Read Rebecca's anthropologically awesome adventures!See reading materials and other websites that makes Rebecca tick!Search through Rebecca's anthropologically awesome adventures!Meet Rebecca and follow her lead!

Class Notes: Geoarchaeology

Friday: May 31, 2013

(Results for selected topic.)

This is a waaaay long overdue post I found in my drafts:

Week 11: Human Impact on the Landscape

Monday:

We talked about the basics of stone tool analysis (mostly involving chert because that is the most common source). There is a lot of theory that can go into this, but most of the intpretations are framed within a life history approach. That is, how the stone was 1) procured, 2) manufactured into a tool, 3) tool use, 4) tool maintenance or recycling into other tools, and 5) discard.

We also had a lab to identify chert types. We were given examples that Dr. M had collected in Indiana. Part of the assignment was to use two different forms to catalogue the chert. Otis Crandell was one of the first to provide a way to standardize a catalogue system for chert, and his form is very thorough. Unfortunately, some confusion exists because of the translation (originally published in Romania, I believe). The other form we used came from Indiana University. Unlike Crandell’s, which came with an article to define how to record each variable, this form was singular. Some of it was easier to follow, but the layout was very crowded and I doubted that I was recording things properly since I did not have reference material. Of course, this likely is not a problem for someone who works with chert or other rock types regularly as the lingo would not be so foreign to them.

Wednesday:

Class discussion over Chapter 9 and:

  • Formation Processes of the Archaeological Record (Chapter 6)
  • The Structure of Archaeological Theory
  • Geoarchaeology in Action
(See the Library for bibliographic information.)
***UPDATE***
Dr. Crandell graciously contacted me to point me to a more in-depth article on chert identification. I direct you here: Macroscopic and Microscopic Analysis of Chert – A Proposal for Standardization of Methodology and Terminology. Happy analyzing!
See other entries with similar topics:

Class Notes: Human Osteology

Monday: January 9, 2012

(Results for selected topic.)

Week 15: Taphonomy

Tuesday:

Since we covered taph the week before, this week was actually centered on case studies and final review. The case studies came directly out of our textbook Human Osteology, so I won’t go into detail here (see the Library page for more information). What we got out of the individual cases was that taphonomy was highly important in a forensic case involving burned bones. The key to bioarchaeology is understanding issues like osteoarthritis at a population level. Only and entire suite of patterns can indicate cannibalism. The oldest known cemetery likely belonged to Homo heidelbergensis, 200,000 years ago (and man oh man, what a crazy complex dig that must be! Google Sima de los Huesos, you shan’t be sorry.)

Thursday:

Dr. S set up more stations, mostly involving paleopathology and taphonomy again. I spent a good portion of class (and later much of the entire day) with the bones I failed the most on: frags of the sphenoid, metatarsals and metacarpals, and long bone shafts.

Friday:

Our skeletal reports were due, and my ex situ commingled stuff was just nearly finished (which was ok since I had already completed the baby). I spent much of the entire day again studying. I was grateful this week that so many undergrads were in the lab. They kept me alive by feeding me with their swipes and entertaining my brain before I got burnt out. Was I ready for the final? No way. Lefts and rights. Rights and lefts. Siding was not my friend, but what more could I do?

Since this post is delayed, I do happen to know my score. It was not what I wanted. It was a high B. What kind of osteologist am I to become?? I was pretty down and out about it. (As my advisor well knows, I think of an A as passing, a B as barely worth it, and a C as failure – this is grad school, yo!) But as all my scores came in, between the tests, quizzes, and skelly projects, I rounded out with an A after all. Phew.

See other entries with similar topics:

Class Notes: Human Osteology

Sunday: January 8, 2012

(Results for selected topic.)

Week 14: Case Studies

Tuesday:

Fall break was not scheduled into the syllabus so we got an extra week to really go over some bioarchaeological issues. On Tuesday, we learned a new inventorying program that was installed in the lab, called Osteoware. Its purpose is to standardize inventorying so that skeletal databases can work in kind. I do not have much experience with it yet, but I see its potentional. I will be interested to see updates come out though because some segments are a little clunky right now. However, considering they offered it for free and I understand through my husband what it takes to program, I have faith that it really can become *the* database of choice. I am always terrible excited when his field mixes with mine for some reason.

We also covered taphonomy. Taphonomy references the changes which occur after death, including all factors from the biological breakdown to the cultural mortuary practices to the geological processes which affect individuals after death. The importance of understanding taphonomy is so that a researcher can distinguish between natural environmental processes and cultural treatments. Taphonomy is also useful in distinguishing either of these from pathology that the individual may have suffered.

Biological agents include animals (namely rodents and carnivores, but any animal can take part in trampling) and plants. Animal evidence is seen through crushing to access marrow, canine punctures, scalloped gnawing, and breaks by trampling. Plants are attracted to mineral rich soil, and decaying organisms provide this environment. Their evidence is seen through root etching and staining, breaking or obliterating bones, and algae, lichen, moss or fungi growth directly on the bones.

Cultural practices can include the preservation of burial or the thermal alteration of cremation, but also other factors. Burial in coffins can lead to coffin staining and coffin wear. Some cultures cleaned flesh from the skeleton prior to internment and this can be noted with cut marks. Further evidence of cut marks, pot polish, and crushing for marrow can be interpreted as cannibalism. Modern machines can disturb grave sites intensely. There are many other ways that people themselves can partake in the processes of taphonomy, these are but a few.

Non-biological agents are varied. Water can leach bone of minerals, weather the cortex, stain bone dark brown, and transport it. The sun can bleach bone to extremes, cracking and splitting it in diagnostic ways. The pH level of soil can either aid or hinder preservation (bone is best preserved in alkaline soil, while soft tissue is best preserved in acidic bogs). Wind can cause transport, aid in drying bone, or wear with sand grains. Gravity is a great transporter as well.

Thursday:

Taphonomy itself has high inter-observer error – maybe not necessarily in observation rates, but in descriptive remarks. It is also difficult at times to declare whether or not something affected the bone just prior to or just after death. Think of scalping, for instance. It is known that people survived being scalped (healed wounds as evidence), so scalping would occur prior to death, but in some instances scalps were taken after death. Only the latter is considered taphonomic, however.

Another point is that all things aside, two individuals will not preserve the same. Children and the elderly often are the first to return to Mother Earth because their bones are smaller and frailer. Therefore, in a population where much of the individuals are middle adult age, it is important to understand whether this is true due to taphonomic processes, is the population did not reach elderly age and the children were buried elsewhere, or if children and elderly both were buried elsewhere.

Friday:

We held a lab on paleopathology and taphonomy. Dr. S set up many stations so we could practice identification and distinguishing between the two.

See other entries with similar topics:

Class Notes: Human Osteology

Saturday: January 7, 2012

(Results for selected topic.)

Week 13: Fall Break

Tuesday:

Another lab day since we missed ours from the week before.

Thursday & Friday:

Closed for Thanksgiving!

See other entries with similar topics:

Class Notes: Human Osteology

Friday: January 6, 2012

(Results for selected topic.)

Week 12: More Paleopathology

Tuesday:

We checked out a bunch of examples from the Fun Box of Paleopatholgy. This included osteomyelitis, misaligned healed fractures, periosteal reactions, osteophytosis, eburnation, enthesopathy, spondylolisis, osteoarthritis, myositis ossificans, cut marks, ankylosis, and ankylosing spondylosis. Yep, it was one of those days that I wondered why I signed up for a field with such huge words to take notes on.

Thursday:

We had a simple lab day to work on our skeletal projects. I don’t recall where I last left off with my posting on this. Originally, I was assigned an infant skelly. Once I finished the baby, I moved on to some commingled remains from our BARFAA project.

Friday:

Friday was a special class because Dr. Wilson from IUPUI came to give us a Transition Analysis lecture/lab. It was the same as the one I sat in during BARFAA but with my class being smaller and more intimate, I felt like I learned more – of course, that may simply be because this was the second time hearing it. Basically, this new method is advocated to be more reliable, replicable, and quantifiable than past methods of scoring data. If I felt qualified enough to delve into detail, I would. Instead, I will cover just the very basic concepts used.

The traditional methods of scoring the auricular surface and pubic symphysis are sometimes called Suchey-Brooks or the Lovejoy methods. Cranial sutures are also scored for aging. Research has shown, however, that these methods tend to provide results which mimic the original reference sample – making the life tables for all kinds of populations look oddly familiar. These methods utilized phases of bone formation and degeneration. Transition analysis introduces using stages instead. Rather than trying to lump all the evidence given by the feature being studied, it measures each variable independently and provides probability statistics based accordingly, unlike the pigeon-hole phenomenon with a phase-based system. The stage system allows for more variability in the measurements because more possible combinations can be recorded (instead of scoring a single general phase for the development of the apex, ventral rampart, surface porosity and whatnot, it allows individual scores for each of these).

Functionally, transition analysis software lets you input each of these individuals independently, then scores the total age range for the given parts in a bell curve for each feature. The program calculated the P value and gives you the most likely age at death. Its best advantage is omitting that 50+ category. The old idea that people in the past didn’t live as long as we do today is not nearly as accurate as the stories tell. It is simply that most of the methods available for calculating age are unable to distinguish ages among older people. Transition analysis, however, can give you much more precise ages, and the P value still allows a check on accuracy. If you ever get a chance to attend a program on transition analysis, I urge you to check it out.

See other entries with similar topics:

Class Notes: Human Osteology

Thursday: January 5, 2012

(Results for selected topic.)

Week 11: Paleopathology

Tuesday:

The study of ancient skeletal alterations due to processes that are deleterious to health is known as paleopathology. Paleopathologists use differential diagnoses; that is, they list all the possible causes for what is observed on the skeleton, then rule out cases and narrow in on the likely cause. Unlike medical practitioners who rightly treat the individual rather than observing the bigger picture, bioarchaeologists examine the pathological evidence within the scope of the entire population and track the history of diseases. Therefore, the study is epidemiological and correlates human action with disease. That is, do certain cultural traits promote or hinder pathological conditions? The study is limited however: there is no communication between the affected and the examiner as in the medical field; there is no evidence of soft tissue involvement (unless in the rare cases of mummies); and chronic diseases are better understand rather than acute ones, which would have killed the afflicted before the skeleton had time to react in the diagnostic ways.

There are several classifications of paleopathology that can be recorded in a skeleton. These are: arthritic changes; trauma; infections; tumors/neoplasms; and congenital, metabolic, endocrine, and circulatory disorders.

