Katz Center Fellow Melissa S. Cradic on Archaeology, Ancient Genetics, and Human Remains
This blog post is part of a series focused on the research of current fellows. In this edition, Katz Center Director Steven Weitzman sits down with Melissa S. Cradic, who recently earned her PhD at the University of California, Berkeley with a dissertation on funerary practices and ancestor lineages in the Bronze Age Levant.
Steven P. Weitzman (SPW): Before we turn to your research, Melissa, I wanted to give our readers a sense of you as a person. What led you to become an archaeologist, and what has your experience taught you about the field that might surprise people who are not familiar with it?
Melissa S. Cradic (MSC): I have been interested in archaeology and the ancient world since childhood. As a Philadelphia-area native, much of this interest stems from visits to the Penn Museum, where I saw antiquities from Mesopotamia and Egypt in person for the first time. The famous finds from the Royal Cemetery at Ur and the sculpture and mummies in the Egypt Gallery captivated my imagination. I continued to explore these topics in my undergraduate studies with Prof. Eric Cline at The George Washington University, where I majored in Archaeology and Classical Humanities, with minors in Anthropology and History. While there, I participated in an archaeological field school at Tel Megiddo, a site that I continue to research and which is one of the primary sources of data for my ongoing projects on human burials.
The patience that is required in the field may surprise people who are unfamiliar with the daily realities of an excavation. Curiosity is a great motivator when scraping a plaster floor for days on end, articulating mudbricks, or digging through fill. The nature of the finds and the research questions motivating a project may also come as a surprise: archaeologists are not out looking for buried treasure--quite the opposite! Trash, debris, and pottery sherds often contain the richest information about daily life that allows us to interpret the ancient world from broad historical trends to the everyday activities of a household. Fieldwork is also challenging in that it requires applying different techniques, tools, and methods to each context, including collecting a range of scientific data and documenting the original locations of finds using geospatial tools, illustrations, and photographs. Contrary to popular depictions of archaeologists in entertainment, we typically do not use small tools like brushes and dental tools every day; these are reserved for contexts that require special care such as exposing an assemblage of smashed pottery. Instead, tools like pickaxes, hoes, buckets, and wheelbarrows are common on site.
SPW: One of the central goals of your work is to help archaeologists and museologists think in new ways about the human body, or human remains, as a part of the archaeological and historical record. Can you explain what you are seeking to accomplish in that regard?
MSC: My work attempts to push the boundaries of the body as part of the material assemblage. Specifically, I focus on fragmented human remains as a meaningful category of material culture in certain contexts, such as the ancient Near East. Human remains comprise one part of the wider burial assemblage, which could include pottery, animal remains, jewelry, weaponry, etc. However, the bones are typically isolated during analysis as biological dataset with little attention to social meanings of fragmentation, unlike the way that a broken pot might be treated in a museum or in archaeological analysis.
I am also interested in the discourse of human remains in archaeology, particularly how bodies are treated as persons, objects, and categories of knowledge. This is a sensitive subject however, because human remains might be treated differently according to their original context and whether they fall under protected status. So, human remains from excavated contexts might be treated as venerated ancestors on the one hand, or as scientific specimens on the other hand. I investigate how these policies and practices relate to ancient concepts of death and burial, and how human remains are received by various stakeholders today. One goal of this research is to explore ways of approaching mortuary archaeology that consider both the concerns of modern descendant communities and the original intentions of burial.
SPW: In recent decades, human remains have yielded a new kind of evidence—vestiges of DNA, which as some readers will know, can be used to illumine human ancestry and how different populations are related to each other biologically. Can you briefly share with us how archaeology of the ancient Near East is making use of genetics, and what it is telling us about the people who lived in the region of ancient Canaan in particular?
MSC: Ancient genetics (aDNA) is just starting to take off as an important and growing dataset that is being used to answer historical and archaeological questions at macro- and micro-scales. For example, there are several large, collaborative projects in the US and Europe which are sampling widely from across the region to address broad, diachronic questions about population genetics and migration. One recent study (Haber et al. 2017) analyzed the DNA of Bronze Age and modern populations in Lebanon. The researchers found that Bronze Age ancestry derives from a mix of local Neolithic Levantine populations and genes related to Chalcolithic Iranians. This ancestry is widespread and shared in present-day Lebanese populations, showing substantial genetic continuity in the region from the Bronze Age.
