Forensic anthropology in conflict zones

The popular press has taken some recent shots at the utility of anthropology specifically, the social sciences generally and, most broadly, a liberal arts education. While this knowledge may not produce a bunch of millionaires, it does make real differences in the lives of real people. We (the Department of Anthropology at UNCG) hosted a great talk this past Wednesday (November 6th) that demonstrates this very process in action. David Hines, a Ph.D. candidate at the University of Florida, presented on his forensic anthropological work excavating mass graves in Iraq. David originally contacted the department because his father taught at UNCG and, during the few months a year that he is in the states, makes him home in Greensboro. Currently, he serves as a forensic anthropology trainer for the Iraq offices of the International Commission on Missing Persons.

The numbers that Hines cited are staggering: an estimated 300,000 to over 1,000,000 missing people are thought to be buried in known or unknown mass graves within the country, most as a consequence of Saddam Hussein's regime. Hines related that most of these deaths occurred during the Iran-Iraq War (1980-1988), political infighting, the murder of political dissidents, terrorism, and the Anfal campaign (the genocide of the Kurds and other non-Arab populations in the late 1980s). He gave a nice overview of the political situation in the country (which is critical to understanding how this sort of work can be carried out) and how they go about finding and excavating the mass graves.

The talk was really, really well attended (350+ showed up), thanks largely to the organizational talents of our Student Anthropological Society. A huge thanks to David for taking the time to visit!

Paleoanthropology and Paleolithic archaeology in the southern Caucasus (oh yea, and the new cranium from Dmanisi)

So, a bit more detail on the workshop in Tbilisi:

• The southern Caucasus is quickly becoming a hotspot for paleoanthropology and Paleolithic archaeology. Of course we have Dmanisi, but the entire region is cholk-full of Paleolithic sites. Western researchers are not as familiar with it, nor do they use it as much, as they should, mainly because most information is published in Georgian, Armenian, and Russian, and the data has generally been of relatively low quality. We are, however, rapidly moving towards the production of a very rich dataset for the region.  
• Tbilisi is a pretty, vibrant city, and the food is really good, particularly for a carnivore such as myself. The Georgian National Museum is also a beautiful, state-of-the-art facility.

Angela Bruch giving introductory remarks in the Georgian National Museum's lecture hall.

• Michael Maerker, a geographer at Tuebingen, gave a talk about using GIS predictive modelling to identify the location of paleo-lakeshores. This is really interesting work given how closely tied early hominins appear to be associated with these sorts of habitats. (He's also a really nice guy and fun to be around.)
• I presented our work on a couple Middle Paleolithic sites that we've started excavating in northern Armenia. One of the complaints I had was that we hadn't found any faunal material yet. Reid Ferring said that he had found several MP sites just north of the border in Georgia with bones, so there's hope I suppose...
• This was not a coincidence, I suspect, but the official announcement of the most recently discovered cranium (D4500) was made during the last day of the workshop. So, that brings the count of hominin crania from the site up to five now. This was particularly interesting since the newest cranium, found in 2005, apparently matches up with the mandible (D2600) that was discovered way back in 2000. David Lordkipanidze, the leader of the Dmanisi team, made the official announcement at the Georgian National Museum (it was all in Georgian, of course). They're basically calling all the specimens Homo erectus and, in fact, are suggesting that all early Homo specimens from this time period should also be referred to that species.  

David Lordkipanidze speaking to the press about the new Dmanisi cranium.

• The highlight of the workshop was, naturally, the visit to Dmanisi. The best part was that we were given a personal tour by Reid Ferring, who's been studying the archaeology and geology of the site for 20 years or so. gave us a fantastic tour of the site and a fantastic explanation of the geology. I have to admit that the site's stratigraphy had always been somewhat of a mystery to me, but Reid's on-site explanation really cleared things up (we had actually visited the site in 2012, but the excavation team was not there that day).

A shot looking down into what's referred to as the M5 Trench at Dmanisi. For scale, the total depth is over 6 meters.

Overall, a really wonderful experience.

Just back from Georgia

I just returned from a really great workshop entitled "The Role of the Southern Caucasus on Early Human Evolution and Expansion−Refuge, Hub or Source Area?" that was held at the Georgian National Museum in Tbilisi from October 15-20. The workshop was organized by the project The Role of Culture in Early Expansions of Humans, whose main goal, according to their website "is to explain the reasons for different hominin expansions." The whole experience was excellent, and I was able to see a few good friends and learn about the latest research in the southern Caucasus. The Dmanisi team also announced the newest hominin cranium (the timing, I think, was not a coincidence). I'll blog about this in more detail soon....   

Bookmarks Festival

Last Saturday (11/7) my wife, Noell, our son Simon, and I went to this year's Bookmarks Festival in Winston-Salem. It's really a wonderful event that brings authors from around the country together to interact with readers. Simon is at the age (just over 3 months) were he is unfortunately too young to enjoy the made-for-kids events like story time but, fortunately, also too young (and immobile) to get overly bored with the adult presentations.

I wanted to go because the eminent Civil War historian James McPherson was talking about his new book War on the Waters: The Union and Confederate Navies, 1861-1865, which examines an under-appreciated aspect of the conflict. Actually, Professor McPherson gave a talk at UNCG the day before, but I was unable to attend.

McPherson framed his discussion around the issue of foreign intervention: the American Civil War was, he pointed out, a rare example of an internal conflict that did not require official intervention by foreign powers (the recent hostilities in Syria, on the other hand, reflect the more common pattern). The Union and Confederate navies played key roles in determining how nations such as France and Britain decided to deal with the belligerents. Three events were particularly important:

• The Trent Affair. In November of 1861 the Union navy intercepted the British mail ship Trent and, with it, two Confederate envoys whose aim was to secure British and French recognition of the Confederacy as a sovereign nation. Without permission from Washington, the Trent was boarded and the two envoys arrested. Although the ship was allowed to continue on its journey, Britain protested that the boarding violated her neutrality and demanded a formal apology and the release of the prisoners. Wanting to avoid an armed conflict, the Lincoln Administration eventually freed the captives. While Britain was focused on maintaining her neutrality throughout the affair, a Union bungling of the situation could certainly have significantly worsened its relationship with Britain (the latter, in fact, had ordered additional troops to Canada and ships to the Atlantic).
• The Union blockade. Almost as soon as hostilities broke out, Lincoln ordered a naval blockade of the entire Confederate coast. This was, of course, a nearly impossible task given that the cordon would need to extend from the Texas border with Mexico all the way to northern Virginia−a distance of around 2,500 miles. According to international law, the legitimacy of a blockade rested partly on its successful implementation; that is, a legitimate blockade is one that can successfully prevent outgoing ships from leaving and in-going ships from entering. The Confederacy pointed to the numerous ships that were able to run the blockade, while the Union maintained its legitimacy. Eventually, foreign powers recognized the blockade. Professor McPherson pointed out that Britain likely took this stance in part because blockading was an important tool for the Royal Navy itself and a failure to acknowledge the Union blockade would have set a potentially damaging precedent.   
• Construction of Confederate ships in foreign ports. Several ships, disguised as merchant vessels, were built in British yards and eventually served as Confederate commerce raiders. Protests from the American government convinced both Britain and France to seize other ships intended for Confederate service.     

My wife and I took a couple of photos during the talk, and you can see Professor McPherson's BookTV on War on the Waters here.

Professor McPherson giving his book talk. Photo by Noell Egeland.