A readily observable pathology is that of arthritis, otherwise known as osteoarthritis or degenerative joint disease. In fact, it is the most common condition found in ancient bones and results from activity-related breakdown of the synovial joints. As the cartilage protecting the joint wears down and disintegrates, the end of one bone will contact the end of another. Bone, being a living tissue, will react first with resorption (seen as pitting), then the bone will expand the joint to disperse the stress (seen as lipping, or extra growth of bone), and followed by eburnation (when the bones physically polish each other to a shiny sheen). Furthermore, some lipping can become extreme and fuse the joint together (ankylosing, or stiffened joint) – a trait seen in toes commonly, I’m told. Typically, this type of reaction is from secondary arthritis, or that cause from a traumatic event. Lipping of the spine has a special classification and is known as osteophytosis (osteoarthritis is a term used strictly for synovial joints; therefore a vertebra may have osteoathritis on the zygopothesis and osteophytosis on the body). Generally, arthritis is age related and the pattern shown on a skeleton can give evidence of activities. For instance, a population with a high percentage of arthritis showing its effect on left shoulder + right knee may mean that percentage of people were doing a similar activity – other clues found through archaeology or history can aid in interpretation. So it has been documented then that agricultural populations tend to show less arthritis than pre-agricultural groups (though not always) and that Eskimos show the highest levels of arthritic changes proving the intensity of their labor in such a harsh environment.

Trauma is the second most common pathology recorded. Patterns found in the fractures of bone indicate terrain topography, occupation activities, violence, and disease. Colle’s fractures (distal end of the radius) are associated with falling (when you throw your arm down to stop yourself) – high percentages likely related to the type of terrain. On the other hand, parry fractures (found on the unla) are associated with self-defense (when you throw your arm up to block something from hitting your head). In that same vein, depressed fractures of the skull often are interpreted for violence but these can also be caused by falling. Pseudoarthritis is also found in the archaeological record – a pathology resulting from a broken bone which never heals together but rather heals apart, creating a false joint. Collapsed vertebrae and vertebral psuedoarthritis are other forms of trauma that is related to disease and will be covered later.The rates of healing and correct versus incorrect alignment are taken into account to interpret medical skill/knowledge/technology of past populations as well.

Speaking of medical knowledge, some populations extensively used trepination and it is thought that they understood this would relieve endocranial pressure. Trepination is when a part of the skull is removed – either through drilling, cutting, or scraping. Fascinatingly, 90% of known trepination cases shows healing which means that the individuals were surviving this type of surgery without modern tools, medicine, or even anesthesia!

Thursday:

Some pathology can share resemblance with osteoathritis. The first is Diffuse Idiopathic Skeletal Hyperostosis, or DISH for short. It’s cause is still unknown and tends to occur in older male adults (those beyond 50 years). It involved fusion of four or more consecutive vertebral bodies, but does not affect the zygopotheses or the cortovertebral joints, nor does it affect the sacroilliac joint. It also preserves the intervertebral space (between each vertebral body). DISH involve excessive bone growth along the anterior longitudinal ligament – so much boney growth that it has been likened to a melted candle stick.

Ankylosing spondylitis is similar but note the differences. It affects almost only males who are young (under 40 and as early as childhood). It effects all parts of the vertebrae and can create fusion with the sacroilliac joint. The annulus fibrous between each vertabrae ossifies, syndesmophytes grow (similar to osteophytes) and complications can make this disease fatal.

Sometimes confused with gout, rheumatoid arthritis is different than osteoarthritis because instead of being related to age and activity, it is an autoimmune disease. Found mostly in females, it affects the hands and knees most commonly. Because it is inflammatory in nature, it causes osteoporosity and cyst formation. It can also lead to ankylosing of a joint.

Gout, on the other hand, is caused by the buildup of uric acid and typically is found in people over 40 years old. Sodium urate crystals can inflame the bone and cartilage. Because it also affects the hands (and commonly the feet), it can be mistaken for rheumatoid arthritis. However, the pitting created by gout can be huge – up to an entire centimeter whereas rheumatoid arthritic pitting is typically only a few millimeters in diameter.

Infection conditions are caused by an external pathogen, which is almost always microbial (parasitic infections from worms is another form). Viruses, bacteria, and fungi can all infect an individual, wreaking havoc on the body and leaving scars on the skeleton. The most easily recognized infections are caused by bacteria though. Periostitis and osteitis are terms used for when there has been evident periosteal reaction to something, but that something is too vague to diagnose (in fact, it may not have been caused by an infection at all).

One of the most prevalent bacterial infections recorded in bioarchaeology is that of tuberculosis. TB has been impacting human lives for thousands of years – dating back 2000 in India, 5000 in Egypt, and up to 9000 in Europe. Contrary to popular belief, it did exist in the Americas before “contact”, although it was rare. Caused by Mycrobacterium tuberculosis, this pulmonary disease (involving the soft tissue of the lungs) will eventually spread to the inside surface of the ribcage and the spine in chronic conditions. Thoracic vertebrae can show smooth walled pitting, which leads to collapse. If TB progresses this far and the verts show this characteristic wedging, it is known as Pott’s disease. TB often causes changes within the midface as well, resorbing the bones around the nasal aperture and sinuses; it can also affect the knees and hips. TB proves an important case for considering the osteological paradox: for TB to be seen on the skeleton, the individual must have lived a long time with the illness in a chronic state. Therefore, when the skeleton is studied, how should that individual’s health be considered? Surely being able to survive the disease long enough to have skeletal changes means your body was more robust against it than the person who died quickly before these changes occurred, leaving a healthy looking skeleton. But alas, there is no way to know if that healthy looking skeleton belonged to an individual who even ever had TB to begin, so perhaps that person may have indeed been healthier. Or perhaps they did both have it, but they suffered from different strains of M. tuberculosis with different virulences. At this point, with DNA studies few and far between due to preservation and resources, who can say. The osteological paradox just needs to keep a researcher on their toes and not leap to interpretations.

Moving on, another common infection found in the bioarchaeological record is that of osteomyelitis.It is a favorite for researchers because the bacteria acts upon the human body today just as it did in the past so it is easily diagnosed in skeletons. It is cause by Staphylococcus aureus bacterium – aka the well known Staph infection. In fact, in recent times there has been a renewed interest in public media due to its drug-resistant form, MRSA (Methicillin-resistant or multidrug-resistant S. aureus). The bacteria on the skin spreads to the bone in the local area of infection due to a build up of pus formation. This can cause a resorptive reaction of the bone, creating lytic lesions. In fact, the bone often reacts so intensely that it literally tries to cut out the infection. Bone resorbs around the infection, boring a hole (termed cloaca) through to the medullary cavity, thus leaving an island of affected bone in the center (the sequestra) . The healthy bone reacts by building up around the hole, forming what is known as an involucrum.

Yikes, right?

Friday:

Another infectious disease common to the archaeological record is  treponemal disease. It has two forms: syphilis (a sexually transmitted disease) and congenital (mother-child at birth). This too has been rumored to not have existed until the time of “contact” but archaeology has proven this not to be the case. Because the illness is slow, it is a chronic condition which leaves evidence on the body in the same manner as TB. Tibias will show a pronounced apposition of bones along the anterior crest, giving the saber shin appearance. This differs from that of rickets- the bones do not bend, but merely appear so. A skull will show lytic lesions in a diagnostic stellate shape, which sometimes progresses into pitting with bump formations, known as caries sicca. If a child contracts the disease during gestation or at birth, it can affect tooth formation. This results in characteristic Hutchinson’s incisors (notched edge) and mulberry molars (where the cusps are poorly developed).

Metabolic diseases are also recognized in past populations. For instance, a vitamin D deficiency can lead to rickets in children, or osteomalacia if extended into adulthood. A lack of vitamin D disrupts the roles of calcium and phosphorus in the body, which means that the rigidity of bone is lessened. Particularly in weight bearing long bones, this causes bones to bend, giving the characteristic bowed leg effect. It is common in people with terribly poor diets, and also in areas with low sunlight, as the sun triggers skin to produce the vitamin. Interestingly, low sunlight is not just an effect of where you are in the world (less light further from the equator, and the problem is exaggerated with darker skin colors), but also the culture. Industrializing cities with long days spent in factories, or religious communities that prefer clothing that covers much of the skin can both be causal factors for rickets and osteomalacia.

Porotic hyperostosis and cribra orbitalia are two other commonly found metabolic diseases, involving what is thought to be a response to low iron levels. PH affects the outer table of the crania, resorbing until the diploe is exposed, giving a “hair-on-end” appearance. CO, on the other hand, affects the orbital roof, sometimes growing spicules.Both are non-specific; that is the cause is unknown. Are the iron levels low due to a poor diet, a parasitic infection, a congenital susceptibility, a protection from worse symptoms, all or none of these? What is known, however, is that they are diseases of childhood. This is because the role of bone in blood production lessons with age and therefore both PH and CO are typically scored as healing/healed in adults.

Briefly covered were some congenital disorders. Pituitary gigantism results from a tumor of the pituitary gland. Because it begins in children prior to fusion of all the epishyses, the body will grow porpotionatly. Also affected is the shape of the sella turcica, or the boney saddle that the gland sits in, which will be enlarged and diagnosable. In addition, gigantism is hard to miss – in the archaeological record, people have been found to have grown 8 feet tall. A more common form of gigantism is that of acromegaly. Because of its later onset, fusion has already been taking place. This leads to only some bones allowed the extra growth: the mandible, clavicle, ribs, etc. You can recognize this form on “smaller giants”, with big chins, wide shoulders, and heavy brows. The opposite of these is achondroplastic dwarfism. It occurs when the growth plates do not form correctly, causing early fusion. It only affects endochondral bones, which is why people affected with this disorder will have a normal size torso and head, but shortened limbs.

And to round things out, a few mischellaneous bits. Myostitis ossificans is a mineralization of tendons at the muscle attachment point. It can form as a result of trauma, which need not be particularly detrimental, or it can from as a result of a congenital disorder which can be more severe, limiting movement and such. A button osteoma is a benign bone tumor. It is fairly common – you may know someone who has one. It is simply a small button-like growth on the skull. Feel around your own head, maybe you even have one yourself!

 

See other entries with similar topics:

Class Notes: Human Osteology

Wednesday: January 4, 2012

(Results for selected topic.)

