![]() ![]() Xiao, who has helped excavate and study some of the most ancient fossils from around the world, said this type of study gives him hope for future discoveries. The center brings together experts from diverse disciplines to solve these complex global challenges and train the next generation of leaders. fellow in the Interfaces of Global Change graduate program. Zhang provided insights on how much oxygen would have been available in the oceans during the time when nitrate increased in abundance.Īll of the Virginia Tech authors are affiliated members of the Fralin Life Sciences Institute’s Global Change Center, with Kang serving as a Ph.D. Reid, who generally focuses her research on Earth’s more recent events, had a special opportunity to offer her nitrogen isotope expertise to these ancient fossils.įeifei Zhang, a geochemist at Nanjing University, was the paper's fourth co-author. ![]() He collaborates with paleontologists to study the record of life preserved in the geological record and examines what potential environmental drivers might have enabled changes in life through history. Gill specializes in reconstructing present and past chemical cycles on our planet. An elemental analyzer coupled to the mass spectrometer allowed the researchers to extract pure nitrogen gas from the samples for analysis. Gill and Rachel Reid, also a College of Science geochemist and co-author of the paper, provided critical analyses through resources, including the mass spectrometer in the Geoscience Stable Isotope Lab at Virginia Tech. Solid collaborationĪ collaborative, international approach was key to connecting this new data with biological events, mostly notably, the rise of eukaryotes. “Once we did this kind of integration and put it into a big picture, we saw the rise of nitrates through time, which happened around 800 million years ago," said Kang. He took the data from the rock samples, entered it into a larger database, and analyzed it across a longer time scale that spanned different geographic locations. “They had been there for a long time in a low-key status until about 820 million years ago, when they became abundant.” “We had some rough ideas of when eukaryotes became ecologically successful,” said Shuhai Xiao, professor of geobiology and a paper co-author. Home to rocks dating back 3.8 billion years ago, the region was once covered by an ocean. “This discovery is unique because nitrogen isotope data are virtually nonexistent from the early Neoproterozoic time period, or between a billion and 800 million years ago,” said Kang.Ĭollaborating with the Nanjing University in Najing, China, Kang has spent two years working to understand what drove the rise of eukaryotes through nitrogen isotope analysis of rock samples from the North China Craton. Previous research focused on phosphorus’ role in the rise of eukaryotes, but Junyao Kang, a doctoral student in the Department of Geosciences and lead author of the paper, was curious about the part nitrogen played in this event. If that did not happen, we would not be here today.” “And this is a key event where we shift from dominantly prokaryotic ecosystems - cells that are much simpler than the ones in our bodies - to eukaryotes. “Where we sit today, with life as it is on the planet, is the sum total of all the events that happened in the past,” said Ben Gill, an associate professor of sedimentary geochemistry and co-author on the paper. ![]() Complex eukaryotic cells evolved into multicellular organisms and are credited for ushering in a whole new era for life on Earth, including animals, plants, and fungi. The team's findings, recently published in Science Advances, reveal an increase in biologically available nitrogen during the time that marine eukaryotes - organisms whose cells have a nucleus - became dominate. Is nitrate responsible for algae, flowers, and even your neighbors?Ī team of Virginia Tech geoscientists have unearthed evidence that may indicate yes. ![]()
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