My wife also pointed out that Adrian Miller would be speaking at the festival, reminding me that we had heard him on NPR a while ago discussing his research on Soul Food. So, we decided to stick around and listen to him, and I'm glad we did. Most importantly, he's a fellow Denverite, something I learned when he came around before his talk and introduced himself to the audience to thank them for coming. He spoke about his book Soul Food: The Surprising Story of an American Cuisine, One Plate at a Time. The most fascinating point that Miller made was that "Soul" or "Southern" food, while partly a modification of African cuisines brought to the New World by slaves, actually partitioned itself by socio-economic status, and not race. That is, both whites and blacks used the same ingredients to make very similar dishes. His point was borne out by how the audience−black and white−nodded in agreement when he would list off classic southern ingredients.

References:

McPherson, J (2012). War on the waters: the Union and Confederate Navies, 1861-1865. University of North Carolina Press, Chapel Hill.

Miller, A (2013). Soul Food: the surprising story of an American cuisine, one plate at a time. University of North Carolina Press, Chapel Hill.

The Immortal Life of Henrietta Lacks

The summer read for this year's freshman class at UNCG is The Immortal Life of Henrietta Lacks, by Rebecca Skloot. Incidentally, we as an anthropology faculty also chose this book to represent the theme (ethics) in our department's senior capstone course for the fall. I had not read the book before (my wife had read it and recommended it highly) so I quickly finished it in order to prepare for a discussion hosted by UNCG's Office of Multicultural Affairs last Wednesday (9/4). A synopsis of the incredible story (from Amazon.com):

Her name was Henrietta Lacks, but scientists know her as HeLa. She was a poor Southern tobacco farmer who worked the same land as her slave ancestors, yet her cells−taken without her knowledge−became one of the most important tools in medicine. The first "immortal" human cells grown in culture, they are still alive today, though she has been dead for more than sixty years. If you could pile all HeLa cells ever grown onto a scale, they'd weigh more than 50 million metric tons-as much as a hundred Empire State Buildings. HeLa cells were vital for developing the polio vaccine; uncovered secrets of cancer, viruses, and the atom bomb's effects; helped lead to important advances like in vitro fertilization, cloning, and gene mapping; and have been bought and sold by the billions.

Yet Henrietta Lacks remains virtually unknown, buried in an unmarked grave.

Now Rebecca Skloot takes us on an extraordinary journey, from the "colored" ward of Johns Hopkins Hospital in the 1950s to stark white laboratories with freezers full of HeLa cells; from Henrietta's small, dying hometown of Clover, Virginia−a land of wooden slave quarters, faith healings, and voodoo−to East Baltimore today, where her children and grandchildren live and struggle with the legacy of her cells.

Henrietta's family did not learn of her "immortality" until more than twenty years after her death, when scientists investigating HeLa began using her husband and children in research without informed consent. And though the cells had launched a multimillion-dollar industry that sells human biological materials, her family never saw any of the profits. As Rebecca Skloot so brilliantly shows, the story of the Lacks family−past and present−is inextricably connected to the dark history of experimentation on African Americans, the birth of bioethics, and the legal battles over whether we control the stuff we are made of.

Over the decade it took to uncover this story, Rebecca became enmeshed in the lives of the Lacks family−especially Henrietta's daughter Deborah, who was devastated to learn about her mother's cells. She was consumed with questions: Had scientists cloned her mother? Did it hurt her when researchers infected her cells with viruses and shot them into space? What happened to her sister, Elsie, who died in a mental institution at the age of fifteen? And if her mother was so important to medicine, why couldn't her children afford health insurance? 

Intimate in feeling, astonishing in scope, and impossible to put down, The Immortal Life of Henrietta Lacks captures the beauty and drama of scientific discovery, as well as its human consequences.

It is an excellent book, and raises many complicated issues. The book discussion was facilitated by Dr. Frank Woods and Michael Cauthen, both a part of the faculty of UNCG's African American Studies program. (Mr. Cauthen received a Master's degree in Anthropology from Purdue.) Dr. Woods wrote a wonderful Op-ed piece on the book in the Greensboro News and Record some time ago, and he read it to start the off discussion. Mr. Cauthen then told the audience what made Henrietta's cells so unique. Most cells are programmed to die (in fact, it's called "programmed cell death," or apoptosis) after about 50 divisions, the so-called Hayflick Limit. What seems to be going on is that our chromosomes' telomeres, which function sort of like an aglet on a shoelace, get shorter and shorter each time our cells divide. We do have an enzyme, telomerase, that does its best to repair our telomeres, but eventually it gets tired out and the telomeres become too short to allow a successful cell division−hence, cell death. This made it very difficult, impossible in fact, to culture, or keep alive indefinitely, human cells for experimentation. Cancer cells, on the other hand, behave much differently: they continue to grow, and grow, and grow, until they coalesce into (sometimes malignant) tumors. At the time her cells were taken in 1951, Henrietta suffered from Type 18 of the Human Papillomavirus (HPV-18), likely acquired from her unfaithful husband. HPV-18 modified Henrietta's telomerase enzyme in such a way that it could repair her cells essentially forever (as far as we know).

After our biology lesson, Dr. Woods posed a couple of questions to the audience:

• Should the Lacks family be financially compensated in some way for the use of their mother's cells?
• Was Henrietta taken advantage of because she was black?
• Do we, or should we, own our tissues once they leave our bodies?
• In the end, did the ends justify the means?

There were opinions on all of these questions, with one audience member suggesting that Henrietta's family should receive free health care for the rest of their lives. I wonder where, or if, one would draw the line on "family": second generation, third, fourth? Some people wondered if George Gey, the scientist who first propagated the HeLa cell line, should have ensured that the Lacks family received money for the cells. However, Gey himself made no money from his work; in fact, once he had cultured the cells, he gave them away for free to any researcher that could use them. Fortunately, Henrietta is gaining some of the thanks today that she so richly deserved while alive. In reponse to the publication of the complete HeLa genome, for example, NIH will now include Lacks family members on the committees that review grants for research on the sequence. At least the family will have some say in how their relative's genome is used. Johns Hopkins, the institute that originally acquired HeLa, now sponsors a yearly Henrietta Lacks Lecture Series, the ultimate goal of which is to "honor Henrietta Lacks and the positive global impact of HeLa cells."

Dr. Woods presented the second questions in another, very interesting, way: would the same thing have happened if Henrietta had been a white woman? After all, the treatment of Henrietta's cancer and the removal of tissue without permission were standard practice at the time. Our department head, Bob Anemone, argued (correctly, I think) that one needs to avoid judging practicioners of the 1950s by today's values and standards. Another audience member made an equally valid point when she responded by asking (I'm paraphrasing), "Ok, but when do you stop using 'but it was way back when' as an excuse to wash our hands of the past?" My thought is that yes, if Henrietta had been a white woman, or any color for that matter, her cancer would have been treated in the same manner and her cells would have been taken without permission. (However, the side effects of her radiation, like vomiting, abdominal pain, and severe headaches, were probably NOT treated the same, as it was "common knowledge" that blacks as a race had a greater tolerance for pain, a misconception that had, and still has, upsetting repercussions.) What would have differed, I suspect, is how a white woman's concerns would have been treated had she, or her family, raised a legal complaint with the hospital (neither Henrietta or her family could afford a lawyer, and it probably wouldn't have mattered if they could).

What about the issue of ownership? As Skloot points out in the book, there is still no law in place that gives individuals legal ownership of their tissue once they have been removed from their bodies. Most courts, in fact, have ruled against the donor (voluntary or otherwise), the most common argument being that granting ownership of tissues to the individuals from whom they were taken creates too many poential barriers to legitimate research. I don't have a good answer for this one, although I was happy to learn that the Supreme Court has ruled that naturally occurring human genes cannot be patented. One audience member thought that the rate of research in the realm is vastly outstripping our ability to create reasonable regulatory policy.

