The simplest way to put it is that osteology is the study of skeletal anatomy, whether it be specific to the human skeletal anatomy or any other animal’s skeletal system. It deals in anything having to do with bones: structure, function, growth, pathology, decay, trauma and healing, individual bones, the evolution of bones, et cetera. That means that, while it really is a subset of the overall study of anatomy, osteology really can be considered a subfield of many disciplines, depending on why you’re studying it.
Osteology can be considered a subfield of anthropology, if one is studying the human (as well as nonhuman primate and/or hominid) skeleton for the purposes of archaeology or palaeoanthropology. I plan to go into bioarchaeology and am very interested in how the health and nutrition of an individual is detailed in their bones, so I should be quite comfortable with the human musculoskeletal system. I need to know how to determine other factors like age, growth as they aged, and any history of disease or trauma to the bones. I will also need to know how to re-articulate (or, put back together) a skeleton, because bones can get quite jumbled up over time, especially when they’re just hanging out underground.
In forensic science and bioarchaeology, it is important to look at human remains with both the naked eye and under the microscope in order to determine things like biological sex (not gender, though that can be inferred through a variety of ways), age, cause of death, and how old the bones themselves are.
Human skeletons are studied for the medical practice of orthopedics, which is the basically osteology in action with live patients. An orthopedic surgeon deals with a wide range of things, from knee arthroplasty (replacement) to congenital bone disorders like osteogenesis imperfecta (brittle bone disease).
Osteology is studied for a variety of things, like archaeology, forensic science, and medicine, but it’s also studied for things like biophysics, fine arts (for drawing human and animal forms), osteopathy, kinesiology, massage therapy, evolutionary biology, developmental biology, and a bunch of other stuff. It’s a study with a multitude of applications.
Michael Peter Edson tweets the best parts of “Smithsonian in 3D” [x]
Hadar hominin fossils assembled for comparative study at Cleveland Museum of Natural History, circa 1979. The A.L. 333 sample occupies the largest area at the center between ‘‘Lucy’’ and Hamann-Todd collection chimpanzee skulls; casts of the Laetoli hominins are at lower left.
(Text and top image source: Kimbel, W.H. and Delezene, L.K. 2009.”‘‘Lucy’’ Redux: A Review of Research on Australopithecus afarensis” in Yearbook of Physical Anthropology 52:2-48; bottom image: Dartmouth College)
Questions regarding the Homo heidelbergensis Sima de los Huesos (Atapuerca) specimens:
“The world’s largest known sample of fossil humans has been classified as the species Homo heidelbergensis but in fact are early Neanderthals, according to a study by Prof Chris Stringer of the Natural History Museum.
This puts the species Homo heidelbergensis back at the heart of human evolution as the last common ancestor that we, Homo sapiens, shared with Neanderthals, Homo neanderthalensis, says Stringer, the Museum’s Research Leader in Human Origins. The Status of Homo heidelbergensis study, which was published in the journal Evolutionary Anthropology this week, reviews the fossil and DNA evidence for the existence of heidelbergensis and its place in the human family tree.
Central to the discussion is the important site of La Sima de los Huesos (meaning ‘Pit of the bones’), in Atapuerca, northern Spain. It has yielded more than 6,000 fossils from about 28 individuals. They had been identified as H. heidelbergensis by the team who originally discovered the fossils, and have been estimated to be about 600,000 years old. For some palaeontologists, such as Stringer, this has confused ideas about where heidelbergensis sits in the human family tree” (read more).
For more information see:
- Homo heidelbergensis (Becoming Human, Institute of Human Origins).
- Homo heidelbergensis (Smithsonian, National Museum of Natural History).
The Mystery of the Pit of Bones, Atapuerca, Spain (Smithsonian, National Museum of Natural History).
- Mounier A, Marchal F, Condemi S. 2009. “Is Homo heidelbergensis a distinct species? New insight on the Mauer mandible,” Journal of Human Evolution 56(3):219-46.
- Rightmire, G.P. 1998. “Human Evolution in the Middle Pleistocene: The Role of Homo heidelbergensis,” Evolutionary Anthropology 6:218-227. (open access).