Week 10: Review & Exam

Tuesday:

Although this week was meant to be used for review and an exam, we instead covered more class notes. In bioarchaeology, there are three main classifications of ancestry. It is critical that you understand what is meant by “ancestry”. Anthropology has come a long way since its inception yet unfortunately many people still believe we speak about differing “races”. Ancestry removes the cultural construct of the concept of race (since physically race does not exist), thereby limiting its definition to the physical form. In bioarchaeological terms, ancestry relates to the geographic location of someone’s ancestors – and until worldwide travel became so efficient, there were three basic groups: those from Africa, from Asia, and from Europe. It also is important to note that there is no “norm” because variation is the norm. As such, those between the two centers of ancestry will show overlapping traits. I will list some traits commonly used for identification, but it is crucial that a suite of traits is used for identification rather than any single marker and it must be understood that most traits lie on a scale rather than a simply being present/not present. Also understand there are a lot more traits to use but I kept the list brief for a simple overview and comparison.

African ancestry: Wider nasal aperture with rounded nasal bones and a guttered margin; alveolar prognathism and a midline diastema common; hyperbolic dental arcade; large molars with cusps 5, 6, and 7; blunt chin and straight mandible edge.

Asian ancestry: Tented nasal bones with a broken gutter nasal sill; prominent zygomatic (cheek) bones giving face a broad appearance; wide angled dental arcade with incisal shoveling common; broad and projecting chin and rocker mandible

European ancestry: Steepled nasal bones with a deep nasal root and a sharp nasal sill; overjet and overbite common; small molars and Carabelli’s cusp common; v-shaped dental arcade; bilobate chin and undulating mandible

Thursday:

 We were allowed lab time to study for our exam. Nothing too exciting to write about.

Friday:

Exam numero 2! It was only a practical (no written part) and the class as a whole did not meet expectations. I was among them myself with a crummy grade. In fact, this was when I first realized that I wasn’t getting it, but I did not understand why and therefore did not know what to do. I met with my teacher and he was surprised (not having known my grade yet since the assistant was the one to go over the test with us and apparently I was one of the better students). He felt his advice was weak since it wasn’t like I was fubbing up on any particular type of problem (my mistakes were all over the board: lefts & rights; identification; sexing; aging; ancestry), but truly it made since: If you think you know what a fragment is, think about everything else that will give evidence to support your hypothesis. I worked hard with this for the rest of the semester.

See other entries with similar topics:

Class Notes: Human Osteology

Wednesday: November 2, 2011

(Results for selected topic.)

Week 9: Age, Ancestry & Sex

Tuesday:

For class purposes, we have defined Young Adult to be 18-35, Middle Adult to be 35-50, and Old Adult to be over 50. For sub-adults, dental formation is key to aging, but for adults all teeth have been erupted so other methods are needed. Aging adults in bioarchaeology is really more about serial relationships among the population than true chronological age of individuals. One of the ways a skeleton can be aged at time of death is by examining the pubic symphysis. As mentioned in an earlier post, this area will experience a break down over time. The 1920’s model by Todd was the first, with 10 stages denoted by qualitative descriptions. In 1990, Suchey and Brooks developed another method similar to Todd’s but with only 6 stages and that also divides between males and females.

A second method of scoring skeletal age at death is through Lovejoy’s examination of the auricular surface. This is the ear-shaped surface created by the joint between the sacrum and the ilium.

A third method is identifying suture closure status of the cranium. Looking at standard points along the suture lines and scoring between open through obliterated can help identify age.

Thursday:

We used the above methods for our skeletal projects. Then we discussed how to sex a skeleton. Obviously without the fleshy bits, this is easier said than done. However, our species like most does incorporate a certain amount of sexual dimorphism in general. Not always true, men tend to be about 5-10% larger than females in both length and robusticity. This includes metric and non-metric traits alike. The best place to find sex indicators is the pelvis, although the skull can also have good evidence.

Friday:

We went into further detail over sexing a skeleton. Males tend to have a larger malar region and larger canines. Their jaws tend to be more vertical and have a wider ramus, while also showing a wider and larger chin. Females tend to have a gonial inversion of their mandibles. In the pelvic area, several indicators are present. These include the symphysis shape, pubic length, shape of obturator, ventral arc, medial aspect ridge, subpubic angle, greater sciatic notch, preauricular sulcus, elevated auricular surface, ischial tuberosity, shape of auricular surface, subpubic concavity, sacrum curl, and size of alae.

It is important to note that these features are not accurate 100% of the time. The dichotomy of sex must be understood as two bell curves with an overlap between them. Indeed, there are effeminate men and masculine women in all cultures and through all time. Young men also will have more slender characteristics than their older counterparts. Older women, after menopause, will start to show masculine traits of their skeleton. Therefore, many different variables need to be scored together to identify sex, and this is often why sometimes you will see “indeterminate sex” because it is a toss up between male and female indicators or not enough indicators were preserved for a confident classification.

 

See other entries with similar topics:

Class Notes: Bioarchaeology

Wednesday: November 2, 2011

(Results for selected topic.)

Week 9: Diet II & Chemistry (Stable Isotopes and Trace Elements)

Tuesday:

Teeth are the only hard tissues in the body that directly interact with the environment. As such, they are of great use for bioarchaeological research. Dental macrowear is scored commonly on Scott’s ordinal scale. Teeth wear over time, and in ancient populations the wear was so great that almost nothing of the tooth would be left, and indeed sometimes the body would purge the tooth altogether. Macrowear studies this pattern, which can have different sequencing depending on diet and subsistence.

Dental topography was developed within the last decade, applying geological mountain mapping software to dental crowns.  This turns what is visually seen in Scott’s scale to quantitative data. [At school, it is part of my job as the research associate to use the 3D plotter machine to profile each tooth from Dr. S’s project to create a virtual catalogue.]

Dental microwear studies a tooth’s microscopic texture, including pitting and scratching. A scanning electron microscope (SEM) is a common method in doing so. Teeth are coated with a very fine layer of metal, then an electron gun shoots the specimen inside a vacuum chamber. The electrons will bounce off the object and the software is able to transform a 3D object into a 2D representation using a horizontal scan. Newer technology does exist to create a 3D model, but this is not yet typical.

A 3D method that is gaining speed, however, is that of the while light confocal microscopy profiler (WLCP). [The major part of my duties in the department.] It is similar to a compound microscope, except a beam of light is shot through the lens and bounces back. This distance is measured to created a vertical scan of the specimen. It uses scale sensitive fractal geometry to calculate variables like complexity of the occlusal surface, anisotropy and heterogeneity of features, and texture fill volume.

As usual, we discussed several case studies to wrap class up.

Thursday:

Class was almost entirely discussion from the texts. I admit that I still need to read these chapters, so this bit may not be the clearest. Stable isotopes and trace elements can provide evidence for the type of diet an individual ate. We discussed measuring carbon, nitrogen, and oxygen with a mass spectrometer. This breaks a sample down to its elemental parts, weighing each element separately. For instance, when measured, the delta of  13C can indicate a marine versus a terrestrial diet. Marine foods will show a delta closer to zero, while terrestrial foods will be closer to -7. Another benefit is that plants discriminate differentially to 13C in their photosynthesis, so C3 plants can be differentiated from C4 plants in the archaeological record. The benefit here is that maize is a C4 plant so the adoption of maize can be noted in archaeological remains. Nitrogen likewise proves a valuable factor of understanding diet, giving a trophic accumulation of 15N. Legumes will provide a base level of 15N, herbivores who eat these legumes will have a slightly higher value, and carnivores who eat the herbivores who eat the legumes will likewise have an even higher value. 15N therefore needs to be understood within the environmental context, because comparisons between environments like coastal versus inland, or arid versus humid will give the incorrect impressions. Oxygen analysis of both bone and teeth (18O), as well as strontium, can show migration patterns because it is linked to the available water source.

See other entries with similar topics:

Class Notes: Geoarchaeology

Wednesday: November 2, 2011

(Results for selected topic.)

Week 9: Aeolian Environments

Monday:

Remember that open note, open book, open internet test I mentioned? That was on the docket for Monday. Obviously this post is behind, but he has not finished grading them yet. I did hear from him that he has checked out 2 of 5 answers from my test and so far I have an A. Woot!

Wednesday:

 Normal class discussion. Chapter 6 and these three articles (see the Library for bibliographic information):

  • Eolian Environments: Sediment Erosion, Transport, and Deposition / Sand Dunes / Loess and Dust / Stone Pavements / Eolian Erosion / Volcanic Ash (Tephra)
  • Sand Dune Morphodynamics and Prehistoric Human Occupation in NW Ireland
  • Geoarchaeology of Dissected Loess Uplands in Western Illinois

One day, if I get more free time, I shall discuss what the big picture from the groups of articles actually is. For now, I settle with a simple inventory.

See other entries with similar topics:

Class Notes: Human Osteology

Tuesday: November 1, 2011

(Results for selected topic.)

Week 8: Skeletal Project

Tuesday:

Fall break, woot!

Thursday:

We discussed morphometrics, which is the relationship between measurements and shape. We also covered the biological profile of age and sex. Age shows a growth threshold, involving both intrinsic developmental factors and extrinsic degeneration factors. Developmental aging includes tooth formation, epiphyseal fusion, bone length, and suture closures. Degenerative aging includes joint morphology, auricular surface appearance, and pubic symphysis break down.

Friday:

Osteometrics lab and more inventorying. I finished the little one and began an adult with some interesting pathology but my focus was asked to be shifted back to the BARFAA group now that my assignment had been finished (the adult would have been just as extra).

 

See other entries with similar topics:

Class Notes: Bioarchaeology

Tuesday: November 1, 2011

(Results for selected topic.)

Week 8: Diet I,Teeth, & 3D Analysis

Tuesday:

Fall break, woot woot!

Thursday:

Incredibly detailed discussed about biomechanical analysis and bone geometry continued. Visual aids would be helpful but I currently don’t have the time to whip them out for you. Just imagine that thinner cortexes may mean the force applied is more torsional, since the cortex is being positioned away from the centroid. Imagine a bone cross-section to have a small medullary cavity, which would indicate compressive forces. Bending forces would show both, as the bone builds a rigid frame to buffer against the directional forces.

After we cleaned up that slightly denser topic, we started on diet. Diet is the food that is actually eaten, and subsistence includes the behavior and resources associated with getting the diet. Indicators of subsistence include:

  • Tools and landscape modification (irrigation canals, for instance)
  • Hearths and middens (evidence of plants and animals)
  • Settlement patterns and architecture (temporary nomadic foragers or sedentary agriculturalists)
There are also indicators of diet itself:
  • Coprolites
  • Stable isotopes and trace elements
  • Dental macrowear (hard or soft diet), microwear (abrasive or smooth diet), and pathology (cariogenic diet or not). This will also help interpreting how food was processed (subsistence).
See other entries with similar topics:

Class Notes: Geoarchaeology

Tuesday: November 1, 2011

(Results for selected topic.)

