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Pearson Named Professor of Earth and Planetary Sciences
Cambridge, Mass. - July 10, 2009 - Organic geochemist Ann Pearson, who brings genomics, isotope geochemistry, and biochemistry to bear on the study of the Earth's history, has been named professor of earth and planetary sciences in Harvard University's Faculty of Arts and Sciences, effective July 1, 2009.
Pearson, 37, was previously Thomas D. Cabot Associate Professor of Earth and Planetary Science at Harvard, where she has been on the faculty since 2001.
"Professor Pearson's research contributions range from the sources and fates of organic carbon in marine sediments to the processes that fueled some of Earth’s most ancient ecosystems," says Jeremy Bloxham, dean of science in FAS. "Her work harnesses major advances in molecular biology and genomics to illuminate basic questions about the sources, fates, and cycling of the Earth's organic matter. In so doing, she is sharpening the tools of organic geochemistry in research on the history of Earth and life."
In her early research, Pearson used radiocarbon analysis to tease apart the composition and origins of organic matter in marine sediment, the source of the vast majority of today's petroleum reserves. Such "burial" of organic matter in the sea also helps control atmospheric levels of oxygen and carbon dioxide to the present day.
Despite its importance, the origin of organic matter in marine deposits was poorly understood prior to Pearson's radiocarbon measurements, made during her Ph.D. work with Timothy Eglinton at the Woods Hole Oceanographic Institute. This work showed striking heterogeneity in the age of sediment components, demonstrating that molecules in sediments could be traced to nearby continents, the overlying ocean, and other locations on the ocean floor. She also showed that ancient organic matter remains available to modern organisms through radiocarbon analysis of very old material in living microbial mats in the Gulf of California.
Pearson's subsequent work overturned a long-held assumption that only aerobic bacteria produce a key class of molecular biomarkers known as hopanoids. In a major departure from previous research, she and colleagues found that bacteria can synthesize hopanoids even in the absence of oxygen, showing that hopanoid presence alone does not establish oxidizing conditions in ancient environments.
Earlier this year, Pearson and colleagues found that a previously unknown reservoir of briny liquid buried deep beneath an Antarctic glacier supports hardy microbes that have lived in total isolation for millions of years. Despite their profound isolation, the microbes are remarkably similar to modern marine species, suggesting they are the remnants of a larger population that once occupied an open fjord or sea.
Pearson earned a B.A. in chemistry from Oberlin College in 1992 and a Ph.D. in marine chemistry and geochemistry from the Massachusetts Institute of Technology (MIT)/Woods Hole Oceanographic Institute (WHOI) Joint Program in Oceanography in 2000. She joined the Harvard faculty as an assistant professor in 2001, becoming associate professor in 2005.
From 1993 to 1994 Pearson served in the Peace Corps in Ecuador and from 2000 to 2001 she was a postdoctoral investigator at WHOI's Reinhart Coastal Research Center. She received the C. G. Rossby Award for Best Dissertation in the Program in Atmospheres, Oceans, and Climate at MIT in 2000 and a David and Lucile Packard Foundation Fellowship in 2004.
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