Taphonomy vs. Pathology in the Archeological Record
by Kerri Wilhelm
As the in-house human osteologist I am responsible for conducting the biological profiles for the numerous sets of human remains that comprise TARL’s Human Osteology (HO) collection. Biological profiles here consist of creating documentation that becomes part of the permanent records for this sensitive collection. Following completion of a physical inventory I attempt to include pertinent information on sex, age at death, stature and ancestral affiliation when possible as revealed through the discriminant functions of FORDISC. I attempt to include information as pertains to evidence of pathology and/or trauma in the remains: healed fractures, lesions, enamel hypoplasia in the dentition, etc. In the fall of this past year I was reviewing several sets of remains in the collection which originated from a cave context. Presenting with what at first appeared to be lytic process affecting the outer table of bone at various locations across the two sets of remains, I was excited that we might potentially have related cases of some identifiable pathology. I was also aware that these ‘lesions’ could also potentially be the result of some taphonomic process that I was unfamiliar with personally. So, what does one do when in need of some human osteological identification assistance? I contact one of my former professors who happens to be a forensic anthropologist and the Physical Anthropology Collections Manager at the Smithsonian’s National Museum of Natural History in D.C.
I contacted Dave and let him know that I needed his assistance to identify the type and nature of a specific ‘signature.’ I forwarded him photographs of the signature as taken at various locations on the two sets of remains. After about a week of back-and-forth, and some research into comparable signatures that could present like a lesion, Dave pointed out that the ‘cavitations’ in the bone progressed from the outer table of the bone inward toward the medullary (marrow) cavity, as opposed to the reverse, originating from the medullary cavity outward. In this instance the former proved to be an indication of a taphonomic process, while the latter would be attributed to a pathologic process such as that which occurs in multiple myeloma (cancer of plasma cells). Now that is was narrowed down to a taphonomic process…what kind was it?
We had to consider the archeological context from which the remains would have originated. A trip down into TARL’s Records Room for the original field notes and final report which resulted from the field investigation revealed that the burial environment was damp, at least seasonally. I also researched the types of scavenging fauna that could potentially produce the ‘cavitations’ while living in the environment in which the burial occurred. The result of the research and identification assistance provided by Dave Hunt, in conjunction with the specific signature observed in the bone, led to an identification of “terrestrial snail activity.” Despite no longer having him as a professor, Dave is still teaching by means of sharing his invaluable experience as a physical and forensic anthropologist. Now our collections documentation can include the identification of the signature on the remains and future researchers here at TARL can benefit from a new tool to better interpret the taphonomic processes involved in the archeology of human burials.
You can learn more about Dave Hunt (photographed above while providing a tour of the NMNH’s ‘mummuy vault’) and his responsibilities, in addition to his research interests and projects, at the National Museum of Natural History website: http://qrius.si.edu/expert/david-hunt
Dr. Deborah Bolnick, a molecular anthropologist and associate professor in UT’s Anthropology Department, has been accessing TARL’s Human Osteology collection at various points over the course of the last few years. In October 2014 she made two visits to the HO collections with Research Fellow Jennifer Raff, also of the Anthropology Department at UT, following allocation of project funding and support provided by the Rock Art Foundation. During these visits, they selected skeletal elements that appeared to best meet the criteria for a specific type of DNA sampling: aDNA. This kind of DNA, “ancient DNA” or aDNA, is characterized as DNA that can be isolated from prehistoric specimens such as mummified soft tissues, skeletal remains and intact teeth. Dr. Bolnick is investigating the biological ancestry of the prehistoric inhabitants of the Lower Pecos region of Texas. Her research will create a genomic map of these populations and identify genetic diversity of these groups, ostensibly allowing scientists to determine genetic associations, as well as rates and direction of gene flow into and out of this culturally rich region spanning the landscape between Texas and Mexico. Recently she was a part of a well-publicized genetic study of a prehistoric adolescent, whose remains were recovered from an underwater cave in Mexico and relative dated to the late Pleistocene (12,000-13,000 years ago). Called “Naia,” and also known as the “Hoyo Negro Girl,” the remains of this female teenager included a tooth which was analyzed by researchers, including UT’s own Dr. Bolnick, for DNA. For the interesting story of Naia and what her prehistoric DNA is revealing about the origins of paleoindians and Native Americans for science, please visit: http://www.futurity.org/native-americans-cave-teen-ancestry/.
Dr. Bolnick’s next round of research will involve sampling of other prehistoric sites represented here at TARL in the HO collections. Along with one of her PhD. students, Austin Reynolds, Dr. Bolnick will be selecting prehistoric skeletal elements for aDNA sampling and then performing the sample retrieval process at her lab on UT’s downtown campus. These samples will become part of her ongoing research into Native American genetic diversity following European contact in North America. In addition to her work with prehistoric remains and aDNA, Dr. Bolnick has also published research that pertains to modern commercial DNA testing and what the general public should know about interpreting the results of such tests in terms of validity and limitations. To read the article about Dr. Bolnick’s perspectives on the new fad of commercially available DNA tests, what the results can actually be used to determine, and how this trend could necessitate redefining ethnic identities and ancestral affiliations, please read the 2007 feature story here: http://www.utexas.edu/features/2007/ancestry/.
Dr. Bolnick has consistently made herself available to meet with staff to discuss her ongoing research, her sampling and testing methodologies and laboratory processes, and is also helping us to understand the value of the knowledge gained through such research. Well-versed in the sensitivities inherent to working with both modern and prehistoric human remains, Dr. Bolnick is a proponent of NAGPRA (Public Law 101-601, http://www.nps.gov/nagpra/mandates/25usc3001etseq.htm) and congenially responded to all of our questions and concerns born of our evolving dedication to NAGPRA here at TARL. An advocate for open dialog with tribal communities and the sharing of knowledge that results from her research efforts with cultural, academic and scientific entities, Dr. Bolnick well recognizes the value of collections like those at TARL. We in turn recognize that collections are best utilized when they continue to serve as resources for the progression of knowledge and understanding, providing researchers like Deborah Bolnick the means to further our understanding of our origins and, ultimately, ourselves.