Regarding the last question, I'll let you read the book and answer it on your own...

References:

Skloot, R (2010). The immortal life of Henrietta Lacks. Random House, New York.

Early hominin habitat preferences

I'm in the middle of working on a paper for a special issue of Quaternary International that will bring together recent work at Olduvai Gorge and Peninj, and my contribution focuses on how (or if) carnivore avoidance played a role in conditioning where hominins chose to concentrate their activities. The overarching question, in essence, is: what it is about the areas that preserve accumulations of stones and bones at Olduvai that made them so attractive to hominins (and carnivores)? I came across a new paper by Rhonda Quinn and her colleagues (2013) that uses isotopes to reconstruct the habitat preferences of early hominins in the Turkana Basin of northern Kenya, so I thought I'd take this opportunity to think out loud about the issue of early hominin habitat preferences.

After describing the paleogeography of the Turkana Basin between about 2.4-1.4 Ma, Quinn et al. discuss how they sampled and analyzed a number of nodular pedogenic (i.e., those formed in soils) carbonates for their carbon isotope composition, which can be indicative of vegetation cover. The key part of their analysis is that they split their samples into two different groups: those not associated with artifacts (which presumably represent the sorts of habitats that were available for hominins to select) and those in close proximity to archaeological sites with lithic material (which represent the habitats that hominins actually chose). In essence, they were testing whether or not hominins selected sites with significantly different vegetation regimes relative to what was present in the region as a whole. Interestingly, the answer seems to be yes: the archaeological sites show higher levels of woody vegetation relative to the environment at large.

These graphs show the number of carbonate samples from archaeological locales (dark gray) and non-archaeological locales (white) that fall within particular vegetation types between (a) 2.4-2.2 Ma, (b) 2.0-1.8 Ma, (c) 1.8-1.6 Ma, and (d) 1.6-1.4 Ma. Note how the distributions from the archaeological localities are shifted slightly to the left (i.e., towards more wooded habitats) relative to the general environment. From Quinn et al. (2013: Figure 5).    

I'll let the authors summarize their thoughts (Quinn et al. 2013: 72-73):

Our results demonstrate that lithic archaeological sites had significantly more wooded vegetation compared with what was present throughout the basin from 2.4 to 1.4 Ma. Even as environments became increasingly more grassy, lithic sites continued to be located in a more wooded landscape. Moreover, as the basin transformed from fluvial to lacustrine and back to fluvial hydrological regimes encompassing numerous microenvironments and highly variable geomorphic settings, hominin lithic sites maintained a constant pattern of f_wc [= fraction woody cover] circa 40%. We suggest that our results demonstrate that tool-making hominins utilized behavioral strategies to maintain a relatively more wooded habitat through time potentially to mitigate the effects of environmental perturbations in the basin.

We interpret our results to indicate that during tool-related activities, hominins demonstrated a preference for more wooded environments in the basin than what was generally available at the time. 

This is a pretty interesting finding, although their time bins are, as they acknowledge, pretty broad (about 200,000 years-a lot can happen in that amount of time). It also would have been very interesting if they had considered in their analysis sites that lack lithic material but preserve butchered bones. Perhaps there is something different about those areas that encouraged hominins to butcher carcasses but take all their tools with them.

The pattern they document in the Turkana Basin seems to compliment what is seen at Olduvai. Many of the archaeological occurrences in Bed I (ca. 1.9-1.8 Ma) are found in more wooded (certainly not grassland) habitats, and this appears to change once you hit upper middle Bed II times (after, say, 1.4 Ma), where sites might be located in more open habitats. This period is not covered by the Quinn et al. study, but the expectation would be that archaeological sites after 1.4 Ma in the Turkana Basin would, like those at Olduvai, start to appear in more open habitats.

We always have to be careful about sampling issues, though. I gave a talk a couple of years ago at the University of Arizona and, after mentioning that the Bed I sites all appeared to be within, or very close to, more closed, wooded habitats, while Bed II sites looked to be located in more open settings, Steve Kuhn asked a really great question: is this a real pattern or perhaps just an artifact of sampling? He was asking, in other words, whether the Bed I sites that have been analyzed to date just happen to be in these sorts of environments and the open habitat sites simply haven't yet been found (and vice verse for the Bed II sites). This is an excellent point since, it should be noted, that most of the Bed I sites cluster within a very small area of the gorge that probably does not offer an unbiased view of either Bed I landscapes or hominin behavior.

References:

Quinn, RL, Lepre, CJ, Feibel, CS, Wright, JD, Mortlock, RA, Harmand, S, Brugal, J-P, Roche, H (2013). Pedogenic carbonate stable isotopic evidence for wooded habitat preference of early Pleistocene tool makers in the Turkana Basin. Journal of Human Evolution 65, 65-78.

Field dispatch: back from the gorge

Just arrived at Washington Dulles from Tanzania this morning, and I'm waiting around for my flight back to North Carolina. By all accounts, the 2013 field season was a great success. At our excavations in the DK area, we piece-plotted several hundred bone specimens, not to mention the hundreds of fragments that were recovered from the screens. There are a handful of possible stone artifacts, although we can't say for sure as of yet. The real key will be to fully analyze the faunal material to identify butchery marks that will confirm that hominins were using stone tools to process animal carcasses. My research assistant, Victoria, and I have washed most of the faunal material from this year's and last year's excavations, and we will return to Tanzania at some future date to do the analysis (we leave all the materials in-country for analysis rather than shipping them back to the states). Best of all, our resident group of giraffes was around again. Goodbye for this year, Olduvai!

Jerry and Nicholas removing backfill at the beginning of the field season.

View of trench before 2013 excavation.

My research assistant, Victoria Johnson, happy to be at her first Paleolithic excavation.

Member of our resident giraffe group in the morning on the way to the site.

Concentration of faunal material in Unit K10.

Tori Johnson at the total station looking on as a Maasai goat herd passes by the site.

View of the trench at the end of the 2013 excavation season.

Field dispatch: update from Olduvai Gorge

University of Colorado-Denver fieldschool student Tracy Lancaster preparing to piece-plot materials in Unit L10.

I'm sitting here at the Sundown Restaurant in Karatu with my first real internet connection in about two weeks. The work at the gorge has been going very well; our excavations at DK have now exposed nearly four square meters of deposit, and faunal material is very common. Importantly, most of it appears to be very well preserved. Unfortunately, we have not come across any definitive stone tools as of yet, although a few pieces that were excavated yesterday may have been produced by hominins. I'll provide a more detailed summary of this year's field season next week when I get another stable internet connection...

View of our excavation trench in the DK area. The thick deposit at the top of the sequence is Tuff IB, which is dated to approximately 1.85 million years ago.

Neandertals suffered from cancer, too

A new article in PLoS ONE by Janet Monge and her colleagues reports the discovery of fibrous dysplasia on a 120,000-year-old Neandertal individual from Krapina. Fibrous dysplasia is a benign cancerous disorder that manifests as abnormal bone growth.

Krapina 120.71 in caudal view (a). The large lesion is located above the tubercular facet and extends laterally. The trabeculae have been destroyed and the cortex appears expansive. The thin cortical bone forming the superior surface of the cavern was broken away postmortem. (b) Krapina 120.6 shows the normal pattern of bony trabeculae in the medullary space. The surface irregularities are postmortem. Caption from Monge et al. (2013: Figure 1).

What's really interesting here is that these sorts of disorders are very rare in the archaeological record. The earliest examples were, until now, only about 1,000-4,000 years old. While it's difficult to determine what caused the tumor, it does demonstrate that these sorts of abnormalities are not found solely with modern pollutants that are often thought to be responsible for the high rates of cancers among contemporary populations.

