Neandertal find areas suggest limited hunting if any at all by Neandertal. It is further suggested that Neandertal could not hunt because they lacked the ability to run and walk as efficiently as Erectus. Studies of femur dysplasia indicate Neandertal did not travel as much as the Erectus version of hominid. Athletes today demonstrate this feature commonly. Note the picture below.

(Image not included at this time)

When persistent stress is applied to modern human bones the muscle attachment points are modified by adulthood. Neandertal bones fail to show such modifications. In addition it was well noted that Neandertal hips showed an increased size in the pelvic opening. This was assumed to be needed to address the larger cranium at birth. To accommodate this increased pelvic opening it was also assumed the hips would fail to place the weight directly over the femur head and thus reduce running efficiency. But again I have to ask the reader not be hasty in our judgments of Neandertal. A recent Discovery Channel MIT study of the increased weight due to the increased size of the frontal brow ridge helps provide potentially a different viewpoint. In conjunction a more recent find of an entire Neandertal hip demonstrates that assumptions in science can often send us down the wrong road.

MIT engaged in research that evaluated the Physics behind the increase of weight and size of the brow ridge. What they found is intriguing. A modern human wearing a headgear ran in place on a treadmill. The headgear was developed to simulate the increased weight and torque on neck muscles while running due to the increased brow ridge. While slowly walking the increased brow ridge made had little to no effect on the visual functions for the tester. As the individual ran with the increased displacement of the simulated brow ridge the testers vision became blurred. The neck muscles of the tester could not respond in a timely fashion to the increased torque generated by the extended and heavier brow line. Then the mask was modified. An artificial occipital bunt was added to the mask. The result was the bunt created a counter balance and the tester's vision stabilized while running. The test demonstrated that the increased brow ridge and elongated occipital worked together to insure a stabilized visual pattern during the process of running. This test alone cannot prove the mobility of Neandertal but it does indicate that from a visual perspective Neandertal could have been a hunter or at least could have maintained rapid mobility.

With the research on the brow ridge and occipital bunt, the excavation of a hyoid, the excavation of a complete Neandertal hip, things begin to change for our assumptions. The total hip does provide evidence that the weight of the Neandertal was clearly centered over the femur. In order to accommodate this the hip is rotated a bit differently than Erectus. As we progress down this road, I hope to provide some insight into why these items are critical finds associated with our origins.


Why should we concern ourselves with the brow ridge of Neandertal? From a personal position I find the brow ridge to be one small but pivotal piece in the puzzle. My roommate in college had a rare gift. Not a gift that many would claim. But you had to understand my roommate. He had been a linebacker at Garner Webb College and then at Clemson University. Understanding football at this point is critical to my discussion. Linebackers, have to be aggressive enough to take on large fullbacks, strong enough to defend themselves from huge linemen and quick enough to respond to elusive quarterbacks. Tom was roughly 6 feet tall. He was tremendously wide and a very strong man. In a division II school like Gardner Webb, Tom excelled as a linebacker. However, at Clemson, a Division I school, he was at best average. This was not for Tom's lack of effort but I believe from his ancestral origins. Tom has white skin and green eyes and one of the largest brow ridges of any modern humans I have ever seen. Tom on occasion would impress others and me with his ability to write using a pencil he held with his forehead. Tom would place the pencil eraser at the top of his nose between his eyes and then furrow his brow. By “squenching” his face he could then hold a pencil with enough force that he could write with it. Or he could scoop cereal from a bowl using a spoon. It was a great bar trick but more importantly it began my view of osteomorphology. Tom has a reduced version of the larger brow ridges seen in Neandertal. Tom also has the skeletal structure of curved thick long bones. Why did Tom have trouble in Division I football? He was too slow. What does that have to do with brow ridges and occipital bunts? – Everything.

Tom and much to a degree myself fall into a group. My wife and I now refer to these groups as tribes. Our phenotypes are clearly related. Tom and I belong to a tribe that may partially descend from Neandertal. Our group is stocky. Our occipital bunts extend a little further than other “tribes”. We have large brow ridges, our foreheads slope back more than some, and we have a large mandible with limited specific clarity of a certain anatomical component known as the mental eminence otherwise known as a chin. These groups of men are often referred to have having a square jaw. Do not misinterpret my discussion here. I know of no one personally that would ever be evaluated as having cranial features that would place them in center of the variation of Neandertal. Matter of fact my discussion is just the opposite. I know and have met or seen a large number of moderns that maintain many suppressed variations of the Neandertal phenotype. Cranial expression of the Neandertal phenotype is only a start. Long bone and other hidden attributes persist in populations today.

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