- Stringer, C. 2012. “The status of Homo heidelbergensis (Schoetensack 1908),” Evolutionary Anthropology 21(3):101-107.
(Text source: Natural History Museum, London)
ADDIS ABABA, Ethiopia (CBS) — A famous fossil that holds key to scientific evidence of human evolution returned home in Ethiopia Wednesday after a five-year tour activity abroad.
Discovered by an archaeological team led by U.S. scientist Donald C. Johanson in 1974,…
I was sick this weekend. The kind of sick where your nose runs so much that you begin to question how the human body can produce so much mucus. My throat hurt. I was coughing. But the worst part was the headache: My head felt like it was being continuously squeezed by a vise, or maybe some sort of medieval torture device. The pain was so bad even my teeth hurt. As I was lying in bed next to my half-empty box of Kleenex, I thought, “This wouldn’t be happening if we had descended from Asian, not African, apes.” (Yes, I was really thinking that.)
But before I explain what apes have to do with my cold, let’s cover some basic biology. When the cold virus (or bacteria or an allergen like ragweed) enters the body, the nose produces mucus to prevent an infection from spreading to the lungs. This results in a runny nose. All of the extra snot can also plug up passages that connect the nose to air-filled pockets in the bones of the skull, called sinuses. Sinuses produce their own mucus and are thought to help humidify air, as well as stabilize and strengthen the skull. But when the passageways between the head’s sinuses and nasal cavity get blocked, the sinuses’ mucus can’t drain and the air pockets fill, causing pressure to build . Sometimes the lining of the sinuses swell, which results in the further production of mucus and build-up of pressure. That pressure hurts.
Humans have four types of sinuses that play a role in sinus headaches: the frontal sinus in the forehead, the maxillary sinus in the cheeks, the ethmoid sinus between the eyes and the sphenoid sinus behind the nose. The African apes, gorillas and chimpanzees, have all four of these sinuses. The Asian apes, orangutans and gibbons (the so-called lesser apes because of their smaller size), have just two, lacking the ethmoid and frontal sinuses.
The ethmoid and frontal sinuses can be traced back at least 33 million years ago to a primate called Aegyptopithecus that lived in Africa before the ape and Old World monkey lineages originated. (Old World monkeys are those that live in Africa and Asia.) These sinuses have also been found in some of the earliest known apes, such as the roughly 20-million-year-old Morotopithecus and 18-million-year-old Afropithecus, both from Africa. Chimpanzees, gorillas and humans inherited these sinuses from the most ancient apes. Gibbons and orangutans, however, each lost these sinuses independently after they diverged from the rest of the apes; gibbons evolved about 18 million years ago while orangutans split from the other great apes roughly 15 million years ago.
It’s not clear why the Asian apes lost the ethmoid and frontal sinuses. In the case of the orangutan, the animal has a much more narrow space between its eyes and a more severely sloped, concave forehead than the African great apes. So there just may not be room for these air pockets to form.
But gibbons and orangutans do still have the maxillary and sphenoid sinuses, which are enough to cause annoying pain and headaches. So I should really apologize to my African ape ancestors. Clearly, I had some misdirected anger. I should have been mad at the virus that invaded my body.
Elaine Morgan is a great communicator and she’s done a remarkable job of delivering the AAH to a wide audience, but I have concerns that the packaging is more impressive than the contents, from a scientific perspective.
In the video Elaine does a cracking job of setting up the AAH in opposition to the more established Savanna Hypothesis (SavH), which suggests that humans diverged from other primates as a result of exploiting more arid environments. She then suggests that the SavH has been discounted on the basis of palaeoenvironmental data, leaving a paradigm gap that should (she suggests) be filled by the AAH.
But of course, a paradigm gap should only be filled by a robust theory and when it comes to plotting evolutionary trajectories there is not solid theoretical foundation on how to do it, beyond relying on the physical evidence provided by the fossil record.