References:

Monge, J, Kricun, M, Radovčić, J, Radovčić, D, Mann, A, Frayer, DW. Fibrous dysplasia in a 120,000+ year old Neandertal from Krapina, Croatia. PLoS ONE 8, e64539.

Genetically identical mice develop individuality

One of the more interesting findings in behavior genetics is the fact that monozygotic twins (essentially genetic clones of one another) that are raised together (essentially in the same general environment) do not develop identical personalities. Clearly, this means that there is some sort of non-shared environmental factors that condition individuality. It is very difficult to pin these factors down in humans because we can't simply throw them into controlled experimental conditions and watch what happens (and rightfully so).

The journal Science has just published a fascinating study by Julia Freund and her colleagues that explores this issue with mice. What they did was take a group of 40 genetically identical female mice (well, about as identical as you can get; they were super inbred, but may vary by a handful of SNPs and/or VNTRs) and let them roam around an enriched environment for a few weeks. They were able to track their movements (in order to examine how "explorative" each individual was) and their hippocampal development (this part of the brain is thought to regulate behavioral plasticity). I'll let the authors pick it up from here (Freund et al. 2013: 758):

This study shows that adult neurogenesis, as an instantiation of brain plasticity, is linked to individual differences in experience among genetically identical individuals who live in a nominally identical environment. About one-fifth of the experiential effects on adult neurogenesis was captured by a measure of roaming through an enriched environment. This finding supports the idea that the key function of adult neurogenesis is to shape hippocampal connectivity according to individual needs and thereby to improve adaptability over the life course and to provide evolutionary advantage...[t]his is in line with the observation that behavioral treaits can be strongly influenced by external stimuli that vary between individuals or populations of individuals...

They continue (Fruend et al., 2013: 759):

Three months of living in a complex environment led to a massive magnification of individual differences in explorative behavior among genetically identical individuals over time, and these differences were related to adult hippocampal neurogenesis. The rich environment lost its "sameness" over time and gave way to the emergence of a personalized "life space" and a "mouse individuality," similar to what has been observed in humans for personality traits.

There has been a lot of discussion regarding cloning. Now, if you wanted to produce two absolutely identical people, think about all the factors you'd have to keep constant, and we're not just talking about minute changes in the intrauterine environment (temperature, etc.), but also all the experiences an individual will have over their lifetimes. Genetically cloning an individual may not be so difficult, but creating two identical human beings may be nigh impossible.

References:

Freund, J, Brandmaier, AM, Lewejohann, L, Kirste, I, Kritzler, M, Krüger, A, Sachser, N, Lindenberger, U, Kempermann, G (2013). Emergence of individuality in genetically identical mice. Science 340, 756-759.

The end of slavery and the Old South

I just finished Bruce Levine's book, The Fall of the House of Dixie: The Civil War and the Social Revolution that Transformed the South. Most of what I've read on the Civil War, while not ignoring the southern perspective, is typically written through northern eyes. I therefore found two things particularly interesting in Levine's book:

• Southern opinion was actually quite diverse on the question of succession and the war. The inevitability of succession was by no means shared by all southern whites, and there were several southern-based groups that actively fought against the Confederacy throughout the war. In fact, Robert E. Lee and other Confederate officers were forced to dispatch regiments from the regular army to help with home defense. 
• While most southern (and northern, for that matter) whites shared a common belief in white supremacy, only a select few at the top of the social hierarchy owned most of the slaves. This means that many of the soldiers fighting for the Confederacy were non-slave holders, and as the war dragged on many of these poorer folks developed a deep resentment for the planter elite. They began to wonder why they should fight such a destructive war to preserve an institution that they never had, nor likely ever would, benefit from.

Levine, in his BookTV lecture (you can also check out an NPR interview here), cites a recent national survey in which 50% of Americans polled "deny that slavery was the main cause of the U.S. Civil War." This view is even more prevalent among those below 30 years of age (nearly 3 out of 5). One of the key points of the book, and most of the contemporary sources appear quite clear on this, is that slavery was in fact a major, if not the major, impetus for the war. Other motivating factors, like the defense of state's rights or the maintenance of southern honor, while certainly important to some individuals, were largely concocted by elite slave owners to inspire the non-slave holding majority to participate, or drudged up years later to justify the war in a postbellum society hostile to slavery.

Although I didn't plan it this way, the North Carolina Museum of History is currently exhibiting an original copy of the Preliminary Emancipation Proclamation, which Lincoln issued in September of 1862 and warned the Confederacy of the Union's intention to grant freedom to slaves within areas still in active rebellion. My wife and I stopped by the exhibit yesterday, and two pages of the proclamation (they never have all seven on display at once), written in the hand of one of  Lincoln's secretaries (I would guess either John Hay or John Nicolay, although I have not been able to confirm this), are on display. The museum will also be showing North Carolina's original copy of the 13th Amendment that abolished slavery in the United States:

References:

Levine, B (2013). The fall of the house of Dixie: The Civil War and the social revolution the transformed the South. Random House, New York.

Congress and NSF face off

The chairman of the House Committee on Science, Space, and Technology, Republican Lamar Smith of Texas, has recently prepared a bill entitled "The High-Quality Research Act" that aims to revise the criteria by which the National Science Foundation would award grants. According to ScienceInsider, the new bill would:

require the NSF director to post on NSF's website, prior to any award, a declaration that certifies the research is (1)...in the interests of the United States to advance the national health, prosperity, or welfare, and to secure national defense by promoting the progress of science; (2)...the finest quality, is groundbreaking, and answer questions or solves problems that are of utmost importance to society at large; (3)...not duplicative of other research projects being funded by the Foundation or other Federal agencies.

The bill is being proposed in response to several social science grants that were identified as a waste of tax-payer money. I am in agreement with arstechnica's John Timmer who, in response to points (2) and (3) of the bill's criteria, argues:

The other two requirements, however, completely misunderstand both basic research and the role of the National Science Foundation. Basic research is largely about exploring the unknown; by definition, it's almost impossible to tell which areas of research will end up being groundbreaking of have commercial applications. And the NSF is specially tasked with funding basic research and science education.

Should NSF and other government funding agencies be required to justify their decisions? Absolutely. But who is best qualified to judge the merit of these projects? I'd say the hard-working, anonymous reviewers who have expertise in each particular field. I'll be keeping an eye on this...

Neandertals on TV

Just a quick note to let readers know that PBS is premiering two documentaries on Neandertals tonight, both of which highlight the very latest science on these extinct humans. One is called "Decoding Neanderthals" and focuses on the new genetic and archaeological data, while the other is part of PBS's "Secrets of the Dead" series and focuses on the forensic-type information gleaned from Neandertal fossils. I've seen a bit of the "Decoding Neanderthals" show (you can view it for free on PBS's website), and it appears to be pretty good.

Can you scan that fossil for me?

Jean-Jacques Hublin, the director of the Department of Human Evolution at the Max Planck Institute for Evolutionary Anthropology, recently commented in the journal Nature on the need to provide free (or at least affordable) access to digital data for paleoanthropologists. Hublin discusses microCT data of hominin fossils in particular, and the Leipzig team just recently released quite a bit of free digital material for the hominin fossils from Kromdraai, South Africa (Skinner et al., 2013).