Week 8: Hydrological Systems

Monday:

Fall break, woot!

Wednesday:

Class discussion resumed as usual. We talked about chapters 4 and 5 then I presented on these three articles (see the Library for bibliographic information):

  • Electromagnetic Conductivity Mapping for Site Prediction in Meandering River Floodplains
  • Geoarchaeology in Alluvial Landscapes
  • Archaeological Sediments in Dryland Alluvial Environments

I suppose I ought to clarify here – it is easier for me to state that I present on all three articles but really it is only two of the three. I just do not have my notes handy usually when I have time to post here and I do not recall which articles I presented versus the undergrad. I read them all each week and write an essay critiquing each one, so they kind of blur together. Just sayin.

We also looked at some stratigraphic photos and used what we learned to identify what was going on in the image. Soil horizons and episodes of deposition and so on. Then we covered what would be expected on our upcoming test. It is never a good sign when the test is essay questions, with a time limit, and open book and notes. Oh, and open internet. Say what?! It put the fear in us.

See other entries with similar topics:

Class Notes: Human Osteology

Tuesday: November 1, 2011

(Results for selected topic.)

Week 7: Osteometrics & Craniometrics

Tuesday:

We ran through some siding techniques for the small carpals and tarsals. Laura added with her “laurisms” and Amber had one of her own too. I’ve also made a few of mine. Here is a breakdown:

Carpals:

Scaphoid: Look at the side that resembles a snail (the convext suface). It crawls to the side its from.

Lunate: Hold it with your thumb in the groove and the box-like projection is on the side its from.

Triquetral: Hold the pinchy facet (the facet that wraps around the corner) and the circle facet at the top will be on the side its from.

Trapezium: Hold it like a cross and the groove will be on the side its from.

Trapezoid: Look at the zippered boot, and the toe points to the side it is from.

Capitate: Look at the flat side and imagine it to be a bust. The flowing hair hangs down on the side its from.

Hamate: Look directly at the pinchy facet and the hammer will be on the side its from.

Pisiform: This bone is not typically worth siding, and techniques do not always work correctly.

Tarsals:

Calcaneous: Hold like a wii remote, and the comfortable hand is the side its from.

Talus: Hold with the ball in your palm and your thumb in the concave facet. The comfortable hand is the side its from.

Navicular: Hold with your thumb in the concave facet and the point under your index finger. It will point to the side its from.

Cuboid: Look at the dinosaur head, and it wants to eat the side its from.

1st Cuneiform: Hold with your thumb on the kidney bean facet, with the L-shaped facet facing you. It is on the side its from.

2nd Cuneiform: Look at the flat non-articular surface as if it is a house. The slanted roof points to the side its from.

3rd Cuneiform: Look at the concave facet with its point down. The more dipped side is on the side its from.

Class discussion then went over how to measure bones using sliding calipers, spreading calipers, an osteometric board, and a measuring tape. Then we began measuring our skeletal projects.

Thursday:

We walked through Fordisc, a discriminant function analysis program which calculates ancestry relationships using a suite of metric data. Today was another lab day for our skeletal project.

Friday:

Quiz and more lab, as usual. No organized discussion, just a lot of inventorying and measuring.

See other entries with similar topics:

Class Notes: Bioarchaeology

Tuesday: November 1, 2011

(Results for selected topic.)

Week 7: Activity Patterns & Bone Geometry

Tuesday:

 A skeleton shows evidence of childhood health in two major ways. The first is an individual’s height. To determine the individual’s growth rate, long bones are measured metrically then compared on a scale to the individual’s tooth eruption sequence. The sequence of tooth eruption is fairly set but bone length will vary. While this has some genetic factors to consider, extrinsic influences also play a major role. However, does a lower growth rate mean the child was less healthy? Not always. While it is true that a person with a sickly childhood will be shorter, it is also true that a shorter person is more adapted to a lower intake of calories, or even cooler climates.

The second childhood health indicator is the teeth themselves. Teeth create a permanent record of stress affecting an individuals during tooth formation. This means that evidence of disease may be recorded during the whole first 18 years of life, to remain there until the teeth are lost. A common one found is linear enamel hypoplasia, or horizontal grooves typically found in the anterior teeth. I presented a chapter to go into this further.

We discussed what types of questions can be answered by looking at children, and these include:

  • Diseases present in childhood
  • Age and size at menarchy, puberty
  • Growth rates
  • Sexual dimorphism prior to adolescence
  • Weaning

Thursday:

 In brief, Wolff’s Law states that there is a biomechanical skeletal response to demand: bone is laid where it is needed and removed where it is not. (An “you use it or lose it” phenomenon.) By applying an engineering model to biology, understanding bones as an I-beam or a cylinder, extrinsic forces can be interpreted via specific bone morphology. Bone is best at displacing compressive forces, but tensile, bending, shearing, and torsional (which can also all be combined) are common stresses. Applying Wolff’s Law, these forces are what gives bones unique characteristics. Our readings and discussions went into great detail, from case studies to polar moments of inertia.

I also borrowed a book from Dr. S to start thinking about my 10 page paper I need to present on for class, The Bioarchaeology of Children: Perspectives from Biological and Forensic Anthropology (see the Library for bibliographic information). I may do something with juveniles, to keep in line with what I am learning in Human Osteology. I may also look into skeletal deformation as another option. Intentional and unintentional. Cranial and Post-cranial. Before and after death even. The possibilities there are great. What I do not understand is why some books are so pricely (Ahem, Cambridge University Press…) while other larger books from the same company are less than half. I have several on my Amazon wishlist that I just may never purchase simply for the price. Costs of healthcare and education should both be brought back down a notch or 6000.

See other entries with similar topics:

Class Notes: Geoarchaeology

Tuesday: November 1, 2011

(Results for selected topic.)

Week 7: Intergrating and Interpreting Data

Monday:

Monday’s lecture has been moved to later in the semester. Instead, we walked through how to turn our data collected with the total station into a contour map using Surfer 9. Then we had class discussion over the readings – chapter 17 from the book and I presented with others on three articles (see the Library for bibliographic information):

  • Darwin Would Be Proud: Bioturbation, Dynamic Denudation, and the Power of Theory in Science
  • Geoarchaeology and the Mid-Holocene Landscape History of the Greater Southeast
  • A Geomorphological Approach to Reconstructing Archaeological Settlement Patterns Based on Surficial Artifact Distribution: Replacing Humans on the Landscape

Wednesday:

Wednesday was a lab day, which was optional if you could find time outside of class to create the contour map, which I most certainly did. Check it:

I made it in pretty orange colors, and chose the Kriging option. The green dots represent all the points where we held the stadia rod. The Smith Mall would be below this image, the library would be above it The rectangular pattern traces the sidewalk edge of the landscaping. Esch Hall is to the left and Martin Hall is at the bottom right. [Basically, in the photos from last week’s post, I was standing just about where it is labeled 102 on the bottom right, just next to 107, looking toward the bottom left corner.]

UIndy contour map

University of Indianapolis campus contour map generated from data collected by a total station and processed in Surfer 9.


See other entries with similar topics:

Class Notes: Human Osteology

Tuesday: November 1, 2011

(Results for selected topic.)

Week 6: Hands and Feet

Tuesday:

Since we had already covered this week’s topic, we moved ahead to receive our assigned skeleton. We discussed the procedure for inventory and the different paperwork that is used by the lab. As I had mentioned, I requested a juvenile to push my limits and the baby was very tiny. I was able to correct classification the archeologists had made, and find one of the tiniest human bones: an ear ossicle (the malleus to be precise).

Thursday:

I do not recall exactly, but due to my lack of notes for this day I imagine we had lab time during class to work on our skeletal inventories.

Friday:

My cohort and I worked on our BARFAA presentation during class time with Dr. S while the undergrads had lab with Laura. We put the final touches on a keynote presentation and walked through it a few times before practicing in front of the class. I had this annoying habit of saying “Upper” Woodland (instead of “Late” Woodland) because my undergrad focus was mostly human evolution and therefore “Upper” Paleolithic and such. This might seem a small detail, but I assure you it is not a mistake I would want to make in front of an anthropologically educated audience!

Cute shoes

Grad school feet in grad school grass.

This was a rough week for me, having BARFAA coming up and the other graduate duties and classwork. I won’t lie, I was pretty stressed and have basically been behind in coursework since. I think the experience was great so no regrets there, but trying to balance it with school work and a weekend husband was not the easiest thing at the beginning of my first semester after a 2.5 year break. Lucky for me, my grades do not reflect the hardship. I hope that stays true for the rest of the semester!

See other entries with similar topics:

Class Notes: Bioarchaeology

Tuesday: November 1, 2011

(Results for selected topic.)

Week 6: Kids

Tuesday:

Week 6 was suppose to cover kids, but trauma is so much fun. We had more class discussions from the text but also learned about case studies that Dr. S has been a part of. A particular one of interest to me has been published so I am free to discuss it. I even purchased the book, Human Variation in the Americas (see full bibliography information at the Library page). Near my home town in Floyd County, a male individual was discovered with a cache of forelimbs possibly representing five different people. To give you some idea of the range of questions a bioarchaeologist may ask, here are a few we tossed around in class: Were these war trophies? Magic vessels for a shaman? Familial keepsakes? We may never know, but we must always keep our minds open.

Thursday:

Case studies discussing the adoption of agriculture were presented followed by a quick chat about why bioarchaeology cannot have one single answer to all there is to discover in history. This is because there are way too many variable factors to consider. Each case must be examined with a full understanding of the site’s context, geographically, temporally, and culturally. And of course always in the back of a bioarchaeologists mind is the Osteological Paradox.

Our discussion then turned towards children and how they are often overlooked in archaeology. Problems begin with differential burial: some populations would bury their children in separate cemeteries, along paths, in house floors, or at other unique places so they rest undiscovered compared to the extent of adults in cemeteries which modern construction breaks in to. Another main problem is that of preservation: children’s bones are tinier and more fragile than adult bones so are far less likely to be preserved. The archaeologists excavating children remains also may not be trained to identify the tiny bones and fragments (an adult has 206 bones on average, while at birth a child has over 300). In addition, children are shadowed in bioarchaeology because so much of the research is dependent on comparisons, including that of male versus female. In children, these differences are almost (if not totally) non-exisitent in skeletal remains, which means that most research is biased towards adults. Another dilemma is that in published research, there is no standardization of identifying “children”. Terms such as fetal, neonate, newborn, infant, child, kid, juvenile, adolescent, and subadult mean very little because an age range was not provided, or the range varies between researchers so that comparisons cannot be drawn.