In this case that would require fossils of human ancestors to be found in primarily aquatic deposits, something which we do not see, which is surprising, since aquatic environments are usually far better for fossil preservation than terrestrial environments. In fact, taphonomy suggests that early hominid fossils would be more common if the individuals were living and dying in water with any frequency. [read more]
Anthropology is a subject that has attracted its fair share of anti-intellectual theorists before. These anti-intellectuals are scientists from other areas of scientific inquiry that attempt to propose their own theories about who we are and where we came from despite having no formal anthropological training. Consequently, these people are usually a massive headache because they have no idea what they are talking about. Dr. Jonathan Marks did a great job elucidating why anthropology may attract this type of anti-intellectualism in a recent podcast I did with him.
Either way, I woke up yesterday to an infuriating article published in the Guardian: Big brains, no fur, sinuses… are these clues to our ancestors’ lives as ‘aquatic apes’? The article gave an international platform to several scientists that support the Aquatic Ape Hypothesis/Theory (AAH/T). This hypothesis proposes that there was a, as yet unidentified, aquatic phase of human evolution causing our ancestors to develop bipedalism, big brains, subcutaneous fat, sinuses, and lack of fur. Supporters of the AAH believe that these features are all indicative of an ancestral past spent living primarily in deep creeks, river banks, and the sea.
But there is one major problem: there is no evidence to support it. No evidence is usually a problem in science. No ancestral hominids have ever been found that lived in an aquatic environment. [read more]
Evolution and the Modern Human Diet
I want to preface this by saying that I’ve spent a considerable amount of time researching this topic, but not in Homo sapiens. I’d find this question a great lot easier to answer if it were about Neandertals or Australopithecines.
To begin, I believe the human diet must be assessed specifically, for the purpose of understanding modern nutrition, through the examination of the physiology and bones of Homo sapiens. It is not fruitful to go beyond this taxon to H. erectus or Australopithecines, for example, because there is a high degree of dietary variability in and between the levels of both genus and taxon. We must confine the analysis to Palaeolithic modern humans. It does not matter if H. erectus primarily ate meat or if a taxon of Australopithecus primarily ate C4 tropical grasses and sedges if H. sapiens has a different diet. What is healthy for one taxon is not necessarily healthy for another, even taxa within the same genus, even one we evolved from. Furthermore, what a taxon adapted to primarily eat does not mean that taxon is physiologically bound to a narrow diet based exclusively on that food. What a taxon adapted to eat is not always what it chooses to eat.
Dental Microwear and Macrowear
There are multiple ways of studying prehistoric diet. We can look at dental microwear, which is useful but that will only tell us what a species ate a few hours to a few days before its last meal. We can look at macrowear on teeth too. Occlusal Fingerprint Analysis is used in macrowear studies. This is based on a complex comparison of two different phases of wear facet areas and dip direction measurements in teeth. Different foods affect the dental relief of teeth through attrition and abrasion to form variable, well defined pitched and flat facets because there is a close relationship between jaw movements, occlusal wear and the physical properties of food. This macrowear compiles during a lifetime to form characteristic patterns that form on different areas of the tooth. Different chewing processes are needed as different foods have different physical properties such as hardness, toughness and brittleness. We can also look at the morphology of teeth to tell us if a species evolved to be able to rip and tear or to crush and chew and we can look at the jaw to see if the muscle attachments were strong and how that relates to chewing.
Chemistry can also help us. Trace element analysis may be useful in determining diet. However we have to be careful about how we determine diet based on chemical analyses. For example, diets with different Ba/Ca and Sr/Ca ratios may be the result of diets with the same ratio of meat but different amounts of Ba, Ca and Sr. Because some plants are low in these elements, they potentially leave no evidence of consumption.
Stable Isotope Analysis
We can also use stable isotope analysis, which can be done on bone collagen and dental enamel bioapatite. Stable isotope analysis measures the ratios of carbon (13C/12C, the δ13C value) and nitrogen (15N/14N, the δ15N value). Carbon and nitrogen isotope ratios in collagen are a reflection of the isotope ratios of dietary protein that has been eaten over approximately the last ten years of the subject’s life (Richards and Schmitz 2008; Richards et al 2001). Dietary nitrogen only derives from dietary protein, thus mammal collagen δ15N values are indicative of the staple source of protein in the long-term diet. These values must be compared to isotope values of associated animal remains.