The question of access has always been a thorny one in paleoanthropology: on the one hand you have the research teams that spend months (even years) recovering the fossils and the museums whose responsibility it is to protect their country's heritage, and, on the other, researchers and educators who would like access to the materials to carry out additional research and teaching. I think open access to data is a good idea in principle, now its just a matter of convincing researchers and museums to open up! Easier said than done. Once you publish a study, the data are, after all, available, but many researchers are hesitant to publish their raw data because they may still want to carry out additional analyses before anyone else (and why not?). In other cases, its simply a matter of data management capabilities and expertise rather than any stinginess.

References:

Hublin, J-J (2013). Free digital scans of human fossils. Nature 497, 183.

Skinner, MM, Kivell, TL, Potze, S, Hublin, J-J (2013). Microtomographic archive of fossil hominin specimens from Kromdraai B, South Africa. Journal of Human Evolution 64, 434-447.

Early hominin meat-eating and expensive tissues

I actually was not aware of its publication until I came across it on John Hawks's weblog, but Joseph Ferraro and his coworkers have come out with a detailed taphonomic analysis of the faunal remains from Kanjera South, an important Oldowan site from Kenya that dates to about 2 million years ago. Their abstract does a nice job of summarizing the significance of the site and the study's findings (I guess this is what abstracts are supposed to do, after all; Ferraro et al., 2013: 1):

The emergence of lithic technology by ~2.6 million years ago (Ma) is often interpreted as a correlate of increasingly recurrent hominin acquisition and consumption of animal remains. Associated faunal evidence, however, is poorly preserved prior to ~1.8 Ma, limiting our understanding of early archaeological (Oldowan) hominin carnivory. Here, we detail three large well-preserved zooarchaeological assemblages from Kanjera South, Kenya. The assemblages date to ~2.0 Ma, pre-dating all previously published archaeofaunas of appreciable size. At Kanjera, there is clear evidence that Oldowan hominins acquired and processed numerous, relatively complete, small ungulate carcasses. Moreover, they had at least occasional access to the fleshed remains of larger, wildebeest-sized animals. The overall record of hominin activities is consistent throughout the stratified sequence - spanning hundreds to thousands of years - and provides the earliest archaeological evidence of sustained hominin involvement with fleshed animal remains (i.e., persistent carnivory), a foraging adaptation central to many models of hominin evolution.

This research team has been working hard out a Kanjera for many years now, and its really nice to see a comprehensive analysis of the faunal material from the site (we'd been getting tantalizing hints in various publications and presentations for some time).

Before we proceed, let me summarize the state of affairs just prior to these latest data. The 1.8 Ma time marker that Ferraro et al. mentions refers to the burst of evidence for meat-eating that emerges almost exclusively from Olduvai Gorge in Tanzania. One site in particular, the very well-known Level 22 at the gorge's FLK locality (also known as the Zinjanthropus Floor), dates to about 1.84 Ma and preserves thousands of fossils, many of which bear clear indications of hominin butchery. Now, up until a few years ago, it was thought that the animal bones from many of the other sites from Beds I and II of the gorge (ca. 1.9-1.2 Ma) were also largely the result of hominin activity. However, my colleagues and I showed that there are really only two sites, the previously mentioned FLK 22 from Bed I, and the site of BK, in upper Bed II (about 1.3 Ma), that are largely the result of hominin butchery (Domínguez-Rodrigo et al., 2007, 2009; Egeland, 2008; Egeland and Domínguez-Rodrigo, 2008). Now, we're not saying that hominins weren't at the sites; they certainly made, used, and left stone tools at these locations, but they were not doing a lot of meat-eating. There are a couple of other Oldowan sites here and there with some evidence for butchery, but if we ignore FLK 22 for the moment, good evidence for lots of meat-eating (or, to use Ferraro et al.'s term, "persistent carnivory") really doesn't pick up until much later, perhaps about 1.5 Ma.

What does all of this have to do with expensive tissues? Well, researchers have come up with several well reasoned, and very popular, human evolutionary models based ultimately on the shift to meat-eating. To start, brains and guts are very expensive tissues: one does a lot of thinking and the other does a lot of digesting, both of which take up good amounts of energy. If you start eating more meat, which is nutrient dense and easy to digest, you can divert energy from the guts to develop bigger noggins. Other possible correlates of a diet based increasingly on meat would be increased range size (carnivores, and other animal that eat high quality, easy to digest foods, tend to have larger ranges) and unique life histories (extracting nutrients using technology, and hunting with technology in particular, are difficult things to learn, and you don't want to die before you learn how to do them well, so perhaps we've evolved extended life spans to fit this need). People have traditionally seen the evolution of Homo erectus, with its bigger brain, long, lanky legs, and ability to leave Africa to colonize parts of Eurasia, around 1.8 Ma as great evidence for these shifts. Ok, all well and good, but, to use an old phrase: where's the beef? In other words, where is the evidence for sustained meat-eating just before and as H. erectus was evolving? Other than a single site, FLK 22, there really wasn't much...until now.

This is what makes the Kanjera evidence so important. I'm not sure it completely quashes my reservations (after all, we still only have two sites with good evidence for regular meat-eating between 2.6 Ma, when stone tools were first invented and used to butcher carcasses, and 1.5 Ma), but it is a good start.

References:

Domínguez-Rodrigo, M, Barba, R, Egeland, CP (2007). Deconstructing Olduvai: A taphonomic study of the Bed I sites. Springer, New York.

Domínguez-Rodrigo, M, Mabulla, AZ, Bunn, HT, Barba, R, Diez-Martín, F, Egeland, CP, Egeland, AG, Yravedra, J, Sánchez, P (2009). Unraveling hominin behavior at another anthropogenic site from Olduvai Gorge (Tanzania): New archaeological and taphonomic research at BK, Upper Bed II. Journal of Human Evolution 57, 260-283.

Egeland, CP, Domínguez-Rodrigo, M (2008). Taphonomic perspectives on hominid site use and foraging strategies during Bed II times at Olduvai Gorge, Tanzania. Journal of Human Evolution 55, 1031-1052.

Ferraro, JV, Plummer, TW, Pobiner, BL, Oliver, JS, Bishop, LC, Braun, DR, Ditchfield, PW, Seaman III, JW, Binetti, KM, Seaman Jr, JW, Hertel, F, Potts, R (2013). Earliest archaeological evidence of persistent hominin carnivory. PLoS ONE 8, e62174.

Archaic humans versus giant hyenas in Pleistocene Europe

María Patrocinio-Espigares and her colleagues have published an interesting study claiming to have identified evidence for competition between archaic humans and giant hyenas for access to a mammoth carcass from a site in Spain dated to over one million years ago. The site, Fuente Nueva-3, is found near the southern Spanish village of Orce, which is an extremely rich area for early Pleistocene fossils, including those of hominins. In fact, Fuente Nueva-3 and a nearby site, Barranco León, dated to 1.3 and 1.4 million years ago, respectively, currently preserve the oldest well accepted evidence for hominin occupation in all of Europe.

The excavations at Fuente Nueva-3 have been ongoing for well over a decade, but this paper reports on a partial skeleton of Mammuthus meridionalis, a species of mammoth, found in association with a few stone tools and, intriguingly, some coprolites (that is, fossilized poop). The materials were deposited near the edge of an ancient lake, and the authors argue that the mammoth (an old female) probably died of natural causes. The skeleton is relatively complete; only the legs and the head are missing.

Photo (A) and map (B) showing the distribution of mammoth bones, stone tools, and coprolites from Fuenta Nueva-3 . From Espigares et al. (2013: Figure 4).