Kids also invoke, once again, the Osteological Paradox. Do more children in a cemetery mean the population is unhealthy? Are more children dying because of the diseases being spread? Or perhaps the population is quite healthy: are more children simply being born? If the percentage of living babies to those buried were known, these questions could be answered.

Also of note is how once grave goods entered our past, children seem to be over-adorned in many places all over the world. Did the children discovered have a socioeconomic status by birth? Were children more important to the population than adults? Were adults providing children goods in consideration of their short lives? Was the community sharing support in a family’s loss?

We then had class discussion over the texts and I presented three chapters.

See other entries with similar topics:

Class Notes: Geoarchaeology

Tuesday: November 1, 2011

(Results for selected topic.)

Week 6: Lab Methods & Stone Sourcing Techniques

Monday:

On Monday, we went outside to use a total station in order to collect data for a contour map. We chose a corner by the library, then pushed a pencil into the grass to mark our Datum 1 and told the computer it was at coordinate 1000, 1000, 100. I was chosen to set up the tripod and level it since most others had, or were introduced to it the prior week. The steps are easy but I didn’t weigh enough to push it into the ground, and leveling a triangle takes skill so it took me a while. Then we set Datum 2 and each student had to take 50 points and hold the stadia rod for 50 points so that we had a total of 400 measurements. By the time class was over, we only had 250 points taken.

Wednesday:

We went outside to finish taking the measurements, and I took some photos of campus while this was being done, so I will share those with you. (Boy had just given me a new camera he purchased off my brother: a Canon PowerShot S95 which I know nothing about because he got it in Hong Kong and it did not come with an English booklet.) I did not take any photos of the total station but I do have some from another dig I participated in which I will share in a later post.

Before the measurements were completed, Dr. M realized it may take us a while so we held our normal discussions out on the lawn until it got dark and went inside. We talked about chapter 16 and covered these three articles (see the Library for bibliographic information):

  • Raw Material Utilization in Carroll County, Indiana: A Small-Scale Analysis of Diachronic Patterns in the Usage of Attica, Kenneth, and Wyandotte Cherts
  • Sourcing Lithic Artifacts by Instrumental Analysis
  • Macroscopic and Microscopic Analysis of Chert. A Proposal for Standardisation of Methodology and Terminology
UIndy campus

University of Indianapolis campus, looking at Smith Mall (the "quad" area). The lower half of this image is a large portion of our contour map.

UIndy campus

University of Indianapolis campus, looking at Esch Hall. The foreground is a large portion of our contour map.

UIndy campus

Fall colors hiding Martin Hall at the University of Indianapolis.

See other entries with similar topics:

Class Notes: Human Osteology

Tuesday: November 1, 2011

(Results for selected topic.)

Week 5: Shoulder and Arms

Tuesday:

The shoulder girdle connects the forelimbs (appendicular skeleton) to the thorax (axial skeleton). It is a very shallow ball and socket joint, allowing for great flexibility. The forelimb design is a common tetrapod design. The proximal half contains a single bone, while the distal end is made of two bones, terminating in the hand, which contains carpals, metacarpals, and free moving phalanges.

The shoulder girdle:

  • Scapula
  • Clavicle

The forelimb:

  • Humerus
  • Ulna
  • Radius
  • Carpals
    • Trapezium
    • Scaphoid
    • Lunate
    • Pisiform
    • Triquetral
    • Hamate
    • Capitate
    • Trapezoid
  • Metacarpals 1-5
  • Manual Phalanges
    • Proximal
    • Intermediate
    • Distal

We learned the various features of each bone and how to side them. Interestingly, I have spent a lot of time on the small bones of the hand which now I find easy, but I am having trouble with the larger bones of the arm. I wonder if this is normal. Remember, we do not get tested over full bones. Fragments are what is found in the archaeological record so fragments I must know.

Thursday:

We jumped ahead to the pelvis and lower limb. The pelvis is a paired group of three bones: the illium (what you feel as your “hip bone”), the ischium (what you sit on), and the pubis (which can be felt in the nether regions). These two sets of bones fuse early on to become two oddly shaped bones, sometimes referred to as the ox coxae or the innominate. The leg is in the same model as the arm: a single bone in the proximal half, two bones in the lower half, terminating into tarsals, metatarsals, and phalanges. My favorite bone pops in at the knee: the patella.

The lower limb:

  • Femur
  • Patella
  • Tibia
  • Fibula

Friday:

  • Tarsals
    • Calcaneous
    • Talus
    • Navicular
    • Cuboid
    • 1st Cuneiform
    • 2nd Cuneiform
    • 3rd Cuneiform
  • Pedal Phalanges
    • Proximal
    • Intermediate
    • Distal

Just like the upper bones, I am pretty confident in the small bits, but the long bones trick me often. I am decent at identifying which bone it is, but siding is still a struggle. I missed the practical lab section here because I was working with my cohort on a presentation for BARFAA coming up on the 8th of October. This is part of my problem with long bones I think, but I should make up for it this week with extra study time.

See other entries with similar topics:

Class Notes: Bioarchaeology

Tuesday: November 1, 2011

(Results for selected topic.)

Week 5: Trauma

Tuesday:

Tuesday was our first exam. It is always a bit disconcerting when tests are open book, but I felt I did alright. Since this post is quite delayed, I can say I did more than alright, I nailed it:)

Thursday:

Trauma includes both intentional and accidental conditions affecting the skeleton. Antemortem trauma (occurring some time prior to death) is recognized by evidence of healing, although in some cases healing can be so complete that the trauma evidence itself is erased. Perimortem trauma (occurring shortly prior to, at, or just after death) will lack healing but usually can be distinguished from postmortem trauma (occurring some time after death, due to taphonomic processes) because living (or very recently living) bone reacts to external forces differently than dry bone.

One common type of trauma found in the archaeological record is fracturing. When a force of energy contacts bone, it will radiate in a certain pattern depending on the bone properties and the type of force. There are several key types of factors:

  • Depressed: At low velocity, these fractures will radiate in concentric rings. At high velocity, the rings are also blown by the force so only a hole remains.
  • Torsional: These are spiral fractures which occur when the proximal end of a bone is forced in the opposite direction of the distal end.
  • Longitudinal: These occur with extremely compressive forces. Greenstick fractures have a longitudinal component.
  • Transverse: Hairline fractures occur when the bone is forced to bend just slightly more than it can handle.
  • Bullseye: Technically this is not considered a traumatic fracture because this occurs when bone gets burned (as in cremation, therefore after death and not trauma).
Some fractures have special identifiers because they are seen so often:
  • Parry fracture: A fracture of the ulna, often associated with self-defense (when your arm goes up to block your face).
  • Colles fracture: A fracture of the radius, associated with falling (when you arm goes down to catch your fall).

We also discussed a little about modern trauma. Bullets can make a keyhole shaped entry with radiating fractures connected by concentric fractures. This is an incredibly simplistic description, though, because a lot of science goes into ballistics. The angle, the gun, the bullet, and the distance combine so a lot of possibilities can occur but also are related in such a way that this is how a forensic team can identify said variables. For instance, another example is a shot from the side through a leg bone. The bullet forces bone particles with it so when it goes through the other leg bone, the damage is greater (this situation is known as the Hertzian cone). People hit by cars experience both compressive and tension stresses on their leg bones, which will cave under the force and a wedged piece of bone will crack off, known as a butterfly fracture.

In bioarchaeology, everything is about patterns seen in populations. Of course there are always exceptions to any rule, but in general, pre-agricultural societies experienced more lower limb bone fractures than agriculturalists. We held class discussions with case studies to delve further into interpretation.

See other entries with similar topics:

Class Notes: Geoarchaeology

Tuesday: November 1, 2011

(Results for selected topic.)

Week 5: Field Methods & Geophysics

Monday:

Archaeologists often use a total station to record the site topography and artifact locations. A total station records X, Y, and Z coordinates by shooting a laser situated in a fixed place at a prism on a stadia rod at other locations around the site. It calculates some wicked math (probably basic trigonometry actually) and creates a digital file which can then be inputted to other programs for analysis. We went outside to see how this is done, setting up the total station tripod over a water drain for our Datum 1 point. Because most of the students were experienced with a total station from field experiences, it was a quick introduction for those of us without prior knowledge of it.

Archaeologists also employ Google Earth, using their database of aerial photos and historic imagery to locate possible locations of archaeological sites. These can be seen by discolorations of the soil, particularly along floodplains which were magnets for ancient populations.

Archaeologists also need to know how to read a topographic map, so we took some time to go over an old map of the school’s area, back when it was known as Indiana Central. Archeologists work with maps primarily at 1:24,000 scale. This means that it is 7.5 minutes latitude by 7.5 minutes longitude. Also indicated are northing and easting units. One section is a square mile, or 640 acres. You can get a small plastic card to further break down the sections, into quadrants and smaller – down to 1/8 square miles.

Wednesday:

We went over how to use Surfer 9, which is a mapping program that the total station file can be imported into, allowing creation of a contour map.

We also talked about the upcoming field trip to Lew Wallace, where geophysics would be seen in action.

Then we went into class discussion on chapter 15 and I presented on these three articles (see the Library for bibliographic information):

  • Current Practices in Archaeogeophysics: Magnetics, Resistivity, Conductivity, and Ground-Penetrating Radar
  • Situating Remote Sensing in Anthropological Archaeology
  • Palaeotopography: The Use of GIS Software with Data Derived from Resistivity Surveys and Stratigraphic Profiles to Reconstruct Sites and Past Terrains


See other entries with similar topics:

Class Notes: Human Osteology

Friday: September 30, 2011

(Results for selected topic.)

Week 4: Spine and Thorax & Review

Tuesday:

 The human body has 24 vertebrae:

  • 7 cervical
  • 12 thoracic
  • 5 lumbar
There are two kinds of curves that create the “S-curve”: lordosis (a ventral curve, employed by  the cervical verts and the lumbar verts) and kyphosis (a dorsal curve, employed by the thoracic verts and sacrum).
Some vertebrae have special identifying features:
  • C1, otherwise known as Atlas, articulates with the skull, allowing us to shake our heads “yes”
  • C2, otherwise known as Axis, articulates specially with C1 via the Odontoid, allowing us to shake our heads “no”
  • C7 is the bump you can feel at the bottom of your neck, and it transitions into the thoracic vertebrae
  • T1 is also transitional between cervical and thoracic, but unlike the cervical verts, all other verts lack transverse foramina
  • T10-T12 transition into lumbar verts, but each still maintains a costal facet which articulates with a rib
  • L5 is transitional to the sacrum (sometimes it even becomes fused with the sacrum)
We also covered the sacrum and coccyx which are each important for muscle attachment. Between each vertebra is an intervertebral disk. This is made of annulus fibrosis, which surrounds the nucleus pulposis, a remnant of the notochord. When a person has a slipped disk, the disk itself does not slip, but the nucleus pulposis is no longer centered. It is estimated that this soft tissue accounts for almost 25% of our vertebral height.

