Spotlight On: Kristin Krueger

I'm both a paleoanthropologist and a bioarcheologist. While paleoanthropologists look at human evolution and early humans, bioarcheologists look at more recent humans. One of the most important things that we can look at, as far as our own evolution, is understanding our diet. There was a particular point in the past when climate change was chaotic and both Neanderthals and early modern humans were present. My research analyzes how diet is altered during climate change to answer the question of why Neanderthals went extinct around this time while humans both survived and flourished across the planet. 

I always wanted to be an archaeologist, even as a kid. In undergrad, I learned how to excavate. During an excavation course in New Mexico, I found a horse skull and realized that I was more interested in bones than cultural material. Then, in my masters program, I learned that teeth are very tight and highly genetically controlled, which means they can tell us about evolutionary relationships. 

And when we're dealing with fossils this old, we have to look at things that preserve well in the fossil record. What's the number one thing that preserves well? Teeth. Enamel is the hardest biological substance in the body. When looking at fossil teeth, you'll find microscopic scratches and pits due to food fracture properties. We always thought we understood what these patterns meant. Since the 1800s, it has been widely accepted that these markings are directly related to diet. For example, teeth with lots of scratches demonstrated that they ate a lot of plant material.  

Well, not anymore. It's back up for debate. There is currently a "Microwear Wars" (not kidding, it's really called that) in the literature where academics are now arguing that the markings don't indicate food or diet. Instead, they tell us about the abrasives stuck on food like sand, grit, or soil that make the microwear patterns. If this is true, it demolishes everything we thought we knew about how teeth wear, what microwear patterns mean, and what people were eating in the past. While they battle it out in the literature, I thought to myself that there must be a way to figure this out experimentally, which is where ART comes in. 

Artificial Resynthesis Technology, or ART, is a chewing simulation technology invented by the University of Minnesota's interdisciplinary Dental Research Center for Biomaterials and Biomechanics. Since its invention, it's gone through several iterations and improvements. ART can now taste, see, and hear to sense elements like crunch and flavor. It's largely been used by industry to understand things like how long flavor lasts in gum, but it's never been used for anthropology. What's really special about ART is that it's not only able to mimic chewing, but things like cheek, tongue, and artificial saliva, which is impossible to factor in with our typical fossil studies. 

A few years ago, I was working with Evan Chwa, an undergraduate student, through a LUROP project. We came across ART and Evan, now a dentist and orthodontics resident at University of Illinois Chicago, suggested that we reach out to the University of Minnesota to ask whether it's possible to create and simulate microwear with it. After reaching out, we were answered with a resounding yes and an invitation to try ART out. We have since traveled to Minnesota several times to test the technology and their team has been incredibly welcoming and supportive. After a successful pilot study, I knew that we needed this technology at Loyola. With this grant from the National Science Foundation, we can build and bring the first ART outside of Minnesota to our campus. 

My goal is to expand ART's technology beyond clinical use and establish the ChEW lab as a hub for interdisciplinary research, training and experiential learning. I currently have seven undergrad students, called the ChEW Crew, working on various projects across anthropology, paleontology, neuroscience, biology, and pre-dental studies. We're all interested in teeth and how they wear, but we're all looking at it from different perspectives. And there is so much potential with this technology. For example, the University of Minnesota has modified the technology to chew like a dog, opening up avenues into veterinary sciences. Here at Loyola, the technology will also be expanded for multiple uses beyond humans, such as primates. We have already received a lot of interest from different schools and companies eager to try it out. 

It's really important to me to integrate undergraduate students into the lab and give them an opportunity for research and experiential learning, especially because anthropology is an undergraduate-only department. I teach a dental anthropology course here at Loyola and the lab will be right next door, which means my students will be able to use ART themselves. Researchers from around the world across many different disciplines will come to use this technology. Students will be able to work with these researchers and build relationships with them, exposing them to subjects they may have never had the opportunity to engage with before.