Butchery marks (cutmarks from stone knives and percussion marks and notches from breaking open bones for marrow; although, some of the so-called percussion notches look a lot like the carnivore-created notches I've seen from modern assemblages) and tooth marks are pretty common on many bones from levels above and below the mammoth skeleton, but none whatsoever have been discovered on the mammoth bones in question. Nevertheless, the authors contend that the carcass was butchered by hominins, who removed the legs for consumption elsewhere, and later partly consumed by giant short-faced hyenas (Pachycrocuta brevirostris; they do not, however, tell us how they know the coprolites are those of a hyena).

I suppose this is possible. The authors correctly note that proboscideans are so big, and are covered by so much tough soft tissue, that butchery and tooth marks are unlikely to be inflicted. Pachycrocuta, though, as a recent paper by many of the same authors tells us, was about one-and-a-half times bigger than modern spotted hyenas and probably better adapted to bone-cracking than any other mammal that ever existed (Palmqvist et al., 2011) so, if anything would have left tooth marks on a mammoth-sized carcass, you would think it would be Pachycrocuta. I'll let the authors summarize their thoughts (Patrocinio-Espigares et al., 2013: 122; see the drawing by the very talented Mauricio Antón below for a reconstruction):

The Upper Archaeological Level of Fuente Nueva-3, dated around 1.3 Ma, provides the oldest evidence of a probable competition between Homo and Pachycrocuta, the two major bone-modifying and accumulating agents during early Pleistocene times in Europe. The evidence lies in the finding of an incomplete skeleton of M. meridionalis surrounded by 34 coprolites and 17 lithic artifacts. The skewed spatial distribution of these elements, the physical characteristics of the coprolites and the absence of the elephant limbs and cranium suggest that both hominins and hyenas scavenged the carcass of this megaherbivore, following a sequence of consumption in which the hominins arrived first, dismembered and transported the limbs, and probably also the cranium, and later the hyenas consumed the rest of the elephant carcass.

Original caption: Reconstruction of the possible sequence of interaction between hominins (A) and hyenas (B) during the exploitation of the carcass of M. meridionalis. From Patrocinio-Espigares et al. (2013: Figure 7). 

These conclusions are all based on indirect evidence (stone tools that may or may not have been used to butcher the animal, coprolites that may belong to hyenas that may have fed on the carcass). Either way, this does bring up the interesting issue of how hominins and carnivores interacted: were they competitors on the landscape for carcasses? Was this competition direct (i.e., fighting over access to carcasses) or indirect (one removing edible carcasses from the environment that the other in turn could not exploit)? Researchers have in fact suggested that competition from large carnivores went a long way towards preventing hominin populations from permanently colonizing Eurasia until after 600,000 years ago or so.

References:

Palmqvist, P, Martínez-Navarro, B, Pérez-Claros, JA, Torregrosa, V, Figueirido, B, Jiménez-Arenas, JM, Patrocinio-Espigares, M, Ros-Montoya, S, De Renzi, M (2011). The giant hyena Pachycrocuta brevirostris: modelling the bone-cracking behavior of an extinct carnivore. Quaternary International 243, 61-79.

Patrocinio-Espigares, M, Martínez-Navarro, B, Palmqvist, P, Ros-Montoya, S, Toro, I, Agustí, J, Sala, R (2013). Homo vs. Pachycrocuta: earliest evidence of competition for an elephant carcass between scavengers at Fuente Nueva-3 (Orce, Spain). Quaternary International 295, 113-125.

How pathological is the Nariokotome Boy?

Regula Schiess and Martin Haeusler (2013) recently published a paper in the American Journal of Physical Anthropology that critically examines the issue of pathology for KNM-WT 15000 (the "Nariokotome Boy"). This analysis comes on the heels of other recent re-examinations of this important 1.5 million year old skeleton. For example, it was thought by many that the Nariokotome Boy, who died between the ages of 8-11 (based on tooth eruption and microanatomy) and 12-15 (based on bone development), would have attained an adult stature of perhaps 6'1" (185 cm). This suggested to many that a linear, heat-adapted physique was characteristic of Homo erectus. Graves and colleagues (2010) questioned this reconstruction, arguing that the individual would have largely finished growing, and that an adult stature of about 5'4" (163 cm) was closer to the mark (John Hawks, on his weblog, provides additional commentary here).

Several authors have suggested that Nariokotome suffered from growth pathologies that, if corroborated, would preclude the use of this particular skeleton as a reference for Homo erectus skeletal biology (things like maturation rate or stature). Schiess and Haeusler (2013) set out to test whether the skeleton possesses evidence for:

• Unusually small, platyspondylic (that is, flattened) vertebrae.
• Spina bifida, which refers to a series of conditions characterized by the failure of one or more neural arches to close and thus fully encircle the spinal cord.
• Condylus tertius, which is an additional condyle found on the anterior margin of the foramen magnum, right between the two occipital condyles.
• Particularly small spinal canals (spinal stenosis).

If present, this complex of symptoms could be linked to a rare growth anomaly that goes by the fun name of spondyloepiphyseal dysplasia tarda. To carry out the analysis, they compare KNM-WT 15000 to a reference sample of 63 modern humans of various ages (I suspect that since these are archaeological specimens, their ages were estimated, rather than known. The researchers get around this by lumping their sample into broad categories, juveniles, adolescents, and adults, rather than specific ages). So, they found that:

• KNM-WT 15000's vertebral heights are more-or-less what you'd expect for his age group (i.e., they are not pathologically flattened relative to modern adolescent humans).
• The skeleton's vertebrae (as measured by superior surface area) do in fact appear to be small.
• The non-sacral neural arches that are preserved show no evidence for non-fusion. The 3rd through 5th sacral elements are unfused (see below).

Sacral elements of KNM-WT 15000. From Schiess and Haeusler (2013: Figure 4).

• A condylus tertius is definitely present.
• KNM-WT-15000's spinal canals are very small compared to the modern reference sample.

Schiess and Haeusler (2013: 372) therefore conclude:

[T]he apparent flatness of the vertebrae is typical for the immature age of the Nariokotome boy. There is no indication for spina bifida sensu stricto. An extension of the sacral hiatus from S5 up to S3 is normal in humans of the same age as the Nariokotome boy. The condylus tertius is a developmental anomaly that is relatively common in the normal population unaffected by spondyloepiphyseal dysplasia tarda. It has no clinical relevance. Both the relative smallness of the vertebral bodies and a narrow spinal canal are not classic features of spondyloepiphyseal dyspasia tarda. The criteria for spinal stenosis are met in the cervical, but not in the thoracolumbar region. Moreover, pedicle and canal shape are not typical of congenital spinal stenosis. Rather, a comparison with other fossils suggests that a narrow spinal canal and small vertebrae might be specific to early hominins.

It would have been nice to have included individuals with these skeletal abnormalities in the reference sample; surely there is variation in how these conditions manifest (I'm not sure how difficult it is to get a hold of such specimens). Overall, however, they make a convincing case. All of this is not to say that the Nariokotome Boy was perfectly healthy. Schiess and Haeusler do note that the last two lumbar vertebrae are asymmetrical, likely the result of a severely herniated disc, which in turn probably caused a significant limp. Nevertheless, these findings show that the incongruities of the skeletal and dental age-at-death estimates are not the result of a developmental disorder and, further, that this wonderfully complete skeleton can still serve as a useful reference for Homo erectus skeletal biology.

References:

Graves, RR, Lupo, AC, McCarthy, RC, Wescott, DJ, Cunningham, DL (2010). Just how strapping was KNM-WT 15000? Journal of Human Evolution 59, 542-554.

Schiess, R, Haeusler, M (2013). No skeletal dysplasia in the Nariokotome Boy KNM-WT 15000 (Homo erectus) - A reassessment of congential pathologies of the vertebral column. American Journal of Physical Anthropology 150, 367-374.