We have twelve pairs of ribs, men and women alike. The first six are sometimes called “true ribs” because they each have a cartilaginous connection to the sternum. Ribs 7 through 10 are sometimes referred to “false ribs” because their cartilaginous connection is shared between them. Ribs 11 and 12 are “floating ribs” because they lack this connection to the sternum.

A sternum has three parts, though these often fuse. The top is called a manubrium. If you have ever seen the movie The English Patient, he referred to the supersternal notch, which is the area we call a jugular notch, between the clavicular notches. The body of the sternum is sometimes referred to as the corpus sterni, or sternabrae. The bottom tip of it is the xiphoid process.

Thursday:

 We had lab time to study for our test. Anna and I spent the entire evening there (much like Tuesday) to go over fragments. I have trouble siding the sphenoid. That bone is not my friend.

Friday:

We had the first test of the semester. 50 written questions, but an additional essay and diagram for the grad students. Then we had 50 practical questions, plus 10 extra hard grad student questions, and an optional 10 question quiz. I got done with both parts early and with time to go over each question to be absolutely sure. There were a few I couldn’t be confident about but overall I think I did alright. My main issue is still balancing time. Two classes demand a lot of time for reading. This class demands a lot of extra lab time. And then I have the Dental Microwear Project to work on also, not to mention commuting and saving time for “weekend husband”. As the semester draws on, I am finally getting the feeling of caught up, so by the end of the semester, I ought to be rocking it.

 

See other entries with similar topics:

Class Notes: Bioarchaeology

Friday: September 30, 2011

(Results for selected topic.)

Week 4: Implications of Disease (and some non-pathogens)

Tuesday:

Bioarchaeologists focus on patterns formed by the relationship between pathological conditions and behavior. Associations of one to the other, however, does not necessitate a causation, but it does allude to the cause in some cases.

Degenerative Joint Disease (DJD) could be caused by genetics, large body size, age, and diet. Take a football player into account: are people of larger body size more likely to get into sports? Is this large body size part of their genetic make up? Do they eat the healthiest diets? Are they tested for DJD while they are young and playing football, or only after they are older and retired? Issues like these are multivariate so controls are used to identify the true effects. DJD begins with the breakdown of soft tissue between the bones of a joint. The bone will react by increasing the surface area and creates lipping, or osteoarthritis. In some cases, the wear can be so extreme that bone on bone contact occurs and this can be identified by the shiny, polished characteristic at joints, known as eburnation.

We discussed osteoporosis as well, which is a growing problem today. It is associated with activities, sedentism, and demographics. Bone increases robusticity through use, so the lack of use found in sedentary lifestyle could be a partial cause to the issue. People in general will lose bone mass as they age, and women experience this during pregnancy, lactation, and menopause which equates to sex being a factor.

In bioarchaeology, the use of controls is limited but it can be done in some cases. If a research question wanted to know the effects of a sedentary lifestyle and rule out agriculture of maize as the cause, an agricultural population can be compared with a coastal population, who is also sedentary but relies on marine resources. If the factor that the bioarchaeologist is looking for exists in both, it could be caused by a sedentary lifestyle. It if is only found in one population, however, it could be related to the diet or some other factor that differentiates the two groups.

Thursday:

We covered how the pervious class discussions can be applied to different sites, expectations from testing a research question, and new questions deriving when those expectations are not met.

See other entries with similar topics:

Class Notes: Geoarchaeology

Friday: September 30, 2011

(Results for selected topic.)

Week 4: Archaeological Soils & Correlations

Monday:

We had a lab using Adobe Illustrator to take shovel test probes provided from real archaeological field notes and reconstruct the strata. As the name implies, holes are dug with a shovel to probe the landscape so as to test for the possibility of an informative feature. The width between the probes varies depending on the site – I have no idea in my representation below if there is a meter or tens of meters between them, but I am able to do a rough estimation of what lies below the ground with the data collected in the field notes.

Shovel Test Probe lab

Statigraphy correlated from shovel test probes done at an archaeological site.

Wednesday:

Soil is different than sediments. Soil itself is weathered sediments that develop over a long period through a stable landscape. Sediments can accrue instantaneously, such as being deposited from a tsunami. Soils are only found on the surface, whereas sediments are found throughout the earth. If a soil surface becomes buried by sediments, it is no longer considered a soil, but instead a paleosol. There are five soil forming processes (also known as pedogenesis).

  • Climate
  • Organisms
  • Relief
  • Parent Material
  • Time
Soil also requires four components to be differentiated from sediments:
  • Inorganic mineral matter (derived from its parent material)
  • Organic matter (derived from the organisms)
  • Soil pore space (empty space between particles with allow water percolation and movement of organisms)
  • Soil water (some will fill the pore space, and others will be bonded to the aggregates themselves)
Soil characteristics for classification include:
  • Color (using the Munsell Soil Color Guide)
  • Texture (relative frequency of particle sizes)
  • Structure (shape of aggregates)
Soils can be described by their orders as well. We covered several:
  • Alfisol (found in upland environments, are older but with higher base and less weathering)
  • Mollisol (found in prairies and flood plains)
  • Entisol (thin layers, very young)
  • Inceptisol (slightly older than Entisol)
  • Histosol (found in marshes and swamps)
  • Oxisol (found in tropical rain forests)
  • Ultisol (like Alfisols, but older and the bases have been lost)
  • Aridosol (found in drylands and deserts)
  • Vertisol (found where clay shrinks and expands)
  • Spondosol (found in confiferous forests, highly acidic)
  • Gelisol (found in permafrost environments)
  • Andisol (volcanic soils)
Soil can be classified through taxonomy as well.  These are known as horizons. Thinking in terms or the surface on top, and going deeper, this is a typical Indiana soil broken into horizons:
  • O : If there is decay of organic material, there will be an O Horizon. Most soils lack this layer because bacteria acts quickly to dissolve it, but it remains where there is leaf litter, peat, or muck.
  • A : This is the most common top soil – it includes the highest concentration of organic matter (when O is not present) and therefore is darker and richer.
  • E : Sometimes there will be a small E Horizon. This occurs when water leaches the fines (clay sized particles), bases, and organic matter, leaving it lighter and sandy. It is most common in coniferous forests or in coastal environments.
  • B : Leaching has caused the loss of all bases, but the fines accumulate. This creates a reddish, more firm version of A due to a higher clay content.
  • C : This is the parent material layer  where the soil rests, and what is being weathered to become the soil, be it a deposit of clay or bedrock, though bedrock itself sometimes gets the designation of an R Horizon.
Tax dollars went into archiving US soils and providing a free website to learn about them (so get your money’s worth and check it out!). The Web Soil Survey allows you to type in an address, or simply zoom in over an area of choice. If you then click on the AOI button (the one with a red rectangle) at the top of the map, you can draw a box to create an area of interest. It will draw a box with diagonal lines. Then click on the Soil Map tab. It will give you a break down of the specific soils in that area. If you poke around some more, it provides all kinds of information. In addition to having fun on the internet, you can order any Soil Survey you create – for free. For instance, this is what campus looks like:
UIndy soil survey

Soil survey of UIndy. I spend most of my time in the basement of the building below the orange bullseye.

UIndy soil survey key

Soil composite of UIndy.

See other entries with similar topics:

Class Notes: Human Osteology

Sunday: September 25, 2011

(Results for selected topic.)

Week 3: Osteometric Landmarks & Teeth

Tuesday:

In class, we covered the view of the interior cranium, the maxilla, and the mandible. We also covered some common craniometric landmarks used to identify ancestry. Since I have these memorized well: gnathion, incision, prosthion, nasospinale, nasion, glabella, bregma, vertex, obelion, lambda, opisthocranion, inion, opisthion, basion, gonion, ectomolare, ectoconchion, dacryon, zygion, porion, euryon, and pterion.

There are 20 deciduous teeth and 32 adult teeth in most instances. I only had 31 teeth because one of my third molars never developed. Cool, huh? Teeth are made of enamel (which is almost entirely protein and is acellular, which means they will never heal), dentin (which is about 75% mineral but is cellular although not well enough to patch cavities), and cement (about 65% mineral, like bone, and is what Sharpey’s Fibers hang on to inside the gomphosis joint).

The human dental formula is 2:1:2:3. This means that for each quadrant of your mouth, you have two incisors, then a canine, then two premolars, followed by three molars. We were briefly taught how to determine each category, and upper versus lower dentition (except for canines). More specific detail of this will be taught in Dental Anthropology next semester.

  • Upper incisors: Crown will be flat, enamel flares out from root, the root is more round, and wear will be linear.
  • Lower incisors: Crown will be flat, enamel continues evenly from root, the root is oblong, and wear will be linear.
  • Canines: Crown will be pointed, and wear will have a central bulge.

Thursday:

  • Upper premolars: Crown will be a rounded rectangle, and evenly cut in half.
  • Lower premolars: Crown will mostly circular and will have two dimples.
  • Upper molars: Crown will be shaped like parallelograms, and generally only have four cusps and three roots.
  • Lower molars: Crown will be more squared, have a Y5 or +4 pattern, and only have two roots.

As a grad student, I also have to be able to determine first, second, and third molars. Third molars are fun because typically the cusps are all messed up and the roots are tiny. First are generally the perfect examples of a molar, and seconds are intermediate between the two.

Friday:

We were given details on our dental topography project. The machine we will be using is part of my Research Associate position. Not only will I scan the teeth for texture with the white light confocal microscope, but I will also profile them in the topography machine (TopoM). This process takes literally about 2 hours to do a single tooth but it builds a three dimensional view of the tooth.

For lab, we went over more skull fragments and began sorting teeth.

See other entries with similar topics:

Class Notes: Bioarchaeology

Sunday: September 25, 2011

(Results for selected topic.)

Week 3: Infectious Pathogens

Tuesday:

Dental caries is the process of  tooth decay. Once a cavity opens up into the pulp chamber of a tooth, bacteria has access to the arteries and nerves inside. It can then move into the alveolar bone, to which the body will react with resorption, forming a puss-filled abscess. This can go on until so much bone has been resorbed that the problem tooth falls out, known in bioarchaeological terms as ante-mortem tooth loss (AMTL). [Side note: researchers today believe there is a causal link between the S. mutans bacteria and heart disease.] Bioarchaeologists will look at dental caries for trends between sexes, social classes, and populations to determine cultural causes of the disease.