Tooth enamel hydroxyapatite δ13C values can reflect blood bicarbonate δ13C values, which reflect the total diet, including lipids, carbohydrates and protein (Richards 2002). Off the top of my head, I cannot name any studies on Pleistocene H. sapiens using this method. It may be useful for those interested to do some research on this.
Stable isotope analysis suggests that Pleistocene modern humans (H. sapiens) from Europe were primarily carnivorous, relying on herbivore meat for survival. They had extremely high trophic levels. By the Solutrean (a late period in the Upper Palaeolithic), dietary diversity appears to have broadened to include the consumption of fish and waterfowl on a regular basis. Stable isotope analysis was used by Richards and Trinkaus (2009) to assess the trophic levels of Palaeolithic modern humans and Neandertals. Modern humans were found to have higher δ15N values than Neandertals who were highly carnivorous. The higher trophic level in modern humans was associated with the consumption of piscivorous fish.
I will note that a diet based solely on lean meat may have severe drawbacks. It can lead to calciuria, rabbit starvation, and due to the high phosphorous content of meat, osteoporosis. Some studies suggest that the negative effects of a lean meat diet must be mitigated by the consumption of fats or carbohydrates (Bilsborough and Mann 2006; Mann 2000). Most wild game has very little intramuscular fat. Modern Inuit are almost entirely carnivorous, but their diet is based on marine mammals, which have a great deal of fat. This may be how their bodies handle large quantities of meat and few vegetables or fruits.
We have little evidence in the archaeological record for the consumption of grains before (and even during) the Upper Palaeolithic. The Gravettian site of Bilancino (Italy) has apparently yielded evidence of plant material on groundstone artefacts (Aregnguren et al. 2007). Grains are not easily recovered and furthermore, they are not systematically screened for during archaeological excavations, and are best found through the water flotation screening method. Most sites do not use water flotation because it is time consuming. Even the best of sites do not systematically screen for phytoliths. In truth, there are probably more recent studies that discuss plant consumption and H. sapiens in the Palaeolithic, but at the moment this will have to do.
Dental Morphology and Other Studies
As noted, the evolution of nutrition can be assessed by palaeoanthropologists who can measure aspects of and changes in tooth and jaw morphology and who can also identify diet related pathologies such as dental caries. However, although tooth morphology may be able to tell us what a hominid was capable of eating, it does not necessarily tell us what it chose to eat. Propithecus teeth (and guts) are adapted for the consumption of leaves and fibrous vegetation, but it mainly eats fruits when it has the opportunity to do so (Yamashita 1998; Norscia et al. 2006). Obviously, our own bodies did not evolve to eat a high sugar and fat diet, but we really like to eat these tasty things. Evolution doesn’t work with intent in mind.
Unfortunately, I am unaware of any stable isotope analysis on Africa Late Stone Age H. sapiens and so I cannot say what vegetal material H. sapiens ate before their arrival in Eurasia. There are also no stable isotope analysis studies of Middle Eastern H. sapiens because bone undergoes a process of diagenisis in hot, arid environments making extraction of useful collagen difficult to impossible. (These studies may exist on enamel but I can’t do the research right now. Busy, busy, busy). What I am trying to say is that because we do not know the level of plant consumption by H. sapiens during the Pleistocene, it is difficult to suggest that we should adopt a Palaeolithic diet. We don’t know exactly what that diet consisted of across a wide geographic range. Someone who is better acquainted with Mesolithic and Neolithic dentition may be able to add more to this. I do believe there are higher rates of caries due to increased grain consumption.
