Revelatory Isotopes: Using Geology to Identify Victims of Homicide, War and Mass Disasters
In this Science and Mathematics Colloquium event at ASU's Polytechnic campus, learn more about how our bodies record the history of where and how we live. The food and water we consume carry with them a signature of their geographic origins, which is preserved in our bones and teeth. By understanding the occurrence and mobility of different elements in the natural environment and how different tissues form, we can start to construct a detailed life history of an individual of unknown origin. Naturally occurring isotopes reveal where you were born, where you've traveled and how you live.
With specific patterns of change with latitude, altitude and distance from large bodies of water, oxygen and hydrogen isotopes vary with the hydrologic cycle. Strontium and lead isotopes depend on the geologic age and type of rock where crops are grown, although lead isotopes are also strongly influenced in the modern environment by human pollution. Teeth preserve a record of our birthplace for the rest of our lives. Bone is a living organ and replaces itself every five or 10 years, while hair can provide a recent travel history of months to years.
Gwyneth Gordon, research scientist in ASU's School of Earth and Space Exploration, will share a case example of how isotope analysis led to the identification of a homicide victim and will discuss her research on testing the accuracy of life history inferences from isotope analysis of known individuals at several human decompositional facilities.
Since joining ASU, she has been working to make ASU a cutting-edge institution for forensic science research. She and colleagues in multiple disciplines and several ASU campuses have collaborated to organize the Forensic Science Initiative to foster interactions between academic researchers and working forensic practitioners. Their goal is to develop use-directed research that is driven by societal needs and guided by ASU’s deep expertise in science, technology, law and social science.
If you’d like to hear more about her forensics research, you can listen to her podcast, Just Hairy Isotopes, produced by the Forensic Center of Excellence.
Gordon trained as a field geologist and received her bachelor's from Stanford University. She went on to study radiogenic isotopes of osmium and their transport in the modern atmosphere, soils and ocean for her doctorate at Yale University. She now manages the W.M. Keck Foundation Laboratory for Environmental Biogeochemistry and applies the tools of isotope geochemistry to a wide variety of problems, with a particular interest in applications to modern humans. These include using isotopes to track bone loss in astronauts, metabolism during exercise, and tracing the geographic origin and travel history of murder victims. Gordon serves as a volunteer crime scene specialist with the Mesa Police Department.
This colloquium series is coordinated by the College of Integrative Sciences and Arts' Faculty of Science and Mathematics at ASU's Polytechnic campus, engaging faculty, students, staff and community in discussions about solutions-oriented research.