Periosteal reactions (PR) are another indicator of interest. These are “non-specific” in that they can be observed, but the cause cannot be determined usually because too many different circumstances lead to the same reaction. They are generally found on shallow bones (shin bones for instance) and are thought to be related to an infection resulting from trauma. A specific form of PR is osteomyelitis, which is diagnostic of the staph infection caused by S. aureus. These systemic infections cause the body to carve out the infection, literally creating a bone island and causing a gaping sore in the skin to drain the fluids.

Treponemal disease is caused by both venerable and non-venerable syphilis, from the T. pallidum bacteria. It is diagnosable from stellate lesions and “saber shins”. Contrary to popular belief, it was not introduced to the New World from Europeans, although contact did put much stress on populations and caused them to grow much denser which rapidly increased the prevalence of treponema.

Tuberculosis (TB) affects the ribs followed by vertebrae, which collapses creating a hunchback appearance known as Pott’s Disease. TB creates a good discussion for the Osteological Paradox. Some individuals may die of TB before their skeleton has had time to react, thereby looking completely healthy compared to an individual who was able to live with the disease long enough for boney reactions to occur, leaving a visibly unhealthy skeleton. The Osteological Paradox is something that must always be considered when working with skeletal populations.

Leprosy is another common disease found in bioarchaeological studies. Caused by M. leprae, it may not always be fatal. Diagnostic characteristics include atrophy of the face, peripherals, and appendages. It is currently thought this this disease was brought to the Americas by the Europeans.

Thursday:

Common non-specific diseases include Cribra Orbitalia (CO) and Porotic Hyperostosis (PH) which are often associated with each other and with iron deficiency, or anemia. These show in the roof of the orbits (CO) or along the flat bones of the skull (PH). It could be an issue of the Osteological Paradox again – are these individuals lacking in iron, or are their bodies fighting off an infection of some kind by limiting the iron available for the infection to feed on? For instance, a person affected with Sickle Cell Anemia has a higher survival rate against malaria because sickle shaped cells prevent the parasite from rapidly reproducing, thus allowing the body time to resist the infection. The idea of health has many facets which must be considered in bioarchaeology.

 

See other entries with similar topics:

Class Notes: Geoarchaeology

Sunday: September 25, 2011

(Results for selected topic.)

Week 3: Archaeological Stratigraphy

Monday:

Stratigraphy refers to the layers of deposition of sediments and soils (which are not the same thing!). All else being equal, there are five geological principals that apply to archaeological strata:

  • Superposition: The oldest layer will be the deepest layer.
  • Original Horizontality: Due to gravity, deposits are layered horizontally.
  • Lateral Continuity: Strata will continue until the materials run out or reach the edge of the depositional basin.
  • Cross-cutting Relations: In order for a deposit to be cut through by another, it must have existed first.
  • Included Fragments: The stuff the deposit is made of is older than the deposit itself (similar to cross-cutting relations).
There are also a few different approaches to defining stratigraphic layers:
  • Lithostratigraphy: Layers are defined by their visible physical properties (color and texture, for instance).
  • Pedostratigraphy: Layers are defined through the soil horizons that separate them (remember, soils are not sediments).
  • Biostratigraphy: Layers are defined by the flora/faunal fossils found in them (changing of shell types, seed types, etc.).
  • Chronostratigraphy: Layers are defined through datable objects found in them.

Depending on the research question, an archaeologist may use any one of these approaches to sort what artifacts are found.

We had a Stratigraphy & Correlations lab to understand how Shovel Test Probes can provide an idea of what the strata look like. We also had to determine, using the geological principals, how the strata became the way they were.

Wednesday:

 Microstratigraphy is a technique geoarchaeologists use to determine site use (is this feature a hearth or where the ash was dumped?), and uses over time (was the hearth used consistently for a long period or was the place chosen over and over again through time?). They take a thin section of soil and can identify different stages of weathering, which means different surfaces over time, through a microscope. To understand this further, we read chapter two and discussed three articles (see the Library for bibliographic information):

  • Microfacies Analysis Assisting Archaeological Stratigraphy
  • Discontinuity in the Stratigraphic Record: Snapshots from Franchthi Cave
  • Chronology and Stratigraphy at Dust Cave, Alabama

 

See other entries with similar topics:

Class Notes: Human Osteology

Saturday: September 24, 2011

(Results for selected topic.)

Week 2: Bone Growth and Joints & Skull

Tuesday:

Bone development (osteogenesis) in the embryonic stage basically forms three layers: the ectoderm, which transforms into skin and teeth enamel; the mesoderm, which forms connective tissues and bone; and the endoderm, which turn into the organs. Mesenchyme in the mesoderm layer will begin to form a cartilaginous skeleton, known as an anlage. This will be followed by a layer of protein matrix which will build the bone shapes. This pre-bone matrix is an osteoid. Mineralization then takes place, creating immature bone. This turns into mature bone once the minerals and proteins become organized through the work of osteoblasts (bone forming cells) and osteoclasts (bone removal cells), to form osteons (organized bone matrix).

Bone repair works in much the same way, beginning with osteoids. If the periosteum becomes strained or torn (the layer on the outside of living bone), a fracture callus will form along with a hematoma (blood mass), allowing osteoids to patch the area until osteoblasts and osteoclasts begin the true remodeling.

There are three classifications of joints:

  • Synarthrosis (fibrous): allows almost no movement (such as that found in cranial sutures)
  • Amphiarthrosis (cartilaginous): allows limited movement (such as that found in gomphosis, which keeps teeth in place)
  • Diarthrosis (synovial): allows much movement (found in synovial joints, which are the typical joints)

Synovial joints come in several forms: ball and socket (ex. hip), hinge (ex. elbow), pivot (ex. shaking head to say “no”), gliding (ex. wrist movement), condyloid (ex. finger joints), and saddle (ex. thumb joint). A synovial joint includes the bones involved, which have a layer of articular cartilage on each of their articular surfaces. This cartilage, along with a synovial membrane, forms the joint, which is filled with synovial fluid. The joint is covered by a fibrous capsule and ligaments keep the capsule in place.

Thursday:

 The first skull appears about 500mya in fish, although it was more osteodentin than true bone. There were no moveable parts, and it acted as armor to protect the notochord. Placoderms derived from this and were the first jawed fish. Chondrichthyes began having a cartilaginous skeleton in addition to the skull plate. Osteichthyes developed a skin covering over the plate, and the plate covered the head, leaving the orbits, nasal, and mouth free. Early tetrapods began the mineralization of the cartilaginous skeleton, and moved out of the water. Their skulls now housed a full brain and teeth.

Today, we see three common types of skulls: anapsids have the boney plate still, but underneath is another boney portion protecting their brain. This set up is heavy, so it works best in aquatic or slow moving animals such as a turtle. Diapsids are similar, except that their boney plate opened up windows to lighten the load. They can move faster on land, and this is seen in alligators. Synapsids opened the window so much that there truly is no longer a window. Instead, synapsids skull is almost entirely only the inner boney portion found in anapsids and diapsids. In fact, the only skull plate left in a synapsid skull is the zygomatic arch (cheek bone). Humans are synapsids.

There are 29 bones in an average human adult skull, along with 32 teeth. In class, we covered the frontal bone, both parietal bones, both temporal bones, the occipital bone, the sphenoid, and the ethmoid.

Friday:

In lab, we examined skull bones to be able to identify features and side fragments.

See other entries with similar topics:

Class Notes: Bioarchaeology

Saturday: September 24, 2011

(Results for selected topic.)

Week 2: Age, Sex, & Ancestry

Tuesday:

Bioarchaeologists begin with determining the biological profile, which would include age, sex, ancestry, and any idiosyncrasies relevant to the individual. It is not clear cut, so the aim is accuracy over precision. For instance, does everyone age in the same way? No. Age has both intrinsic and extrinsic factors: individual development which is then affected by lifestyle stresses. Is a person’s sex truly reflected in their skeleton? Can molecular testing positively identify ancient DNA? Not always. Although sex is genetically determined, the environment can affect the indicators – more physical stresses can lead to more robustness, skewing the indicators of females, for instance. Genetic sex itself is not always concrete either, with developmental issues and hormonal problems, in addition to poor rates of preservation. Is ancestry a discreet classification? No. Ancestry actually is easier than perhaps aging and sexing in older populations because they were small and isolated, but it is still not exacting. This is especially due to limited preservation of certain traits needed to be confident in identifying an ancestral relation. Idiosyncrasies can be more specific since they are blatantly observable in most cases, but even these sometimes are considered “non-specific” because the cause is unknown. When the individuals are then brought together to understand a population, paleodemography can be discussed.

Thursday:

Demographic factors can be affected by age and stress. Stress (trauma, disease, nutrition, lifestyle, etc.) can interrupt the normal growth trajectory of an individual. This is why stature is often used to determine the health of a population. Harris lines can occur in long bones, which may represent periods of stress on the skeleton as well, though these will heal over the course of a lifetime. The development of teeth in children can also be interrupted, which forms linear enamel hypoplasia (LEH) – horizontal lines typically found in the front teeth, but even something like a fever can cause them so they are not explicitly used to determine overall health. Sometimes the development rate of teeth and the epiphyseal fusing of long bones no longer match as they should, and this may represent a period of stress as well.

Overall, bioarchaeologists have been able to determine that with the adoption of an agricultural lifestyle, health in populations did decline. In part, this is because the hunting-foraging diet is much more widely varied and therefore highly nutritional compared to a concentration on a few staples, particular maize in North America. Perhaps a much more crucial cause of this trend is that an agricultural population is a sedentary one, which will have a denser concentration of people. This creates sanitation issues and the ability for diseases to spread rapidly, either from domesticated animals to humans, or simply humans to other humans.

See other entries with similar topics:

Class Notes: Geoarchaeology

Saturday: September 24, 2011

(Results for selected topic.)

Week 2: Archaeological Sediments (continued)

Monday:

Being Labor Day, there was no class.

Wednesday:

We discussed what geoarchaeology is, namely using geosciences to answer archaeological questions. Geosciences typically work at massive scales, but for archaeology the largest scale is a macro-region. An example could be all of North America, or more specific such as Eastern United States. A regional scale is smaller, such as Indiana, or specifically the Ohio River Valley. An archaeological site varies depending on the research question and could mean a specific cave dwelling, a village occupation, or multiple villages in close proximity. The smallest level of archaeological inquiry is at the stratum level – the layers of dirt and sediments in which archaeological sites are contained. This is where geoarchaeology comes in handy.