We need to see what modern medicine/science tells us about the modern (as in today at this point in 2013) human body. Just because we can eat something doesn’t mean we should eat it. What I mean is, just because we can physically digest it doesn’t mean we should base the majority of our diet on high fructose corn syrup. Questions that need answering are : what foods are most healthful and how can we cultivate plants and raise livestock in an environmentally friendly and humane way that can sustain large populations? I do not know the answer to these questions. A medical doctor that specialises in human nutrition may be the best person to ask about what we should be eating and why. However, I do not necessarily think adopting a strict palaeodiet is the answer to our ailments. Yet, I also do not think highly processed foods, high fructose corn syrup, and industrialised and inhumane farming are going to be part of the answer. The idea, I believe, whether you are a vegetarian, as I am, a vegan or an omnivore, is to consume the requisite number of calories, vitamines, minerals and nutrients for a fully functioning body. We need to keep active and not be sedentary.
Lastly, don’t use this post to fat shame anyone. The ingredients for a healthful diet are not always economically feasible, physically available in shops or even wanted. Adults can chose what to put into their bodies. However, that choice may be a difficult one to make and is affected by numerous extenuating circumstances.
- Arenguren, B. et al. 2007. “Grinding flour in Palaeolithic Europe (25000 years bp),” Antiquity 81(314): 845-855.
- Bilsborough, S. and Mann, N. 2006. “A review of issues of dietary protein intake in humans,” International Journal of Sports Nutrition and Exercise Metabolism 16(2): 129-152.
- Mann, N. 2000. “Dietary lean red meat and human evolution,” European Journal of Nutrition 39: 71-79.
- Norscia, I., Carrai, V., and Borgognini-Tarli, S. 2006. “Influence of dry season and food quality and quantity on behavior and feeding strategy of Propithecus verreauxi in Kirindy, Madagascar,” International Journal of Primatology 27: 1001-1022
- Richards, M.P. 2002. “A brief review of the archaeological evidence for Palaeolithic and Neolithic subsistence,” European Journal of Clinical Nutrition 56(12):1262.
- Richards, M.P. and Trinkaus, E. 2009. “Isotopic evidence for the diets of European Neanderthals and early modern humans,” PNAS 106(38): 16034-16039.
- Sponheimer, M. and Lee Thorpe, J.2007. “Hominin Paleodiets: the Contribution of Stable Isotopes,” Winfried Henke and Ian Tattersall (eds.), Handbook of Paleoanthropology. Springer: 555-586.
- Yamashita, N. 1998. “Functional dental correlates of food properties in five Malagasy lemur species,” American Journal of Physical Anthropology 106: 169-188.
Neolithic Iceman Ötzi Had Bad Teeth: Periodontitis, Tooth Decay, Accident-Related Dental Damage in Ice Mummy
“For the first time, researchers from the Centre for Evolutionary Medicine at the University of Zurich together with colleagues abroad have been able to provide evidence of periodontitis, tooth decay and accident-related dental damage in the ice mummy ‘Ötzi’. The latest scientific findings provide interesting information on the dietary patterns of the Neolithic Iceman and on the evolution of medically significant oral pathologies.
The Neolithic mummy Ötzi (approximately 3300 BC) displays an astoundingly large number of oral diseases and dentition problems that are still widespread today. As Prof. Frank Rühli, head of the study, explains, Ötzi suffered from heavy dental abrasions, had several carious lesions — some severe — and had mechanical trauma to one of his front teeth which was probably due to an accident.
Although research has been underway on this important mummy for over 20 years now, the teeth had scarcely been examined. Dentist Roger Seiler from the Centre for Evolutionary Medicine at the University of Zurich has now examined Ötzi’s teeth based on the latest computer tomography data and found that: “The loss of the periodontium has always been a very common disease, as the discovery of Stone Age skulls and the examination of Egyptian mummies has shown. Ötzi allows us an especially good insight into such an early stage of this disease,” explains Seiler. He specializes in examining dental pathologies in earlier eras” (read more).
(Source: Science Daily)
“Human ancestors were fashioning sophisticated hunting weapons half a million years ago. An analysis of stone points from a site in South Africa called Kathu Pan 1 indicates that they were attached to shafts of wood and used as spears. The finding pushes the earliest appearance of hafted multicomponent tools back by some 200,000 years.
