Ellis, Meredith

This thesis analyzes cranial modification from various sites and locations within coastal Ecuador. This research aims to identify the various types of tabular cranial modification and understand the methods used to classify each subtype of tabular modification. From this, I discussed the different types of modification and then used that information to contrast between North American and South American bioarchaeological methods of classifying cranial modification. Additionally, I reconstructed the biological profiles of some of the crania. The importance of this research is to introduce a method of identifying cranial modification that has been previously used in South American bioarchaeology to North American bioarchaeology. Furthermore, information on cranial modification regarding the coastal populations of Ecuador is lacking. The data in this thesis contributes a significant amount of knowledge about this practice, allowing this project to provide new information to the field of anthropology and the country of Ecuador.

The study of cranial modifications is valuable to the fields of bioarcheology, and other areas of anthropology. This thesis focuses on analyzing cranial modification in Santander, Colombia. Research focuses on a variety of crania in museums of this region. There is not much known about the crania and there are just a few academic works about them from the social/cultural perspective. Some records do mention that a specific group called “Guane” inhabited the region where the crania were discovered. This investigation from the perspective of bioarcheology is particularly important for better understanding and documenting of these specimens. This research will also help the different museums and collections in documenting the crania they have and provide data to others that may also be interested in these collections.
A general aspect of the methodology that was used to achieve the conclusions were photos, measurements and the determination of the sex and age. It was determined that there is no association between the cranial modifications and the sex. Also, the different modifications, including the form, variety and degree was determined for each cranium.

Microcephaly is neurological condition within which the brain fails to develop to a normal size resulting in the appearance of a smaller head. Microcephaly often accompanies various neurodevelopmental disorders. The corpus callosum is the largest white matter structure in the brain, comprised primarily of heavily myelinated axons. The corpus callosum connects the left and right hemisphere and allows for communication to occur between hemispheres. Using MRI measurements from a sample of 18 microcephalic patients, I analyzed whether the corpus callosum was impacted as a result of microcephaly. When compared to normocephalic controls, the corpus callosum was generally smaller in relation to overall cerebral hemispheric volume, suggesting that white matter brain tissues may be affected by microcephaly. A deeper understanding of the brain through research on the underlying mechanisms responsible for brain evolution and development is critical to our ability to detect, treat and prevent neurodevelopmental, neurodegenerative and psychiatric disorders.

The most direct way available to modern day researchers to reconstruct individual
and population level behavior is to analyze markers of activity from skeletal remains
(Ruff et al., 2004). An analysis of the population at the Republic Groves site (8HR4) was
conducted, using the entheseal change score system, the Coimbra method, developed by
Henderson et al. (2015). This study examined the implication of analyzing a commingled
and fragmentary population with this methodology. Reconstructing specific behavior
cannot be done with this type of approach; however, entheseal changes can be compared
to specific patterns of behavior for consistency. An atlatl was found with the human
remains and thus provided a suggestion of behavior for comparison. Entheses were
chosen in line with a throwing motion of the atlatl and focused exclusively on the
humerus, radius, and ulna. The application of the Coimbra methodology to the Republic
Groves population was successful, at least in part. Overall, there was low variability of
results, mostly 0, some 1, and with very few high 2 scores. The entheseal changes from Republic Groves were consistent with the throwing of an atlatl; however, this does not
mean that this is the only behavior that could have generated that kind of change.

When unidentified skeletal remains are found, researchers utilize a number of
methods to apportion details for a biological profile. While these practices are used and
professed through generations of students, they also require a reevaluation of the methods.
This project estimates the ancestry and sex of nine unknown skeletal individuals through
two different mechanisms. Modified biological profiles were completed through two
different methodologies: anthroscopic traits (Buikstra and Ubelaker 1994; White et al.
2012) and geometric morphometrics using 3D-ID (Slice and Ross 2009). The results
serve two purposes: (1) to provide ancestry and sex (2) to compare two methodologies
through outcomes and repeatability of results. Intra-observer error testing was conducted
on both methods. All outputs resulted in low intra-rater reliability, highlighting the
repeatability error in one observer’s collection methods. These results conclude and
encourage the reevaluation and standardization of the procedures and comparison groups
used to assess ancestry and sex.