Cultural misunderstandings: a case study from the British settlement of North America

I'm in the middle of reading Bernard Bailyn's latest book, The Barbarous Years: The Peopling of British North America: The Conflict of Civilizations 1600-1675, and I came across a very interesting example of two cultures talking past one another. A little background: the colony at Jamestown was founded in 1607, and over the next few years, colonists, including the now famous John Smith, undertook expeditions to map the area and to collect (or steal) provisions from the Indians (the colonists were in bad shape almost constantly during the first decades). As might be expected, both cultures were feeling each other out in order to maximize their respective advantages. On the one hand, while the Indians were interested in European trade goods, they wanted to constrain the colonists within small, coastal settlements focused on trade (rather than permanent homesteads). The Europeans were also looking to trade but, for myriad reasons, many where also looking to stay and settle permanently on land occupied by various tribes. Ok, I'll have Bailyn (2012: 57-58) pick it up at the point where he describes a cultural misunderstanding relating to power relationships (note the olde English spelling in the quotes):

In three days of elaborate ceremony and elusive conversation, fending off Powhatan's [a local chief] question of the colonists' purpose in settling, [John] Smith was urged, on behalf of his people, to acknowledge Powhatan 'as their lord' and to accept for himself the role of a subordinate chief. This, of course, to the extent that he understood the proposal, he ignored, but in the end, symbolically at least, he had no choice. After being feasted 'in their best barbarous manner' and treated like a defeated enemy about to be slain, he was brought to what appeared to be an execution block, surrounded by warriors 'ready with clubs to beate out his braines.' Then at the final moment he was suddenly released, adopted as a subordinate werowance, and by extension his people were symbolically enclosed within the constraints of Powhatan's regime. Never, of course, experiencing these events as acts of subordination, and declining the benefits offered, Smith recorded the story of his captivity at first briefly and with little drama (he 'procured his owne liberty'), then elaborated it in retelling, finally embellished it as an elaborate ceremony on the tale of how Pocahontas 'the King's dearest daughter' (who was eleven at the time) 'got his head in her armes, and laid her own upon his to save him from death.'

The parallel effort to subordinate and control barbarous and threatening people, at least symbolically, was played out reciprocally by the English the next year. Smith and Newport [describe him], on order from London, led a troop of musketeers to present Powhatan with a plethora of gifts, inlcuding copper objects, a bedstead and bedclothes  a red coat, and a copper crown, the last a gift heavily freighted with symbolism from the great King James. When with difficulty they managed to place the crown on Powhatan's forcibly bowed head, the ceremonial reduction of the chief of chiefs to the status of a vassal or local lord of King James was complete, symbolically confined within England's sovereign power.

In other words, both cultures carried out elaborate ceremonies that, while meant to subordinate each other, were perceived as meaningless rites because neither culture recognized them for what they were intended to be. The same thing happens all the time with modern cultures; sometimes these interactions can be humorous, but many times they can have serious, even tragic, consequences. For those who say that understanding other cultures is a waste of time, proceed at your own peril...

UPDATE 4.28.13

I've just finished the book, and it was a fascinating read. What struck me most was how heterogeneous the colonizing populations from Europe really were. Recent histories of colonial America have stressed, and correctly so, that Native Americans were not a single, monolithic unit but rather a diverse collection of rich cultures. So too for the incoming Europeans, whose various nationalities, religious views, and socio-economic circumstances determined to a great extent how they interacted with both native cultures and each other.

My Human Biological Variation class was recently engaged in a discussion about the biological reality of race among modern humans and, and it often does, the point that the concept's definition differs from place to place was raised. One student, originally from England, was surprised at how obsessed Americans seemed to be with their origins: people identify as African-American, German, Irish, Native American, and so on, while it is very rare for an English citizen to identify as, say, German-English or African-English. I bring this up because I came across a passage in the book that was particularly salient within this context. In his description of the complex socio-ethnic conditions of a Manhattan recently conquered by the English, Bailyn (2012: 516) outlines the response of the newly incorporated citizenry:

In the late 1660s and 1670s the new English province of New York was far different from its neighboring New England  It was a world in flux, its people caught up in complex ethnic tensions, its economy growing but shifting in organization  it government newly established and weakly related to the society it ruled. The great majority of New Yorkers in Manhattan (an estimated 76 percent of a significant sample) were Dutch, as were the settlers sin what were now called Albany and Schenectady, and they expected to remain Dutch under the English regime. In fact, their "Dutchness" was becoming more prominent  as a process of what Joyce Goodfriend has called the "crystallization" of ethnic groups set in. The various groups, she explains, now in a more open society became more self-aware and felt the need to define themselves in institutional form and to preserve their distinctive characteristics  So the Dutch, despite the differences among them, began to "coalesce"-to consciously value their distinct common ground  in the language, religion, customs  and values. So too other groups sought their own places in this province of tolerated diversity.

I'm not sure how "tolerated" all that diversity really was, but this "crystallization" really does seem to be a common response among peoples within multi-ethnic communities, and it may may go some way in explaining the desire of Americans to be so self-aware of their ancestry.

References:

Bailyn, B (2012). The barbarous years: The peopling of British North America: the conflict of civilizations 1600-1675. Alfred E. Knopf, New York.

Goodfriend, JD (1992). Before the melting pot: society and culture in colonial New York City, 1664-1730. Princeton University Press, Princeton.

Bead-making in the early Upper Paleolithic

Mary Stiner and her colleagues (2013) recently published a really fun analysis of shell beads from the Paleolithic site of Üçağızlı Cave I in Turkey. The levels at the site date to the early Upper Paleolithic, between about 41,000 and 29,000 radiocarbon years ago (calibrated dates place the occupations between about 45,000 and 35,000 years ago).

Examples of perforated shells from Üçağızlı Cave I. From Stiner et al. (2013: Figure 5). 

After demonstrating (convincingly) that the modified shells are, in fact, artificially punctured beads, Stiner et al. (2013) show that the types of shells brought back to the cave, and the types that were chosen as beads, change over time. They provide four hypotheses to explain the change in shell type frequencies: (1) environmental changes determined what sorts of shelled animals were living near the cave, and thus what was available for bead exploitation; (2) the distance from raw materials (mediated by sea level fluctuation) changed over time, in which case people would accumulate more "junk" when raw materials were close and/or convenient and be very selective (i.e., only take the best stuff) when raw materials were distant and/or inconvenient; (3) the diversity of shell types is a function of the number and heterogeneity of shell collectors and users (that is, the more folks, and the more types of folks, exploiting shells will result in greater shell diversity); (4) cultural "conformism," where norms determine the types of shells used during any one time period.

The first hypothesis was not supported, as habitats don't appear to have changed significantly over time. The second hypothesis found some support in the fact that the diversity of ornament shells increased in those levels with evidence of frequent shellfish consumption. The latter would, theoretically, signal that the coast, and thus the raw materials for beads, were relatively close by and people became less picky about what they brought back to the cave for ornamental use. However, Stiner et al. (2013) question whether the distances to, and the weight of, the shells would have played much of a role in mediating what was, or was not, transported to the cave.