Most aDNA evidence comes from excavated burials, where archaeologists are operating on a smaller scale, using aDNA to answer questions about the genetic origins and identities of the populations at their sites. Several teams have recently published their results, for example Feldman et al. (2019), who sequenced the genomes of ten individuals buried at the settlement of Ashkelon dating from the Middle Bronze Age through early Iron Age (ca. 18th–10th centuries BCE). The study argues that four infants buried under Iron Age I houses showed higher proportions of European DNA than their Bronze Age predecessors as well as later Iron Age populations, both of whom showed greater affinities with the earlier, local Bronze Age populations. The implication is that these infants’ genetics may support hypotheses about Philistine settlement in the region around the same time. The underlying assumption is that Philistines originated in southern Europe, and so their DNA is different from, and more European than, the local populations of the Bronze and early Iron Age Levant. Large-scale population movement in the early Iron Age, some argue, is supported by historical evidence as well as archaeological evidence of upheaval and cultural change, including the introduction of new material culture, architecture, and food practices.
This is an interesting study, but it should be noted that its wide-ranging historical conclusions are based on a limited dataset—only ten out of 108 samples yielded sufficient amounts of aDNA due to poor preservation conditions, and only four of those contained higher proportions of European DNA. Moreover, the Philistines were not necessarily a unified genetic or cultural group, nor were they necessarily from a single place of origin. It is problematic in my view to claim a Philistine presence and identity—and by extrapolation a mass migration from Europe—based on the aDNA of four infants. As the field of aDNA advances, additional data could certainly make these results much more convincing and fill in the picture of the genetic ancestry of those who lived in the region during different periods.
SPW: One reason that the alliance of archaeology with genetics is controversial is that, to some, it feels like a revival of race science, the use of science to justify dividing people into separate and unequal races. Sir Flinders Petrie (1835-1942), a pioneering figure in the history of archaeology in Egypt and pre-state Palestine, is cited as an example; his interpretations of the material evidence were skewed by racist assumptions. What do you make of the argument that contemporary population genetics represents a 21st-century version of race science? Do you have any reservations of your own about the use of genetics to study ancient populations?
MSC: Ancient DNA (aDNA) studies have much to add to knowledge about the populations of the ancient world. However, it is important to acknowledge that this is still a relatively new field of study, and one that is advancing theoretically and methodologically as more data become available, and as chronological resolution of the data become more refined.
One of the main issues with aDNA has less to do with the actual genetics research going on and more to do with the ways that the results could be distorted or appropriated to serve specific historical and political narratives. There is a risk of essentializing ancient peoples into categories of race—a premise that has been invalidated as a biological reality—when correlating the genetics of various populations with archaeological groups. The main problem is that archaeological evidence of ancient peoples and their identities, such as material culture, behavior, practices, and languages, are not biological phenomena. These characteristics are cultural constructs and, as such, do not map onto genetics in a simple one-to-one match up. Moreover, neither genetics nor cultural traits are closed datasets, in the sense that they can be shared and reproduced among people of different groups and identities. In other words, a cultural group may not be a unified genetic group and vice-versa. Therefore, aDNA is not well suited to explaining human behavior, cultural developments, and change using genetic evidence alone. It is one dataset among many that must be contextualized.
Likewise, I can anticipate some problems with ancient genetics arising in the archaeology of the Levant specifically. For example, attempts to “find” ancient populations known from Biblical text through genetics, such as Amorites, Israelites, Philistines, or others, risks conflating genetics with social categories of language, text, material culture, and identity. Moreover, such questions could potentially contribute to the already-volatile conflicts over identity politics and etiology in the region today.
SPW: Turning to your work here—what are you working on during your time at the Center and at Penn? How does your work relate to the year's focus on the home?
MSC: At the Katz Center this year, I am working on several publication projects including a book based on my dissertation, which I completed in 2017 at the University of California, Berkeley. My research focuses on human burials and the role of the body in constructing household lineages in the Bronze Age and Iron Age. Primarily, I focus re-used burial spaces which contained multiple-successive burials. Some of these burials were located underneath the floors of occupied houses, providing a close and intimate connection to the house and home, while others were located outside of settlements in cemeteries, in caves, and in chamber tombs cut into bedrock. These contexts contained the remains of several dozen individuals who were buried over the span of many decades. The longevity of the tombs indicates that they were an important part of intergenerational funerary rituals. I argue that these burials served as metaphors for the collective homes of the dead, and that the bodies represented the accumulative household lineage.
Often, the bodies of those who were previously interred in these tombs were moved around when a new corpse was placed in the grave. As a result, the bones of many individuals became fragmented and intermixed together. I’m also interested in how the bodies were transformed from whole corpses into intermixed and fragmented body parts. My goal is to connect the static result visible in the archaeological record—fragmented artifacts and assemblages—with the dynamic activities that created them. This process was deliberately carried out by living inhabitants who chose to interact with the bodies of the dead in destructive ways. Traditionally in Levantine archaeology, these co-mingling remains have been interpreted as evidence that deceased bodies in antiquity were not treated with care and respect. In contrast, I argue that the process of dismemberment was a major component of commemoration rituals that took place at different stages after burial. Finally, I also seek to identify the sensory experiences of those who were interacting with corpses in this way, which would have involved specialized tactile, olfactory, and visual stimuli in the dark, enclosed environment of a tomb.