Previous discoveries had hinted at the potential antiquity of this technology. Based on evidence that both early modern humans and our closest relatives, the Neandertals, made stone-tipped spears, some researchers hypothesized that their common ancestor—a species called Homo heidelbergensis–shared this know-how. At half a million years old, the newfound stone points are old enough to be the handiwork of this common ancestor.
No wooden shafts were preserved at Kathu Pan 1, but marks on the bases of the stone points and fractures on their tips were consistent with hafting and impact, respectively. Furthermore the edge damage on the ancient points matched up with damage obtained experimentally when new points made from the same raw material as the old ones were hafted onto wooden dowels and thrusted into antelope carcasses. Jayne Wilkins of the University of Toronto and her colleagues describe the work in the November 16 Science.
These new findings follow on the heels of last week’s revelation that bow-and-arrow technology is older than previously thought and add to a growing body of evidence that, on the whole, our long-ago predecessors were more innovative than they are often given credit for. Stay tuned—more on this theme to come”.
***OK, kids. Who remembers this article from December? I clearly remember discussing it with alphacaeli because when it came down to phylogeny we were both like…say what? I’m not arguing against hafting at 500ky cos that’s not my area of expertise and hey, it sounds cool to me. However, I’m confused about other stuff. I’ll just repeat verbatim my previous response:
- “Who wants to talk about her opinion about H. heidelbergensis as the LCA of Neanderthals and H. sapiens? Who wants to talk about his opinion about the presence of H. heidelbergensis in South Africa or even the northern Africa? Who has the patience right now to deal with taxonomy and phylogeny? Who wants to touch upon the last part of the [December] article, the part about the earliest parietal art having been made by Neanderthals and not AMH? I’m cooking up several posts that are sucking the life out of me [those posts are still half baked as of right now], so the answer to those questions is: not me. At least not right now. Did I just miss the point of the article getting wrapped up in details again? Where is the forest? I see only trees. Many, many trees and I have something to say about all of them.” My answer stands as is.
- Wilkins, Jayne. 2012. A video about her dissertation. University of Toronto.
(Source: Scientific American)
Leaving well alone the dubious phylogenetic status of H. heidelbergensis, the thing that really annoys me about articles like this is that they’re often missing the anatomical detail or at least fail to discuss it adequately. This is understandable. If you’re speciality is projectile weaponry and lithics, you don’t want to be remonstrated for being a Renaissance Man by stepping too far outside your bailiwick especially if you get it a bit wrong. The artifact evidence can stand on its own but phylogenetic conclusions based only on congruent temporal data are inadequate.
So what about the morphology of H. heidelbergensis? One metric that to me is particularly interesting is the glenoid index. This is a measure of relative width to height of the glenoid fossa of the scapula. Wide glenoid fossae (as represented by high glenoid indices) are well suited to habitual throwing because throwing generates significant dorsoventral loading at the shoulder in addition to abduction and marker external rotation of the humerus. The sum total of these forces is posterior translation of the humeral head. In this biomechanical context, a shoulder characterised by a low glenoid index (narrow gelnoid fossa) would be poorly suited to an activity that routinely moves the humeral head almost past the glenoid margins. This is the morphological pattern we see in the shoulders of both H. neanderthalensis and H. heidelbergensis (but interestingly not modern humans or even early modern humans from Mousterian contexts). What we would expect to see if they were habitual throwers in this case is a distinct pattern of joint degeneration and degenerative joint diseases like osteoporosis at the shoulder. The fact that we don’t generally see this is pretty suggestive, I think.
This isn’t to say they were incapable of throwing. They were. H. heidelbergensis had all the requisite shoulder architecture to be proficient throwers but I would like to advocate caution when making phylogenetic conclusions based on experimental and artifact evidence alone. There’s clearly more happening in the fossil record than we’re accounting for.
(If anyone would like references, send me a message and I’ll put together a list. I should also mention for my abundance of new followers [?!] that I specialise in hominin shoulder morphology and evolutionary biomechanics so these tend to be the things I respond to most often. Also taxonomy.)