In the end, they feel that group size and composition and conformist behavior best explain the patterning in shell usage at the site. This is based on two observations. First, an inverse relationship exists between the diversity of species brought back to the site and the frequency of shells that were actually perforated for use as beads. That is, during time periods where many different types of shell were collected, only a few of those types appear to have been utilized for bead use. In the earliest levels, on the other hand, people transported only a few types of shells back to the cave, but most of them were subsequently perforated. Second, the size and shape of perforated specimens is relatively consistent regardless of time period. Stiner et al. (2013: 396) therefore conclude that:

Several factors contributed to the variation in the UcI ornament assemblages. Sample size effects were addressed early in the analysis and do not explain the patterns that concern us. The taxonomic diversity of the assemblages as a whole stems first from the natural biotic diversity of the marine environment. However, changes in littoral habitats to not seem to account for the differences between assemblages or changes over time. Many other aspects of the variation developed as the material was filtered by human choices. The narrow range of shapes and shell sizes is clearly attributable to human preferences, as are the bias toward whole specimens and the methods of modifying the shells for suspension. The extent of 'noise' or variance in the ornament assemblages is a product of the relationship between raw material collection activities and ornament manufacture and use. 

The fact that the taxonomic diversity of the UcI shell ornaments increased with time while the percentage of holed specimens decreased demonstrates that variation in the assemblages must be considered according to two distinct technological stages: raw material collection and artifact manufacture. The more playful and less constrained stage of artifact life history is raw material collection. Variation in overall raw material diversity among the assemblages related in part to how convenient access was to the shoreline and/or the overall importance of marine foraging from UcI. Variation in raw material also correlates with increasing occupation intensity and dietary breadth; the least variable assemblages formed during the lightest occupations. Changes in the size and complexity of the social groups that occupied UcI therefore may have played a role in shaping variation in the ornament assemblages. Unfortunately, the predictions for neutral social effects (more people on site or present for longer periods) and high-grading effects (raw material access) are difficult to distinguish in this particular case. What we can be certain about is that more 'junk' found its way into the shell raw material brought to the site at some intervals and that very different criteria took over at the manufacture stage. As the times collected were streamed into more formal uses, their characteristics narrowed, and many of the shells initially collected were rejected before further modification. It is for these reasons that we conclude that post-manufacture characteristics of the ornament assemblages most clearly reflect the influence of shared esthetic and visual norms. 

I actually ran into this article while I was mining the latest publications on modern human origins, which we are currently covering in my Paleolithic Archaeology class. One of the traits that many archaeologists associate with "modern" behavior is the use of personal adornment, since it is extremely likely that these items were used by ancient people as symbols to transmit information about themselves (just as jewelry does today). Stiner and her colleagues do not involve themselves in the modern human origins debate (as they note, the beads are not among the oldest in the world, or even in the Levant), but there analysis got me thinking about the importance of group size and complexity in the production of symbols. There is, in fact, quite a bit of recent work in Paleolithic archaeology that invokes the importance of demographic factors (mainly population size and density), rather than cognitive factors, to explain the appearance (and disappearance) of symbolic objects among pre-Upper Paleolithic cultures. Think about it: if you interacted with other groups only very rarely, or you ran into the same groups over and over again, there is very little incentive, even if you were cognitively able, to create a ton information transmitters (i.e., symbols) of any kind, much less those that would preserve in the archaeological record.

References:

Stiner, MC, Kuhn, SL, Güleç, E (2013). Early Upper Paleolithic shell beads at Üçağızlı Cave I (Turkey): Technology and the socioeconomic context of ornament life-histories. Journal of Human Evolution 64, 380-398.

Problem-based learning and STEM education

I am part of a network at UNCG called RISE (Research and Instruction in STEM Education), which is a collection of faculty and staff interested in promoting science education. From the network's website:

The goal of the RISE Network is to enhance and expand the already strong partnership between researchers, educators, and science, mathematics, and technology educators in the community and at UNCG. This will be accomplished by developing a network of interested partners to better coordinate STEM education and research across campus. This network will enhance UNCG's ability to broaden access to STEM fields by:

Creating a more coordinated web of opportunities for undergraduate and graduate students to engage in inquiry-based STEM experiences

Supporting curriculum development through revising STEM courses in order to offer an inquiry-based collaborative method of instruction designed to foster skills in critical thinking, quantitative reasoning, and communication, with the goal of promoting the STEM literacy of our graduates

Enhancing the extent to which UNCG supports high-quality STEM education in pre-K–12 classrooms by designing research-based projects that generate and disseminate knowledge about STEM content and pedagogy and are responsive to student, teacher, and district needs

Facilitating collaboration between local community and business leaders and UNCG concerning scientific literacy skills, skills needed for the next generation of the (local) workforce, and instructional policies and programs to meet these needs 

Providing support for faculty and staff who seek external funding to support the above efforts

I attended the latest event this past Monday, which was a workshop entitled, "Is it Really Teaching if Learning Doesn't Happen?" The network brought in Dr. Ann Lambros, who is Assistant Dean of Medical Education and Assistant Professor of Social Sciences and Health Policy at the Wake Forest School of Medicine, to talk about problem-based learning strategies. "Problem-based learning," along with other buzzwords (or buzz phrases, perhaps?) like "high-impact learning," has garnered quite a bit of recent attention from education policy makers. Although I had heard the term before, I have to admit that I really didn't have a concrete sense of what problem-based learning (or PBL) was.

Essentially, PBL begins with a problem, and learning is achieved as students gather information and test hypotheses to solve the problem. We were provided with a really nice review article on the approach by John R. Savery (2006: 12-15), who, after mining the literature, identified several key components of PBL:

• Students must have the responsibility for their own learning
• The problem simulations used in problem-based learning must be ill-structured and allow for free inquiry
• Learning should be integrated from a wide range of disciplines or subjects
• Collaboration is essential
• What students learn during their self-directed learning must be applied back to the problem with reanalysis and resolution
• A closing analysis of what has been learned from working with the problem and a discussion of what concepts and principles have been learned are essential
• Self and peer assessment should be carried out at the completion of each problem and at the end of every curricular unit
• The activities carried out in problem-based learning must be those valued in the real world
• Student examinations must measure student progress towards the goals of problem-based learning

In her introduction, Dr. Lambros related why Wake Med made the switch to PBL. Studies had shown that med students were struggling to (1) solve problems, (2) stay engaged, and (3) make connections between various concepts. So, they were looking for a new way of doings things; after all, Dr. Lambros said, and I liked the analogy that was made, memorizing a maze was easy enough to do, but the learning becomes useless if the exit is moved.

The attendees went through a PBL exercise, and it works more-or-less like this: First, a real-world problem is presented that requires both some prior knowledge and the acquisition of new knowledge. The group must lay out the facts that are known, decide what sorts of assumptions can or cannot be made, and relate the problem to existing knowledge. Second, students need to identify what additional information is required and, through self-directed learning and open inquiry, will procure this information and formulate hypotheses. Finally, students are asked to present and defend their hypotheses...and the process starts again with the newly gained knowledge serving as the existing knowledge for the next round.

PBL learning model. From the University of Queensland.

I think any teacher will tell you that one of the biggest obstacles to learning is motivation. While grades are meant to fill this role, students become invested in the grade rather than learning. One of the things I like about the PBL approach is that in the process of exploring a problem and eventually being forced to defend hypotheses based on information they themselves gathered, students are invested in the accuracy of their findings and, in the end, feel a sense of ownership. The other major roadblock to learning is relevance: Students must see that what they are learning is going to be relevant in some concrete way. PBL also addresses this by focusing on real-world problems.

There is, however, one glaring issue here: research has failed to show that PBL actually results in systematically better performance relative to more traditional approaches. The major advantage, it seems, is that students report a preference for PBL. The other problem is that PBL only seems to work well when it is implemented at all levels of a curriculum, and this of course requires that faculty and staff buy in to the approach (something that is MUCH easier said than done). The debate will no doubt go on, but I can see myself designing and implementing PBL lessons to see how it works.

References:

Savery, JR (2006). Overview of problem-based learning: definitions and distinctions. Interdisciplinary Journal of Problem-based Learning 1, 9-20.