In order to understand fully what questions can be answered with geoarchaeology, however, we need to have a full grasp of the field’s study materials so we continued talking about sediments. There are three kinds:

  • Clastic (those derived from parent minerals or rocks, such as gravel)
  • Chemical (those created through precipitation from a solution, such as travertine)
  • Organic (those created from organisms, such as sea shells or nut shells)
They then can be classified further by identifying composition (clastic, chemical, and organic), texture (clay, silt, sand, gravel, pebble, cobble, boulder), and physical characteristics (surface features, sorting characteristics, roundness or angularity, and form).
We also held class discussions over the intro and first chapters of the book and three assigned articles (see the Library for bibliographic information).
  • Archaeological Sediments in Cultural Environments
  • Socializing Geoarchaeology: Insights from Bourdieu’s Theory of Practice Applied to Neolithic and Bronze Age Crete
  • Archaeological Sediments in Coastal Environments
See other entries with similar topics:

Class Notes: Human Osteology

Saturday: September 10, 2011

(Results for selected topic.)

Week 1: What is Bone? & Histology & Introductory Terminology

The course objectives are to give students the abilities of:

  • Know every single bone in the human body
  • Know the function of every bone
  • Understand the microscopic anatomy of bone
  • Determine biological profile of a human skeleton
  • Understand how paleopathology, dietary reconstruction, and paleodemography shed light on early human lifeways
  • Complete the analysis of a human skeleton

Books assigned for class are: Human Osteology and Standards for Data Collection from Human Skeletal Remains. Recommended is also: Identification of Pathological Conditions in Human Skeletal Remains. (See the Library page for bibliographic information.)

There are nine students (6 undergrads and 3 grads). The separation lies in that graduates are expected to not only identify a bone but side it, sex and age it when possible, and note any pathology. Instead of being teamed up to work on the skeletal project, we will do it independently. And we must get at least 70% on each quiz in order to pass.

Tuesday:

The skeleton functions to provide support for the body, anchors for movement of muscles, and protections of organs. It also makes blood, stores minerals, and assists with breathing, digestion, the immune system, and the central nervous system.

Briefly, bones are composed of roughly 65% calcium phosphate mineral (part of the hydroxyapatite composition), which gives bones their strength. The other part of the make-up is collagen, which gives bone enough elasticity to not be brittle. We went into detail of long bones, which have three main parts: the diaphysis (the long shaft), the metaphysis (widening of the shaft at either end), and the epiphysis (the end cap which forms separately and fuses during growth).

The diaphysis is made up of dense cortical bone, which then fades into thin subchondral bone (which is covered by cartilage) at the metaphysis and covers the epiphysis. The ends of long bones have trabecular bone, otherwise known as spongy bone. This is so that a bone can absorb impact without shattering. The outside of a bone is covered with a living tissue called periosteum, while the inside of the bone along the medullary cavity (which is where marrow is stored) is lined with endosteum. Because a bone must grow and also remodel after trauma, it needs nourishment like any other part of the body. Therefore, between the marrow (which houses fat and calcium as well as creates blood cells) and the periosteum,the cortical bone is made of osteons.

Osteons are small tubes of lamellar bone which form concentric circles around a Haversian canal. Through the canal, blood, lymph, and nerve endings are channeled. Between osteons are Volkamm’s canals which further channel the means necessary for nourishment. Within the lamellae are lacunae, or small cavities where the actual living cells of bone (osteocytes) needing the nourishment are housed. These are then connected to the entire system via tiny channels called canaliculi.

Thursday:

We went into further detail of the histology of bone and teeth but I will spare you the details (you can check it out at Wiki). Then we covered the anatomical position and its reference planes/directional terms. These include midsagittal, parasagittal, transverse, coronal, and oblique planes. Also, anterior/posterior, ventral/dorsal, superior/inferior, and medial/lateral directions.

Particular kinds of bone landmarks were also mentioned. The list is long but a few of them are foramina (holes), sutures (the squiggly lines on a skull), condyles (where two bones articulate), and fontanelle (the soft spots on a newborns head).

Friday:

Fridays are lab days. They begin with a quiz and the rest of the time is spent working on a packet of material. We covered what I have already mentioned in detail and we had to be able to draw certain items (like an osteon or the parts of a long bone) and label features on a bone (like a protuberance, a turbercle, and a tuberosity). The three hours scheduled truly is not enough time to really grasp it all. It is a little daunting to know how much harder the course will become and how much less free time I will have to hit the lab after hours, but I am excited for the challenge that Human Osteology will give me. Bring it!

See other entries with similar topics:

Class Notes: Bioarchaeology

Saturday: September 10, 2011

(Results for selected topic.)

Week 1: What is bioarchaeology?

The course objectives are to inform students of:

  • History of bioarchaeology
  • Theoretical rubrics that surround bioarchaeological analysis
  • New directions of bioarchaeological study
  • Ethics of studying the ancient dead

We are assigned two texts for the course: Bioarchaeology and Ancient Health. Grad students have an additional book: Biological Anthropology of the Human Skeleton. (See the Library page for bibliographic information.)

This class is cross-listed with undergrads (eleven of them, three of us grads). The main difference is the extra text and the discussions that we will lead from it, in a form similar to seminars.

Tuesday:

We discussed what bioarchaeology is, and the method involved of mixing biological theory with social theory. Very briefly, bioarchaeology examines past human remains (mostly hard tissues of bone and teeth although the occasional mummy comes to light) to understand behavior, subsistence practices, and sociopolitical organization of a population.

We then went over the history of the field. During the 1800s, C. B. Moore was considered an “archaeologist” and gave a lot of artifacts to museums (how he obtained them may be a bit dubious). Only recently, in the early 1900s did skeletal remains begin to be seen as an important source of information. A. Hrdlicka, perhaps the first “bioarchaeologist”, founded the American Journal of Physical Anthropology, still active today. After having studied different native groups (also quite dubiously), he realized that there were certain physical traits present (such as shoveled incisors, also common to those with Asian descent). Following him, people began to use analytical methods to understand how skeletons age throughout life. Only in the 70’s did the term bioarchaeology get coined and still yet not until 1990 was the Native American Graves Protection Act passed that really set the stage for respectful and professional studies of past populations (of course, I suspect some “professionals” are yet still dubious themselves, unfortunately).

I completely respect the viewpoint that the dead should remain buried. Unfortunately, as America changes and construction goes on, old grave sites get dug up or discovered all the time. In place is Cultural Resource Management, which is a sector that I may pursue after my degree. CRM bioarchaeologists are hired on rescue missions when a new street or new office basement uncovers human remains. If possible, the population is identified so that they can be repatriated to the closest native group for proper ceremony and reburial. Don’t get me wrong though – immigrant (“American”) burials are in just as much peril, if not more, than native groups. Side note: some people find skeletons and all that to be creepy but I would like to point out that if I could just examine my own skeleton I would be more excited than if I won the lotto. True story.

Thursday:

We discussed how the turn from foraging hunter-gatherer societies to sedentary agricultural societies is one of the worse decisions ever as far as health is concerned. Close living with higher populations leads to unsanitary conditions and rapid spread of disease. Nutritionally, agri diets are far less varied in nutrients and are often focus on one type (ie. maize) which can lead to health problems itself (cavities). Think about your own diet – how many different types of food do you truly eat on a regular bases? (And think about what the potential is across the globe!)

The context in which a skelly is found is critical. For instance, cultural phenomena can be seen in burials. The burial itself is evidence that the society had a specific way of laying their beloveds to rest. Social stratification can be seen – elite class people may be buried closer to a monument, whereas the common class may be at the outskirts. To further this thought, do the elites show better health in their skeletons than the commoners? What type of grave goods do each get? Are men treated differently in burials than women? Than children? These are only a few questions that can be answered and interpreted from a burial.

But much like anything else, bioarchaeology does have some limitations. For starters, those discovered are only a subsample of the whole population. Maybe not everyone was buried in the particular area. Maybe not everyone was found or even preserved to be found. Obviously, bones will not show everything and sometimes cannot be fully recognized for classifications. The processes which occur after a burial (called taphonomic processes) can disrupt the bones as well as the burial.

As the program goes on, I will try to explain some of these ideas in further detail.

See other entries with similar topics:

Class Notes: Geoarchaeology

Saturday: September 10, 2011

(Results for selected topic.)

Week 1: Archaeological Sediments

Monday:

We simply covered the syllabus and expectations in the class. The course objectives are to enable students with the abilities of:

  • Theoretical and methodological foundation for interpreting the physical remains of human activities
  • Use earth-science concepts to answer archaeological research questions in both the field and lab
  • Generate topographic and archaeological site maps
  • Identify earth materials like rocks, minerals, and native metals used by prehistoric peoples in Indiana
  • Locate and identify archaeological sites, interpret site formation processes, and reconstruct prehistoric human behavior
  • Participate in an on-going research project

The book assigned for class is: Practical and Theoretical Geoarchaeology. (See the Library page for bibliography information.)

There are 8 people in my class, which is cross-listed with undergrads (four to four ratio). The main separation is that we (the grads) read more articles and have essays due every week.

There is also a field trip involved to participate in the on-going research project which is scheduled later in the semester.

Wednesday:

We had a geology lab to identify minerals, and igneous, sedimentary, and metamorphic rocks. This was not one of my best classes as an undergrad (colors are much too subjective for me!) so hopefully the focus quickly changes to something I am better at.

Minerals can be identified by: luster, color, hardness, cleavage, streak, and sometimes special properties. We identified: copper, halite, quartz, calcite, chert, k-feldspar, galena, hornblende, biotite, muscovite, kaolinite, pyrite, hematite, magnetite, and fluorite.

Igneous rocks can be identified by: color, texture, and the essential mineral or accessories mineral components. We identified: pink granite, basalt, obsidian, gabbro, rhyolite, and pumice.

Sedimentary rocks can be identified by: origin, texture, particle size, composite or diagnostic features, and likely sedimentary environment. We identified: shale, conglomerate, fossiliferous limestone, arkose, lithographic limestone, bituminous coal, dolostone, sedimentary breccia, siltstone, peat, travertine, rock salt, and coquina. Other possible ones we looked at were: chalk or claystone and quartz-sandstone or oolitic limestone (the lab has not yet been graded so I am not sure what I was actually examining).

Metamorphic rocks can be identified by: color, texture, grain size, and diagnostic minerals. We identified: marble, quartzite, slate, schist, and gneiss.

The grads were paired with undergrads and I worked primarily with Lori. Having just taken a geo class as a pre-req to get into this one, she taught me well!

See other entries with similar topics:
World Map World Map
australopithechic.anthroclub.com: copyright 2011 and beyond