Duluth Campus Faculty Member Works to Deepen Understanding of Human History

University of Minnesota Medical School, Duluth Campus assistant professor Dr. Alexandra Zachwieja was part of an international research team that has identified fossils pushing back the timeline of human arrival in Southeast Asia.

Human history is a tapestry of events, discoveries and adaptations that have shaped the world as we know it today. Over centuries, archaeological investigations and anthropological studies have provided valuable insights into our ancient origins and the progression of human civilization. However, there is still much that’s unknown, and every so often, a groundbreaking discovery emerges that challenges our existing perceptions and reshapes our understanding of the timeline of human history. 

One such discovery was recently made by a team of international researchers that included University of Minnesota Medical School, Duluth Campus assistant professor Dr. Alexandra Zachwieja. Dr. Zachwieja and a team of 30 researchers from the United States, France, Australia and Laos published an article in Nature sharing findings that push back the timing of human arrival in mainland southeast Asia by roughly 20,000 years. 

The research team discovered a frontal bone and tibial fragment in Tam Pà Ling cave in northeastern Laos, which they identified as human. The bones then went through several different dating processes, including Uranium series dating—which measures the rate of radioactive decay of surrounding rocks to determine the age of materials—and luminescence dating—a measurement that calculates the time since the soil surrounding the fossil was last exposed to radiation from the sun. Dr. Zachwieja, who has a PhD in Physical and Biological Anthropology, says this discovery helps us better understand the trials early humans may have faced.

“It’s really helpful in terms of our understanding of the interplay between fossil record and the genetic record,” she elaborates.

Dr. Zachwieja’s specific role on the broader research team is conducting paleoecological climate modeling to understand the types of climate conditions and ecological dynamics that humans would have experienced.

“I think one of the unique reasons that pushing back the dates is important is it tells me that people back then were moving through and handling climate change very differently than how we thought,” she says. “They weren’t just coming into this place and it was nice and warm and tropical and beautiful. They were also experiencing ice ages and different types of environmental pressures.”

Modern humans continue to face climate challenges, and having information about how our ancestors may have managed these difficulties helps researchers think about how we are dealing with climate change today. 

“If we can understand how people lived through all these different climatic changes, we might gain some insight into things that we might be able to do successfully today,” Dr. Zachwieja says.

As a biological anthropologist, Dr. Zachwieja is a generalist of the whole body and uses her expertise in her role as an assistant professor of human anatomy at the Medical School. Both her teaching and research have proven to her time and again the extraordinary resilience of the human species.

“We are a resilient species, that is so obvious to me,” she emphasizes. “We evolved and dispersed, and we’re one of the only species to live successfully all over the globe. I think this all speaks to our species’ ability to help each other and get through hard things.”