Research Methods in Human Skeletal Biology

Elizabeth A. DiGangi, Megan K. Moore, Elizabeth A. DiGangi, Megan K. Moore

• Publisher: Academic Press
• Year: 2012
• ISBN:
  9780123851901
• Topic: Medicina
• Subtopic: Ortopedia

Research Methods in Human Skeletal Biology serves as the one location readers can go to not only learnhow to conduct research in general, but how research is specifically conducted within human skeletal biology. It outlines the current types of research being conducted within each sub-specialty of skeletal biology, and gives the reader the tools to set up a research project in skeletal biology. It also suggests several ideas for potential projects. Each chapter has an inclusive bibliography, which can serve as a good jumpstart for project references.

• Provides a step-by-step guide to conducting research in human skeletal biology
• Covers diverse topics (sexing, aging, stature and ancestry estimation) and new technologies (histology, medical imaging, and geometric morphometrics)
• Excellent accompaniment to existing forensic anthropology or osteology works

Chapter 1

Introduction to Skeletal Biology

Elizabeth A. DiGangi and Megan K. Moore

Goals of this Textbook

This book is designed as an intermediary text to fit between introductory textbooks for new undergraduates and advanced texts for graduate students and professors. Advanced undergraduates or first-year graduate students are often expected to generate their own original research project. However, no comprehensive texts geared towards this specific student demographic previously existed for skeletal biology that unified the following six themes: (1) the specifics of the scientific method; (2) overviews and theory behind each subfield within skeletal biology; (3) the types of scientific questions that each subfield seeks to answer; (4) the specific methods used in each subfield for research; (5) how to narrow down an area of interest and steps to take once that has occurred; and (6) how to present and publish results. This book addresses all of these aforementioned topics and therefore aims to act as a “pocket” advisor.

Some of the readers of this volume will have outstanding advisors who provide sage and timely advice throughout the entire academic process, others will have advisors who take less of a hands-on approach. This book has been written for students in both of the above situations, as well as for those who fall somewhere in the middle. We hope to shed light on how research projects are developed by walking students through the process of choosing a research direction, highlighting not only background but exciting new developments in each area of skeletal biology. Each chapter presents one or more case studies that break down a research project in different ways for the reader. Finally, the ultimate responsibility of scientists is to share their results, so at the end of the volume we offer suggestions about how to present papers and submit manuscripts for publication. Reading these pages will hopefully reduce the mystery of the research process and set the student reader on the path towards becoming a successful skeletal biologist. This chapter will therefore begin the journey by providing a brief introduction and history of biological anthropology and the specialization of skeletal biology.

There are several authoritative books that should be used as complements to this one. We recommend Standards for Data Collection from Human Skeletal Remains by Buikstra and Ubelaker (1994) for a detailed treatment on how to record the cranial and postcranial skeleton. In addition, there are other excellent resources covering many of the topics herein; however, these works assume that the reader already understands how to develop a problem-oriented question (e.g., Katzenberg and Saunders, 2008; Blau and Ubelaker, 2011). The text here is rather directed to the new researcher early in their academic career to guide them in developing a research focus that will later develop into a research program. Each chapter either specifically recommends further reading, or the bibliographies can be used as starting points for further exploration.

This text is not exclusively geared towards either bioarchaeology or forensic anthropology. We chose to focus on skeletal biology because the inherent themes are relevant for practitioners of both fields within biological anthropology, with potential relevance for other areas as well. This book assumes that the reader’s knowledge of biological anthropology is at or above the level of an undergraduate major or minor in anthropology. Specific anthropological terms and concepts are therefore used with the presupposition that the reader understands the context. We do not cover anatomical orientations, names of bones and features, or how to measure bones. For bone features, several authoritative textbooks are available, including Human Osteology (White et al., 2012), and Developmental Juvenile Osteology (Scheuer and Black, 2000), which you should have on your bookshelf. A glossary containing bolded terms throughout the volume is found at the end of the book to serve as a reference for terminology.

One of the key figures in the development of our discipline, Aleš Hrdlička, famously asked a colleague to make an announcement following a paper at the American Association of Physical Anthropologists’ meeting in 1940: “Statistics will be the ruination of the science” (quoted in Brace, 2005:226). Despite this proclamation, much has changed over the decades. Today, to be a successful researcher in skeletal biology, comfort with statistical analysis is a requirement. However, comprehensive coverage of statistical methods applicable for skeletal biology projects is beyond this book’s scope. Therefore, while quantitative statistical analysis is essential to research methods in biological anthropology, only the chapters for which statistics is inextricably linked with method go into the details for conducting specific analyses (e.g., Konigsberg and Frankenberg [Chapter 11]).

