A piece of seaweed from a billion years ago and a fossilized 550 million-year-old bug — among many other significant paleontological discoveries — helped set in motion Thursday’s awarding of the National Academy of Sciences’ prestigious Mary Clark Thompson Medal to Geosciences professor Shuhai Xiao.

Presented every six years, the $20,000 prize went to the renowned paleobiologist for “re-envisioning our understanding of evolution” through his research into “the interactions between the biosphere and its environments at critical transitions in Earth history,” according to the National Academy of Sciences. 

“I am truly humbled and honored,” said Xiao, 53, in the Department of Geosciences in the College of Science, “particularly when I looked at the list of previous recipients, who are giants in my field.” 

Among them, Xiao notes: 

  • Charles Doolittle Walcott, the medal’s inaugural recipient in 1921, who served as the president of the National Academy of Sciences, director of U.S. Geological Survey, and Secretary of the Smithsonian Institution;
  • Amadeus Grabau, in 1936, considered the father of Chinese geology and paleontology who helped found the geology department at Peking University where Xiao first studied geology;
  • Andrew Knoll, in 2012, Xiao’s doctoral advisor at Harvard University and the winner of the International Prize for Biology in 2018.

“On behalf of the university, congratulations to Dr. Xiao for this well-deserved recognition,” said Virginia Tech President Tim Sands. “To be named by your colleagues as one of fewer than 40 scientists over the last century having made the most important contributions to geology and paleontology is truly remarkable.” 

Xiao, who last year was named the Patricia Caldwell Faculty Fellow by the Board of Visitors, said he has been lucky to have worked with a number of exceptional students and postdoctoral students in his lab, “and collaborated with many colleagues who helped me with my career development at Virginia Tech.”

That collegial appreciation is mutual, said Ron Fricker, interim dean of the College of Science. 

“Dr. Xiao’s research into the interaction of Earth’s biosphere with its environments hundreds of millions of years ago is truly pathbreaking,” said Fricker. “It has literally changed our understanding of the way life has evolved on Earth. We are so very proud to have Shuhai as our colleague in the College of Science.”

Xiao wasn’t always destined to be a paleontologist.

“I grew up in a very poor area in south China and my family didn’t have a lot of college education,” he said. “My father was a middle school teacher and my mother was a housewife.” 

When it came time for college, he contemplated a degree in biology, given an interest in plants stemming from the rural farming region of his childhood. But all of the university brochures he read cautioned against biology students who suffered, as Xiao did, from allergies. 

“Then I saw something in a pamphlet about paleobiology, and it didn’t mention anything about allergies,” he said. “It wasn’t really until my second year of college when I saw the first fossil of my life. I slowly began to develop an interest in it, though it took some time. I began to like it because the class had some field trips.”

After graduating from Peking University, he worked three years for the Chinese Academy of Sciences and for an oil company in the Gobi Desert before deciding to pursue a Ph.D. at Harvard University. There he studied under Andrew Knoll, who encouraged a collaborative approach to research, for instance, geochemists and sedimentologists working side by side.

“The most important discoveries are typically made at the interface of different fields that offer new technologies or new perspectives and ways of looking at things,” Xiao explained.

Since arriving at Virginia Tech in 2003, Xiao has led interdisciplinary field trips all over the United States, China, Australia, Siberia, and Canada.

One trip to an area of northern China that once was under ocean uncovered a 1 billion-year-old seaweed fossil, which could provide some clues to the origins of modern land plants. This discovery, led by post-doctoral fellow Qing Tang in Xiao’s lab, was published in Nature Ecology and Evolution and featured in February 2020 in USA Today.

Separate excursions near the Chinese city of Yichang revealed fossils that included the bodies and trails left by millipede-like “bilaterians,” or bilaterally symmetric creatures with segmented bodies and directional mobility — evidence that such early animal evolution occurred in the Ediacaran Period, between 635 and 539 million years ago.

“Shuhai has established himself as one of the world's premier experts on the Ediacaran Period — a period in Earth's history when the first multicellular animals appeared,” said W. Steven Holbrook, professor and head of the Department of Geosciences. “Shuhai is not just an excellent researcher — he is also an outstanding teacher and a terrific departmental colleague who takes on many important service responsibilities. Virginia Tech is a better place because of him.”

While his research involves fossils hundreds of million of years old, its relevance is vital to our world today and others in our universe.

“Environmental change is a pressing issue with global warming, pollution, deoxygenation of our oceans,” Xiao said. “These are very practical issues that threaten our own Earth and our own lives.” 

Having a solid geological record from which we can compare today’s environmental conditions to those in our past allows us to gauge the severity of these threats and more intelligently respond to them.

As for beyond this world?

“Let’s say one day we collect samples on Mars,” Xiao said. “We need to know how life evolved on Earth and have a reference so that we can determine if Mars had life in its past. What kind of samples should we collect on Mars? What tools should be used to look at the Martian rocks in order to see if there was life? 

“The answers lie on our home planet.”

— Written by Michael Hemphill