For a detailed introduction to statistics, the following texts are written for the novice: Introduction to the Practice of Statistics (Moore et al., 2010) and Discovering Statistics Using SPSS (Field, 2009). For more advanced multivariate analyses,¹ Using Multivariate Statistics (Tabachnick and Fidell, 2012) and Principles of Multivariate Analysis (Krzanowski, 2000) are recommended. We additionally suggest that college statistics courses be taken to increase competency in this area.

Why Study the Human Skeleton?

Skeletal biology is, quite simply, the study of the biology of the human skeleton. The study of the skeleton therefore includes its evolution, its structure, its function, its growth and development, and how it is affected by the environment. Biology itself is the study of life, and as such, remember that the skeleton is (or once was) a living thing. Muscles attach to it via tendons, bones articulate with other bones, and it receives nutrients from the bloodstream. Due to the durability of skeletal tissues, bones and teeth are often all that remains of a once living person. When faced with dry bones, it can be easy to forget that the skeleton once was not only a dynamic living thing, but it had a very specific purpose, reflected in its morphology. This was not just on the level of the individual, but reflecting long-term evolution, on the level of the population (defined below) as well. We therefore study the skeleton to learn about the individual and the population overall.

In biological anthropology, we are interested in studying human populations, as stated. A human population can be defined as a group of individuals who are contemporaneous, occupy relatively the same area geographically, have a shared culture (language, traditions, belief systems, etc.), and who tend to find mates from within the same group. For example, a population in prehistory can consist of all of the people under Inca rule in South America between 1400 and 1532 A.D., or it can be the people who lived in the city of Cuzco (the Inca capital) during the same time. We also make a distinction between the population and the sample that we have access to as a result of what was recovered archaeologically. Recovery and preservation bias will affect which individuals of the population are recovered,² and therefore this will affect the types of questions we are able to pose. We try to comprise our samples so that they are representative of the population overall, but as stated, sometimes this is not possible. We may also choose specific demographics of individuals from within the sample to study. Therefore, a sample can be individuals falling into each age cohort from an Incan cemetery in Cuzco, or all the females of child-bearing age from that same cemetery in Cuzco, or only the high-status individuals who were ethnically Inca (as opposed to high-status people of other ethnicities ruled by the Inca), and so forth.

Because each population of people experiences life in a particular way given environmental (e.g., nutrition, climate, presence of disease), cultural³ (e.g., differential access to resources, psychosocial stress, activity level), and evolutionary forces (e.g., gene flow resulting from people from different populations mating with each other⁴), populations differ from one another and this is often recorded in many ways in the bones of individuals in the archaeologically recovered skeletal sample. We refer to the experience of each population as population history.

Bones record basic biological characteristics of an individual (age, sex, ancestry, and stature);⁵ how that individual may have fit into their society or experienced life (via social status, occupation, diet, disease, etc.);⁶ and other aspects such as a person’s geographical place of origin;⁷ the demographic profile of populations and relationships between different populations (biological distance);⁸ and adaptations to behavior and activity in addition to insults that may have occurred to the individual during or after life.⁹ Thus, skeletal biology overall is a major focus in many aspects of biological anthropology: bioarchaeology, forensic anthropology, paleoanthropology, and comparative primate anatomy. This volume, however, has as its focus skeletal biology as it relates to modern humans.

The Biocultural Perspective

The biocultural perspective, as defined by Armelagos and Van Gerven (2003), is that culture is an environmental force affecting and interacting with biological adaptation. Humans therefore have a unique biocultural evolutionary history as a result of the mutual interaction of biology and culture. While early physical anthropology (with the notable exception of Franz Boas, discussed below) largely ignored the influence of culture on biology,¹⁰ biological anthropology today is increasingly cognizant of the interrelationship between (1) environment, (2) culture, and (3) biology. Cartmill (1999:658) states (emphasis added), “… culture always affects the interaction between genes and environment in our species.” This is because human experience is constrained by the three major factors mentioned above.

You are able to read this text because (1) reading exists in your culture and (2) your culture has decided that literacy is important; and therefore you were taught how to read as a child. However, your environment, including the social environment of where you were raised played a role as well: your parents or caretakers made the decision for you that you would learn to read, and they provided the necessary resources for you to be able to do so (transportation to school, school supplies, shelter at night, proper nutrition, preventive and curative medical care, etc.). Further, the fact that you were provided with proper nutrition and medical care affected your biology so that your brain and body could focus on more than just staying alive. Had you been born into a different culture where written language did not exist, you would not have learned how to read, even given your biological potential to be able to do so (a functioning human brain and sensory organs). If you had experienced different sociocultural circumstances as a child, perhaps the same would be true. Therefore, all three variables are inextricably linked: your sociocultural surroundings are just as much a part of your environment as climate, nutrition, diet, and exposure to pathogens are due to their mutual interaction. Therefore, biology is affected by both culture and physical environment.

As a result, in biological anthropology our analyses are focused on this dynamic interaction. We cannot understand the individual, never mind the population to which the individual belonged if we do not...